WorldWideScience

Sample records for axillary region positron

  1. Prospective evaluation of fluorodeoxyglucose positron emission tomography/computed tomography scan (FDG-PET/CT) for axillary staging in breast cancer

    International Nuclear Information System (INIS)

    Yamaguchi, Masahide; Noguchi, Akinori; Tani, Naoki

    2008-01-01

    Seventy-two patients from 2005 October to 2007 February with operative breast cancer underwent fluorodeoxyglucose positron emission tomography/computed tomography scan (FDG-PET/CT) of chest and body, ultrasound scan (US) and enhanced computed tomography scan (CT) followed by sentinel lymph node biopsy (SLNB) and axillary lymph node dissection (ALND). The results of PET/CT were compared with histopathological diagnosis of SLNB and ALND. Sensitivity, specificity and accuracy of PET/CT for detection of axillary lymph node metastases were 61%, 96% and 88%, respectively. Seven false-negative and two false-positive of PET/CT results were found. In patients with false-negative of PET/CT results there are two skin-invasive breast cancer patients and axillary lymph node metastases were detected in three patients with US, in one with CT and in four with SLNB. In clinical method for diagnosis of axillary lymph node metastases SLNB should be recommended because sensitivity of PET/CT for early breast cancer patients were low and positive diagnosis of axillary lymph node metastases with PET needs more than 1 cm size of lesion. PET/CT is useful for not-early breast cancer patients. To decide the operation of axillary lymph node disection needs total diagnosis of US, CT, SLNB and clinical findings. (author)

  2. Characterization of Staphylococcus and Corynebacterium clusters in the human axillary region.

    Directory of Open Access Journals (Sweden)

    Chris Callewaert

    Full Text Available The skin microbial community is regarded as essential for human health and well-being, but likewise plays an important role in the formation of body odor in, for instance, the axillae. Few molecular-based research was done on the axillary microbiome. This study typified the axillary microbiome of a group of 53 healthy subjects. A profound view was obtained of the interpersonal, intrapersonal and temporal diversity of the human axillary microbiota. Denaturing gradient gel electrophoresis (DGGE and next generation sequencing on 16S rRNA gene region were combined and used as extent to each other. Two important clusters were characterized, where Staphylococcus and Corynebacterium species were the abundant species. Females predominantly clustered within the Staphylococcus cluster (87%, n = 17, whereas males clustered more in the Corynebacterium cluster (39%, n = 36. The axillary microbiota was unique to each individual. Left-right asymmetry occurred in about half of the human population. For the first time, an elaborate study was performed on the dynamics of the axillary microbiome. A relatively stable axillary microbiome was noticed, although a few subjects evolved towards another stable community. The deodorant usage had a proportional linear influence on the species diversity of the axillary microbiome.

  3. Fenestration of axillary vein by a variant axillary artery.

    Science.gov (United States)

    Hadimani, S; Desai, S D; Bagoji, I B; Patil, B S

    2013-01-01

    Variations of venous pattern in the arm are common. In this case report, we present a variation of axillary artery and vein. During routine educational dissections of axillary region, it was observed that a fenestrated axillary vein was perforated by a variant axillary artery in right arm of an old male cadaver. The axillary artery which was fenestrated through axillary vein had only two branches arising from its second part and no branches from its remaining distal parts. The branches are thoraco-acromial (usual) and another large collateral (unusual) branch. This collateral branch is the origin of several important arteries as the subscapular, circumflex scapular, posterior circumflex humeral and lateral thoracic arteries. We propose to name this artery as collateral axillary arterial trunk. The course of this collateral axillary arterial trunk and its branches and also clinical significance of this variation are discussed in the paper.

  4. Diagnostic performance of fluorodeoxyglucose-positron emission tomography/computed tomography of breast cancer in detecting axillary lymph node metastasis. Comparison with ultrasonography and contrast-enhanced CT

    International Nuclear Information System (INIS)

    Monzawa, Shuichi; Adachi, Shuji; Suzuki, Kayo; Hirokaga, Koichi; Takao, Shintaro; Sakuma, Toshiko; Hanioka, Keisuke

    2009-01-01

    The purpose of this retrospective study was to evaluate the diagnostic performance of positron emission tomography/computed tomography (PET/CT) with fluorine-18-labeled 2-fluoro-2-deoxy-D-glucose (FDG) in comparison with that of ultrasonography and contrast-enhanced computed tomography (CT) in detecting axillary lymph node metastasis in patients with breast cancer. Fifty patients with invasive breast cancer were recruited. They had received no neoadjuvant chemotherapy and underwent PET/CT, ultrasonography and contrast-enhanced CT before mastectomy. The clinical stage was I in 34 patients, II in 15 patients, and III in one patient. The images of these modalities were interpreted in usual practice before surgery and the diagnostic reports were reviewed for analysis. Sensitivity, specificity, positive predictive value, and negative predictive value of each modality were obtained taking histopathological results of axillary lymph node dissection or sentinel lymph node biopsy as the reference standard. Axillary lymph node metastasis was confirmed in 15 of 50 patients by histopathological studies. PET/CT identified lymph node metastasis in three of these 15 patients. The overall sensitivity and specificity, positive predictive value, and negative predictive value of PET/CT in the diagnosis of axillary lymph node metastasis were 20, 97, 75, and 74%, and those of ultrasonography were 33, 94, 71, and 77% and those of contrast-enhanced CT were 27, 97, 80, and 76%, respectively. PET/CT showed poor sensitivity and high specificity in the detection of axillary lymph node metastasis of breast cancer. Diagnostic performance of PET/CT was not superior to that of ultrasonography and contrast-enhanced CT. (author)

  5. Perforation of Axillary Vein by a Branch of the Axillary Artery: an Anatomical Study

    OpenAIRE

    Mahajan, Anita; Rana, K. K; Saha, S

    2012-01-01

    Anatomical variations in the region of axilla and pectoral region are very common. These variations need attention to avoid complications arising during surgeries and diagnostic and interventional invasive procedures in this region such as surgeries for breast carcinoma, venous access during central venous line, pacemaker and cardiac defibrillator implantation etc. During routine cadaveric dissection we had noticed a rare variation of axillary vein and artery. In this case axillary vein, just...

  6. Comparative analysis of multi-slice spiral CT and positron emission tomography-CT in evaluation of axillary lymph nodes in breast cancer patients

    International Nuclear Information System (INIS)

    Sun Xianchang; Zhang Ruyi; Liu Qingwei; Zhao Suhong; Zu Degui; Li Xin

    2008-01-01

    Objective: To evaluate and compare spiral CT and positron emission tomography-CT (PET-CT) in characterization of of axillary lymph nodes in breast cancer patients. Methods: Forty patients with pathologically proven breast cancer underwent contrast-enhanced spiral CT of the breast and axilla, 13 of them also underwent PET-CT examination. One hundred and fifty-eight axillary lymph nodes were found in the 40 patients through contrast enhanced spiral CT, while 57 lymph nodes were found in the 13 patients through PET-CT. Three radiologists rated the lymph nodes found in CT images on a five-point scale. If the score was equal to or greater than 3, it was defined as positive (metastatic), otherwise negative. Visual observation and semiquantitative analysis were used to classify lymph nodes in PET-CT images. The results of spiral CT observation and PET-CT observation of lymph nodes were compared with pathological results. The relative value of CT and PET-CT was analyzed. Exact probability statistics were employed. Results: One hundred and fifty eight lymph nodes of 40 patients were detected by spiral CT, 91 of them were diagnosed as positive and 67 as negative Among the lymph nodes found in spiral CT, 99 were positive and 59 were negative pathologicall. A total of 57 lymph nodes were found by PET-CT. Thirty-nine of them were defined as positive and 18 as negative. Among the lymph nodes found in PET-CT, 39 were positive and 18 were negative pathologically. The sensitivity, specificity, accuracy, positive and negative predictive values in CT prediction in axillary lymph nodes metastases were 88.89%, 94.91%, 91.14%, 96.70%, and 83.58%, respectively. The sensitivity, specificity, accuracy, positive and negative predictive values in PET-CT prediction in axillary lymph nodes metastases were 97.44%, 94.44%, 96.49%, 97.44%, and 94.44%, respectively. PET-CT had no significant difference with spiral CT in sensitivity, accuracy, positive and negative predictive values for detection

  7. Role of fluorine-18-labeled 2-fluoro-2-deoxy-D-glucose positron emission tomography-computed tomography in the evaluation of axillary lymph node involvement in operable breast cancer in comparison with sentinel lymph node biopsy

    International Nuclear Information System (INIS)

    Challa, Vasu Reddy; Srivastava, Anurag; Dhar, Anita; Parshad, Rajinder; Bal, Chandrasekhar; Gona, Rama Mohan Reddy; Kumar, Rakesh; Sharma, Punit; Gupta, Siddhartha Datta

    2013-01-01

    Role of (18(F)fluorine-18-labeled 2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography-computed tomography (PET-CT) in the evaluation of axillary lymph node involvement in T1T2N0 breast cancer and compare results with sentinel lymph node biopsy (SLNB). SLN was identified in 32 of 37 patients with an identification rate of 86.48% (32/37). With combined technique SLN identification rate was 100% (6/6) while with blue dye alone; it was 83.8% (26/31). Among 37 patients, 16 had axillary metastases of which 12 had macrometastases and four had micrometastases detected by immunohistochemistry (IHC). Of 12 patients with axillary macrometastases, skip metastases were present in two patients in whom SLN was negative and in two patients SLN was not identified, but axillary dissection showed metastases. PET-CT had shown sensitivity, specificity, negative predictive value and positive predictive value of 56%, 90%, 73%, and 81.8%, respectively. IHC of SLN detected four patients with micrometastases upstaging the disease by 11% (4/37). Because FDG PET-CT has a high specificity in the evaluation of axillary lymph node involvement in T1T2N0 breast cancer patients according to the results of this study if FDG PET-CT is positive in axillary lymph nodes, axillary lymph node dissection may be considered instead of SLNB

  8. The Clinical Value of Axillary Ultrasonogra- phy for Detection of Axillary Lymph Node Metastasis in Cases with Breast Cancer

    Directory of Open Access Journals (Sweden)

    Sedigheh Tahmasebi

    2014-10-01

    Full Text Available Background: The axillary lymph node stage is one of the single most important determinants in the prognosis of breast cancer patients. The disadvantages of the two previous methods used for evaluating axillary node metastasis, i.e., axillary lymph node dissection and sentinel lymph node biopsy, have directed researchers to investigate new techniques for this purpose. The aim of the current study was to evaluate the clinical usefulness of axillary ultrasonography in detecting axillary metastasis. Methods: This study was conducted during a 12-month period. The breast cancer cases included in this study were all clinically diagnosed as stages I and II, with no prior treatment to the axillary region by surgery and/or chemo-radiotherapy. Excluded from the study group were patients with palpable axillary lymph nodes, those who had major organ failure or concomitant malignancy. All included patients with non-palpable axillary lymph nodes underwent axillary ultrasound examination. An ultrasound- guided core needle biopsy was performed on patients with suspected metastasis. Results: There were 125 female patients with a mean age of 49.6 years included in this study. From these, 16 (12.8% cases had positive axillary sonographic findings. Pathologic evaluation of tissue specimens (taken by ultrasound-guided core needle biopsy in 10 (62.5% out of 16 patients were positive, and in the patient group of 6 (37.5% cases, studies were negative. Axillary ultrasonography had a sensitivity of 35.7%, specificity of 93.8%, positive predictive value of 62.5%, and negative predictive value of 83.5%. Conclusion: The axillary ultrasonogram is a reliable technique in the determination of axillary nodal metastatic involvement in breast cancer patients. By use of this method a significant amount of complications and costs related to the previous techniques can be avoided.

  9. False-positive axillary lymph node on F-18 FDG PET/CT due to moxibustion therapy

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Shin Young; Lee, Sang Woo; Ahn, Byeong Cheol; Lee, Jae Tae [Kyungpook National University Hospital, Daegu (Korea, Republic of); Seo, Ji Hyoung [Inje University Haeundae Paik Hospital, Busan (Korea, Republic of)

    2010-12-15

    A 30-year-old female was diagnosed with papillary thyroid cancer and underwent total thyroidectomy and high-dose radioiodine ablation. F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for recurrence detection of thyroid carcinoma was performed at 3 years after total thyroidectomy. Moxibustion is a traditional Chinese medicine therapy using moxa or the mugwort herb. Moxibustion is the burning of a small, thimble-sized, smoldering plug of dried leaves such as moxa or mugwort on the skin at an acupuncture point. Acupuncture and moxibustion induce hyperemia and a local inflammatory reaction. Complications associated with moxibustion such as skin bums or infection of the site have been reported previously. False-positive FDG uptake in PET may result from inflammation, infection, and variations in physiological uptake. In the present case, the hypermetabolic axillary lymph node disappeared without any treatment. Well-known of false-positive FDG uptake in axillary lymph noes such as arthritis of the upper extremity, extravasation of injected FDG, and vaccination were not found. Thus, left axillary lymph node uptake was

  10. False-positive axillary lymph node on F-18 FDG PET/CT due to moxibustion therapy

    International Nuclear Information System (INIS)

    Jeong, Shin Young; Lee, Sang Woo; Ahn, Byeong Cheol; Lee, Jae Tae; Seo, Ji Hyoung

    2010-01-01

    A 30-year-old female was diagnosed with papillary thyroid cancer and underwent total thyroidectomy and high-dose radioiodine ablation. F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for recurrence detection of thyroid carcinoma was performed at 3 years after total thyroidectomy. Moxibustion is a traditional Chinese medicine therapy using moxa or the mugwort herb. Moxibustion is the burning of a small, thimble-sized, smoldering plug of dried leaves such as moxa or mugwort on the skin at an acupuncture point. Acupuncture and moxibustion induce hyperemia and a local inflammatory reaction. Complications associated with moxibustion such as skin bums or infection of the site have been reported previously. False-positive FDG uptake in PET may result from inflammation, infection, and variations in physiological uptake. In the present case, the hypermetabolic axillary lymph node disappeared without any treatment. Well-known of false-positive FDG uptake in axillary lymph noes such as arthritis of the upper extremity, extravasation of injected FDG, and vaccination were not found. Thus, left axillary lymph node uptake was

  11. Supine MRI for regional breast radiotherapy: imaging axillary lymph nodes before and after sentinel-node biopsy

    Science.gov (United States)

    van Heijst, Tristan C. F.; Eschbach-Zandbergen, Debora; Hoekstra, Nienke; van Asselen, Bram; Lagendijk, Jan J. W.; Verkooijen, Helena M.; Pijnappel, Ruud M.; de Waard, Stephanie N.; Witkamp, Arjen J.; van Dalen, Thijs; Desirée van den Bongard, H. J. G.; Philippens, Marielle E. P.

    2017-08-01

    Regional radiotherapy (RT) is increasingly used in breast cancer treatment. Conventionally, computed tomography (CT) is performed for RT planning. Lymph node (LN) target levels are delineated according to anatomical boundaries. Magnetic resonance imaging (MRI) could enable individual LN delineation. The purpose was to evaluate the applicability of MRI for LN detection in supine treatment position, before and after sentinel-node biopsy (SNB). Twenty-three female breast cancer patients (cTis-3N0M0) underwent 1.5 T MRI, before and after SNB, in addition to CT. Endurance for MRI was monitored. Axillary levels were delineated. LNs were identified and delineated on MRI from before and after SNB, and on CT, and compared by Wilcoxon signed-rank tests. LN locations and LN-based volumes were related to axillary delineations and associated volumes. Although postoperative effects were visible, LN numbers on postoperative MRI (median 26 LNs) were highly reproducible compared to preoperative MRI when adding excised sentinel nodes, and higher than on CT (median 11, p  <  0.001). LN-based volumes were considerably smaller than respective axillary levels. Supine MRI of LNs is feasible and reproducible before and after SNB. This may lead to more accurate RT target definition compared to CT, with potentially lower toxicity. With the MRI techniques described here, initiation of novel MRI-guided RT strategies aiming at individual LNs could be possible.

  12. Clinical applications of positron emission tomography in breast cancer patients

    International Nuclear Information System (INIS)

    Roemer, W.; Avril, N.; Schwaiger, M.

    1997-01-01

    Increased glucose metabolism by malignant tissue can be visualized with positron emission tomography (PET), using the radiolabeled glucose analogue F-18 fluorodeoxyglucose (FDG). Depending on the criteria of image interpretation FDG-PET allows detection of breast cancer with a sensitivity of 68% to 94 % and a specificity of 84 % to 97 %. However, sensitivity to visualize small tumors (< 1 cm) is limited. Positron emission tomography demonstrates tumor involvement of regional lymph nodes with high accuracy, predominantly in patients with advanced breast cancer. The sensitivity for the detection of axillary lymph node metastases was 79% with a corresponding specificity of 96 %. Lymph node metastases could not be identified in four of six patients with small primary breast cancer (stage pT1), resulting in a sensitivity of only 33% in these patients. By visualizing primary tumors and metastases in one imaging procedure, PET imaging may allow the effective staging of breast cancer patients. Further studies are needed to define the role of scintigraphic techniques for the diagnostic work-up in patients. (author)

  13. Positron-acoustic waves in an electron-positron plasma with an electron beam

    International Nuclear Information System (INIS)

    Nejoh, Y.N.

    1996-01-01

    The nonlinear wave structures of large-amplitude positron-acoustic waves are studied in an electron-positron plasma in the presence of an electron beam with finite temperature and hot electrons and positrons. The region where positron-acoustic waves exist is presented by analysing the structure of the pseudopotential. The region depends sensitively on the positron density, the positron temperature and the electron beam temperature. It is shown that the maximum amplitude of the wave decreases as the positron temperature increases, and the region of positron-acoustic waves spreads as the positron temperature increases. 11 refs., 5 figs

  14. Axillary bud development in chrysanthemum

    NARCIS (Netherlands)

    Ruiter, de H.A.

    1996-01-01


    Each chrysanthemum cutting originates from an axillary bud. For an improvement of the cultivation of cuttings or more specific their quality, it is necessary that the development of an axillary bud can be controlled as good as possible. Axillary bud development can be distinguished into

  15. Midterm Experience of Ipsilateral Axillary-Axillary Arteriovenous Loop Graft as Tertiary Access for Haemodialysis

    Directory of Open Access Journals (Sweden)

    J. P. Hunter

    2014-01-01

    Full Text Available Objectives. To present a series of ipsilateral axillary artery to axillary vein loop arm grafts as an alternative vascular access procedure for haemodialysis in patients with difficult access. Design. Retrospective case series. Methods. Patients who underwent an axillary loop arteriovenous graft from September 2009 to September 2012 were included. Preoperative venous imaging to exclude central venous stenosis and to image arm/axillary veins was performed. A cuffed PTFE graft was anastomosed to the distal axillary artery and axillary vein and looped on the arm. Results. 25 procedures were performed on 22 patients. Median age was 51 years, with 9 males and 13 females. Median number of previous access procedures was 3 (range 0–7. Median followup was 16.4 months (range 1–35. At 3 months and 1 year, the primary and secondary patency rates were 70% and 72% and 36% and 37%, respectively. There were 11 radiological interventions in 6 grafts including 5 angioplasties and 6 thrombectomies. There were 19 surgical procedures in 10 grafts, including thrombectomy, revision, repair for bleeding, and excision. Conclusions. Our series demonstrates that the axillary loop arm graft yields acceptable early patency rates in a complex group of patients but to maintain graft patency required high rates of surgical and radiological intervention, in particular graft thrombectomy.

  16. [Axillary pathologic response after neoadjuvant chemotherapy in locally advanced breast cancer with axillary involvement].

    Science.gov (United States)

    Jiménez-Ballvé, A; Serrano-Palacio, A; García-Sáenz, J A; Ortega Candil, A; Salsidua-Arroyo, O; Román-Santamaría, J M; Pelayo Alarcón, A; Fuentes Ferrer, M E; Carreras-Delgado, J L

    2015-01-01

    To compare axillary involvement (N+) at initial staging in locally advanced breast cancer (LABC) with axillary lymphadenectomy histologic results after neoadjuvant chemotherapy treatment (NeoChemo). Retrospective study between November 2011 and September 2013 of LABC cases treated with neoadjuvant chemotherapy based on docetaxel (associated with trastuzumab in HER2 positive cases and carboplatin/adriamycin in HER2 negative cases). Those clinically or radiologically suspected cases of axillary involvement were histologically confirmed. When there was no suspicion of axillary involvement, sentinel lymph node radioguided biopsy (SLNRB) was performed using intradermal injection of (99m)Tc-nanocolloid albumin prior to neoadjuvant treatment. Axillary lymphadenectomy after NeoChemo was undertaken in all cases with positive axilla. Final pathologic response was classified as complete (pCR) when there was no evidence of tumoral disease and as non-pathologic complete response (no pCR) in the opposite case. A total of 346 patients treated with docetaxel were reviewed, identifying 105 LABC. Axillary involvement at initial staging was detected in 70 (67%) before starting NeoChemo. From these 70, 73% (n=51) were N+ (fine needle biopsy and/or biopsy) and the remaining 19 (27%) were occult N+ detected by SLNRB. Axillary lymphadenectomy detected pCR in 56% (39/70), increasing up to 84% pCR when initial N+ status was reached using SNLB. On the other hand, when N+ was detected using fine needle biopsy/lymph biopsy, pCR was only 45%. More than 50% of women affected by locally advanced breast cancer with tumoral axillary involvement at initial diagnosis present free metastatic axilla after therapeutic neoadjuvant chemotherapy effect. This increases up to almost 90% in case of occult metastatic axilla detected with sentinel node biopsy prior starting neoadjuvant chemotherapy. Copyright © 2014 Elsevier España, S.L.U. and SEMNIM. All rights reserved.

  17. Potentials of positron emission tomography for regional cerebral blood flow evaluation

    International Nuclear Information System (INIS)

    Depresseux, J.C.

    1982-01-01

    A general overview of the potentials of positron emission tomography and of positron-emitting radiopharmaceuticals for the evaluation of regional cerebral blood flow is proposed and discussed. Specific characteristics of this technique are described, with special stress on conceptual and methodological implications. Four different approaches to the problem of the determination of cerebral blood flow are distinguished: trapping equilibrium methods, steady state equilibrium methods, clearance methods and convoluted kinetic methods [fr

  18. Ontogeny of axillary buds and shoots in roses: Leaf initiation and pith development.

    NARCIS (Netherlands)

    Marcelis-van Acker, C.A.M.

    1994-01-01

    The ontogeny of an axillary bud (in the middle region of a shoot) from initiation up to flowering of the subsequent shoot was studied. The first secondary buds appeared in the axillary bud (primary bud) when the leaf subtending the primary bud unfolded. By that time, the primary bud contained seven

  19. FDG uptake in axillary lymph nodes after vaccination against pandemic (H1N1)

    International Nuclear Information System (INIS)

    Panagiotidis, Emmanouil; Exarhos, Demetrios; Housianakou, Irene; Bournazos, Apostolos; Datseris, Ioannis

    2010-01-01

    To alert the imaging community to potential false positive findings related to current immunization programmes against H1N1 influenza virus. We reviewed 10 patients referred for positron emission tomography/computed tomography (PET/CT) who had undergone recent vaccination. All studies showed 18 F-fluorodeoxyglucose (FDG) uptake in the draining axillary lymph nodes close to the vaccination site, while low-dose CT revealed lymph nodes ranged between 0.5 cm and 1.2 cm at the same site. This potential pitfall in PET/CT should be borne in mind during current vaccination programmes. (orig.)

  20. Biofeedback device for patients on axillary crutches.

    Science.gov (United States)

    Ang, E J; Goh, J C; Bose, K; Toh, S L; Choo, A

    1989-08-01

    The axillary crutch is commonly prescribed as an ambulatory aid to patients with temporal or permanent disability in the lower extremity. When fitting the axillary crutch, it is important that the user be instructed not to bear excessive weight on the axillary bar. Excessive weight bearing on the axillary bar can result in a sevenfold increase in the reaction force under the armpit. This force may be a contributory factor to crutch paralysis or thrombosis of the axillobrachial artery. In order to prevent this occurrence an electronic biofeedback device was designed and developed for use in the training of 3-point swing-through axillary crutch ambulation. It detects excessive weight bearing on the axillary bar during crutch ambulation and produces an audible signal which prompts the patient to make necessary adjustment to relieve load bearing on the axillary bar. The design and development of the biofeedback device is discussed in this paper.

  1. Partial axillary dissection in early breast cancer

    Directory of Open Access Journals (Sweden)

    Tarek Abdel Halim El-Fayoumi

    2013-09-01

    Full Text Available Background: In order to reduce the probability of later clinical involvement of the axilla and at establishing a sound basis for adjuvant treatment planning axillary dissection is an important operative procedure. So, partial axillary dissection has been applied to decrease the morbidity and postoperative axillary complications.Aim of the work was to study the reliability of partial axillary lymph node dissection in patients with breast carcinoma with clinically negative axilla. Methods: Eighteen patients underwent modified radical mastectomy, while the other two patients who were fulfilling the criteria for conservative breast surgery underwent lumpectomy. All patients did complete axillary lymph nodes dissection. Intraoperative leveling of the axilla was performed and level I axillary lymph nodes were identified according to their relation to pectoralis minor muscle; then they were subjected to intraoperative pathological examination by frozen section examination followed by complete axillary clearance. Then post operative histopathological examination of the tumor and all lymph nodes was done. Results: By intraoperative pathological examination; five patients (25% were found positive for malignant invasion, while 15 patients (75% were pathologically free. While paraffin section showed six patients (30% with malignant invasion, and 14 patients (70% were pathologically free. There was a false negative rate of 5% in level I axillary lymph nodes by intraoperative pathological examination which was positive for metastasis by paraffin section that revealed microinvasion in one lymph node out of 8 in level I. Only two cases out of 20 were found positive for metastasis in level II and III. Conclusion: Partial axillary lymph node dissection is a minimally invasive, feasible and sufficient technique that can predict the axillary lymph node status. KEYWORDS: Breast cancer, Axillary lymph nodes clearance

  2. Axillary irradiation omitting axillary dissection in breast cancer: is there a role for shoulder-sparing proton therapy?

    Science.gov (United States)

    Farace, P; Deidda, M A; Amichetti, M

    2015-10-01

    The recent EORTC 10981-22023 AMAROS trial showed that axillary radiotherapy and axillary lymph node dissection provide comparable local control and reduced lymphoedema in the irradiated group. However, no significant differences between the two groups in range of motion and quality of life were reported. It has been acknowledged that axillary irradiation could have induced some toxicity, particularly shoulder function impairment. In fact, conventional breast irradiation by tangential beams has to be modified to achieve full-dose coverage of the axillary nodes, including in the treatment field a larger portion of the shoulder structures. In this scenario, alternative irradiation techniques were discussed. Compared with modern photon techniques, axillary irradiation by proton therapy has the potential for sparing the shoulder without detrimental increase of the medium-to-low doses to the other normal tissues.

  3. Axillary radiotherapy in conservative surgery for early-stage breast cancer (stage I and II).

    Science.gov (United States)

    García Novoa, Alejandra; Acea Nebril, Benigno; Díaz, Inma; Builes Ramírez, Sergio; Varela, Cristina; Cereijo, Carmen; Mosquera Oses, Joaquín; López Calviño, Beatriz; Seoane Pillado, María Teresa

    2016-01-01

    Several clinical studies analyze axillary treatment in women with early-stage breast cancer because of changes in the indication for axillary lymph node dissection. The aim of the study is to analyze the impact of axillary radiotherapy in disease-free and overall survival in women with early breast cancer treated with lumpectomy. Retrospective study in women with initial stages of breast carcinoma treated by lumpectomy. A comparative analysis of high-risk women with axillary lymph node involvement who received axillary radiotherapy with the group of women with low risk without radiotherapy was performed. Logistic regression was used to determine factors influencing survival and lymphedema onset. A total of 541 women were included in the study: 384 patients (71%) without axillary lymph node involvement and 157 women (29%) with 1-3 axillary lymph node involvement. Patients with axillary radiotherapy had a higher number of metastatic lymph node compared to non-irradiated (1.6±0.7 vs. 1.4±0.6, P=.02). The group of women with axillary lymph node involvement and radiotherapy showed an overall and disease-free survival at 10 years similar to that obtained in patients without irradiation (89.7% and 77.2%, respectively). 3 lymph nodes involved multiplied by more than 7 times the risk of death (HR=7.20; 95% CI: 1.36 to 38.12). The multivariate analysis showed axillary lymph node dissection as the only variable associated with the development of lymphedema. The incidence of axillary relapse on stage I and II breast cancer is rare. In these patients axillary radiotherapy does not improve overall survival, but contributes to regional control in those patients with risk factors. Copyright © 2016 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

  4. Positron annihilation studies on bulk metallic glass and high intensity positron beam developments

    International Nuclear Information System (INIS)

    Asoka-Kumar, P.; Stoeffl, W.

    2003-01-01

    Positron annihilation spectroscopy is an ideal probe to examine atomic scale open-volume regions in materials. Below, we summarize the recent results on studies of open-volume regions of a multicomponent Zr-Ti-Ni-Cu-Be bulk metallic glass. Our studies establish two types of open-volume regions, one group that is too shallow to trap positrons at room temperature and becomes effective only at low temperatures and the other group that localizes positrons at room temperature and is large enough to accommodate hydrogen. The second half of the paper will concentrate on the high intensity positron program at Lawrence Livermore National Laboratory. A new positron production target is under development and we are constructing two experimental end stations to accommodate a pulsed positron microprobe and an experiment on positron diffraction and holography. Important design considerations of these experiments will be described. (author)

  5. Accumulation of FDG in axillary sweat glands in hyperhidrosis: a pitfall in whole-body PET examination

    International Nuclear Information System (INIS)

    Jacobsson, H.; Celsing, F.; Ingvar, M.; Stone-Elander, S.; Larsson, S.A.

    1998-01-01

    A diabetic male with severe autonomic neuropathy and recently discovered Hodgkin's disease demonstrated bilateral uptake of [2- 18 F]-2-fluoro-2-deoxy-d-glucose (FDG) in the axillary sweat glands during profuse sweating caused by hypoglycaemia at positron emission tomography examination. It is not yet clear whether the sweating interfered with the distribution of the radiopharmaceutical. Regardless of the cause or mechanism for the uptake, the finding is clinically relevant. A bilateral symmetrical accumulation of FDG in the axillae of a tumour patient does not necessarily indicate malignant involvement of the lymph nodes. (orig.)

  6. Biomechanical study on axillary crutches during single-leg swing-through gait.

    Science.gov (United States)

    Goh, J C; Toh, S L; Bose, K

    1986-08-01

    This paper describes a kinetic and kinematic study on axillary crutches during one-leg swing-through gait. The primary objective is to evaluate the interplay of forces at the crutch and body interfaces and to relate them in the understanding of problems associated with the use of axillary crutches. Ten normal adult male subjects with simulated left leg impairment participated in the study. For data acquisition, the VICON kinematic system, a Kistler force plate and an instrumented crutch (with force transducers at the two upper struts close to the axillary bar and one near the crutch tip) were used. Results showed that the peak ground reaction force on the weight-bearing leg during lower limb stance increased by 21.6 percent bodyweight. The peak reaction force transmitted to the arm during crutch stance was 44.4 percent bodyweight. These increased loadings could be detrimental to patients with unsound weight-bearing leg and upper extremities respectively. When the crutches were used incorrectly, 34 percent bodyweight was carried by the underarm. This could cause undue pressure over the neurovascular structures at the axillary region.

  7. Technique for axillary radiotherapy using computer-assisted planning for high-risk skin cancerΤ

    International Nuclear Information System (INIS)

    Fogarty, G.B.; Martin, J.M.; Fay, M.; Ainslie J; Cassumbhoy, R.

    2007-01-01

    High-risk skin cancer arising on the upper limb or trunk can cause axillary nodal metastases. Previous studies have shown that axillary radiotherapy improves regional control. There is little published work on technique. Technique standardization is important in quality assurance and comparison of results especially for trials. Our technique, planned with CT assistance, is presented. To assess efficacy, an audit of patients treated in our institution over a 15-month period was conducted. Of 24 patients treated, 13 were treated with radical intent, 11 with this technique. With a follow up of over 2 years, the technique had more than a 90% (10/11) regional control in this radical group. Both of the radical patients who were not treated according to the technique had regional failure. One case of late toxicity was found, of asymptomatic lymphoedema in a radically treated patient. This technique for axillary radiotherapy for regional control of skin cancer is acceptable in terms of disease control and toxicity as validated by audit at 2 years

  8. A predictive tool to estimate the risk of axillary metastases in breast cancer patients with negative axillary ultrasound

    DEFF Research Database (Denmark)

    Meretoja, T J; Heikkilä, P S; Mansfield, A S

    2014-01-01

    of this study was to evaluate the risk factors for axillary metastases in breast cancer patients with negative preoperative axillary ultrasound. METHODS: A total of 1,395 consecutive patients with invasive breast cancer and SNB formed the original patient series. A univariate analysis was conducted to assess...... risk factors for axillary metastases. Binary logistic regression analysis was conducted to form a predictive model based on the risk factors. The predictive model was first validated internally in a patient series of 566 further patients and then externally in a patient series of 2,463 patients from......BACKGROUND: Sentinel node biopsy (SNB) is the "gold standard" in axillary staging in clinically node-negative breast cancer patients. However, axillary treatment is undergoing a paradigm shift and studies are being conducted on whether SNB may be omitted in low-risk patients. The purpose...

  9. Studies of defects in the near-surface region and at interfaces using low energy positron beams

    International Nuclear Information System (INIS)

    Asoka-Kumar, P.

    1995-01-01

    Positron Annihilation Spectroscopy (PAS) is a powerful probe to study open-volume defects in solids. Its success is due to the propensity of positrons to seek out low-density regions of a solid, such as vacancies and voids, and the emissions of gamma rays from their annihilations that carry information about the local electronic environment. The development of low-energy positron beams allows probing of defects to depths of few microns, and can successfully characterize defects in the near-surface and interface regions of several technologically important systems. This review focuses on recent studies conducted on semiconductor-based systems

  10. Studies of defects in the near-surface region and at interfaces using low energy positron beams

    International Nuclear Information System (INIS)

    Asoka-Kumar, P.

    1997-01-01

    Positron annihilation spectroscopy (PAS) is a powerful probe to study open-volume defects in solids. Its success is due to the propensity of positrons to seek out low-density regions of a solid, such as vacancies and voids, and the emissions of gamma rays from their annihilations that carry information about the local electronic environment. The development of low-energy positron beams allows probing of defects to depths of few microns, and can successfully characterize defects in the near-surface and interface regions of several technologically important systems. This review focuses on recent studies conducted on semiconductor-based systems. (author)

  11. Fibroadenoma in axillary supernumerary breast: case report

    Directory of Open Access Journals (Sweden)

    Délio Marques Conde

    Full Text Available CONTEXT: Supernumerary breast tissue may be affected by the same diseases and alterations that compromise topical breast tissue. Nevertheless, reports of fibroadenoma in supernumerary breast tissue in the axillae are rare. OBJECTIVE: To describe a case of fibroadenoma in an axillary supernumerary breast. DESIGN: Case report. CASE REPORT: A 39-year-old woman was referred to the gynecology and obstetrics outpatient clinic at Hospital Estadual Sumaré, complaining of bilateral axillary masses. The patient reported cosmetic problems and local pain and discomfort. On physical examination, alterations compatible with bilateral axillary accessory breasts, without palpable nodules, were observed. Supplementary examinations (mammography and ultrasonography revealed a 1.1 cm mass in the right axillary breast. The patient underwent resection of the supernumerary breasts and histopathological examination revealed fibroadenoma of the right axillary breast tissue.

  12. Ultrasound-guided block of the axillary nerve

    DEFF Research Database (Denmark)

    Rothe, C; Lund, J; Jenstrup, M T

    2012-01-01

    The specific blocking of the axillary nerve has never been investigated clinically. We present four cases illustrating potential applications of the axillary nerve block in the perioperative setting and discuss possible directions for future research in this area. The axillary nerve blocks were all...... performed using a newly developed in-plane ultrasound-guided technique. In one patient undergoing arthroscopic shoulder surgery, we used the axillary nerve block as the only analgesic combined with propofol sedation and spontaneous breathing. Chronic shoulder pain was eliminated after the axillary nerve...... block in two patients. The pain score after arthroscopic shoulder surgery in these two patients remained low until termination of the nerve block. In a fourth patient, severe post-operative pain after osteosynthesis of a displaced proximal humerus fracture was almost eliminated after performing...

  13. Axillary bud development in rose

    NARCIS (Netherlands)

    Marcelis - van Acker, C.A.M.

    1994-01-01

    Axillary buds form the basis of flower production of a rose crop. Within a rose crop there exists an undesired large variation in shoot number and size, which affects flower yield. Part of this variation may be traced back to early variation in axillary buds. The aim of the research

  14. Measurement of regional cerebral glucose utilization in man by positron emission tomography

    International Nuclear Information System (INIS)

    Baron, J.C.

    1986-05-01

    The various methods available for the study of regional cerebral glucose consumption in man by positron emission tomography are described and their applications, limitations and principal physiopathological results are presented [fr

  15. Factors associated with involvement of four or more axillary nodes for sentinel lymph node-positive patients

    International Nuclear Information System (INIS)

    Katz, Angela; Niemierko, Andrzej; Gage, Irene; Evans, Sheila; Shaffer, Margaret; Smith, Frederick P.; Taghian, Alphonse; Magnant, Colette

    2006-01-01

    Purpose: Sentinel lymph node-positive (SLN+) patients who are unlikely to have 4 or more involved axillary nodes might be treated with less extensive regional nodal radiation. The purpose of this study was to define possible predictors of having 4 or more involved axillary nodes. Methods and Materials: The records of 224 patients with breast cancer and 1 to 3 involved SLNs, who underwent completion axillary dissection without neoadjuvant chemotherapy or hormonal therapy were reviewed. Factors associated with the presence of 4 or more involved axillary nodes (SLNs plus non-SLNs) were evaluated by Pearson chi-square test of association and by simple and multiple logistic-regression analysis. Results: Of 224 patients, 42 had involvement of 4 or more axillary nodes. On univariate analysis, the presence of 4 or more involved axillary nodes was positively associated with increased tumor size, lobular histology, lymphovascular space invasion (LVSI), increased number of involved SLNs, decreased number of uninvolved SLNs, and increased size of SLN metastasis. On multivariate analysis, the presence of 4 or more involved axillary nodes was associated with LVSI, increased number of involved SLNs, increased size of SLN metastasis, and lobular histology. Conclusions: Patients with 1 or more involved SLN, LVSI, or SLN macrometastasis should be treated to the supraclavicular fossa/axillary apex if they do not undergo completion axillary dissection. Other SLN+ patients might be adequately treated with less extensive radiation fields

  16. Breast-axillary complex in HIV/AIDS patients.

    Science.gov (United States)

    Eni, U E; Naaya, H U; Yawe, K D T; Lawan, M A; Bakari, A A

    2010-01-01

    HIV/AIDS have not only increased the health care burden especially in developing countries, it equally complicates the presentation of many diseases. Some well known disease entities now occur in fulminant complexities not previously described or known as such. The objective of this article is to report an unusual presentation of HIV/AIDS patients to the surgeon with Axillary and ipsilateral breast swelling. This is a report of three cases seen and managed by the authors. Three adult female patients presented with progressively increasing axillary and ipsilateral breast swellings. They also had associated fevers and weight loss. Their main concern had been development of breast cancer. One of the patients was a known retroviral positive on Highly Active Anti-Retroviral Therapy (HAART). Examination revealed axillary abscess and ipsilateral breast oedema in two cases. The patient on HAART had a hard breast-axillary mass complex. Biopsy (FNAB) revealed inflammatory cells and no malignancy in all three cases. HIV screening was positive in all cases. One of the patients had excision of breast-axillary mass complex, and the histology showed features of chronic inflammation, with no malignant cells. The other two had incision and drainage of their axillary abscess. This shows the ubiquitous presentation of HIV/AIDS in our environment and surgeons should be aware of the breast axillary complex in HIV/AIDS. Medical practitioners should be careful to obtain accurate diagnosis before embarking on treatment especially mutilating surgical procedures.

  17. Regional myocardial blood flow, metabolism and function assessed noninvasively by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Schelbert, H.R.; Phelps, M.E.; Hoffman, E.; Huang, S.; Kuhl, D.E.

    1979-01-01

    Positron emission computed tomography is a new technique for the noninvasive measure of myocardial blood flow, mechanical function and, in particular, metabolism. The capability of this new study means is due to the technological innovations of the imaging device and the availability of radioactive tracers that are specific for blood flow and metabolism. The device permits recording of cross-sectional images of the left ventricular myocardium that reflect quantitatively regional tracer tissue concentrations. By employing tracer kinetic models this new technique permits the measurement of regional glucose and fatty acid metabolism of the heart. While already an important new tool for investigative studies into cardiac physiology and pathophysiology, the clinical utility of positron emission tomography remains to be defined.

  18. Regional myocardial blood flow, metabolism and function assessed noninvasively by positron emission tomography

    International Nuclear Information System (INIS)

    Schelbert, H.R.; Phelps, M.E.; Hoffman, E.; Huang, S.; Kuhl, D.E.

    1979-01-01

    Positron emission computed tomography is a new technique for the noninvasive measure of myocardial blood flow, mechanical function and, in particular, metabolism. The capability of this new study means is due to the technological innovations of the imaging device and the availability of radioactive tracers that are specific for blood flow and metabolism. The device permits recording of cross-sectional images of the left ventricular myocardium that reflect quantitatively regional tracer tissue concentrations. By employing tracer kinetic models this new technique permits the measurement of regional glucose and fatty acid metabolism of the heart. While already an important new tool for investigative studies into cardiac physiology and pathophysiology, the clinical utility of positron emission tomography remains to be defined

  19. Harmonic Scalpel Versus Electrocautery in Axillary Dissection in Carcinoma Breast.

    Science.gov (United States)

    Nawaz, Allah; Waqar, Sadaf; Khan, Ahsan; Mansoor, Rashid; Butt, Usman Ismat; Ayyaz, Mahmood

    2015-12-01

    To compare the results between harmonics scalpel and electrocautery use in axillary dissection for carcinoma breast. Randomized controlled trial. Department of Surgery, Services Hospital, Lahore, from December 2013 to June 2014. Eighty patients fulfilling the inclusion criteria were selected and equally divided in two groups. Axillary dissection for carcinoma breast was performed by using the harmonic scalpel in one group and by using electrocautery in the other group. Total mean axillary drain output and frequency of axillary numbness were noted in both groups and compared. All the patients were females with mean age of 53.52 ± 9.8. Mean axillary drain output in harmonic scalpel group was 167.75 ± 43.90 as compared to 310.00 ± 60.09 in electrocautery group while only 12.5% of patients were positive for axillary numbness in harmonic scalpel group as compared to 100% of patients who were positive for electrocautery group. Use of harmonic scalpel in axillary dissection resulted in decreased total mean axillary drain output and lowered frequency of axillary numbness when compared to utilizing electrocautery.

  20. Added value of dedicated axillary hybrid 18F-FDG PET/MRI for improved axillary nodal staging in clinically node-positive breast cancer patients. A feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Nijnatten, Thiemo J.A. van; Goorts, B. [Maastricht University Medical Center+, Department of Radiology and Nuclear Medicine (Netherlands); Maastricht University Medical Center+, Department of Surgery, Maastricht (Netherlands); Maastricht University Medical Center+, GROW - School for Oncology and Developmental Biology, Maastricht (Netherlands); Voeoe, S.; Wildberger, J.E. [Maastricht University Medical Center+, Department of Radiology and Nuclear Medicine (Netherlands); Boer, M. de [Maastricht University Medical Center+, GROW - School for Oncology and Developmental Biology, Maastricht (Netherlands); Maastricht University Medical Center+, Division of Internal Medicine, Department of Medical Oncology, Maastricht (Netherlands); Kooreman, L.F.S. [Maastricht University Medical Center+, GROW - School for Oncology and Developmental Biology, Maastricht (Netherlands); Maastricht University Medical Center+, Department of Pathology, Maastricht (Netherlands); Heuts, E.M. [Maastricht University Medical Center+, Department of Surgery, Maastricht (Netherlands); Mottaghy, F.M. [Maastricht University Medical Center+, Department of Radiology and Nuclear Medicine (Netherlands); RWTH Aachen University, Department of Nuclear Medicine, University Hospital, Aachen (Germany); Lobbes, M.B.I. [Maastricht University Medical Center+, Department of Radiology and Nuclear Medicine (Netherlands); Maastricht University Medical Center+, GROW - School for Oncology and Developmental Biology, Maastricht (Netherlands); Smidt, M.L. [Maastricht University Medical Center+, Department of Surgery, Maastricht (Netherlands); Maastricht University Medical Center+, GROW - School for Oncology and Developmental Biology, Maastricht (Netherlands)

    2018-02-15

    To investigate the feasibility and potential added value of dedicated axillary 18F-FDG hybrid PET/MRI, compared to standard imaging modalities (i.e. ultrasound [US], MRI and PET/CT), for axillary nodal staging in clinically node-positive breast cancer. Twelve patients with clinically node-positive breast cancer underwent axillary US and dedicated axillary hybrid 18F-FDG PET/MRI. Nine of the 12 patients also underwent whole-body PET/CT. Maximum standardized uptake values (SUVmax) were measured for the primary breast tumor and the most FDG-avid axillary lymph node. A positive axillary lymph node on dedicated axillary hybrid PET/MRI was defined as a moderate to very intense FDG-avid lymph node. The diagnostic performance of dedicated axillary hybrid PET/MRI was calculated by comparing quantitative and its qualitative measurements to results of axillary US, MRI and PET/CT. The number of suspicious axillary lymph nodes was subdivided as follows: N0 (0 nodes), N1 (1-3 nodes), N2 (4-9 nodes) and N3 (≥ 10 nodes). According to dedicated axillary hybrid PET/MRI findings, seven patients were diagnosed with N1, four with N2 and one with N3. With regard to mean SUVmax, there was no significant difference in the primary tumor (9.0 [±5.0] vs. 8.6 [±5.7], p = 0.678) or the most FDG-avid axillary lymph node (7.8 [±5.3] vs. 7.7 [±4.3], p = 0.767) between dedicated axillary PET/MRI and PET/CT. Compared to standard imaging modalities, dedicated axillary hybrid PET/MRI resulted in changes in nodal status as follows: 40% compared to US, 75% compared to T2-weighted MRI, 40% compared to contrast-enhanced MRI, and 22% compared to PET/CT. Adding dedicated axillary 18F-FDG hybrid PET/MRI to diagnostic work-up may improve the diagnostic performance of axillary nodal staging in clinically node-positive breast cancer patients. (orig.)

  1. Added value of dedicated axillary hybrid 18F-FDG PET/MRI for improved axillary nodal staging in clinically node-positive breast cancer patients. A feasibility study

    International Nuclear Information System (INIS)

    Nijnatten, Thiemo J.A. van; Goorts, B.; Voeoe, S.; Wildberger, J.E.; Boer, M. de; Kooreman, L.F.S.; Heuts, E.M.; Mottaghy, F.M.; Lobbes, M.B.I.; Smidt, M.L.

    2018-01-01

    To investigate the feasibility and potential added value of dedicated axillary 18F-FDG hybrid PET/MRI, compared to standard imaging modalities (i.e. ultrasound [US], MRI and PET/CT), for axillary nodal staging in clinically node-positive breast cancer. Twelve patients with clinically node-positive breast cancer underwent axillary US and dedicated axillary hybrid 18F-FDG PET/MRI. Nine of the 12 patients also underwent whole-body PET/CT. Maximum standardized uptake values (SUVmax) were measured for the primary breast tumor and the most FDG-avid axillary lymph node. A positive axillary lymph node on dedicated axillary hybrid PET/MRI was defined as a moderate to very intense FDG-avid lymph node. The diagnostic performance of dedicated axillary hybrid PET/MRI was calculated by comparing quantitative and its qualitative measurements to results of axillary US, MRI and PET/CT. The number of suspicious axillary lymph nodes was subdivided as follows: N0 (0 nodes), N1 (1-3 nodes), N2 (4-9 nodes) and N3 (≥ 10 nodes). According to dedicated axillary hybrid PET/MRI findings, seven patients were diagnosed with N1, four with N2 and one with N3. With regard to mean SUVmax, there was no significant difference in the primary tumor (9.0 [±5.0] vs. 8.6 [±5.7], p = 0.678) or the most FDG-avid axillary lymph node (7.8 [±5.3] vs. 7.7 [±4.3], p = 0.767) between dedicated axillary PET/MRI and PET/CT. Compared to standard imaging modalities, dedicated axillary hybrid PET/MRI resulted in changes in nodal status as follows: 40% compared to US, 75% compared to T2-weighted MRI, 40% compared to contrast-enhanced MRI, and 22% compared to PET/CT. Adding dedicated axillary 18F-FDG hybrid PET/MRI to diagnostic work-up may improve the diagnostic performance of axillary nodal staging in clinically node-positive breast cancer patients. (orig.)

  2. Postoperative peri-axillary seroma following axillary artery cannulation for surgical treatment of acute type A aortic dissection

    Directory of Open Access Journals (Sweden)

    Katsanos Konstantinos

    2010-05-01

    Full Text Available Abstract The arterial cannulation site for optimal tissue perfusion and cerebral protection during cardiopulmonary bypass (CPB for surgical treatment of acute type A aortic dissection remains controversial. Right axillary artery cannulation confers significant advantages, because it provides antegrade arterial perfusion during cardiopulmonary bypass, and allows continuous antegrade cerebral perfusion during hypothermic circulatory arrest, thereby minimizing global cerebral ischemia. However, right axillary artery cannulation has been associated with serious complications, including problems with systemic perfusion during cardiopulmonary bypass, problems with postoperative patency of the artery due to stenosis, thrombosis or dissection, and brachial plexus injury. We herein present the case of a 36-year-old Caucasian man with known Marfan syndrome and acute type A aortic dissection, who had direct right axillary artery cannulation for surgery of the ascending aorta. Postoperatively, the patient developed an axillary perigraft seroma. As this complication has, not, to our knowledge, been reported before in cardiothoracic surgery, we describe this unusual complication and discuss conservative and surgical treatment options.

  3. Harmonic scalpel versus electrocautery in axillary dissection in carcinoma breast

    International Nuclear Information System (INIS)

    Nawaz, A.; Khan, A.; Mansoor, R.; Butt, U.I.

    2015-01-01

    To compare the results between harmonics scalpel and electrocautery use in axillary dissection for carcinoma breast. Study Design: Randomized controlled trial. Place and Duration of Study: Department of Surgery, Services Hospital, Lahore, from December 2013 to June 2014. Methodology: Eighty patients fulfilling the inclusion criteria were selected and equally divided in two groups. Axillary dissection for carcinoma breast was performed by using the harmonic scalpel in one group and by using electrocautery in the other group. Total mean axillary drain output and frequency of axillary numbness were noted in both groups and compared. Results: All the patients were females with mean age of 53.52 ± 9.8. Mean axillary drain output in harmonic scalpel group was 167.75 ± 43.90 as compared to 310.00 ± 60.09 in electrocautery group while only 12.5% of patients were positive for axillary numbness in harmonic scalpel group as compared to 100% of patients who were positive for electrocautery group. Conclusion: Use of harmonic scalpel in axillary dissection resulted in decreased total mean axillary drain output and lowered frequency of axillary numbness when compared to utilizing electrocautery. (author)

  4. Routine use of standard breast MRI compared to axillary ultrasound for differentiating between no, limited and advanced axillary nodal disease in newly diagnosed breast cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Nijnatten, T.J.A. van, E-mail: Thiemovn@gmail.com [Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht (Netherlands); Department of Surgery, Maastricht University Medical Center+, Maastricht (Netherlands); GROW – School for Oncology and Developmental Biology, Maastricht University Medical Center+, Maastricht (Netherlands); Ploumen, E.H. [Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht (Netherlands); Department of Surgery, Maastricht University Medical Center+, Maastricht (Netherlands); Schipper, RJ. [Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht (Netherlands); Department of Surgery, Maastricht University Medical Center+, Maastricht (Netherlands); GROW – School for Oncology and Developmental Biology, Maastricht University Medical Center+, Maastricht (Netherlands); Department of Surgery, Catharina Hospital, Eindhoven (Netherlands); Goorts, B. [Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht (Netherlands); Department of Surgery, Maastricht University Medical Center+, Maastricht (Netherlands); GROW – School for Oncology and Developmental Biology, Maastricht University Medical Center+, Maastricht (Netherlands); Andriessen, E.H. [Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht (Netherlands); Department of Surgery, Maastricht University Medical Center+, Maastricht (Netherlands); Vanwetswinkel, S.; Schavemaker, M. [Department of Radiology and Nuclear Medicine, Maastricht University Medical Center+, Maastricht (Netherlands); Nelemans, P. [Department of Epidemiology, Maastricht University Medical Center+, Maastricht (Netherlands); Vries, B. de [Department of Pathology, Zuyderland Hospital, Heerlen (Netherlands); and others

    2016-12-15

    Objectives: To compare standard breast MRI to dedicated axillary ultrasound (with or without tissue sampling) for differentiating between no, limited and advanced axillary nodal disease in breast cancer patients. Methods: All patients who underwent breast MRI and dedicated axillary ultrasound between 2009 and 2014 were eligible. Exclusion criteria were recurrent disease, neoadjuvant systemic therapy and not receiving completion axillary lymph node dissection after positive sentinel lymph node biopsy (SLNB). Two radiologists independently reassessed all MRI exams. Axillary ultrasound findings were retrospectively collected. Probability of advanced axillary nodal disease (pN2-3) given clinically node negative (cN0) or limited (cN1) findings was calculated, with corresponding negative predictive value (NPV) to exclude pN2-3 and positive predictive value (PPV) to identify axillary nodal disease. Histopathology served as gold standard. Results: A total of 377 cases resulted in 81.4% no, 14.4% limited and 4.2% advanced axillary nodal disease at final histopathology. Probability of pN2-3 given cN0 for breast MRI and axillary ultrasound was 0.7–0.9% versus 1.5% and probability of pN2-3 given cN1 was 11.6–15.4% versus 29.0%. When cN1 on breast MRI was observed, PPV to identify positive axillary nodal disease was 50.7% and 59.0%. Conclusions: Evaluation of axillary nodal status on standard breast MRI is comparable to dedicated axillary ultrasound in breast cancer patients. In patients who underwent preoperative standard breast MRI, axillary ultrasound is only required in case of suspicious nodal findings on MRI.

  5. Effects of positron density and temperature on large amplitude ion-acoustic waves in an electron-positron-ion plasma

    International Nuclear Information System (INIS)

    Nejoh, Y.N.

    1997-01-01

    The nonlinear wave structures of large amplitude ion-acoustic waves are studied in a plasma with positrons. We have presented the region of existence of the ion-acoustic waves by analysing the structure of the pseudopotential. The region of existence sensitively depends on the positron to electron density ratio, the ion to electron mass ratio and the positron to electron temperature ratio. It is shown that the maximum Mach number increases as the positron temperature increases and the region of existence of the ion-acoustic waves spreads as the positron temperature increases. 12 refs., 6 figs

  6. Positron emission computed tomography

    International Nuclear Information System (INIS)

    Grover, M.; Schelbert, H.R.

    1985-01-01

    Regional mycardial blood flow and substrate metabolism can be non-invasively evaluated and quantified with positron emission computed tomography (Positron-CT). Tracers of exogenous glucose utilization and fatty acid metabolism are available and have been extensively tested. Specific tracer kinetic models have been developed or are being tested so that glucose and fatty acid metabolism can be measured quantitatively by Positron-CT. Tracers of amino acid and oxygen metabolism are utilized in Positron-CT studies of the brain and development of such tracers for cardiac studies are in progress. Methods to quantify regional myocardial blood flow are also being developed. Previous studies have demonstrated the ability of Positron-/CT to document myocardial infarction. Experimental and clinical studies have begun to identify metabolic markers of reversibly ischemic myocardium. The potential of Positron-CT to reliably detect potentially salvageable myocardium and, hence, to identify appropriate therapeutic interventions is one of the most exciting applications of the technique

  7. Muscular Variations During Axillary Dissection: A Clinical Study in ...

    African Journals Online (AJOL)

    muscle and the coracoid process, without interruption by any type of tendinous fibres. The axillary arch muscle crossed anteriorly over the axillary vein [Figure 1]. The mastectomy along with axillary dissection was completed uneventfully. There was left sided absence of pectoralis major and minor muscles in a 45 years old ...

  8. Comparison of rectal and axillary temperatures in dogs and cats.

    Science.gov (United States)

    Goic, Joana B; Reineke, Erica L; Drobatz, Kenneth J

    2014-05-15

    To compare rectal versus axillary temperatures in dogs and cats. Prospective observational study. 94 dogs and 31 cats. Paired axillary and rectal temperatures were measured in random order with a standardized method. Animal signalment, initial complaint, blood pressure, blood lactate concentration, and variables associated with vascular perfusion and coat were evaluated for associations with axillary and rectal temperatures. Axillary temperature was positively correlated with rectal temperature (ρ = 0.75 in both species). Median axillary temperature (38.4°C [101.1°F] in dogs, and 38.4°C [101.2°F] in cats) was significantly different from median rectal temperature in dogs (38.9°C [102.0°F]) but not in cats (38.6°C [101.5°F]). Median rectal-axillary gradient (difference) was 0.4°C (0.7°F; range, -1.3° to 2.3°C [-2.4° to 4.1°F]) in dogs and 0.17°C (0.3°F; range -1.1° to 1.6°C [-1.9° to 3°F]) in cats. Sensitivity and specificity for detection of hyperthermia with axillary temperature were 57% and 100%, respectively, in dogs and 33% and 100%, respectively, in cats; sensitivity and specificity for detection of hypothermia were 86% and 87%, respectively, in dogs and 80% and 96%, respectively, in cats. Body weight (ρ = 0.514) and body condition score (ρ = 0.431) were correlated with rectal-axillary gradient in cats. Although axillary and rectal temperatures were correlated in dogs and cats, a large gradient was present between rectal temperature and axillary temperature, suggesting that axillary temperature should not be used as a substitute for rectal temperature.

  9. Partial axillary dissection in early breast cancer

    African Journals Online (AJOL)

    Tarek Abdel Halim El-Fayoumi

    ORIGINAL ARTICLE. Partial axillary dissection in early breast cancer. Tarek Abdel Halim El-Fayoumi *. Department of General Surgery, Faculty of Medicine, Alexandria University, Egypt. Received 16 October 2012; accepted 7 January 2013. Available online 7 March 2013. KEYWORDS. Breast cancer;. Axillary lymph nodes.

  10. Positron annihilation in disordered regions in neutron-irradiated Ge and Si

    International Nuclear Information System (INIS)

    Pustovoit, A.K.; Konopleva, R.F.; Kupchishin, A.I.; Mukashev, K.M.

    1989-01-01

    The method of angular distribution of annihilation photons was used to investigate the formation and annealing of radiation defects in Ge and Si irradiated with reactor neutrons. These effects were studied as a function of the type of conduction of the dopant concentration. The nature of annealing demonstrated positron annihilation at multivacancy complexes located within disordered regions

  11. Pretreatment axillary ultrasonography and core biopsy in patients with suspected breast cancer: Diagnostic accuracy and impact on management

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Ortega, Maria Jose, E-mail: rserranogan@telefonica.net [Breast Imaging Center, Radiology Department, Hospital Universitario Reina Sofia, Avda. Menendez Pidal s/n, 14004 Cordoba (Spain); Alvarez Benito, Marina, E-mail: marinaalvarezbenito@telefonica.net [Breast Imaging Center, Radiology Department, Hospital Universitario Reina Sofia, Avda. Menendez Pidal s/n, 14004 Cordoba (Spain); Fuentes Vahamonde, Elena, E-mail: elena.fuentes.sspa@juntadeandalucia.es [Pathology Department, Hospital Universitario Reina Sofia, Avda. Menendez Pidal s/n, 14004 Cordoba (Spain); Rioja Torres, Pilar, E-mail: priojat@yahoo.es [Clinical Management Unit, Department of General and Digestive Surgery, Hospital Universitario Reina Sofia, Avda. Menendez Pidal s/n, 14004 Cordoba (Spain); Benitez Velasco, Ana, E-mail: abvelazco@yahoo.es [Nuclear Medicine Department, Hospital Universitario Reina Sofia, Avda. Menendez Pidal s/n, 14004 Cordoba (Spain); Martinez Paredes, Maria, E-mail: mariaparedes@uco.es [Radiology and Physical Medicine Area, University of Cordoba Medical School, Avda. Menendez Pidal s/n, 14004 Cordoba (Spain)

    2011-07-15

    Preoperative diagnosis of axillary metastases in breast cancer patients enables treatment planning. We aimed to evaluate the diagnostic accuracy of axillary ultrasonography and percutaneous biopsy, both alone and in combination, in detecting axillary metastases in patients with breast cancer and to assess the impact of these techniques on the patients' management. Materials and methods: Retrospective study of consecutive patients with suspected breast cancer examined between October 2006 and December 2008. The diagnosis of a primary tumor was histologically confirmed in all patients. All patients underwent axillary ultrasonography and percutaneous core biopsy (14G) of suspicious lymph nodes. We evaluated the morphological characteristics of the lymph nodes by ultrasonography. We calculated the diagnostic accuracy of ultrasonography and of core biopsy, and assessed the impact of these techniques on patients' treatment. Results: We evaluated 675 axillary regions and performed 291 core biopsies of axillary lymph nodes in 662 patients. In 650 patients, breast cancer was histologically confirmed and in 12 patients malignant tumors in other locations were confirmed. The sensitivity and specificity of axillary ultrasonography were 63.2% and 88.7%, respectively. The absence of a fatty hilum within the lymph node was the ultrasonographic finding with the highest positive predictive value for malignancy (93.1%). The sensitivity and specificity of axillary core biopsy were 69.1% and 100%, respectively. Sentinel lymph node biopsy was avoided in 33% of initial candidates and immediate breast reconstruction was undertaken in 35.1% of the patients with mastectomy and negative axillary core biopsy. Conclusions: Ultrasonography and axillary core biopsy enable adequate pretreatment staging in patients with breast cancer and has a positive impact on their management.

  12. Ultrasound-guided axillary nerve block for ED incision and drainage of deltoid abscess.

    Science.gov (United States)

    Lyons, Claire; Herring, Andrew A

    2017-07-01

    Deltoid abscesses are common and painful, often a consequence of injection drug use and seen frequently in emergency departments (EDs). The required incision and drainage can be completed successfully with effective pain relief using a peripheral nerve block. The brachial plexus nerve block works well, however it is technically complex with a low, but potentially serious, risk of complications such as phrenic nerve paralysis. Selective blockade of the axillary nerve eliminates the risks associated with a brachial plexus block, while providing more specific anesthesia for the deltoid region. Our initial experience suggests that the axillary nerve block (ANB) is a technically simple, safe, and effective way to manage the pain of deltoid abscesses and the necessary incision and drainage (I&D). The block involves using ultrasound guidance to inject a 20mL bolus of local anesthetic into the quadrangular space surrounding the axillary nerve (inferior to the posterolateral aspect of the acromion, near the overlap of the long head of triceps brachii and teres minor). Once injected the local will anesthetize the axillary nerve resulting in analgesia of the cutaneous area of the lateral shoulder and the deeper tissues including the deltoid muscle. Further research will clarify questions about the volume and concentration of local anesthetic, the role of injected adjuncts, and expected duration of analgesia and anesthesia. Herein we present a description of an axillary nerve block successfully used for deltoid abscess I&D in the ED. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. The value of completion axillary treatment in sentinel node positive breast cancer patients undergoing a mastectomy: a Dutch randomized controlled multicentre trial (BOOG 2013-07)

    International Nuclear Information System (INIS)

    Roozendaal, L. M. van; Wilt, J. HW de; Dalen, T. van; Hage, J. A. van der; Strobbe, L. JA; Boersma, L. J.; Linn, S. C.; Lobbes, M. BI; Poortmans, P. MP; Tjan-Heijnen, V. CG; Van de Vijver, K. KBT; Vries, J. de; Westenberg, A. H.; Kessels, A. GH; Smidt, M. L.

    2015-01-01

    Trials failed to demonstrate additional value of completion axillary lymph node dissection in case of limited sentinel lymph node metastases in breast cancer patients undergoing breast conserving therapy. It has been suggested that the low regional recurrence rates in these trials might partially be ascribed to accidental irradiation of part of the axilla by whole breast radiation therapy, which precludes extrapolation of results to mastectomy patients. The aim of the randomized controlled BOOG 2013–07 trial is therefore to investigate whether completion axillary treatment can be safely omitted in sentinel lymph node positive breast cancer patients treated with mastectomy. This study is designed as a non-inferiority randomized controlled multicentre trial. Women aged 18 years or older diagnosed with unilateral invasive clinically T1-2 N0 breast cancer who are treated with mastectomy, and who have a maximum of three axillary sentinel lymph nodes containing micro- and/or macrometastases, will be randomized for completion axillary treatment versus no completion axillary treatment. Completion axillary treatment can consist of completion axillary lymph node dissection or axillary radiation therapy. Primary endpoint is regional recurrence rate at 5 years. Based on a 5-year regional recurrence free survival rate of 98 % among controls and 96 % for study subjects, the sample size amounts 439 per arm (including 10 % lost to follow-up), to be able to reject the null hypothesis that the rate for study and control subjects is inferior by at least 5 % with a probability of 0.8. Results will be reported after 5 and 10 years of follow-up. We hypothesize that completion axillary treatment can be safely omitted in sentinel node positive breast cancer patients undergoing mastectomy. If confirmed, this study will significantly decrease the number of breast cancer patients receiving extensive treatment of the axilla, thereby diminishing the risk of morbidity and improving quality of

  14. Merkel cell carcinoma with axillary metastasis; a case report of a rare disease

    Directory of Open Access Journals (Sweden)

    Serdar Culcu

    2018-04-01

    Full Text Available Merkel cell carcinoma is a rare primer neuroendocrine carcinoma of the skin. It is an extremely aggressive tumor. This rare carcinoma is seen with high local and regional recurrence ratios and distant metastasis. We report that a 64 years old female patient who had undergo an excision in another center because of a mass on 4 cm proximal of her right elbow had been diagnosed with Merkel cell carcinoma with positive surgical margins. She was treated with wide re-excision and axillary dissection at our clinic. Keywords: Merkel cell carcinoma, Skin, Axillary metastasis

  15. Axillary Hodgkin's disease in manual workers.

    Science.gov (United States)

    Andrieu, J M; Weh, H J; Teillet, F; Asselain, B

    1979-01-01

    Between 1965 and 1974, 16 patients were clinically staged as having unique axillary localizations of Hodgkin's disease. Sex ratio (4.3), mean age (40.8 years) and professional occupations (12 out of the 16 patients were engaged in manual work) were significantly different from that of all patients observed during the same period. These facts lead us to suppose the existence of a link between manual work and initial axillary localizations.

  16. Posttraumatic True Aneurysm of the Axillary Artery Following Blunt Trauma

    Directory of Open Access Journals (Sweden)

    Tugrul Goncu

    2010-01-01

    Full Text Available The majority of the axillary artery aneurysm cases arise as pseudoaneurysms secondary to blunt or iatrogenic trauma. Isolated traumatic true axillary artery aneurysm is a relatively unusual disorder and generally occurs with repetitive blunt trauma. A 22-year-old female patient with distal axillary artery true aneurysm due to simple blunt axillothoracic trauma is presented. The aneurysm was excised with subpectoral-axillary approach and saphenous vein graft interposition was applied. Long-term follow-up with the patient was uneventful.

  17. Noninvasive measurement of regional myocardial glucose metabolism by positron emission computed tomography

    International Nuclear Information System (INIS)

    Schelbert, H.R.; Phelps, M.E.

    While the results of regional myocardial glucose metabolism measurements using positron emission computed tomography ( 13 N-ammonia) are promising, their utility and value remains to be determined in man. If this technique can be applied to patients with acute myocardial ischemia or infarction it may permit delineation of regional myocardial segments with altered, yet still active metabolism. Further, it may become possible to evaluate the effects of interventions designed to salvage reversibly injured myocardium by this technique

  18. Rupture of an expander prosthesis mimics axillary cancer recurrence.

    LENUS (Irish Health Repository)

    Ismael, T

    2005-10-01

    Regional silicone gel migration from a ruptured breast implant has been reported at different locations including the upper extremity, chest wall muscles, axilla and back. We report a patient who presented with an axillary mass that mimicked a regional recurrence 5 years after breast cancer reconstruction with a latissimus dorsi musculocutaneous flap and silicon gel expander-prosthesis. Surgical exploration revealed that the mass contained silicone gel around the port of the breast expander that had ruptured. The mass was confluent with an intracapsular silicone leak through a tract along the tube of the expander port.

  19. Axillary lymph nodes and arm lymphatic drainage pathways are spared during routine complete axillary clearance in majority of women undergoing breast cancer surgery.

    Science.gov (United States)

    Szuba, A; Chachaj, Z; Koba-Wszedybylb, M; Hawro, R; Jasinski, R; Tarkowski, R; Szewczyk, K; Bebenek, M; Forgacz, J; Jodkowska, A; Jedrzejuk, D; Janczak, D; Mrozinska, M; Pilch, U; Wozniewski, M

    2011-09-01

    Alterations in axillary lymph nodes (ALNs) after complete axillary lymph node dissection (ALND) in comparison to the preoperative status were evaluated using lymphoscintigraphy performed preoperatively and 1-6 weeks after surgery in 30 women with a new diagnosis of unilateral, invasive breast carcinoma. Analysis of lymphoscintigrams revealed that ALNs after surgery were present in 26 of 30 examined women. In comparison to preoperative status, they were visualized in the same location (12 women), in the same and additionally in different locations (9 women), or only in different locations (4 women). No lymph nodes were visualized in one woman and lymphocoele were in 4 women. Thus, after ALND, a variable number of axillary lymph nodes remain and were visualized on lymphoscintigraphy in the majority of women. The classical ALND, therefore, does not allow complete dissection and removal of axillary nodes with total disruption of axillary lymphatic pathways, accounting in part for the variable incidence and severity of lymphedema after the procedure.

  20. Study of the electron-positron annihilation in the galactic center region with the Integral/SPI spectrometer

    International Nuclear Information System (INIS)

    Sizun, P.

    2007-04-01

    A spectral feature was detected in 1970 in the gamma-ray emission from the central regions of the Milky Way, during balloon flight observations. Located near 511 keV, this feature was soon attributed to the gamma-ray line tracing the annihilation of electrons with their anti-particles, positrons. However, none of the multiple astrophysical scenarios contemplated to explain the production of positrons in the Galactic bulge has been able to reproduce the high injection rate deduced from the flux of the 511 keV line, close to 10 43 positrons per second. Launched in 2002, the European gamma-ray satellite INTEGRAL was provided with a spectrometer, SPI, whose unprecedented imaging and spectral capabilities in this energy range enable us to further study the source of the 511 keV line detected in the Galactic centre region. Indeed, a better determination of the spatial extent of the source, the intrinsic width of the line and the fraction of positrons annihilating in-flight, directly or via the formation of ortho-Positronium atoms would improve our knowledge of both the annihilation medium and the initial source of positrons, and could allow us to discriminate between the various explanatory scenarios. The first part of this thesis deals with a key ingredient in the extraction of the annihilation spectrum: the optimization of the instrumental background model. New data screening and tracer selection procedures are presented. Classical multi-linear models are compared to neural and Bayesian networks. Finally, three years of observation are used to constrain the width of the source and derive its spectrum. The second part of the thesis focuses on one of the possible scenarios explaining the high positron injection rate deduced from the flux of the 511 keV line: the annihilation of light dark matter particles into electron-positron pairs. The various radiation mechanisms involved are modeled and confronted to observations in order to set an upper limit on the injection

  1. Presentation of Axillary Metastases from Occult Breast Carcinoma

    Institute of Scientific and Technical Information of China (English)

    Xin Wang

    2007-01-01

    Axillary presentation from occult breast cancer is uncommon and continues to be a diagnostic and therapeutic challenge to physicians.Once the diagnosis of adenocarcinoma metastatic to an axillary lymph node has been confirmed,a preoperative workup should be done.The current experience is based on several relatively small retrospective reviews and case reports.It is difficult to determine the best management of occult breast cancer.However,treatmenl of axillary Iymph node dissection is recommended for local control and complete staging information.Treatment of breast should be a choice between breast conservation with whole-breast radiotherapy and mastectomy.Adjuvant systemic treatment should be offered.

  2. Positron annihilation near fractal surfaces

    International Nuclear Information System (INIS)

    Lung, C.W.; Deng, K.M.; Xiong, L.Y.

    1991-07-01

    A model for positron annihilation in the sub-surface region near a fractal surface is proposed. It is found that the power law relationship between the mean positron implantation depth and incident positron energy can be used to measure the fractal dimension of the fractal surface in materials. (author). 10 refs, 2 figs

  3. Breast cancer with axillary lymph node involvement

    International Nuclear Information System (INIS)

    Belaid, A.; Kanoun, S.; Kallel, A.; Ghorbel, I.; Azoury, F.; Heymann, S.; Marsiglia, H.; Bourgier, C.; Belaid, A.; Ghorbel, I.; Kanoun, S.; Kallel, A.; Pichenot, C.; Verstraet, R.; Marsiglia, H.

    2010-01-01

    Breast cancer is the most frequent cancer of women in western countries. There are one million new cases per year in the world which represents 22% of all female cancers, and more than 370.000 deaths due to breast cancer per year (14% of cancer mortality). More than half of breast cancers are associated with axillary nodal involvement. Post-operative radiation therapy (XRT) is a crucial part of locoregional treatment in axillary nodal involvement breast cancer owing to a 15-years risk reduction of locoregional recurrence of 70% and to a 5.4% risk reduction of specific mortality. In 3D-conformal irradiation in such breast cancers, target volumes are chest wall when mastectomy was performed or breast and boost of tumor bed in case of breast conservative surgery, and supra-clavicular and/or axillary and/or internal mammary node areas. The main organs at risk are ipsilateral lung, heart and brachial plexus. The aim of this article is to describe epidemiologic, radio anatomic and prognostic features of axillary nodal involvement breast cancer and to propose guidelines for 3D-conformal treatment planning in locally advanced breast cancers. This review is illustrated by a case report. (authors)

  4. Muscular variations during axillary dissection: A clinical study in fifty patients

    Directory of Open Access Journals (Sweden)

    Upasna

    2015-01-01

    Methods: The anatomy of axilla regarding muscular variations was studied in 50 patients who had an axillary dissection for the staging and treatment of invasive primary breast cancer over one year. Results: In a period of one year, two patients (4% with axillary arch and one patient (2% with absent pectoralis major and minor muscles among fifty patients undergoing axillary surgery for breast cancer were identified. Conclusions: Axillary arch when present should always be identified and formally divided to allow adequate exposure of axillary contents, in order to achieve a complete lymphatic dissection. Complete absence of pectoralis major and minor muscles precludes the insertion of breast implants and worsens the prognosis of breast cancer.

  5. Positron astronomy with SPI/INTEGRAL

    International Nuclear Information System (INIS)

    Weidenspointner, G.; Diehl, R.; Strong, A.; Weidenspointner, G.; Skinner, G.K.; Skinner, G.K.; Jean, P.; Knoedlseder, J.; Von Ballmoos, P.; Cordier, B.; Schanne, S.; Winkler, C.

    2008-01-01

    We provide an overview of positron astronomy results that have been obtained using the INTEGRAL spectrometer SPI, and discuss their implications for the still mysterious origin of positrons in our Galaxy. It has long been known that the 511 keV positron annihilation emission is strongest from the central region of our Galaxy. Recently, it has been discovered with the SPI spectrometer that the weaker 511 keV line emission from the inner Galactic disk appears to be asymmetric, with the emission to the west of the Galactic center being about twice as strong than that to the east. This distribution of positron annihilation resembles that of low mass X-ray binaries as observed with the INTEGRAL imager IBIS at hard X-ray energies, suggesting that these systems could provide a significant portion of the positrons in our Galaxy. In addition, the spectrometer SPI has permitted unprecedented spectroscopy of annihilation radiation from the bulge and disk regions of the Galaxy, which commences to yield important insights into the conditions of the medium in which the positrons annihilate. (authors)

  6. Cardiac positron tomography

    International Nuclear Information System (INIS)

    Geltmann, E.M.; Roberts, R.; Sobel, B.E.

    1980-01-01

    Positron emission tomography (PET) performed after the administration of the positron-emitting radionuclides carbon-11 ( 11 C), nitrogen-13 ( 13 N), oxygen-15 ( 15 O) and fluorine-18 ( 18 F) has permitted the improved noninvasive assessment of the regional myocardial metabolism of normal physiologic substrates and intermediates and their cogeners. In experimental animals, the rate of oxidation of 11 C-palmitate correlates closely with other indexes of oxygen consumption, and the extraction of 11 C-palmitate (like that of 18 F-fatty acids and 18 F-fluoredoxyglucose) ist markedly diminished in regions of myocardial ischemia. In both experimental animals and in patients, myocardial infarct site and size, determined by positron emission tomography after the intravenous injection of 11 C-palmitate, correlate closely with the electrocardiographic infarct locus and enzymatically estimated infarct size as well as with the location and extent of regional left ventricular wall motion abnormalities. PET offers promise for assessment of flow as well despite the complexities involved. PET with 13 NH 3 appears to provide one useful qualitative index, although this tracer ist actively metabolized. Because of the quantitative capabilities of positron emission tomography and the rapid progress which is being made in the development of fast scan, multi-slice, and gated instrumentation, this technique is likely to facilitate improved understanding and characterization of regional myocardial metabolism and blood flow in man under physiological and pathophysiological conditions. (orig.) [de

  7. Automatic detection of axillary lymphadenopathy on CT scans of untreated chronic lymphocytic leukemia patients

    Science.gov (United States)

    Liu, Jiamin; Hua, Jeremy; Chellappa, Vivek; Petrick, Nicholas; Sahiner, Berkman; Farooqui, Mohammed; Marti, Gerald; Wiestner, Adrian; Summers, Ronald M.

    2012-03-01

    Patients with chronic lymphocytic leukemia (CLL) have an increased frequency of axillary lymphadenopathy. Pretreatment CT scans can be used to upstage patients at the time of presentation and post-treatment CT scans can reduce the number of complete responses. In the current clinical workflow, the detection and diagnosis of lymph nodes is usually performed manually by examining all slices of CT images, which can be time consuming and highly dependent on the observer's experience. A system for automatic lymph node detection and measurement is desired. We propose a computer aided detection (CAD) system for axillary lymph nodes on CT scans in CLL patients. The lung is first automatically segmented and the patient's body in lung region is extracted to set the search region for lymph nodes. Multi-scale Hessian based blob detection is then applied to detect potential lymph nodes within the search region. Next, the detected potential candidates are segmented by fast level set method. Finally, features are calculated from the segmented candidates and support vector machine (SVM) classification is utilized for false positive reduction. Two blobness features, Frangi's and Li's, are tested and their free-response receiver operating characteristic (FROC) curves are generated to assess system performance. We applied our detection system to 12 patients with 168 axillary lymph nodes measuring greater than 10 mm. All lymph nodes are manually labeled as ground truth. The system achieved sensitivities of 81% and 85% at 2 false positives per patient for Frangi's and Li's blobness, respectively.

  8. Positron annihilation studies in the field induced depletion regions of metal-oxide-semiconductor structures

    Science.gov (United States)

    Asoka-Kumar, P.; Leung, T. C.; Lynn, K. G.; Nielsen, B.; Forcier, M. P.; Weinberg, Z. A.; Rubloff, G. W.

    1992-06-01

    The centroid shifts of positron annihilation spectra are reported from the depletion regions of metal-oxide-semiconductor (MOS) capacitors at room temperature and at 35 K. The centroid shift measurement can be explained using the variation of the electric field strength and depletion layer thickness as a function of the applied gate bias. An estimate for the relevant MOS quantities is obtained by fitting the centroid shift versus beam energy data with a steady-state diffusion-annihilation equation and a derivative-gaussian positron implantation profile. Inadequacy of the present analysis scheme is evident from the derived quantities and alternate methods are required for better predictions.

  9. Positron annihilation studies in the field induced depletion regions of metal-oxide-semiconductor structures

    International Nuclear Information System (INIS)

    Asoka-Kumar, P.; Leung, T.C.; Lynn, K.G.; Nielsen, B.; Forcier, M.P.; Weinberg, Z.A.; Rubloff, G.W.

    1992-01-01

    The centroid shifts of positron annihilation spectra are reported from the depletion regions of metal-oxide-semiconductor (MOS) capacitors at room temperature and at 35 K. The centroid shift measurement can be explained using the variation of the electric field strength and depletion layer thickness as a function of the applied gate bias. An estimate for the relevant MOS quantities is obtained by fitting the centroid shift versus beam energy data with a steady-state diffusion-annihilation equation and a derivative-gaussian positron implantation profile. Inadequacy of the present analysis scheme is evident from the derived quantities and alternate methods are required for better predictions

  10. Axillary nerve injury associated with sports.

    Science.gov (United States)

    Lee, Sangkook; Saetia, Kriangsak; Saha, Suparna; Kline, David G; Kim, Daniel H

    2011-11-01

    The aim of this retrospective study was to present and investigate axillary nerve injuries associated with sports. This study retrospectively reviewed 26 axillary nerve injuries associated with sports between the years 1985 and 2010. Preoperative status of the axillary nerve was evaluated by using the Louisiana State University Health Science Center (LSUHSC) grading system published by the senior authors. Intraoperative nerve action potential recordings were performed to check nerve conduction and assess the possibility of resection. Neurolysis, suture, and nerve grafts were used for the surgical repair of the injured nerves. In 9 patients with partial loss of function and 3 with complete loss, neurolysis based on nerve action potential recordings was the primary treatment. Two patients with complete loss of function were treated with resection and suturing and 12 with resection and nerve grafting. The minimum follow-up period was 16 months (mean 20 months). The injuries were associated with the following sports: skiing (12 cases), football (5), rugby (2), baseball (2), ice hockey (2), soccer (1), weightlifting (1), and wrestling (1). Functional recovery was excellent. Neurolysis was performed in 9 cases, resulting in an average functional recovery of LSUHSC Grade 4.2. Recovery with graft repairs averaged LSUHSC Grade 3 or better in 11 of 12 cases Surgical repair can restore useful deltoid function in patients with sports-associated axillary nerve injuries, even in cases of severe stretch-contusion injury.

  11. Correction of accessory axillary breast tissue without visible scar.

    Science.gov (United States)

    Kim, Young Soo

    2004-01-01

    Various methods for correction of accessory axillary breast tissue have been proposed, including simple excision, diamond-shaped excision, a Y-V technique, and lipoplasty. We present an effective method for correction of a prominent axillary mound that combines lipoplasty with excision of accessory breast tissue along the axillary transverse line. Preoperative markings included an incision within the natural wrinkle line in the axillary fold, and demarcation of areas in which lipoplasty and excision were to be performed. After lipoplasty, deep dissection was performed to isolate and remove accessory breast tissue and excess fat tissue. A compression dressing was applied for 1 to 2 weeks postoperatively, and the patient was instructed to wear a sports bra for 1 to 2 months after removal of the dressing. We treated 7 patients using this procedure between October 1999 and March 2003. No major postoperative complications were detected and recurrence was not noted during the follow-up periods. Aesthetic results were satisfactory. We believe that a procedure that combines lipoplasty and excision provides numerous advantages as a surgical option in treating a prominent axillary mound. The main advantage is that the final scar is laid in the natural axillary fold, rendering scars less conspicuous and eliminating the need to remove excess skin. The one disadvantage was that elevation of the skin flap via small, remote incisions initially produced surgical difficulties, but these were overcome with experience.

  12. Axillary arthrotomography of the glenoid labrum

    International Nuclear Information System (INIS)

    Kleinman, P.K.; Kanzaria, P.K.; Goss, T.P.; Pappas, A.M.

    1984-01-01

    In a study of 67 shoulders evaluated by axillary arthrotomography, tears of the glenoid labrum were accurately detected in all 26 surgically confirmed cases. One false-positive case was identified in the five patients without labral tears; there were no false-negative cases. Only 40% of the patients had clinical evidence of subluxation or dislocation. Axillary arthrotomography provides important information about the integrity of the labrum that may be helpful in planning surgery for patients without clinical subluxation or dislocation but with pain, clicking, or vague shoulder discomfort secondary to labral pathology (functional instability)

  13. Axillary artery injury secondary to inferior shoulder dislocation.

    Science.gov (United States)

    Plaga, Brad R; Looby, Peter; Feldhaus, Steven J; Kreutzmann, Karl; Babb, Aaron

    2010-11-01

    Dislocation injuries of the glenohumeral joint are common in the general public and generally are corrected without complication. One serious complication with shoulder dislocations, or the subsequent reduction, is a lesion to the axillary artery. This specific complication is most frequently seen in the elderly population, where vascular structures have become less flexible. Also, these injuries are most common in association with anterior dislocations of the shoulder. To bring awareness to the possibility of axillary artery injury with inferior dislocation of the shoulder, the treatment options, and a review. We report a 15-year-old male athlete who inferiorly dislocated his shoulder during wrestling practice. The injury was reduced at the scene with manual traction and the patient was transferred to our clinic for evaluation. The patient was determined to have a pseudoaneurysm of the axillary artery, and the history and treatment of the illness are presented. Axillary artery injuries secondary to shoulder dislocations are rare, especially in the young athlete, and proper recognition and treatment offer patients a full recovery. Copyright © 2010. Published by Elsevier Inc.

  14. Multi-detector row CT in the assessment of axillary lymph node metastasis in breast cancer

    International Nuclear Information System (INIS)

    Murakami, Shogo

    2003-01-01

    The purpose of this study is to evaluate the diagnostic capability instead of clinical efficacy of multi-detector row CT (MDCT) in the assessment of axillary lymph node metastasis in breast cancer. MDCT was performed in 63 patients with breast cancer, and multiplanar reformation (MPR) and volume rendering (VR) images were reconstructed for the evaluation of bilateral axillary lymph nodes. Two hundred sixty eight lymph nodes were depicted with MDCT, and correlation with pathological findings was performed. The short axis length of lymph node was measured on MPR image, and the shape of the nodes was analyzed with the pathological results statistically. The diagnostic criteria on size and shape of lymph node metastasis were discussed Dynamic study with contrast media was also performed, and the CT value ratios (CTVR) of the lymph nodes and breast tumors were calculated. No relevance of axillary lymph node metastasis was noted to the pathological types of breast cancer. The average short axis length of the ipsilateral axillary nodes was 8.9 mm±3.8 (SD) while that of the contralateral nodes was 4.9 mm±1.1 (SD) showing significant difference. More than 6.5 mm in short length of the lymph node was thought to be an effective criterion for positive metastasis, and its sensitivity was 96%. Soybean-shape lymph node was statistically common in metastasis, while non-metastatic nodes were commonly demonstrated as letter ''c'' shape or ring-like shape. Statistical relevance was obtained between the CTVR of axillary lymph nodes and that of breast tumors, suggesting clinical usefulness of dynamic study using contrast media in the evaluation of lymph node metastasis. With MPR and VR images using MDCT, more accurate morphological evaluation of axillary lymph nodes was possible. When soybean-shape node with more than 6.5 mm in short axis is depicted in the axillar region on MDCT metastasis should be the consideration. Comparison with the contralateral side as a control in coronal

  15. [Population genetic differentiation of Phrynocephalus axillaris in east of Xinjiang Uygur Autonomous Region based on sequence variation of mitochondrial ND4-tRNALeu gene].

    Science.gov (United States)

    Li, Jun; Guo, Xian-Guang; Wang, Yue-Zhao

    2010-08-01

    A 838 bp fragment of mtDNA ND4-tRNALeu gene was sequenced for 66 individuals from five populations (DB: Dabancheng, TU: Turpan, SS: Shanshan, HL: Liushuquan, HD: East district of Hami) of Phrynocephalus axillaris distributed in east of Xinjiang Uygur Autonomous Region. Seventeen haplotypes were identified from 29 nucleotide polymorphic sites in the aligned 838 bp sequence. Excluding DB, there were relatively high haplotype diversity [(0.600+/-0.113)oscillation since Pleistocene and genetic drift.

  16. Para-axillary subcutaneous endoscopic approach in torticollis: tips and tricks in the surgical technique.

    Science.gov (United States)

    Tokar, Baran; Karacay, Safak; Arda, Surhan; Alici, Umut

    2015-04-01

    An obvious scar on the neck may appear following the open surgery for congenital muscular torticollis (CMT). The cosmetic result may displease the patient and the family. In this study, we describe a minimally invasive technique, para-axillary subcutaneous endoscopic approach (PASEA) in CMT. A total of 11 children (seven girls and four boys with the age range between 1 and 15 years) were operated for torticollis by PASEA. All patients had facial asymmetry and head and neck postural abnormality. Following an incision at the ipsilateral para-axillary region, a subcutaneous cavernous working space is formed toward sternocleidomastoid (SCM) muscle. The muscle and fascia are cut by cautery under endoscopic vision. The patients had postoperative 2nd-week and 3rd-month visits. The incision scar, inspection, and palpation findings of the region, head posture, and shoulder position of the affected side were considered in evaluation of the cosmetic outcome. Preoperative and postoperative range of motion of the head and neck were compared for functional outcome. We preferred single incision surgery in our last two patients; the rest had double para-axillary incision for port insertion. Incomplete transection of the muscle was not observed. There was no serious complication. Postoperatively, head posture and shoulder elevation were corrected significantly. Range of motion of the head was improved. Postoperatively, all the patients had rotation capacity with more than 30 degrees. The range of postoperative flexion and extension movements was between 45 and 60 degrees. The open surgery techniques of CMT causes visible lifelong incision scar on the neck. PASEA leaves a cosmetically hidden scar in the axillary region. A single incision surgery is also possible. A well-formed cavernous working space is needed. External manual palpation, delicate dissection, and cutting of SCM muscle with cautery are the important components of the procedure. Surgeons having experience in pediatric

  17. Utility of 18F-fluoro-deoxyglucose emission tomography/computed tomography fusion imaging (18F-FDG PET/CT) in combination with ultrasonography for axillary staging in primary breast cancer

    International Nuclear Information System (INIS)

    Ueda, Shigeto; Ishida, Jiro; Abe, Yoshiyuki; Mochizuki, Hidetaka; Tsuda, Hitoshi; Asakawa, Hideki; Omata, Jiro; Fukatsu, Kazuhiko; Kondo, Nobuo; Kondo, Tadaharu; Hama, Yukihiro; Tamura, Katsumi

    2008-01-01

    Accurate evaluation of axillary lymph node (ALN) involvement is mandatory before treatment of primary breast cancer. The aim of this study is to compare preoperative diagnostic accuracy between positron emission tomography/computed tomography with 18 F-fluorodeoxyglucose ( 18 F-FDG PET/CT) and axillary ultrasonography (AUS) for detecting ALN metastasis in patients having operable breast cancer, and to assess the clinical management of axillary 18 F-FDG PET/CT for therapeutic indication of sentinel node biopsy (SNB) and preoperative systemic chemotherapy (PSC). One hundred eighty-three patients with primary operable breast cancer were recruited. All patients underwent 18 F-FDG PET/CT and AUS followed by SNB and/or ALN dissection (ALND). Using 18 F-FDG PET/CT, we studied both a visual assessment of 18 F-FDG uptake and standardized uptake value (SUV) for axillary staging. In a visual assessment of 18 F-FDG PET/CT, the diagnostic accuracy of ALN metastasis was 83% with 58% in sensitivity and 95% in specificity, and when cut-off point of SUV was set at 1.8, sensitivity, specificity, and accuracy were 36, 100, and 79%, respectively. On the other hand, the diagnostic accuracy of AUS was 85% with 54% in sensitivity and 99% in specificity. By the combination of 18 F-FDG PET/CT and AUS to the axilla, the sensitivity, specificity, and accuracy were 64, 94, and 85%, respectively. If either 18 F-FDG PET uptake or AUS was positive in allixa, the probability of axillary metastasis was high; 50% (6 of 12) in 18 F-FDG PET uptake only, 80% (4 of 5) in AUS positive only, and 100% (28 of 28) in dual positive. By the combination of AUS and 18 F-FDG PET/CT, candidates of SNB were more appropriately selected. The axillary 18 F-FDG uptake was correlated with the maximum size and nuclear grade of metastatic foci (p = 0.006 and p = 0.03). The diagnostic accuracy of 18 F-FDG PET/CT was shown to be nearly equal to ultrasound, and considering their limited sensitivities, the high radiation

  18. Axillary Phlebography; An analysis of 33 cases of healthy person

    International Nuclear Information System (INIS)

    Kim, Chu Wan

    1974-01-01

    It has been well established that axillary phlebography is excellent method in diagnosis of the primary and secondary thrombotic conditions of axillary vein. But the evaluation of veins of axilla is often difficult due to individual variation of veins and to various methods of venography. Axillary phlebographies were made in thirty-three normal Korean adults by modified bolus technique and various measurements and consideration were done for the evaluation of normal anatomical variations. Results were as follows; 1. Axillary vein was visualized satisfactory in 32 cases among 33 cases, basilic vein in 28 cases, and cephalic vein and brachial vein in 15 cases. 2. Bifid basilic vein was observed in 4 cases and trifid basilic vein in 1 case. Anastomosis between cephalic and brachial vein was observed in 5 case. In 1 case, anastomotic site of median cubital vein with basilic vein is more proximal than usual. 3. Average diameter of axillary vein were 9 mm (7-11 mm) in male and 8 mm (5-10 mm) in female at axillary border of scapula and 14 mm (11-18 mm) in male and 13 mm (11-15 mm) in female at midportion of first rib. 4. Streaming and dilution of contrast media, and deformities by valve action were observed in many cases, which may be mistaken as abnormality

  19. Dose to level I and II axillary lymph nodes and lung by tangential field radiation in patients undergoing postmastectomy radiation with tissue expander reconstruction

    International Nuclear Information System (INIS)

    Russo, James K; Armeson, Kent E; Rhome, Ryan; Spanos, Michele; Harper, Jennifer L

    2011-01-01

    To define the dosimetric coverage of level I/II axillary volumes and the lung volume irradiated in postmastectomy radiotherapy (PMRT) following tissue expander placement. Twenty-three patients were identified who had undergone postmastectomy radiotherapy with tangent only fields. All patients had pre-radiation tissue expander placement and expansion. Thirteen patients had bilateral expander reconstruction. The level I/II axillary volumes were contoured using the RTOG contouring atlas. The patient-specific variables of expander volume, superior-to-inferior location of expander, distance between expanders, expander angle and axillary volume were analyzed to determine their relationship to the axillary volume and lung volume dose. The mean coverage of the level I/II axillary volume by the 95% isodose line (V D95% ) was 23.9% (range 0.3 - 65.4%). The mean Ipsilateral Lung V D50% was 8.8% (2.2-20.9). Ipsilateral and contralateral expander volume correlated to Axillary V D95% in patients with bilateral reconstruction (p = 0.01 and 0.006, respectively) but not those with ipsilateral only reconstruction (p = 0.60). Ipsilateral Lung V D50% correlated with angle of the expander from midline (p = 0.05). In patients undergoing PMRT with tissue expanders, incidental doses delivered by tangents to the axilla, as defined by the RTOG contouring atlas, do not provide adequate coverage. The posterior-superior region of level I and II is the region most commonly underdosed. Axillary volume coverage increased with increasing expander volumes in patients with bilateral reconstruction. Lung dose increased with increasing expander angle from midline. This information should be considered both when placing expanders and when designing PMRT tangent only treatment plans by contouring and targeting the axilla volume when axillary treatment is indicated

  20. Axillary local anesthetic spread after the thoracic interfacial ultrasound block – a cadaveric and radiological evaluation

    Directory of Open Access Journals (Sweden)

    Patricia Alfaro de la Torre

    2017-11-01

    Full Text Available Background: Oral opioid analgesics have been used for management of peri- and postoperative analgesia in patients undergoing axillary dissection. The axillary region is a difficult zone to block and does not have a specific regional anesthesia technique published that offers its adequate blockade. Methods: After institutional review board approval, anatomic and radiological studies were conducted to determine the deposition and spread of methylene blue and local anesthetic injected respectively into the axilla via the thoracic inter-fascial plane. Magnetic Resonance Imaging studies were then conducted in 15 of 34 patients scheduled for unilateral breast surgery that entailed any of the following: axillary clearance, sentinel node biopsy, axillary node biopsy, or supernumerary breasts, to ascertain the deposition and time course of spread of solution within the thoracic interfascial plane in vivo. Results: Radiological and cadaveric studies showed that the injection of local anesthetic and methylene blue via the thoracic inter-fascial plane, using ultrasound guide technique, results in reliable deposition into the axilla. In patients, the injection of the local anesthetic produced a reliable axillary sensory block. This finding was supported by Magnetic Resonance Imaging studies that showed hyper-intense signals in the axillary region. Conclusions: These findings define the anatomic characteristics of the thoracic interfascial plane nerve block in the axillary region, and underline the clinical potential of this novel nerve block. Resumo: Justificativa: Os analgésicos orais à base de opioides têm sido usados para o manejo da analgesia nos períodos peri e pós-operatório de pacientes submetidos à linfadenectomia axilar. A região axilar é uma zona difícil de bloquear e não há registro de uma técnica de anestesia regional específica que ofereça o seu bloqueio adequado. Métodos: Após a aprovação do Conselho de Ética institucional

  1. Ultrasound Guidance Versus Peripheral Neurostimulation for Brachial Plexus Block Anesthesia with Axillary Approach and Multiple Injection Technique

    Directory of Open Access Journals (Sweden)

    Lazar Alexandra

    2017-09-01

    Full Text Available Introduction: There are several approaches for brachial plexus anesthesia: supraclavicular, infraclavicular, interscalenic and axillary. Out of these, the axillary approach is considered to be the safest because of the low risk of lesioning the adjacent structures, low risk of phrenic nerve blockade or of producing an iatrogenic pneumothorax. The block can be performed by one single injection at the site, by two injections or by several injection, among each nerve of the plexus. Ultrasound was introduced in regional anesthesia since 1978, being used initially as an auxiliary method to peripheral neurostimulator.

  2. A case of recurrent metastasis in the supraclavicular and axillary lymph nodes and vertebrae following irradiation and paclitaxel plus bevacizumab administration

    International Nuclear Information System (INIS)

    Nishiyama, Yasuyuki; Nishimura, Reiki; Ohsako, Tomofumi; Tashima, Rumiko; Nakano, Masahiro; Fujisue, Mamiko

    2013-01-01

    A 48-year-old woman with invasive ductal carcinoma of the left breast underwent breast-conserving surgery and axillary dissection; 19 months after surgery, she developed local recurrence. Subsequently, she underwent mastectomy and received endocrine therapy and chemotherapy. At 47 years of age, she developed pleural metastasis, which directly invaded the vertebrae as well as the right supraclavicular and right axillary lymph nodes. In addition, liver metastasis was observed. To avoid acute transverse myelopathy, the patient received radiation therapy to the vertebrae and the right supraclavicular and right axillary lymph nodes followed by paclitaxel plus bevacizumab administration. After 2 courses of paclitaxel plus bevacizumab, we observed a remarkable shrinkage of the vertebral tumor, and skin necrosis was observed in the right supraclavicular and right axillary region; in contrast, the liver metastasis had increased in size. After discontinuation of the combination therapy, the patient died of blood loss from the axillary skin defect. This wound healing complication might have arisen because of the synergistic effects of paclitaxel plus bevacizumab and irradiation. (author)

  3. Blunt traumatic axillary artery truncation, in the absence of associated fracture.

    Science.gov (United States)

    Bokser, Emily; Caputo, William; Hahn, Barry; Greenstein, Josh

    2018-02-01

    Axillary artery injuries can be associated with both proximal humeral fractures (Naouli et al., 2016; Ng et al., 2016) [1,2] as well as shoulder dislocations (Leclerc et al., 2017; Karnes et al., 2016) [3,4]. We report a rare case of an isolated axillary artery truncation following blunt trauma without any associated fracture or dislocation. A 58-year-old male presented to the emergency department for evaluation after falling on his outstretched right arm. The patient was found to have an absent right radial pulse with decreased sensation to the right arm. Point of care ultrasound showed findings suspicious for traumatic axillary artery injury, and X-rays did not demonstrate any fracture. Computed tomography with angiography confirmed axillary artery truncation with active extravasation. The patient underwent successful vascular repair with an axillary artery bypass. Although extremity injuries are common in emergency departments, emergency physicians need to recognize the risk for vascular injuries, even without associated fracture or dislocation. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. In vitro PROLIFERATION ABILITY OF AXILLARY BUDS IN Musa spp

    African Journals Online (AJOL)

    AISA

    The proliferation rate of Axillary and apical buds and other growth parameters ... types of buds after four to five sub cultures in all the varieties except for CRBP 39 where the axillary bud exhibits ..... propagation, conservation and exchange.

  5. Horizontal right axillary minithoracotomy: aesthetic and effective option for atrial and ventricular septal defect repair in infants and toddlers

    Directory of Open Access Journals (Sweden)

    Luciana da Fonseca da Silva

    2014-04-01

    Full Text Available Introduction: Congenital heart defects treatment shows progressive reduction in morbidity and mortality, however, the scar, resulting from ventricular (VSD and atrial septal defect (ASD repair, may cause discomfort. Right axillary minithoracotomy approach, by avoiding the breast growth region, is an option for correction of these defects that may provide better aesthetic results at low cost. Since October 2011, we have been using this technique for repairing VSD and ASD defects as well as associated defects. Objectives: To evaluate the efficacy of this method in children undergoing correction of VSD and ASD, to compare perioperative clinical outcomes with those repaired by median sternotomy, and to evaluate the aesthetic result. Methods: Perioperative clinical data of 25 patients submitted to axillary thoracotomy were compared with data from a paired group of 25 patients with similar heart defects repaired by median sternotomy, from October 2011 to August 2012. Results: Axillary approach was possible even in infants. There was no mortality and the main perioperative variables were similar in both groups, except for lower use of blood products in the axillary group (6/25 vs. control (13/25, with statistical difference (P =0.04. The VSD size varied from 7 to 15 mm in axillary group. Cannulation of the aorta and vena cavae was performed through the main incision, whose size ranged from 3 to 5 cm in the axillary group, with excellent aesthetic results. Conclusion: The axillary thoracotomy was effective, allowing for a heart defect repair similar to the median sternotomy, with more satisfactory aesthetic results and reduced blood transfusion, and it can be safely used in infants.

  6. Defects in Czochralski-grown silicon crystals investigated by positron annihilation

    Energy Technology Data Exchange (ETDEWEB)

    Ikari, Atsushi; Kawakami, Kazuto; Haga, Hiroyo [Nippon Steel Corp., Sagamihara, Kanagawa (Japan). Electronics Research Labs.; Uedono, Akira; Wei, Long; Kawano, Takao; Tanigawa, Shoichiro

    1994-10-01

    Positron lifetime and Doppler broadening experiments were performed on Czochralski-grown silicon crystals. A monoenergetic positron beam was also used to measure the diffusion length of positrons in the wafer. From the measurements, it was observed that the value of diffusion length of positrons decreased at the region where microdefects were formed during the crystal growth process. It was also found that the line shape parameter S decreased and the lifetime of positrons increased at the region. These results can be attributed to the annihilation of positrons trapped by vacancy oxygen complexes which are formed in association with the microdefects. (author).

  7. Comparison of ultrasound and ultrasound plus nerve stimulator guidance axillary plexus block

    International Nuclear Information System (INIS)

    Demirelli, G.; Baskan, S.; Karabeyoglu, I.; Aytac, I.; Omek, D.H.; Erdogmus, A.; Baydar, M.

    2017-01-01

    To evaluate the characteristics of axillary plexus blockade applied using ultrasound only and using ultrasound together with nerve stimulator in patients undergoing planned forearm, wrist or hand surgery. Methods: This randomised, prospective, double-blinded, single-centre study was conducted at Ankara Numune Training and Research Hospital, Ankara, Turkey, from November 2014 to August 2015, and comprised patients undergoing forearm, wrist or hand surgery. Participants were separated into 2 groups. In Group 1, the nerve roots required for the surgical site were located one by one and local anaesthetic was applied separately to each nerve for the block. In Group 2, the vascular nerve bundle was located under ultrasound guidance and a total block was achieved by administering all the local anaesthetic within the nerve sheath. In the operating room, standard monitorisation was applied. Following preparation of the skin, the axillary region nerve roots and branches and vascular structures were observed by examination with a high-frequency ultrasound probe. In both groups, a 22-gauge, 5cm block needle was entered to the axillary region with visualisation of the whole needle on ultrasound and 20ml local anaesthetic of 0.5% bupivacaine was injected. SPSS 19 was used for data analysis. Results: Of the 60 participants, there were 30(50%) in each group. The mean age was 39.1+-15 years in the group 1 which was the ultrasound nerve stimulation group, and 41.5+-14.3 years in group 2. The duration of the procedure was longer in group I than in group 2 (p<0.05). Patient satisfaction values during the procedure were higher in group 2(p<0.05). In the ulnar sensory examination, the values of the patients in group 1 were higher at 10, 15, 20 and 25 minutes (p<0.05). In the median, radial and ulnar motor examination, the values of the patients in group 1were higher at 15 and 20 minutes (p<0.05). Conclusion: Brachial plexus blockade via axillary approach guided by ultrasound offered

  8. A systematic review of microwave-based therapy for axillary hyperhidrosis.

    Science.gov (United States)

    Hsu, Tzu-Herng; Chen, Yu-Tsung; Tu, Yu-Kang; Li, Chien-Nien

    2017-10-01

    To systematically analyse the literature on the use of the microwave-based device for subdermal thermolysis of the axilla and its efficacy for the treatment of axillary hyperhidrosis. A systematic review was conducted using PubMed, Embase, SCOPUS and Cochrane databases on 2 June 2016. The inclusion criteria including: (1) studies with human subjects, (2) full-text articles published in English, (3) a microwave-based device used to treat axillary hyperhidrosis and (4) trials that precisely evaluated axillary hyperhidrosis. Exclusion criteria were the following: (1) studies that did not fit the inclusion criteria mentioned above and (2) case reports and reviews. We reviewed five clinical trials and 189 patients, all of which were published between 2012 and 2016. There was one randomized controlled trial, one retrospective study and the remainder were prospective studies. Although all of the studies were conducted with a small sample size, the results indicated that microwave-based device treatment of axillary hyperhidrosis had long-term efficacy with mild adverse effects. In addition, most patients were satisfied with the outcomes in these studies. Microwave-based device treatment may be an effective alternative treatment for axillary hyperhidrosis. However, further investigation is necessary to determine its long-term efficacy and safety.

  9. Utility of 18F-fluoro-deoxyglucose emission tomography/computed tomography fusion imaging (18F-FDG PET/CT in combination with ultrasonography for axillary staging in primary breast cancer

    Directory of Open Access Journals (Sweden)

    Tamura Katsumi

    2008-06-01

    Full Text Available Abstract Background Accurate evaluation of axillary lymph node (ALN involvement is mandatory before treatment of primary breast cancer. The aim of this study is to compare preoperative diagnostic accuracy between positron emission tomography/computed tomography with 18F-fluorodeoxyglucose (18F-FDG PET/CT and axillary ultrasonography (AUS for detecting ALN metastasis in patients having operable breast cancer, and to assess the clinical management of axillary 18F-FDG PET/CT for therapeutic indication of sentinel node biopsy (SNB and preoperative systemic chemotherapy (PSC. Methods One hundred eighty-three patients with primary operable breast cancer were recruited. All patients underwent 18F-FDG PET/CT and AUS followed by SNB and/or ALN dissection (ALND. Using 18F-FDG PET/CT, we studied both a visual assessment of 18F-FDG uptake and standardized uptake value (SUV for axillary staging. Results In a visual assessment of 18F-FDG PET/CT, the diagnostic accuracy of ALN metastasis was 83% with 58% in sensitivity and 95% in specificity, and when cut-off point of SUV was set at 1.8, sensitivity, specificity, and accuracy were 36, 100, and 79%, respectively. On the other hand, the diagnostic accuracy of AUS was 85% with 54% in sensitivity and 99% in specificity. By the combination of 18F-FDG PET/CT and AUS to the axilla, the sensitivity, specificity, and accuracy were 64, 94, and 85%, respectively. If either 18F-FDG PET uptake or AUS was positive in allixa, the probability of axillary metastasis was high; 50% (6 of 12 in 18F-FDG PET uptake only, 80% (4 of 5 in AUS positive only, and 100% (28 of 28 in dual positive. By the combination of AUS and 18F-FDG PET/CT, candidates of SNB were more appropriately selected. The axillary 18F-FDG uptake was correlated with the maximum size and nuclear grade of metastatic foci (p = 0.006 and p = 0.03. Conclusion The diagnostic accuracy of 18F-FDG PET/CT was shown to be nearly equal to ultrasound, and considering their

  10. Effect of temperature on development and growth potential of axillary buds in roses

    NARCIS (Netherlands)

    Marcelis-van Acker, C.A.M.

    1995-01-01

    The effect of temperature during axillary bud formation on axillary bud development and subsequent shoot growth was investigated. Growth potential of the axillary buds was studied either in situ, by pruning the parent shoot above the bud, or in isolation, by grafting the bud or by culturing the bud

  11. Positron deep level transient spectroscopy — a new application of positron annihilation to semiconductor physics

    Science.gov (United States)

    Beling, C. D.; Fung, S.; Au, H. L.; Ling, C. C.; Reddy, C. V.; Deng, A. H.; Panda, B. K.

    1997-05-01

    Recent positron mobility and lifetime measurements made on ac-biased metal on semi-insulating GaAs junctions, which have identified the native EL2 defect through a determination of the characteristic ionization energy of the donor level, are reviewed. It is shown that these measurements point towards a new spectroscopy, tentatively named positron-DLTS (deep level transient spectroscopy), that is the direct complement to conventional DLTS in that it monitors transients in the electric field of the depletion region rather than the inversely related depletion width, as deep levels undergo ionization. In this new spectroscopy, which may be applied to doped material by use of a suitable positron beam, electric field transients are monitored through the Doppler shift of the annihilation radiation resulting from the drift velocity of the positron in the depletion region. Two useful extensions of the new spectroscopy beyond conventional capacitance-DLTS are suggested. The first is that in some instances information on the microstructure of the defect causing the deep level may be inferred from the sensitivity of the positron to vacancy defects of negative and neutral charge states. The second is that the positron annihilation technique is intrinsically much faster than conventional DLTS with the capability of observing transients some 10 6 times faster, thus allowing deep levels (and even shallow levels) to be investigated without problems associated with carrier freeze-out.

  12. Axillary web syndrome following sentinel node biopsy for breast cancer.

    Science.gov (United States)

    Nieves Maldonado, S M; Pubul Núñez, V; Argibay Vázquez, S; Macías Cortiñas, M; Ruibal Morell, Á

    2016-01-01

    A 49 year-old woman diagnosed with infiltrating lobular breast carcinoma, underwent a right mastectomy and sentinel node biopsy (SLNB). The resected sentinel lymph nodes were negative for malignancy, with an axillary lymphadenectomy not being performed. In the early post-operative period, the patient reported an axillary skin tension sensation, associated with a painful palpable cord. These are typical manifestations of axillary web syndrome (AWS), a poorly known axillary surgery complication, from both invasive and conservative interventions. By presenting this case we want to focus the attention on a pathological condition, for which its incidence may be underestimated by not including it in SLNB studies. It is important for nuclear medicine physicians to be aware of AWS as a more common complication than infection, seroma, or lymphoedema, and to discuss this possible event with the patient who is consenting to the procedure. Copyright © 2016 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

  13. Energy expenditure during ambulation with ortho crutches and axillary crutches.

    Science.gov (United States)

    Hinton, C A; Cullen, K E

    1982-06-01

    Thirteen normal male college students were studied during unassisted ambulation and nonweight-bearing ambulation with Ortho crutches and axillary crutches to determine energy expenditure. Subjects walked at self-selected velocities. Energy expenditure was determined by analyzing expired air collected by a calorimeter. Heart rate was monitored by telemetry. During the first 2.5 minutes of walking, heart rate and energy expenditure were significantly greater for ambulation with axillary crutches than with Ortho crutches. After 11.5 minutes of walking, no difference in energy cost was found between crutch types; however, heart rate increased significantly (p less than .01) during ambulation with axillary crutches. Differences in energy cost and heart rate were attributed to increased upper extremity work performed when using axillary crutches. We concluded that during nonweight-bearing ambulation for short periods of time or over a short distance, the Ortho crutch is less taxing in terms of energy cost and heart rate demands.

  14. Indications for axillary ultrasound use in breast cancer patients.

    Science.gov (United States)

    Joh, Jennifer E; Han, Gang; Kiluk, John V; Laronga, Christine; Khakpour, Nazanin; Lee, M Catherine

    2012-12-01

    Axillary ultrasound has been adopted for preoperative planning in breast cancer. Our objective was to determine features predictive of abnormal AUS and/or positive axillary node needle biopsy (NBx). Single-institution database of breast cancer patients identified patients with preoperative AUS. Patient characteristics and outcomes were correlated with AUS and NBx. Significant features were identified using univariable and multivariable analysis and correlative statistics. Three hundred thirteen breast cancers were evaluated. Abnormal AUS was demonstrated in 250 cases (80%). Node needle biopsy was performed in 247 cases (79%). Sensitivity and specificity was 93% and 48% for AUS and 86% and 100% for NBx, respectively. Palpable axillary adenopathy was significant in logistic regression model (P AUS and NBx (P AUS. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Positron studies of metal-oxide-semiconductor structures

    Science.gov (United States)

    Au, H. L.; Asoka-Kumar, P.; Nielsen, B.; Lynn, K. G.

    1993-03-01

    Positron annihilation spectroscopy provides a new probe to study the properties of interface traps in metal-oxide semiconductors (MOS). Using positrons, we have examined the behavior of the interface traps as a function of gate bias. We propose a simple model to explain the positron annihilation spectra from the interface region of a MOS capacitor.

  16. Axillary brachial plexus block duration with mepivacaine in patients with chronic renal failure. Case-control study.

    Science.gov (United States)

    Mojica, V; Nieuwveld, D; Herrera, A E; Mestres, G; López, A M; Sala-Blanch, X

    2017-04-01

    Regional anaesthesia is commonly preferred for arteriovenous fistula (AVF) creation. Previous studies suggest a shorter block duration in patients with chronic renal failure, maybe because of the changes in regional blood flow. The aim of our study was to evaluate the duration of the axillary block with 1.5% mepivacaine in patients with chronic renal failure scheduled for AVF compared with healthy controls. Patients scheduled for AVF creation for the first time (GIRC) were included. They were compared with patients without renal failure (GC), with similar anthropometric characteristics. Ultrasound-guided axillary blocks with 20mL of 1.5% mepivacaine were performed on all patients. We evaluated onset time, humeral artery diameter and blood flow before and after the block, as well as the block duration. Twenty-three patients (GIRC: 12 and GC: 11) were included. No differences between groups were observed in block duration (GIRC: 227±43min vs GC: 229±27min; P=.781), or in onset time (GIRC: 13±5min vs GC: 12.2±3min; P=.477). The humeral blood flow before and after block was significantly lower in the GIRC (pre-block: GIRC: 52±21ml/min GC: 100±62ml/min; P=.034 and p ost block: GIRC: 130±57ml/min and GC: 274±182ml/min; P=.010). There was no significant correlation between the duration of the block and the preblock humeral blood flow (Spearman Rho: 0.106; P=.657) or the postblock humeral blood flow (Spearman Rho: 0.267; P=.254). The duration of the axillary block with 1.5% mepivacaine in patients with chronic renal failure was similar to that of the control patients. The duration of axillary brachial plexus block seems not to be related to changes in regional blood flow. Copyright © 2016 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  17. Positron Emission Tomography/Magnetic Resonance Imaging for Local Tumor Staging in Patients With Primary Breast Cancer: A Comparison With Positron Emission Tomography/Computed Tomography and Magnetic Resonance Imaging.

    Science.gov (United States)

    Grueneisen, Johannes; Nagarajah, James; Buchbender, Christian; Hoffmann, Oliver; Schaarschmidt, Benedikt Michael; Poeppel, Thorsten; Forsting, Michael; Quick, Harald H; Umutlu, Lale; Kinner, Sonja

    2015-08-01

    This study aimed to assess the diagnostic performance of integrated positron emission tomography (PET)/magnetic resonance imaging (MRI) of the breast for lesion detection and local tumor staging of patients with primary breast cancer in comparison to PET/computed tomography (CT) and MRI. The study was approved by the local institutional review board. Forty-nine patients with biopsy-proven invasive breast cancer were prospectively enrolled in our study. All patients underwent a PET/CT, and subsequently, a contrast-enhanced PET/MRI of the breast after written informed consent was obtained before each examination. Two radiologists independently evaluated the corresponding data sets (PET/CT, PET/MRI, and MRI) and were instructed to identify primary tumors lesions as well as multifocal/multicentric and bilateral disease. Furthermore, the occurrence of lymph node metastases was assessed, and the T-stage for each patient was determined. Histopathological verification of the local tumor extent and the axillary lymph node status was available for 30 of 49 and 48 of 49 patients, respectively. For the remaining patients, a consensus characterization was performed for the determination of the T-stage and nodal status, taking into account the results of clinical staging, PET/CT, and PET/MRI examinations. Statistical analysis was performed to test for differences in diagnostic performance between the different imaging procedures. P values less than 0.05 were considered to be statistically significant. Positron emission tomography/MRI and MRI correctly identified 47 (96%) of the 49 patients with primary breast cancer, whereas PET/CT enabled detection of 46 (94%) of 49 breast cancer patients and missed a synchronous carcinoma in the contralateral breast in 1 patient. In a lesion-by-lesion analysis, no significant differences could be obtained between the 3 imaging procedures for the identification of primary breast cancer lesions (P > 0.05). Positron emission tomography/MRI and

  18. Simulation of the annihilation emission of galactic positrons; Modelisation de l'emission d'annihilation des positrons Galactiques

    Energy Technology Data Exchange (ETDEWEB)

    Gillard, W

    2008-01-15

    Positrons annihilate in the central region of our Galaxy. This has been known since the detection of a strong emission line centered on an energy of 511 keV in the direction of the Galactic center. This gamma-ray line is emitted during the annihilation of positrons with electrons from the interstellar medium. The spectrometer SPI, onboard the INTEGRAL observatory, performed spatial and spectral analyses of the positron annihilation emission. This thesis presents a study of the Galactic positron annihilation emission based on models of the different interactions undergone by positrons in the interstellar medium. The models are relied on our present knowledge of the properties of the interstellar medium in the Galactic bulge, where most of the positrons annihilate, and of the physics of positrons (production, propagation and annihilation processes). In order to obtain constraints on the positrons sources and physical characteristics of the annihilation medium, we compared the results of the models to measurements provided by the SPI spectrometer. (author)

  19. Obesity predisposes to increased drainage following axillary node clearance: a prospective audit.

    OpenAIRE

    Banerjee, D.; Williams, E. V.; Ilott, J.; Monypenny, I. J.; Webster, D. J.

    2001-01-01

    BACKGROUND: Whilst sentinel node biopsy is being evaluated for optimising treatment of the axilla, axillary dissection remains the gold standard. Seroma formation, a common sequel to axillary dissection, has been shown to be associated with an increased incidence of wound infection, delayed healing, and lymphoedema. This study was conducted to evaluate the possible contributory role of obesity in axillary drainage following lymphatic dissection. PATIENTS AND METHODS: This study comprised a pr...

  20. A study of positron irradiated porous silicon

    International Nuclear Information System (INIS)

    Huang Yuanming; Xue Qing; Zhai Baogai; Xu Aijun; Liu Shewen; Yu Weizhong

    1998-01-01

    The effect of positron irradiation on photoluminescence (PL) of porous silicon has been studied. After four hour positron irradiation, the red PL spectrum of porous silicon blue shifts into greenish spectral region, and a higher energy luminescence band is introduced into this blueshifted spectrum. The fourier transform infrared absorption experiment shows that the positron irradiation can cause further oxidization of porous silicon. A possible mechanism causing this change of PL spectra after positron irradiation is suggested

  1. Regional cerebral glucose metabolism during sevoflurane anaesthesia in healthy subjects studied with positron emission tomography

    DEFF Research Database (Denmark)

    Schlünzen, L; Juul, N; Hansen, K V

    2010-01-01

    BACKGROUND: The precise mechanism by which sevoflurane exerts its effects in the human brain remains unknown. In the present study, we quantified the effects of sevoflurane on regional cerebral glucose metabolism (rGMR) in the human brain measured with positron emission tomography. METHODS: Eight...... areas by 48-71% of the baseline (Pbrain metabolic reduction of GMR in all regions...... of the human brain, with the most marked metabolic suppression in the lingual gyrus, thalamus and occipital lobe....

  2. Positron emission tomography (PET) for oncologic applications in oral region

    International Nuclear Information System (INIS)

    Shozushima, Masanori; Terasaki, Kazunori

    2004-01-01

    A rapidly emerging clinical application of positron emission tomography (PET) is the detection of cancer with radionuclide tracer, because it provides information unavailable by ultrasound, computed tomography or magnetic resonance imaging. The most commonly used radiotracer for PET oncologic imaging is fluorine-18-labeled fluorodeoxyglucose ( 18 F-FDG). Early studies show PET has potential value in viewing the region of the tumor, detecting, staging, grading, monitoring response to anticancer therapy, and differentiating recurrent or residual disease from post treatment changes. However, limitations of FDG-PET in the head and neck region, namely, physiological FDG uptake in the salivary glands and palatine tonsils, have been reported, increasing the false-positive rates in image interpretation. This review was designed to address these distinctions of oral cancer PET imaging: specialization of PET equipment, cancer cell metabolism, proliferation and tracers, clinical diagnosis of oral cancer with PET, pitfalls in oncologic diagnosis with FDG-PET imaging. (author)

  3. Primary infiltrating ductal carcinoma of the axillary breast with metastasis to the contralateral chest wall

    Directory of Open Access Journals (Sweden)

    Li-Min Sun

    2013-06-01

    Full Text Available Primary infiltrating ductal carcinoma of the axillary breast is rare and has a high frequency of lymph node (LN involvement. We report a woman with primary infiltrating ductal carcinoma arising from the right axillary breast with metastasis to the contralateral chest wall. Excisional biopsy of the left chest wall nodule and the right axillary mass was carried out and both showed invasive ductal carcinomas histologically. The lesion of the right axillary mass arose from the breast tissue, rather than the LN. Further surgery proved the right axillary LN metastasis. After further review, a primary infiltrating ductal carcinoma of the right axillary breast with metastasis to axillary LNs and contralateral chest wall was diagnosed. The patient also received chemotherapy and radiation and there was no evidence of tumor recurrence after treatment. The present report demonstrated a rare case with uncommon manifestation. Lesions of uncertain origin around the periphery of the breast should be suspected for breast carcinoma.

  4. SOME ASPECTS OF THE ANATOMY OF AXILLARY LYMPH NODES

    Directory of Open Access Journals (Sweden)

    A. I. Shvedavchenko

    2009-01-01

    Full Text Available The paper concisely reviews the classifications of axillary lymph nodes (LN and considers various approaches to their formation. The authors identify the axillary lymph chain consisting of lateral, central, and apical groups of nodes through which lymph outflows into the overlying lymph collectors, as well as of subscapular and medial groups of nodes from where lymph makes its way into the auxil- lary lymph chain.

  5. Theory, development, and applications of the scanning positron microbeam and positron reemission microscope

    International Nuclear Information System (INIS)

    Brandes, G.R.

    1990-01-01

    The theory, design, development, and applications of two new imaging instruments, the scanning positron microbeam (SPM) and positron reemission microscope (PRM), are discussed. The SPM consists of a sectored lens which focuses and rasters the positrons from the beam across the sample. The results of rastering the 10μm x 50μm beam across a test grid demonstrate the SPM's ability to scan a 500μm diameter region and to resolve features with ∼ 5μm resolution. The SPM was used to examine the location of defects in a Si-on-SiO 2 sample. Possible applications to three dimensional defect spectroscopy and the observation of small samples are considered. In the PRM, the positrons from the brightness-enhanced beam are focused at 5keV to an 8/Am diameter spot (FWHM) onto a thin metal single crystal. An image of the opposing side of the film is formed by accelerating and focusing the reemitted thermalized positrons with a cathode lens objective and a projector lens. The final image (real) is a record of the thermal positron emission intensity versus position. Images of surface and subsurface defect structures, taken at magnifications up to 4400x and with a resolution up to 80nm, are presented and discussed. The ultimate resolution capabilities and possible applications of the PRM are examined. The implantation and diffusion process of positrons was studied with the PRM by examining the positron emission profile of 3-9keV positrons implanted into a 2200 angstrom thick Ni single crystal

  6. Cytokinins and polar transport of auxin in axillary pea buds

    Directory of Open Access Journals (Sweden)

    Petr Kalousek

    2010-01-01

    Full Text Available The influence of cytokinin on auxin transport during release of axillary buds from apical dominance was studied. Expression of auxin-carrier coding genes PsAUX1 (AUXIN RESISTANT 1 and PsPIN1 (PIN-FORMED 1 was explored in axillary buds of the 2nd node of 7-day pea plants (Pisum sativum L. cv. Vladan after decapitation or after exogenous application of benzyladenine (6-benzylaminopurine onto axillary buds of intact plants. Localization of the PsPIN1 protein, the key factor for polar transport of auxin in axillary buds, was visualised by immunohistochemistry. After exogenous application of cytokinin the expression of PsAUX1 and PsPIN1 rapidly increased with a simultaneous rapid decrease in PsDRM1 and PsAD1 expression – genes related to bud dormancy. The same changes in expression were observed after decapitation, however they were markedly slower. The PsPIN1 auxin efflux carrier in the inhibited axillary buds of intact plants was localised in a non-polar manner. After exogenous application of cytokinin gradual polarisation of the PsPIN1 protein occurred on the basal pole of polar auxin transport competent cells. Despite the fact that direct auxin application to buds of intact plants led to an increase in PsAUX1 and PsPIN1 expression, the buds remained dormant (non-growing what was accompanied by persistent expression of the dormancy markers PsDRM1 and PsAD1. The results indicate a possible effect of cytokinins on biosynthesis, and/or transport of auxin in axillary buds and they highlight the importance of auxin-cytokinin crosstalk in the regulation of bud outgrowth after breaking of apical dominance.

  7. Impact on regional recurrence and survival of axillary surgery in women with node-negative primary breast cancer

    DEFF Research Database (Denmark)

    Axelsson, C K; Düring, M; Christiansen, P M

    2009-01-01

    -negative primary breast cancer treated solely by surgery. Median follow-up was 9 years. RESULTS: The number of lymph nodes removed correlated with a reduction in the rate of subsequent axillary recurrence (from 2.1 to 0.4 per cent; P = 0.037), local recurrence (from 7.4 to 3.8 per cent; P

  8. A unique branching pattern of the axillary artery: a case report.

    Science.gov (United States)

    Bagoji, Ishwar B; Hadimani, Gavishiddappa A; Bannur, Balappa M; Patil, B G; Bharatha, Ambadasu

    2013-12-01

    During routine dissection classes for under graduate students, we found a unique and unusual case regarding the anomalous branching in the third part of the axillary artery was terminated into subscapular arterial trunk, superficial brachial artery and deep brachial artery. The subscapular arterial trunk was origin of several important arteries as the circumflex scapular, thoracodorsal, posterior circumflex humeral, thoraco-acromial and lateral thoracic arteries. The deep brachial artery in the arm gave anterior circumflex humeral artery at the surgical neck of humerus, which terminated in the cubital fossa by dividing into radial and ulnar arteries. The superficial brachial artery gave two profunda brachii arteries, both of which passed through spiral groove, along with radial nerve and three muscular branches, to brachialis muscle. This variation is very rare. As per our knowledge, we did not find any literature which explained variations which were similar to this. The normal and abnormal anatomy of the axillary region has practical importance among vascular radiologists and surgeons and it should be known for making an accurate diagnostic interpretation.

  9. Positron emission tomography of the lung

    International Nuclear Information System (INIS)

    Wollmer, P.

    1984-01-01

    Positron emission tomography enables the distribution of positron emitting isotopes to be imaged in a transverse plane through the body and the regional concentration of the isotope to be measured quantitatively. This thesis reports some applications of positron emission tomography to studies of pulmonary pathophysiology. Measurements in lung phantoms showed that regional lung density could be measured from a transmission tomogram obtained with an external source of positron emitting isotope. The regional, fractional blood volume was measured after labelling the blood with carbon-11-monoxide. Regional extravascular lung density (lung tissue and interstitial water per unit thoracic volume) was obtained by subtracting fractional blood volume from lung density. Measurements in normal subjects revealed large regional variations in lung density and fractional blood volume in the supine posture. Extravascular lung density showed a more uniform distribution. The technique has been used to study patients with chronic interstitial pulmonary oedema, pulmonary sarcoidosis and fibrosis, pulmonary arterial hypertension and patients with intracardiac, left-to-right shunt. Tomographic measurements of pulmonary tissue concentration of radionuclides are difficult, since corrections for the blood content and the inflation of the lung must be applied. A simultaneous measurement of lung density and fractional blood volume allows such corrections to be made and the extravascular tracer concentration to be calculated. This has been applied to measurements of the tissue penetration of carbon-11-labelled erythromycin in patients with lobar pneumonia. (author)

  10. Theory of the temperature dependence of positron bulk lifetimes-implications for vacancy formation enthalpy measurements via positron experiments

    International Nuclear Information System (INIS)

    Tam, S.W.; Sinha, S.K.; Siegel, R.W.

    1977-02-01

    Temperature dependent effects, which may have a bearing on determinations of vacancy formation enthalpies in metals by positron annihilation, have been observed in certain metals. These effects have been observed to occur both at temperatures below those at which positron annihilation is most sensitive to equilibrium vacancies and at temperatures well within the vacancy-sensitive region. The effect of thermal lattice displacements on positron lifetimes in metals was investigated to help understand these phenomena

  11. A simulation study of a method to reduce positron annihilation spread distributions using a strong magnetic field in positron emission tomography

    International Nuclear Information System (INIS)

    Iida, H.; Kanno, I.; Miura, S.; Murakami, M.; Takahashi, V.; Kemura, K.

    1986-01-01

    The positron trajectories have been three-dimensionally simulated using a Monte-Carlo method under various strength of the magnetic field. More than 5 tesla of the field confined the positrons effectively, resulting in increase of the probability of the annihilation within a limited small region, hence the higher spatial resolution in positron emission tomography

  12. Simulation of the annihilation emission of galactic positrons; Modelisation de l'emission d'annihilation des positrons Galactiques

    Energy Technology Data Exchange (ETDEWEB)

    Gillard, W

    2008-01-15

    Positrons annihilate in the central region of our Galaxy. This has been known since the detection of a strong emission line centered on an energy of 511 keV in the direction of the Galactic center. This gamma-ray line is emitted during the annihilation of positrons with electrons from the interstellar medium. The spectrometer SPI, onboard the INTEGRAL observatory, performed spatial and spectral analyses of the positron annihilation emission. This thesis presents a study of the Galactic positron annihilation emission based on models of the different interactions undergone by positrons in the interstellar medium. The models are relied on our present knowledge of the properties of the interstellar medium in the Galactic bulge, where most of the positrons annihilate, and of the physics of positrons (production, propagation and annihilation processes). In order to obtain constraints on the positrons sources and physical characteristics of the annihilation medium, we compared the results of the models to measurements provided by the SPI spectrometer. (author)

  13. Partial lower axillary dissection for patients with clinically node-negative breast cancer.

    Science.gov (United States)

    Kodama, H; Mise, K; Kan, N

    2012-01-01

    To evaluate retrospectively the outcomes of partial lower axillary lymph node dissection caudal to the intercostobrachial nerve in patients with clinically node-negative (N(0)) breast cancer. Numbers of dissected and metastatic nodes, overall and disease-free survival rates, postoperative complication rates, and axillary recurrence were compared between patients who underwent breast cancer surgery with partial axillary node dissection (n = 1043) and historical controls who underwent conventional dissection (n = 1084). The 5-year overall and disease-free survival rates were 95.6% and 89.7%, and 94.9% and 88.4%, respectively, in the partial dissection and conventional dissection groups; the differences were not significant. Mean duration of surgery (41.6 min versus 60.9 min), intraoperative blood loss (28.0 ml versus 51.3 ml), volume of lymphatic drainage at 2 weeks postoperatively (488 ml versus 836 ml), and persistent arm lymphoedema (0.0% versus 11.8%) were significantly different between the partial and conventional dissection groups, respectively. Partial axillary lymph node dissection was associated with similar survival rates (but lower postoperative complication rates) compared with conventional axillary dissection and is recommended in patients with N(0) breast cancer.

  14. Real-time three-dimensional ultrasound-assisted axillary plexus block defines soft tissue planes.

    Science.gov (United States)

    Clendenen, Steven R; Riutort, Kevin; Ladlie, Beth L; Robards, Christopher; Franco, Carlo D; Greengrass, Roy A

    2009-04-01

    Two-dimensional (2D) ultrasound is commonly used for regional block of the axillary brachial plexus. In this technical case report, we described a real-time three-dimensional (3D) ultrasound-guided axillary block. The difference between 2D and 3D ultrasound is similar to the difference between plain radiograph and computer tomography. Unlike 2D ultrasound that captures a planar image, 3D ultrasound technology acquires a 3D volume of information that enables multiple planes of view by manipulating the image without movement of the ultrasound probe. Observation of the brachial plexus in cross-section demonstrated distinct linear hyperechoic tissue structures (loose connective tissue) that initially inhibited the flow of the local anesthesia. After completion of the injection, we were able to visualize the influence of arterial pulsation on the spread of the local anesthesia. Possible advantages of this novel technology over current 2D methods are wider image volume and the capability to manipulate the planes of the image without moving the probe.

  15. Measurement of regional cerebral blood flow by positron emission tomography

    International Nuclear Information System (INIS)

    Herscovitch, P.; Powers, W.J.

    1987-01-01

    The principal advantage of positron emission tomography over other methods for measuring cerebral blood flow stems from the accurate, quantitative three-dimensional measurements of regional brain radioactivity that are possible with this technique. As a result, accurate quantitative measurements of regional cerebral blood flow can be obtained for both superficial and deep cerebral structures. The value of PET for investigating central nervous system physiology and pathology extends far beyond this, however. Through the use of different radiotracers and appropriate mathematical models, PET can be applied to the measurement of a wide variety of physiologic variables. Measurements of rCBF tell only part of the story. Experience with PET and with a variety of other techniques has taught us that rCBF is at times a poor indicator of the metabolic, functional, and biochemical status of cerebral tissue. It is only by understanding the interaction of all of these factors that our understanding of neurologic disease can advance. It is in the investigation of these complex relationships that the real value of PET resides

  16. Near-Threshold Ionization of Argon by Positron Impact

    Science.gov (United States)

    Babij, T. J.; Machacek, J. R.; Murtagh, D. J.; Buckman, S. J.; Sullivan, J. P.

    2018-03-01

    The direct single-ionization cross section for Ar by positron impact has been measured in the region above the first ionization threshold. These measurements are compared to semiclassical calculations which give rise to a power law variation of the cross section in the threshold region. The experimental results appear to be in disagreement with extensions to the Wannier theory applied to positron impact ionization, with a smaller exponent than that calculated by most previous works. In fact, in this work, we see no difference in threshold behavior between the positron and electron cases. Possible reasons for this discrepancy are discussed.

  17. Primary breast lymphoma presenting as non-healing axillary abscess.

    Science.gov (United States)

    Anele, Chukwuemeka; Phan, Yih Chyn; Wong, Suanne; Poddar, Anil

    2015-10-07

    A 67-year-old woman with non-insulin dependent diabetes mellitus with a history consistent with a right axillary abscess, presented to her general practitioner (GP). A diagnosis of folliculitis was made and the GP started a course of flucloxacillin. Despite antibiotics, the patient's symptoms worsened and the abscess increased in size. This prompted her GP to perform an incision and drainage procedure of the abscess. The practice nurse subsequently oversaw the follow-up care of the wound. Two months after the incision and drainage, and after regular wound dressing, the patient was referred to the acute surgical team with a complicated, non-healing right axillary abscess cavity and associated generalised right breast cellulitis. There was no history of breast symptoms prior to the onset of the axillary abscess. The patient underwent wound debridement, washout and application of negative pressure vacuum therapy. Biopsies revealed primary breast lymphoma (B-cell). She underwent radical chemotherapy and is currently in remission. 2015 BMJ Publishing Group Ltd.

  18. Positron-emission tomography of brain regions activated by recognition of familiar music.

    Science.gov (United States)

    Satoh, M; Takeda, K; Nagata, K; Shimosegawa, E; Kuzuhara, S

    2006-05-01

    We can easily recognize familiar music by listening to only one or 2 of its opening bars, but the brain regions that participate in this cognitive processing remain undetermined. We used positron-emission tomography (PET) to study changes in regional cerebral blood flow (rCBF) that occur during listening to familiar music. We used a PET subtraction technique to elucidate the brain regions associated with the recognition of familiar melodies such as well-known nursery tunes. Nonmusicians performed 2 kinds of musical tasks: judging the familiarity of musical pieces (familiarity task) and detecting deliberately altered notes in the pieces (alteration-detecting task). During the familiarity task, bilateral anterior portions of bilateral temporal lobes, superior temporal regions, and parahippocampal gyri were activated. The alteration-detecting task bilaterally activated regions in the precunei, superior/inferior parietal lobules, and lateral surface of frontal lobes, which seemed to show a correlation with the analysis of music. We hypothesize that during the familiarity task, activated brain regions participate in retrieval from long-term memory and verbal and emotional processing of familiar melodies. Our results reinforced the hypothesis reported in the literature as a result of group and case studies, that temporal lobe regions participate in the recognition of familiar melodies.

  19. Regional myocardial oxygen consumption estimated by carbon-11 acetate and positron emission tomography before and after repetitive ischemia

    DEFF Research Database (Denmark)

    Kofoed, K F; Hansen, P R; Holm, S

    2011-01-01

    Preserved myocardial oxygen consumption estimated by carbon 11-acetate and positron emission tomography (PET) in myocardial regions with chronic but reversibly depressed contractile function in patients with ischemic heart disease have been suggested to be caused by repeated short episodes of acu...

  20. Comparison of rectal, tympanic membrane and axillary temperature measurement methods in dogs.

    Science.gov (United States)

    Lamb, V; McBrearty, A R

    2013-11-30

    The aim of this study was to compare axillary and tympanic membrane (TM) temperature measurements to rectal temperature in a large group of clinical canine patients. We also sought to ascertain whether certain factors affected the differences between the measurements and to compare the ease of measurement. Axillary temperatures were easy to obtain but tended to be lower than rectal readings (median difference 0.6°C). In 54.7 per cent of dogs there was a difference of >0.5°C between the two readings. Weight, coat length, body condition score and breed size were significantly associated with the difference between the rectal and axillary temperature. TM temperatures were more similar to rectal temperatures (median difference 0°C) but in 25 per cent of dogs, there was a difference of >0.5°C between rectal and TM readings. TM measurements were less well tolerated than axillary measurements. None of the factors assessed were associated with the difference between the rectal and TM temperature. As a difference of >0.5°C has previously been described as unacceptable for different methods of temperature measurement, neither axillary nor TM temperatures are interchangeable with rectal temperatures for the measurement of body temperature.

  1. Technetium-99m-tetrofosmin in diagnosis of breast cancer and axillary lymph node involvement

    International Nuclear Information System (INIS)

    Jaukovic, Dj.; Ajdinovic, B.Z.; Jankovic, Z. D.; Strbac, M.

    2006-01-01

    The aim of this study was to evaluate the accuracy of breast cancer seeking agent Tc-99m-Tetrofosmin in the detection of breast malignancy and axillary lymph node metastases. Twenty-eight female patients (mean age 52.4) with 30 breast lesions suspected of malignancy were enrolled in the study. All the patients underwent clinical investigation, Tc-99m Tetrofosmin scintimammography (SMM), mammography (MM) and biopsy/surgery for final histopathologic diagnosis. Patients were injected intravenously with 555 MBq of Tc-99m Tetrofosmin, cubitally, in the contralateral arm to the side of suspicious lesion. Seven minute static scans or at least 2.0 million counts were obtained using single head gamma camera (Orbiter 75, Siemens). Planar images were acquired in left and right prone lateral view as well as in the supine position for an anterior view of chest and axillary region. SMM scans of 30 breast lesions were compared to the definitive histopathology findings (HP) using decision matrix. In the group of 23 patients with positive SMM scans 19 had breast malignancy: 15 infiltrating ductal cancer, three patients with one infiltrating lobular, one papillary, one colloidal cancer and one patient with cystosarcoma phyllodes-malignant type. SMM detected primary breast malignancy with 95% sensitivity, 60% specificity and 83% accuracy. Axillary dissection was performed in 19/20 with malignant disease. The number of lymph nodes extracted and HP evaluated varied from 4 to 23 per patient. Metastatic involvement was confirmed by HP in 9 out of 20 patients. SMM detected axillary metastases with 55% sensitivity and 80% accuracy. Our results showed that SMM might be useful as a complementary test to improve the sensitivity and specificity of conventional imaging modalities, although SMM in the staging of breast carcinoma was less reliable. Further studies to evaluate the role of SMM in metastatic node involvement are necessary. (author)

  2. Single incision thoracoscopic sympathectomy for palmar and axillary hyperhidrosis

    Directory of Open Access Journals (Sweden)

    Aram Baram

    2014-02-01

    Full Text Available Background: Primary hyperhidrosis is characterized by excessive sweating beyond physiological needs. It is a common disease (incidence 2.8% that causes intense discomfort for patients. In the last decade, advantages of Single-Incision Thoracoscopic Sympathectomy have become clear, particularly in decreasing morbidity of sympathectomy. Patients and methods: From January 2010 to December 2012, 39 patients (29 females and 10 males with primary palmar or axillary hyperhidrosis were treated by thoracoscopic sympathectomy. The age ranged from 18 to 40 years with a mean of 26.28 years. We used single incision thoracoscopic electrocoagulation through 10 mm incision for thoracic sympathetic chain (T2–T4. Results: The mean follow-up was 23.6 ± 14.2 months (range = 4–24 months. A total of 97.42% of patients were satisfied with the results. A total of 72.5% of patients had cure, one patient (2.5% and another patient (2.5% presented with recurrent axillary hyperhidrosis. The morbidity was 10.2% with no mortality. Percentage of compensatory sweating and gustatory sweating were 5.1% (p = .353 and 2.5% (p = .552, respectively. The result of sympathectomy in patients with both palmar and axillary hyperhidrosis was significantly better (17, 43.58% compared to palmar type (14, 35.89% or axillary type (7, 17.94%. Conclusion: Thoracoscopic sympathectomy is a simple, safe, and cost-effective therapy with good results and low complications.

  3. Intense positron beam and its application to surface science

    International Nuclear Information System (INIS)

    Ito, Y.; Hirose, M.; Kanazawa, I.; Sueoka, O.; Takamura, S.; Okada, S.

    1992-01-01

    Intense pulsed slow positron beam has been produced using the 100 MeV electron LINAC of JAERI · Tokai. In order to use the beam for surface studies such as positron diffraction and positron microscopy, it was transferred from the solenoid magnetic field to field free region and then was brightness-enhanced. The beam size was reduced from 10 mmφ (in the magnetic field) to 0.5 mmφ after two stages of re-moderation. Using the intense brightness-enhanced positron beam we have observed for the first time RHEPD (Reflection High-Energy Positron Diffraction) patterns. A design of re-emission positron microscopy is also described. (author)

  4. Bilateral axillary skin fold flaps used for dorsal thoracic skin wound closure in a dog : clinical communication

    Directory of Open Access Journals (Sweden)

    B. G. Nevill

    2010-05-01

    Full Text Available A 10-year-old greyhound-cross dog was presented with a large, chronic skin wound extending over the interscapular region. The substantial skin defect was closed by making use of bilateral axillary skin fold flaps. It was possible to elevate the 2 skin flaps sufficiently to allow them to meet at the dorsal midline and thus facilitate complete closure of a large and awkwardly positioned wound. Small dorsal areas of the skin flaps underwent necrosis, but the resulting defects were closed without difficulty in a subsequent procedure. To the author's knowledge, this is the 1st clinical report of the use of bilateral axillary skin fold flaps in this fashion and describes an additional use of a versatile skin flap procedure.

  5. Simulation of the annihilation emission of galactic positrons

    International Nuclear Information System (INIS)

    Gillard, W.

    2008-01-01

    Positrons annihilate in the central region of our Galaxy. This has been known since the detection of a strong emission line centered on an energy of 511 keV in the direction of the Galactic center. This gamma-ray line is emitted during the annihilation of positrons with electrons from the interstellar medium. The spectrometer SPI, onboard the INTEGRAL observatory, performed spatial and spectral analyses of the positron annihilation emission. This thesis presents a study of the Galactic positron annihilation emission based on models of the different interactions undergone by positrons in the interstellar medium. The models are relied on our present knowledge of the properties of the interstellar medium in the Galactic bulge, where most of the positrons annihilate, and of the physics of positrons (production, propagation and annihilation processes). In order to obtain constraints on the positrons sources and physical characteristics of the annihilation medium, we compared the results of the models to measurements provided by the SPI spectrometer. (author)

  6. Negative pressure wound therapy, staged excision and definitive closure with split-thickness skin graft for axillary hidradenitis suppurativa: a retrospective study.

    Science.gov (United States)

    Pearce, F B; Richardson, K A

    2017-01-02

    Bilateral axillary hidradenitis is a chronic, suppurative, and scarring disease that is most effectively treated by complete excision of all hair-bearing tissues. We assessed our staged procedure for excision and placement of a split-thickness skin graft for bilateral axillary hidradenitis in terms of costs, outcomes, and timing of excision. An IRB approved retrospective case analysis was performed on patients that underwent bilateral axillary hidradenitis skin excision with eventual placement of split-thickness skin grafting using the current LSUHSC/University Health hidradenitis surgical treatment protocol. Using ICD-9 codes (705.83) and CPT codes (11041, 11042, 11451, 11600, 11601, 11602, 11603, 11604) we reviewed cases performed at our institution from 1 January 2008 to 24 Febuary 2014 and we selected patients based on bilateral axillary involvement (alone) and >1 year history of active disease. Patients were excluded if resection of tissue encompassed regions outside of the immediately adjacent axillary. A total of seven patients matching criteria for bilateral axillary hidradenitis were selected for analysis. Clinical course, cost and surgical techniques were assessed. Of the seven patients, six required admission throughout their treatment due to lack of funding making use of negative pressure wound therapy at home not possible. These patients stayed an average of 10 days with a mean hospital charge of $35,178 and a mean hospital provider charge of $10,019. No recurrence was demonstrated. All patients attained full range of motion, post grafting. No patient required a further operation due to graft failure. Split-thickness skin grafting without use of bilayer dermal regenerative templates yielded definitive results with acceptable cosmesis and functionality, without the added cost of treatments such as a bilayer dermal regenerative template.

  7. Comparison of axillary and rectal temperatures for healthy Beagles in a temperature- and humidity-controlled environment.

    Science.gov (United States)

    Mathis, Justin C; Campbell, Vicki L

    2015-07-01

    To compare axillary and rectal temperature measurements obtained with a digital thermometer for Beagles in a temperature- and humidity-controlled environment. 26 healthy Beagles (17 sexually intact males and 9 sexually intact females). Dogs were maintained in a temperature- and humidity-controlled environment for 56 days before rectal and axillary temperatures were measured. Axillary and rectal temperatures were obtained in triplicate for each dog by use of a single commercially available manufacturer-calibrated digital thermometer. Mean rectal and axillary temperatures of Beagles maintained in a temperature- and humidity-controlled environment were significantly different, with a median ± SD difference of 1.4° ± 0.15°C (range, 0.7° to 2.1°C). Mean rectal and axillary temperatures were 38.7°C (range, 37.6° to 39.5°C) and 37.2°C (range, 36.6° to 38.3°C), respectively. Results of this study indicated that the historical reference of a 0.55°C gradient between rectal and axillary temperatures that has been clinically used for veterinary patients was inaccurate for healthy Beagles in a temperature- and humidity-controlled environment. Rectal and axillary temperatures can be measured in veterinary patients. Reliable interpretation of axillary temperatures may accommodate patient comfort and reduce patient anxiety when serial measurement of temperatures is necessary. Further clinical studies will be needed.

  8. The PEP [positron-electron-proton] electron-positron ring: An update

    International Nuclear Information System (INIS)

    1975-03-01

    The first stage of the positron-electron-protron (PEP) colliding-beam system, which has been under joint study by a Lawrence Berkeley Laboratory--Stanford Linear Accelerator Center team for the past two years, will be the electron-positron storage ring. The physics justification for the e + e/sup /minus// ring is summarized briefly and the proposed facility is described. The ring will have six arcs having gross radii of about 220 m and six interaction regions located at the centers of straight sections about 130 m long. The longitudinal distance left free for experimental apparatus around the interaction regions was set provisionally at 20 m. The range of operating beam energies will be from 5 GeV to 15 GeV. The design luminosity at 15 GeV will be 10 32 cm/sup /minus/2/s/sup /minus/1/, and the luminosity will vary approximately as the square of the beam energy. Alternative methods under consideration for adjusting the beam cross section are discussed. The designs of the storage ring subsystems and of the conventional facilities including the experimental halls at the interaction regions are described. 7 figs., 3 tabs

  9. Value of FNAC in abnormal axillary lymph nodes with non specific mammograms

    Directory of Open Access Journals (Sweden)

    Rania S.M. Ibrahim

    2018-06-01

    Conclusions: FNAC was a good cytological predictor in the majority of patients with abnormal lymph nodes and nonspecific mammography. FNAC is cost effective in assessing axillary lymph node status especially in limited resource setting like in our developing country. FNAC is preferred diagnostic tool in all cases of abnormal axillary lymph adenopathy.

  10. Axillary Lymph Node Evaluation Utilizing Convolutional Neural Networks Using MRI Dataset.

    Science.gov (United States)

    Ha, Richard; Chang, Peter; Karcich, Jenika; Mutasa, Simukayi; Fardanesh, Reza; Wynn, Ralph T; Liu, Michael Z; Jambawalikar, Sachin

    2018-04-25

    The aim of this study is to evaluate the role of convolutional neural network (CNN) in predicting axillary lymph node metastasis, using a breast MRI dataset. An institutional review board (IRB)-approved retrospective review of our database from 1/2013 to 6/2016 identified 275 axillary lymph nodes for this study. Biopsy-proven 133 metastatic axillary lymph nodes and 142 negative control lymph nodes were identified based on benign biopsies (100) and from healthy MRI screening patients (42) with at least 3 years of negative follow-up. For each breast MRI, axillary lymph node was identified on first T1 post contrast dynamic images and underwent 3D segmentation using an open source software platform 3D Slicer. A 32 × 32 patch was then extracted from the center slice of the segmented tumor data. A CNN was designed for lymph node prediction based on each of these cropped images. The CNN consisted of seven convolutional layers and max-pooling layers with 50% dropout applied in the linear layer. In addition, data augmentation and L2 regularization were performed to limit overfitting. Training was implemented using the Adam optimizer, an algorithm for first-order gradient-based optimization of stochastic objective functions, based on adaptive estimates of lower-order moments. Code for this study was written in Python using the TensorFlow module (1.0.0). Experiments and CNN training were done on a Linux workstation with NVIDIA GTX 1070 Pascal GPU. Two class axillary lymph node metastasis prediction models were evaluated. For each lymph node, a final softmax score threshold of 0.5 was used for classification. Based on this, CNN achieved a mean five-fold cross-validation accuracy of 84.3%. It is feasible for current deep CNN architectures to be trained to predict likelihood of axillary lymph node metastasis. Larger dataset will likely improve our prediction model and can potentially be a non-invasive alternative to core needle biopsy and even sentinel lymph node

  11. Tumour and lymph node uptakes on dual-phased 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography correlate with prognostic parameters in breast cancer.

    Science.gov (United States)

    Chang, Chin-Chuan; Tu, Hung-Pin; Chen, Yu-Wen; Lin, Chia-Yang; Hou, Ming-Feng

    2014-12-01

    To examine correlations between the uptake of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) by primary tumours and axillary lymph nodes, and clinical and biological tumour prognostic parameters, in patients with newly diagnosed breast cancer. Newly diagnosed breast cancer patients who had received a dual-phased FDG positron emission tomography/computed tomography scan for pretreatment staging were enrolled retrospectively. Maximal standardized uptake values at 1 h (SUV1), 2 h (SUV2), and retention indices (RI) of the tumours and ipsilateral axillary lymph nodes were measured. SUV and RI were compared with clinical and biological prognostic parameters. A total of 32 patients participated in the study. Tumour FDG uptake correlated with histological grade and tumour size. FDG uptake in axillary lymph nodes correlated positively with lymph node status, metastasis status and clinical stage. RI values for the tumour and lymph nodes were significantly positively correlated with human epidermal growth factor receptor-2 positivity. FDG uptake in tumours and lymph nodes showed correlations with some clinical and biological parameters, and may serve as a predictive marker of tumour biological behaviour in breast cancer. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  12. Positron probes of the Ge(1 0 0) surface: The effects of surface reconstructions and electron-positron correlations on positron trapping and annihilation characteristics

    International Nuclear Information System (INIS)

    Fazleev, N.G.; Jung, E.; Weiss, A.H.

    2007-01-01

    Positron annihilation induced Auger electron spectroscopy (PAES) has been applied to study the Ge(1 0 0) surface. The high-resolution PAES spectrum from the Ge(1 0 0) surface displays several strong Auger peaks corresponding to M 4,5 N 1 N 2,3 , M 2,3 M 4,5 M 4,5 , M 2,3 M 4,5 V and M 1 M 4,5 M 4,5 Auger transitions. The integrated peak intensities of Auger transitions are used to obtain experimental annihilation probabilities for the Ge 3d and 3p core level electrons. These experimental results are analyzed by performing calculations of positron surface states and annihilation characteristics of surface trapped positrons with relevant Ge core-level electrons for the non-reconstructed and reconstructed Ge(1 0 0)-p(2 x 1), Ge(1 0 0)-p(2 x 2) and Ge(1 0 0)-c(4 x 2) surfaces. It is found that the positron surface state wave function extends into the Ge lattice in the regions where atoms are displaced from their ideal terminated positions due to reconstructions. Estimates of the positron binding energy and the positron annihilation characteristics reveal their sensitivity to the specific atomic structure of the topmost layers of Ge(1 0 0). A comparison with PAES data reveals an agreement with theoretical core annihilation probabilities for the Auger transitions considered

  13. Rapid on-site evaluation of axillary fine-needle aspiration cytology in breast cancer.

    LENUS (Irish Health Repository)

    O'Leary, D P

    2012-06-01

    Axillary ultrasonography (AUS) and fine-needle aspiration cytology (FNAC) can establish axillary lymph node status before surgery, although this technique is hampered by poor adequacy rates. To achieve consistently high rates of FNAC adequacy, rapid on-site evaluation (ROSE) of FNAC samples was introduced.

  14. Positron-molecule interactions and corresponding positron attachment to molecules. As a basis for positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Tachikawa, Masanori; Kimura, Mineo; Pichl, Lukas

    2007-01-01

    Through positron and electron interactions, they annihilate emitting primarily two gamma rays with 180-degree opposite directions. Positron spectroscopy using the characteristics of these gamma rays has been employed for analyzing various properties of material as well as for positron emission tomography (PET). However, its fundamental physics of positron-electron interactions and resulting features of emitting gamma rays are not well understood. By obtaining better understanding of positron interactions, it should become possible to provide the firm bases for positron spectroscopy in finer accuracy and quality. Here, we propose a significant mechanism for positron annihilation through positron attachment process, which may help increase the quality of positron spectroscopy. (author)

  15. Positron emission tomography studies of brain receptors

    International Nuclear Information System (INIS)

    Maziere, B.; Maziere, M.

    1991-01-01

    Probing the regional distribution and affinity of receptors in the brain, in vivo, in human and non human primates has become possible with the use of selective ligands labelled with positron emitting radionuclides and positron emission tomography (PET). After describing the techniques used in positron emission tomography to characterize a ligand receptor binding and discussing the choice of the label and the limitations and complexities of the in vivo approach, the results obtained in the PET studies of various neurotransmission systems: dopaminergic, opiate, benzodiazepine, serotonin and cholinergic systems are reviewed

  16. Axillary iodine-131 accumulation due to perspiration

    International Nuclear Information System (INIS)

    Camponovo, E.J.; Goyer, P.F.; Silverman, E.D.; Kistler, A.M.; Yudt, W.M.

    1989-01-01

    A case of spurious axillary uptake of I-131 proven to be caused by perspiration is presented. False-positive localizations of radioiodine, both pathologic and physiologic, are reviewed to avoid confusion of these entities with functioning thyroid carcinoma metastases

  17. Self-taught axillary vein access without venography for pacemaker implantation: prospective randomized comparison with the cephalic vein access.

    Science.gov (United States)

    Squara, Fabien; Tomi, Julien; Scarlatti, Didier; Theodore, Guillaume; Moceri, Pamela; Ferrari, Emile

    2017-12-01

    Axillary vein access for pacemaker implantation is uncommon in many centres because of the lack of training in this technique. We assessed whether the introduction of the axillary vein technique was safe and efficient as compared with cephalic vein access, in a centre where no operators had any previous experience in axillary vein puncture. Patients undergoing pacemaker implantation were randomized to axillary or cephalic vein access. All three operators had no experience nor training in axillary vein puncture, and self-learned the technique by reading a published review. Axillary vein puncture was fluoroscopy-guided without contrast venography. Cephalic access was performed by dissection of delto-pectoral groove. Venous access success, venous access duration (from skin incision to guidewire or lead in superior vena cava), procedure duration, X-ray exposure, and peri-procedural (1 month) complications were recorded. results We randomized 74 consecutive patients to axillary (n = 37) or cephalic vein access (n = 37). Axillary vein was successfully accessed in 30/37 (81.1%) patients vs. 28/37 (75.7%) of cephalic veins (P = 0.57). Venous access time was shorter in axillary group than in cephalic group [5.7 (4.4-8.3) vs. 12.2 (10.5-14.8) min, P < 0.001], as well as procedure duration [34.8 (30.6-38.4) vs. 42.0 (39.1-46.6) min, P = 0.043]. X-ray exposure and peri-procedural overall complications were comparable in both groups. Axillary puncture was safe and faster than cephalic access even for the five first procedures performed by each operator. Self-taught axillary vein puncture for pacemaker implantation seems immediately safe and faster than cephalic vein access, when performed by electrophysiologists trained to pacemaker implantation but not to axillary vein puncture. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For Permissions, please email: journals.permissions@oup.com.

  18. Positron annihilation studies of high dose Sb implanted silicon

    International Nuclear Information System (INIS)

    Schut, H.; Eijt, S.W.H.; Beling, C.D.; Ho, K.; Takamura, Y.

    2005-01-01

    The formation and evolution of vacancies and precipitates created by implantation of 60 keV, 2 x 10 16 cm -2 Sb + in pre-amorphized (0 0 1) Cz-Si is studied using the Doppler broadening (DB) and two-dimensional angular correlation of annihilation radiation (2D-ACAR) positron beam techniques. After implantation, samples were laser annealed (LTA) and subsequently thermal annealed at temperatures ranging from 400 to 1000 deg. C. Implantation-induced vacancy-type defects were detected up to a depth of 280 nm. After LTA, positron annihilation related to both Sb and remaining defects is observed in the first 100 nm below the surface. The deeper region only shows positron trapping at vacancy-type defects with strong reduced concentration. Complete removal is obtained after 600 deg. C anneal. At this temperature, the positron data for the upper region reveals trapping at Sb and Si sites only. With increasing annealing time (at 600 deg. C) or increasing temperature (up to 1000 deg. C) positron annihilation at Sb-sites associated with neighboring vacancies becomes apparent. Results are correlated with the observed Sb electrical deactivation above 600 deg. C, the shift from small Sb aggregates to precipitates and out-diffusion of Sb from the implantation region at higher temperatures

  19. First on-line positron experiments en route to pair-plasma creation

    Energy Technology Data Exchange (ETDEWEB)

    Stanja, Juliane; Hergenhahn, Uwe; Stenson, Eve V. [Max-Planck-Institut fuer Plasmaphysik (Germany); Niemann, Holger; Sunn Pedersen, Thomas [Max-Planck-Institut fuer Plasmaphysik (Germany); Ernst-Moritz-Arndt Universitaet Greifswald (Germany); Saitoh, Haruhiko [Max-Planck-Institut fuer Plasmaphysik (Germany); The University of Tokyo (Japan); Stoneking, Matthew R. [Lawrence University (United States); Hugenschmidt, Christoph; Piochacz, Christian [Technische Universitaet Muenchen (Germany); Schweikhard, Lutz [Ernst-Moritz-Arndt Universitaet Greifswald (Germany)

    2016-07-01

    Electron-positron plasmas are predicted to show a fundamentally different behavior from traditional ion-electron plasmas, because of the equal masses of the two species. Using up to 10{sup 9} positrons per second provided by the NEPOMUC (Neutron-Induced Positron Source Munich) facility, the APEX/PAX team aims to create the first such plasma confined in a toroidal magnetic trap. Positron beam parameters as well as efficient injection and confinement schemes for both species in toroidal geometries are fundamental to the project. In this contribution we present results from first on-line positron experiments. Besides characterizing the NEPOMUC beam we conducted positron injection experiments into a dipole magnetic field configuration. Using static electric fields, a 5-eV positron beam was transported across magnetic field lines into the confinement region. With this method, up to 38% of the incoming particles reach the confinement region and make at least a 180 revolution around the magnet. Under dedicated experimental conditions confinement on the order of 1 ms was realized.

  20. The MEG positron spectrometer

    International Nuclear Information System (INIS)

    Nishiguchi, Hajime

    2007-01-01

    We have been developing an innovative spectrometer for the MEG experiment at the Paul Scherrer Institute (PSI) in Switzerland. This experiment searches for a lepton flavour violating decay μ + →e + γ with a sensitivity of 10 -13 in order to explore the region predicted by supersymmetric extensions of the standard model. The MEG positron spectrometer consists of a specially designed superconducting solenoidal magnet with a highly graded field, an ultimate low-mass drift chamber system, and a precise time measuring counter system. This innovative positron spectrometer is described here focusing on the drift chamber system

  1. Positron annihilation study in La2CuO4

    International Nuclear Information System (INIS)

    Kubo, Y.; Asano, S.

    1992-01-01

    The positron annihilation study for La 2 CuO 4 are performed using the full-potential linearized augmented-plane-wave(FLAPW) calculated electron and positron densities. The electron-positron momentum density(EPMD) is computed, and the well known Lock-Crisp-West(LCW) zone folding of the EPMD is produced. In the LCW analysis, small residual variations of order about 3 % are observed. The calculations show that the relative weights of the Fermi surface discontinuities are substantially altered due to the positron preferentially sampling the Cu-O plane region

  2. Positron beam studies of transients in semiconductors

    International Nuclear Information System (INIS)

    Beling, C.D.; Ling, C.C.; Cheung, C.K.; Naik, P.S.; Zhang, J.D.; Fung, S.

    2006-01-01

    Vacancy-sensing positron deep level transient spectroscopy (PDLTS) is a positron beam-based technique that seeks to provide information on the electronic ionization levels of vacancy defects probed by the positron through the monitoring of thermal transients. The experimental discoveries leading to the concept of vacancy-sensing PDLTS are first reviewed. The major problem associated with this technique is discussed, namely the strong electric fields establish in the near surface region of the sample during the thermal transient which tend to sweep positrons into the contact with negligible defect trapping. New simulations are presented which suggest that under certain conditions a sufficient fraction of positrons may be trapped into ionizing defects rendering PDLTS technique workable. Some suggestions are made for techniques that might avoid the problematic electric field problem, such as optical-PDLTS where deep levels are populated using light and the use of high forward bias currents for trap filling

  3. Application of position-sensitive detectors to positron imaging

    International Nuclear Information System (INIS)

    Yamashita, Takaji; Uchida, Hiroshi; Watanabe, Mitsuo; Omura, Tomohide

    1994-01-01

    Positron imaging including positron emission tomography (PET) is expected to be a promising tool for basic and clinical research, because it makes possible the study of regional chemistry within multiple organs of the body in living human beings and experimental animals. New schemes of high resolution block detectors have been developed to improve the performance of positron imaging systems, which employ small segments of bismuth germanate (BGO) arrays and position-sensitive photomultiplier tubes (PS-PMT). The coincidence detector resolution of less than 2.0 mm in full width at half maximum was achieved with the detectors, which is very close to the theoretical resolution limit in positron imaging. (author)

  4. The PEP [positron-electron-proton] electron-positron ring: PEP Stage I

    International Nuclear Information System (INIS)

    Rees, J.R.

    1974-01-01

    The first stage of the positron-electron-proton (PEP) colliding-beam system which has been under joint study by a Lawrence Berkeley Laboratory-Stanford Linear Accelerator Center team for the past two years, will be the electron-positron storage ring. The physics justification for the e/sup /plus//e/sup /minus// ring is summarized briefly and the proposed facility is described. The ring will have six arcs having gross radii of about 220 m and six interaction regions located at the centers of straight sections about 130 m long. The longitudinal distance left free for experimental apparatus around the interaction regions will be 20 m. The range of operating beam energies will be from 5 GeV to 15 GeV. The design luminosity at 15 GeV will be 10 32 cm/sup /minus/2/s/sup/minus/1/, and the luminosity will vary approximately as the square of the beam energy. Alternative methods under consideration for adjusting the beam cross-section are discussed. The designs of the storage ring subsystems and of the conventional facilities including the experimental halls at the interaction regions are described. 7 refs., 8 figs., 3 tabs

  5. Bilateral axillary artery aneurysms after Bentall procedure in Marfan syndrome.

    Science.gov (United States)

    Haruki, Takashi; Ito, Hiroshi; Sakata, Kensuke; Kobayashi, Yurio

    2015-11-01

    A man with Marfan syndrome underwent a Bentall procedure for annuloaortic ectasia and severe aortic regurgitation at 43 years of age. Twenty-eight years after the Bentall procedure, he developed bilateral axillary artery aneurysms (length × diameter: right: 80 × 39 mm; left: 103 × 45 mm). Aneurysmectomy and reconstruction of the axillary artery were performed using an artificial vascular graft. Histological examination revealed cystic medial necrosis. The postoperative course was uneventful, but long-term follow-up is necessary. © The Author(s) 2014.

  6. Positron-annihilation studies on the Bi-Sr-Ca-Cu-O superconductor

    International Nuclear Information System (INIS)

    Sundar, C.S.; Bharathi, A.; Ching, W.Y.; Jean, Y.C.; Hor, P.H.; Meng, R.L.; Huang, Z.J.; Chu, C.W.

    1991-01-01

    The results of positron-lifetime measurements as a function of temperature, across T c , and as a function of heat treatment are presented. The lifetime in Bi-Sr-Ca-Cu-O does not show any variation with temperature in the range of 10 to 300 K, a result that is in contrast with other cuprate superconductors. The absence of lifetime variation across T c is understood in terms of the calculated positron-density distribution, which indicates that the maximum of the positron density is in the region between the Bi-O layers with no significant density in the superconducting CuO 2 layers. Positron-lifetime measurements as a function of heat treatment indicate a decrease in lifetime as the annealing temperature is lowered from 800 degree C to 100 degree C. The decrease in lifetime, which is correlated with the increase in the weight of the sample, is explained in terms of the intercalation of the excess oxygen in the region between the Bi-O layers, which is the region probed by the positron

  7. Positron-containing systems and positron diagnostics

    International Nuclear Information System (INIS)

    1978-01-01

    The results of the experimental and theoretical investigations are presented. Considered are quantum-mechanical calculations of wave functions describing the states of positron-containing atomic systems and of cross-sections of the processes characterizing different interactions, and also the calculations of the behaviour of positrons in gases in the presence of an electric field. The results of experimental tests are presented by the data describing the behaviour of positrons and positronium in liquids, polymers and elastomers, complex oxides and in different solids. New equipment and systems developed on the basis of current studies are described. Examined is a possibility of applying the methods of model and effective potentials for studying the bound states of positron systems and for calculating cross-sections of elementary processes of elastic and inelastic collisions with a positron involved. The experimental works described indicate new possibilities of the positron diagnosis method: investigation of thin layers and films of semiconductor materials, defining the nature of chemical bonds in semiconductors, determination of the dislocation density in deformed semiconductors, derivation of important quantitative information of the energy states of radiation defects in them

  8. Positron probes of the Ge(1 0 0) surface: The effects of surface reconstructions and electron-positron correlations on positron trapping and annihilation characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Fazleev, N.G. [Department of Physics, University of Texas at Arlington, Box 19059, Arlington, TX 76019-0059 (United States) and Department of Physics, Kazan State University, Kazan 420008 (Russian Federation)]. E-mail: Fazleev@uta.edu; Jung, E. [Department of Physics, University of Texas at Arlington, Box 19059, Arlington, TX 76019-0059 (United States); Weiss, A.H. [Department of Physics, University of Texas at Arlington, Box 19059, Arlington, TX 76019-0059 (United States)

    2007-08-15

    Positron annihilation induced Auger electron spectroscopy (PAES) has been applied to study the Ge(1 0 0) surface. The high-resolution PAES spectrum from the Ge(1 0 0) surface displays several strong Auger peaks corresponding to M{sub 4,5}N{sub 1}N{sub 2,3}, M{sub 2,3}M{sub 4,5}M{sub 4,5}, M{sub 2,3}M{sub 4,5}V and M{sub 1}M{sub 4,5}M{sub 4,5} Auger transitions. The integrated peak intensities of Auger transitions are used to obtain experimental annihilation probabilities for the Ge 3d and 3p core level electrons. These experimental results are analyzed by performing calculations of positron surface states and annihilation characteristics of surface trapped positrons with relevant Ge core-level electrons for the non-reconstructed and reconstructed Ge(1 0 0)-p(2 x 1), Ge(1 0 0)-p(2 x 2) and Ge(1 0 0)-c(4 x 2) surfaces. It is found that the positron surface state wave function extends into the Ge lattice in the regions where atoms are displaced from their ideal terminated positions due to reconstructions. Estimates of the positron binding energy and the positron annihilation characteristics reveal their sensitivity to the specific atomic structure of the topmost layers of Ge(1 0 0). A comparison with PAES data reveals an agreement with theoretical core annihilation probabilities for the Auger transitions considered.

  9. Clinical investigation: Regional nodal failure patterns in breast cancer patients treated with mastectomy without radiotherapy

    International Nuclear Information System (INIS)

    Strom, Eric A.; Woodward, Wendy A.; Katz, Angela; Buchholz, Thomas A.; Perkins, George H.; Jhingran, Anuja; Theriault, Richard; Singletary, Eva; Sahin, Aysegul; McNeese, Marsha D.

    2005-01-01

    Purpose: The purpose of this study was to describe regional nodal failure patterns in patients who had undergone mastectomy with axillary dissection to define subgroups of patients who might benefit from supplemental regional nodal radiation to the axilla or supraclavicular fossa/axillary apex. Methods and Materials: The cohort consisted of 1031 patients treated with mastectomy (including a level I-II axillary dissection) and doxorubicin-based systemic therapy without radiation on five clinical trials at M.D. Anderson Cancer Center. Patient records, including pathology reports, were retrospectively reviewed. All regional recurrences (with or without distant metastasis) were recorded. Median follow-up was 116 months (range, 6-262 months). Results: Twenty-one patients recurred within the low-mid axilla (10-year actuarial rate 3%). Of these, 16 were isolated regional failures (no chest wall failure). The risk of failure in the low-mid axilla was not significantly higher for patients with increasing numbers of involved nodes, increasing percentage of involved nodes, larger nodal size or gross extranodal extension. Only 3 of 100 patients with 20% involved axillary nodes, and the presence of gross extranodal extension (10-year actuarial rates 15%, 14%, and 19%, respectively, p 20% involved axillary nodes, or gross extranodal extension are at increased risk of failure in the supraclavicular fossa/axillary apex and should receive radiation to undissected regions in addition to the chest wall

  10. Detection of regional derangements in myocardial metabolism by positron computed tomography in Duchenne's muscular dystrophy

    International Nuclear Information System (INIS)

    Henze, E.; Schelbert, H.R.; Perloff, J.K.; Schwaiger, M.; Phelps, M.E.

    1982-01-01

    Duchenne's Muscular Dystrophy is unique in genetically targeting for disease a specific region of myocardium: the postero-basal left ventricular wall. Postmortem examinations revealed focal fibrous degenerations in the postero-basal segment, while the coronary arteries were usually not affected. A predystrophic metabolic fault has been postulated for this region. This hypothesis was tested with positron computed tomography as a new means for the noninvasive study of regional myocadial perfusion and metabolism and to determine the incidence of regional and global left ventricular dysfunction and perfusion abnormalities using Thallium-201 and gated blood pool imaging. Myocardial perfusion was evaluated with N-13 ammonia while regional myocardial glucose uptake was studied with the glucose analog F-18 DG. The sensitivity of each diagnostic test for detecting cardiac involvement in Duchenne's Muscular Dystrophy was evaluated. It was highest for ammonia and glucose imaging and it was low for Thallium and radionuclide blood pool imaging

  11. PREFACE: The International Workshop on Positron Studies of Defects 2014

    Science.gov (United States)

    Sugita, Kazuki; Shirai, Yasuharu

    2016-01-01

    The International Workshop on Positron Studies of Defects 2014 (PSD-14) was held in Kyoto, Japan from 14-19 September, 2014. The PSD Workshop brought together positron scientists interested in studying defects to an international platform for presenting and discussing recent results and achievements, including new experimental and theoretical methods in the field. The workshop topics can be characterized as follows: • Positron studies of defects in semiconductors and oxides • Positron studies of defects in metals • New experimental methods and equipment • Theoretical calculations and simulations of momentum distributions, positron lifetimes and other characteristics for defects • Positron studies of defects in combination with complementary methods • Positron beam studies of defects at surfaces, interfaces, in sub-surface regions and thin films • Nanostructures and amorphous materials

  12. Positron annihilation in germanium in thermal equilibrium at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Uedono, Akira; Moriya, Tsuyoshi; Komuro, Naoyuki; Tanigawa, Shoichiro [Tsukuba Univ., Ibaraki (Japan). Inst. of Materials Science; Kawano, Takao; Ikari, Atsushi

    1996-09-01

    Annihilation characteristics of positrons in Ge in thermal equilibrium at high temperature were studied using a monoenergetic positron beam. Precise measurements of Doppler broadening profiles of annihilation radiation were performed in the temperature range between 300 K and 1211 K. The line shape parameters of Doppler broadening profiles were found to be almost constant at 300-600 K. The changes in these parameters were observed to start above 600 K. This was attributed to both the decrease in the fraction of positrons annihilating with core electrons and the lowering of the crystal symmetry around the region detected by positron-electron pairs. This suggests that behaviors of positrons are dominated by some form of positron-lattice coupling in Ge at high temperatures. The temperature dependence of the diffusion length of positrons was also discussed. (author)

  13. Positron deep-level transient spectroscopy in semi-insulating-GaAs using the positron velocity transient method

    International Nuclear Information System (INIS)

    Tsia, M.; Fung, S.; Beling, C.D.

    2001-01-01

    Recently a new semiconductor defect spectroscopy, namely positron deep level transient spectroscopy (PDLTS) has been proposed that combines the energy selectivity of deep level transient spectroscopy with the structural sensitivity of positron annihilation spectroscopy. This paper focuses on one variant of PDLTS, namely positron velocity PDLTS, which has no sensitivity towards vacancy defects but nevertheless is useful in studying deep levels in semi-insulators. In the present study the electric field within the depletion region of semi-insulating GaAs is monitored through the measurement of the small Doppler shift in the annihilation radiation that comes from this region as a result of positron drift. The drift is the result of an increasing electric field produced by space charge building up from ionizing deep level defects. Doppler shift transients are measured between 50-300 K. The EL2 level emission transients are clearly seen at temperatures around 300 K that yield E C -0.78±0.08eV for the energy of EL2. The EL2 electron capture rate is found to have an activation energy of 0.61±0.08eV which most probably arises from freeze out of conduction electrons. We find the surprising result that emission and capture transients can be seen at temperatures below 200 K. Possible reasons for these transients are discussed. (orig.)

  14. 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (FDG-PET/CT) Imaging in the Staging and Prognosis of Inflammatory Breast Cancer

    International Nuclear Information System (INIS)

    Alberini, J.L.; Wartski, M.; Gontier, E.; Madar, O.; Pecking, A.P.; Lerebours, F.; Fourme, E.; Le Stanc, E.; Cherel, P.; Alberini, J.L.

    2009-01-01

    Background: To prospectively assess fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) staging and prognosis value in patients with suspected inflammatory breast cancer (IBC). Methods: Sixty-two women (mean age 50.7 ± 11.4 years) presenting with unilateral inflammatory breast tumors (59 invasive carcinomas; 3 mastitis) underwent a PET/CT scan before biopsy. Results: PET/CT scan was positive for the primary malignant tumor in 100% and false positive in 2 of 3 benign mastitis. In 59 IBC patients, FDG nodal foci were detected in axillary (90%; n = 53) and extra-axillary areas (56%; n = 33) ipsilateral to the cancer. Compared with clinical examination, the axillary lymph node status by PET/CT was upstaged and down staged in 35 and 5 patients, respectively. In 7 of 9 N0 patients, the axillary lymph node positivity on PET/CT was correct, as revealed by pathological post surgery assessment (not available in the 2 remaining patients). The nodal foci were compared with preoperative fine needle aspiration and/or pathological post chemotherapy findings available in 44 patients and corresponded to 38 true positive, 4 false-negative, and 2 false-positive cases. In 18 of 59 IBC patients (31%), distant lesions were found. On the basis of a univariate analysis of the first enrolled patients (n = 42), among 28 patients who showed intense tumoral uptake (standard uptake value(max)≥5), the 11 patients with distant lesions had a worse prognosis than the 17 patients without distant lesions (P =.04). Conclusions: FDG-PET/CT imaging provides additional invaluable information regarding nodal status or distant metastases in IBC patients and should be considered in the initial staging. It seems also that some prognostic information can be derived from FDG uptake characteristics. (authors)

  15. Irradiation damage of alkali halide crystals during positron bombardment

    International Nuclear Information System (INIS)

    Arefiev, K.P.; Arefiev, V.P.; Vorobiev, S.A.

    1978-01-01

    The bleaching effect of positron irradiation of KCl and KBr single crystals previously coloured with electrons or protons was investigated. Positrons injection in the coloured alkali halide samples reduced the F-centres concentration considerably. For KCl crystals thicker than the positrons range the appearance of additional bands in the absorption spectra is noticeable. The experimental data show that the bleaching phenomenon should be observed merely throughout the positron exposure both for irradiated and non-irradiated regions of the sample. Irradiation effects, due to positron source, on the peak counting rate of (γ-γ) angular correlation in KCl crystals under applied magnetic field were also investigated. The growth of peak counting rate shows the increase of positronium-like states formation near defects of cation sublattice. (author)

  16. Instrumentation for positron emission tomography

    International Nuclear Information System (INIS)

    Budinger, T.F.; Derenzo, S.E.; Huesman, R.H.

    1984-01-01

    Positron emission tomography with a spatial resolution of 2 mm full width at half maximum for quantitation in regions of interest 4 mm in diameter will become possible with the development of detectors that achieve ultrahigh resolution. Improved resolution will be possible using solid-state photodetectors for crystal identification or photomultiplier tubes with many small electron multipliers. Temporal resolution of 2 seconds and gating of cyclic events can be accomplished if statistical requirements are met. The major physical considerations in achieving high-resolution positron emission tomography are the degradation in resolution resulting from positron range, emission angle, parallax error, detector sampling density, the sensitivity of various detector materials and packing schemes, and the tradeoff between temporal resolution and statistical accuracy. The accuracy of data required for physiological models depends primarily on the fidelity of spatial sampling independent of statistical constraints

  17. Positron imaging in the evaluation of ischemia and myocardial infarction

    International Nuclear Information System (INIS)

    Goldstein, R.A.

    1985-01-01

    Positron emission tomography (PET) is a unique imaging approach since it allows quantification of regional myocardial radioactivity by virtue of its decay characteristics. Studies of regional myocardial metabolism are possible since there are positron emitting isotopes of carbon, oxygen and nitrogen that can be used to synthesize labeled fatty acids, amino acids or carbohydrate. Recent studies from the author's group have focused on Rb-82, a diffusible cation with a short half-life that is obtained from a generator and thus, has the potential for routine clinical use without a cyclotron. In this chapter, the basic principles of positron imaging and their application to imaging of acute myocardial infarction are discussed

  18. Evaluation of regional cerebral blood flow and volume of rapidly exchangeable water in man by positron emission tomography

    International Nuclear Information System (INIS)

    Depresseux, J.C.; Cheslet, J.P.; Hodiaumont, J.

    1982-01-01

    The present investigation uses bolus inhalation of C 15 O 2 and sequential positron emission tomography of the brain in view to simultaneously evaluate regional cerebral blood flow and regional cerebral volume of rapidly exchangeable water in normal human subjects. Arguments allow to infer that the cerebral distribution volume of radiowater does vary with time during the initial period of invasion of tissue by the indicator. Implications of this variation on the validity of classical data procedures is discussed and an alternative original method is proposed [fr

  19. Electron-positron collision physics: 1 MeV to 2 TeV

    International Nuclear Information System (INIS)

    Perl, M.L.

    1988-07-01

    An overview of electron-positron collision physics is presented. It begins at 1 MeV, the energy region of positronium formation, and extends to 2 TeV, the energy region which requires an electron- positron linear collider. In addition, the concept of searching for a lepton-specific forces is discussed. 18 refs., 15 figs., 1 tab

  20. Ultrasound-guided core biopsy: an effective method of detecting axillary nodal metastases.

    LENUS (Irish Health Repository)

    Solon, Jacqueline G

    2012-02-01

    BACKGROUND: Axillary nodal status is an important prognostic predictor in patients with breast cancer. This study evaluated the sensitivity and specificity of ultrasound-guided core biopsy (Ax US-CB) at detecting axillary nodal metastases in patients with primary breast cancer, thereby determining how often sentinel lymph node biopsy could be avoided in node positive patients. STUDY DESIGN: Records of patients presenting to a breast unit between January 2007 and June 2010 were reviewed retrospectively. Patients who underwent axillary ultrasonography with or without preoperative core biopsy were identified. Sensitivity, specificity, positive predictive value, and negative predictive value for ultrasonography and percutaneous biopsy were evaluated. RESULTS: Records of 718 patients were reviewed, with 445 fulfilling inclusion criteria. Forty-seven percent (n = 210\\/445) had nodal metastases, with 110 detected by Ax US-CB (sensitivity 52.4%, specificity 100%, positive predictive value 100%, negative predictive value 70.1%). Axillary ultrasonography without biopsy had sensitivity and specificity of 54.3% and 97%, respectively. Lymphovascular invasion was an independent predictor of nodal metastases (sensitivity 60.8%, specificity 80%). Ultrasound-guided core biopsy detected more than half of all nodal metastases, sparing more than one-quarter of all breast cancer patients an unnecessary sentinel lymph node biopsy. CONCLUSIONS: Axillary ultrasonography, when combined with core biopsy, is a valuable component of the management of patients with primary breast cancer. Its ability to definitively identify nodal metastases before surgical intervention can greatly facilitate a patient\\'s preoperative integrated treatment plan. In this regard, we believe our study adds considerably to the increasing data, which indicate the benefit of Ax US-CB in the preoperative detection of nodal metastases.

  1. Sentinel node detection in pre-operative axillary staging.

    Science.gov (United States)

    Trifirò, Giuseppe; Viale, Giuseppe; Gentilini, Oreste; Travaini, Laura Lavinia; Paganelli, Giovanni

    2004-06-01

    The concept of sentinel lymph node biopsy in breast cancer surgery is based on the fact that the tumour drains in a logical way via the lymphatic system, from the first to upper levels. Since axillary node dissection does not improve the prognosis of patients with breast cancer, sentinel lymph node biopsy might replace complete axillary dissection for staging of the axilla in clinically N0 patients. Sentinel lymph node biopsy would represent a significant advantage as a minimally invasive procedure, considering that about 70% of patients are found to be free from metastatic disease, yet axillary node dissection can lead to significant morbidity. Subdermal or peritumoural injection of small aliquots (and very low activity) of radiotracer is preferred to intratumoural administration, and (99m)Tc-labelled colloids with most of the particles in the 100-200 nm size range would be ideal for radioguided sentinel node biopsy in breast cancer. The success rate of radioguidance in localising the sentinel lymph node in breast cancer surgery is about 97% in institutions where a high number of procedures are performed, and the success rate of lymphoscintigraphy in sentinel node detection is about 100%. The sentinel lymph node should be processed for intraoperative frozen section examination in its entirety, based on conventional histopathology and, when necessary, immune staining with anti-cytokeratin antibody. Nowadays, lymphoscintigraphy is a useful procedure in patients with different clinical evidence of breast cancer.

  2. Threshold law for positron-atom impact ionisation

    International Nuclear Information System (INIS)

    Temkin, A.

    1982-01-01

    The threshold law for ionisation of atoms by positron impact is adduced in analogy with the author's approach to the electron-atom ionisation. It is concluded the Coulomb-dipole region of potential gives the essential part of the interaction in both cases and leads to the same kind of result: a modulated linear law. An additional process which enters positron ionisation is positronium formation in the continuum, but that will not dominate the threshold yield. The result is in sharp contrast to the positron threshold law as recently derived by Klar (J. Phys. B.; 14:4165 (1981)) on the basis of a Wannier-type (Phys. Rev.; 90:817 (1953)) analysis. (author)

  3. Study of the electron-positron annihilation in the galactic center region with the Integral/SPI spectrometer; Etude de l'annihilation electron-positon dans la region du centre galactique avec le spectrometre INTEGRAL/SPI

    Energy Technology Data Exchange (ETDEWEB)

    Sizun, P

    2007-04-15

    A spectral feature was detected in 1970 in the gamma-ray emission from the central regions of the Milky Way, during balloon flight observations. Located near 511 keV, this feature was soon attributed to the gamma-ray line tracing the annihilation of electrons with their anti-particles, positrons. However, none of the multiple astrophysical scenarios contemplated to explain the production of positrons in the Galactic bulge has been able to reproduce the high injection rate deduced from the flux of the 511 keV line, close to 10{sup 43} positrons per second. Launched in 2002, the European gamma-ray satellite INTEGRAL was provided with a spectrometer, SPI, whose unprecedented imaging and spectral capabilities in this energy range enable us to further study the source of the 511 keV line detected in the Galactic centre region. Indeed, a better determination of the spatial extent of the source, the intrinsic width of the line and the fraction of positrons annihilating in-flight, directly or via the formation of ortho-Positronium atoms would improve our knowledge of both the annihilation medium and the initial source of positrons, and could allow us to discriminate between the various explanatory scenarios. The first part of this thesis deals with a key ingredient in the extraction of the annihilation spectrum: the optimization of the instrumental background model. New data screening and tracer selection procedures are presented. Classical multi-linear models are compared to neural and Bayesian networks. Finally, three years of observation are used to constrain the width of the source and derive its spectrum. The second part of the thesis focuses on one of the possible scenarios explaining the high positron injection rate deduced from the flux of the 511 keV line: the annihilation of light dark matter particles into electron-positron pairs. The various radiation mechanisms involved are modeled and confronted to observations in order to set an upper limit on the injection

  4. Characterization of lacunar defects by positrons annihilation

    CERN Document Server

    Barthe, M F; Blondiaux, G

    2003-01-01

    Among the nondestructive methods for the study of matter, the positrons annihilation method allows to sound the electronic structure of materials by measuring the annihilation characteristics. These characteristics depend on the electronic density as seen by the positon, and on the electron momentums distribution which annihilate with the positon. The positon is sensible to the coulombian potential variations inside a material and sounds preferentially the regions away from nuclei which represent potential wells. The lacunar-type defects (lack of nuclei) represent deep potential wells which can trap the positon up to temperatures close to the melting. This article describes the principles of this method and its application to the characterization of lacunar defects: 1 - positrons: matter probes (annihilation of electron-positon pairs, annihilation characteristics, positrons sources); 2 - positrons interactions in solids (implantation profiles, annihilation states, diffusion and trapping, positon lifetime spec...

  5. A comparative study of thoracoscopic sympathicotomy versus local surgical treatment for axillary hyperhidrosis

    DEFF Research Database (Denmark)

    Heidemann, Erik; Licht, Peter B

    2013-01-01

    Axillary hyperhidrosis affects approximately 1.4% of the population. Medical management is often frustrating, and the response generally transient. Surgical methods include thoracoscopic sympathectomy or sympathicotomy and local axillary surgery such as suction-curettage or en-bloc skin resection....... Many case series with retrospective follow-up are available in the literature, but no comparative studies between surgical techniques have been published....

  6. {sup 18}F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (FDG-PET/CT) Imaging in the Staging and Prognosis of Inflammatory Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Alberini, J.L.; Wartski, M.; Gontier, E.; Madar, O.; Pecking, A.P. [Nuclear Medicine Department, Cancer Research Center Rene Huguenin, Saint-Cloud (France); Lerebours, F. [Oncology Department, Cancer Research Center Rene Huguenin, Saint-Cloud (France); Fourme, E. [Biostatistics Department, Cancer Research Center Rene Huguenin, Saint-Cloud (France); Le Stanc, E. [Nuclear Medicine Department, Foch Hospital, Suresnes (France); Cherel, P. [Radiology Department, Cancer Research Center Rene Huguenin, Saint-Cloud (France); Alberini, J.L. [School of Medicine, Versailles Saint-Quentin University (France)

    2009-07-01

    Background: To prospectively assess fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) staging and prognosis value in patients with suspected inflammatory breast cancer (IBC). Methods: Sixty-two women (mean age 50.7 {+-} 11.4 years) presenting with unilateral inflammatory breast tumors (59 invasive carcinomas; 3 mastitis) underwent a PET/CT scan before biopsy. Results: PET/CT scan was positive for the primary malignant tumor in 100% and false positive in 2 of 3 benign mastitis. In 59 IBC patients, FDG nodal foci were detected in axillary (90%; n = 53) and extra-axillary areas (56%; n = 33) ipsilateral to the cancer. Compared with clinical examination, the axillary lymph node status by PET/CT was upstaged and down staged in 35 and 5 patients, respectively. In 7 of 9 N0 patients, the axillary lymph node positivity on PET/CT was correct, as revealed by pathological post surgery assessment (not available in the 2 remaining patients). The nodal foci were compared with preoperative fine needle aspiration and/or pathological post chemotherapy findings available in 44 patients and corresponded to 38 true positive, 4 false-negative, and 2 false-positive cases. In 18 of 59 IBC patients (31%), distant lesions were found. On the basis of a univariate analysis of the first enrolled patients (n = 42), among 28 patients who showed intense tumoral uptake (standard uptake value(max){>=}5), the 11 patients with distant lesions had a worse prognosis than the 17 patients without distant lesions (P =.04). Conclusions: FDG-PET/CT imaging provides additional invaluable information regarding nodal status or distant metastases in IBC patients and should be considered in the initial staging. It seems also that some prognostic information can be derived from FDG uptake characteristics. (authors)

  7. Millimeter positron focusing using a hybrid lens design

    International Nuclear Information System (INIS)

    Cheung, C.K.; Kwan, P.Y.; Shan, Y.Y.; Naik, P.S.; Weng, H.M.; Beling, C.D.; Fung, S.

    2004-01-01

    The study of metal-semiconductor and metal-oxide-semiconductor systems with low energy positrons is made considerably easier if structures of millimeter dimension can be studied. For this reason the production of a positron beam of sub-millimeter dimension has been a long-term goal of the positron research group at the university of Hong Kong. The hybrid lens system employed consists of a standard Soa extraction lens in a magnetic field free region followed by a gridded Einzel lens that focuses positrons into a 100G magnetic funnel at an energy of 10keV for transportation to the target. Here we report on the present progress, by showing the capability of obtaining millimeter diameter focusing at a preliminary 7.5 kV beam energy. (orig.)

  8. Planned Positron Factory project

    International Nuclear Information System (INIS)

    Okada, Sohei

    1990-01-01

    The Japan Atomic Energy Research Institute, JAERI, has started, drafting a construction plan for the 'Positron Factory', in which intense energy-controllable monoenergetic positron beams are produced from pair-production reactions caused by high-energy electrons from a linac. The JAERI organized a planning committee to provide a basic picture for the Positron Factory. This article presents an overview of the interactions of positrons, intense positron sources and the research program and facilities planned for the project. The interactions of positrons and intense positron sources are discussed focusing on major characteristics of positrons in different energy ranges. The research program for the Positron Factory is then outlined, focusing on advanced positron annihilation techniques, positron spectroscopy (diffraction, scattering, channeling, microscopy), basic positron physics (exotic particle science), and positron beam technology. Discussion is also made of facilities required for the Positron Factory. (N.K.)

  9. Ion-irradiated polymer studied by a slow positron beam

    International Nuclear Information System (INIS)

    Kobayashi, Yoshinori; Kojima, Isao; Hishita, Shunichi; Suzuki, Takenori.

    1995-01-01

    Poly (aryl-ether-ether ketone) (PEEK) films were irradiated with 1MeV and 2MeV 0 + ions and the positron annihilation Doppler broadening was measured as a function of the positron energy. The annihilation lines recorded at relatively low positron energies were found to become broader with increasing the irradiation dose, suggesting that positronium (Ps) formation may be inhibited in the damaged regions. A correlation was observed between the Doppler broadening and spin densities determined by electron spin resonance (ESR). (author)

  10. Positron sources

    International Nuclear Information System (INIS)

    Chehab, R.

    1989-01-01

    A tentative survey of positron sources is given. Physical processes on which positron generation is based are indicated and analyzed. Explanation of the general features of electromagnetic interactions and nuclear β + decay makes it possible to predict the yield and emittance for a given optical matching system between the positron source and the accelerator. Some kinds of matching systems commonly used - mainly working with solenoidal fields - are studied and the acceptance volume calculated. Such knowledge is helpful in comparing different matching systems. Since for large machines, a significant distance exists between the positron source and the experimental facility, positron emittance has to be preserved during beam transfer over large distances and methods used for that purpose are indicated. Comparison of existing positron sources leads to extrapolation to sources for future linear colliders

  11. Development of a Simple Positron Age-Momentum Setup

    Science.gov (United States)

    Sheffield, Thomas; Quarles, C. A.

    2009-04-01

    A positron age-momentum setup that uses NIM Bin electronic modules and a conventional multichannel analyzer (MCA) is described. The essential idea is to accumulate a Doppler broadened spectrum (sensitive to the annihilation electron momentum) using a high purity Germanium detector in coincidence with a BaF2 scintillation counter, which also serves as the stop signal in a conventional positron lifetime setup. The MCA that collects the Doppler spectrum is gated by a selected region of the lifetime spectrum. Thus we can obtain Doppler broadening spectra as a function of positron lifetime: an age-momentum spectrum. The apparatus has been used so far to investigate a ZnO sample where the size of different vacancy trapping sites may affect the positron lifetime and the Doppler broadening spectrum. We are also looking at polymer and rubber carbon-black composite samples where differences in the Doppler spectrum may arise from positron trapping or positronium formation in the samples. Correction for background and contribution from the positron source itself to the Doppler spectrum will be discussed.

  12. Nipple adenoma arising from axillary accessory breast: a case report

    Directory of Open Access Journals (Sweden)

    Shioi Yoshihiro

    2012-11-01

    Full Text Available Abstract Nipple adenoma is a relatively rare benign breast neoplasm, and cases of the disease arising from the axillary accessory breast have very seldom been reported in the English literature. We report a case of nipple adenoma arising from axillary accessory breast including clinical and pathological findings. An 82-year-old woman presented with the complaint of a small painful mass in the right axilla. Physical examination confirmed a well-defined eczematous crusted mass that was 8 mm in size. The diagnosis of nipple adenoma was made from an excisional specimen on the basis of characteristic histological findings. Microscopic structural features included a compact proliferation of small tubules lined by epithelial and myoepithelial cells, and the merging of glandular epithelial cells of the adenoma into squamous epithelial cells in the superficial epidermal layer. Because clinically nipple adenoma may resemble Paget’s disease and pathologically can be misinterpreted as tubular carcinoma, the correct identification of nipple adenoma is an important factor in the differential diagnosis for axillary tumor neoplasms. Virtual slides The virtual slide(s for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1186821489769063

  13. [Comparison of body temperatures in children measured using 3 different thermometers: tympanic, skin and digital axillary].

    Science.gov (United States)

    Padilla-Raygoza, Nicolás; Ruiz-Paloalto, M Laura; Díaz-Guerrero, Rosalina; Olvera-Villanueva, Georgina; Maldonado, Angélica; Raygoza-Mendoza, María Del Pilar

    2014-01-01

    To compare body temperature measurements using tympanic, skin and digital axillary thermometers. Hospitalized or outpatient children from the General Hospital Celaya, ISSSTE Hospital Clinic and General Hospital No. 4 IMSS, and the pediatric private service in Celaya, Guanajuato, from 1 day of life until 16 years old, were recruited over a one month period, after their parents signed the consent form. The order of each institution was selected by simple randomization. Body temperatures were measured in triplicate using tympanic, skin and digital axillary thermometers. The sample consisted of 554 children. The Pearson r between the tympanic and digital axillary thermometers was 0.57 to 0.65, with a positive linear relationship (P<.05); between the skin and the digital axillary thermometers, it was between 0.47 and 0.52 with a positive linearrelationship (P<.05). The intra-observer Kappa for the tympanic thermometer was 0.86, and for the inter-observer was 0.77; for the skin thermometer it was 0.82 and 0.67, respectively, and for the digital axillary thermometer it was 0.86 for intra-observer reliability and 0.78 for inter -observer reliability. Tympanic and axillary thermometers showed better precision in measuring the body temperature in children than skin thermometers. Copyright © 2013 Elsevier España, S.L. All rights reserved.

  14. Validation of quantitation of regional myocardial blood flow in vivo with 11C-labeled human albumin microspheres and positron emission tomography

    International Nuclear Information System (INIS)

    Wilson, R.A.; Shea, M.J.; De Landsheere, C.M.; Turton, D.; Brady, F.; Deanfield, J.E.; Selwyn, A.P.

    1984-01-01

    Use of radiolabeled microspheres is a standard method to measure regional myocardial perfusion in animals. Human albumin microspheres have been given safely to patients, but positron-emitting 67 Ga-labeled human albumin microspheres are characterized by an unstable radiolabel. A new labeling procedure that covalently binds 11 C to human albumin microspheres via 11 CH 3 I was developed. Seven open-chest and two closed-chest dogs were studied. Reference and 11 C-labeled human albumin microspheres (2 to 25 mCi) were both injected into the left atrium. Positron tomographic images were obtained of the myocardial distribution of the 11 C-labeled microspheres. Timed arterial withdrawal was used for both reference gamma-labeled microspheres and 11 C-labeled human albumin microspheres. Regional myocardial perfusion calculated by this technique correlated well with values obtained with reference microspheres over a range of 0.2 to 3.5 ml/min/g. Thus, 11 C human albumin microspheres are stable radiochemically and can be used as a quantitative measure of regional myocardial perfusion

  15. Axillary lymph nodes siliconoma in a woman with intracapsular implant rupture

    International Nuclear Information System (INIS)

    Plachkov, I.; Cvetankov, K.; Hadjidekov, G.

    2013-01-01

    Full text: Introduction: Siliconoma, or silicone granuloma is the migration of silicon particles in the axillary lymph nodes, muscle and other non- ruptured or intact silicone implant. The latter is a relatively rare finding, and usually occurs in patients with extracapsular rupture of silicone prosthesis and has a typical ultrasound image. We present a case of a young woman with bilateral silicone prostheses placed 5 years ago, where in the right axilla are enlarged, structurally altered lymph nodes in the clinical and ultrasonography studies. Subsequent magnetic resonance examination shows intracapsular rupture ipsilateral silicone prosthesis and migration of silicon particles in the axillary lymph nodes. What you will learn: In this case we present twenty-three year old woman who reported pain and ‘swelling’ in the right axilla. The patient is with bilateral silicone prosthesis, she is not febrile and not reported other illness. After physical examination enlarged and tender lymph nodes in the right axilla was found. Several structurally altered and enlarged lymph nodes were visualized by ultrasound. These lymph nodes are hypoechogenic with obliterated fatty hilus. Due to the suspicion of silicone ‘extravasation’ in axillary lymph nodes, a magnetic resonance study of both mammary glands was performed. The images show intracapsular rupture of the right prosthesis without reliable data on silicone gel outside the fibrous capsule. Discussion: Siliconoma is a complication after plastic surgery of the breast and can affect both the axillary lymph nodes, and other lymphatic chains and also muscle and lung. Most frequently it occurs at damage of the extracapsular silicone prostheses. More rarely siliconoma occurs in siliconoma intracapsular damage, as in the presented case or in a silicone gel microbleed. Conclusion: The presence of siliconoma in axillary lymph nodes is relatively rare complication in plastic surgery of the breast. Methods of imaging diagnostic

  16. Axillary fine needle aspiration cytology for pre-operative staging of patients with screen-detected invasive breast carcinoma.

    LENUS (Irish Health Repository)

    Hayes, Brian D

    2012-02-01

    INTRODUCTION: Fine needle aspiration cytology (FNAC) of radiologically abnormal axillary lymph nodes in patients with breast cancer can identify patients suitable for primary axillary clearance (AC) rather than sentinel node biopsy, enabling surgical axillary staging by a single operation. This study assessed the accuracy of FNAC in predicting positive axillary lymph nodes. METHODS: 161 patients with screen-detected invasive carcinoma and who had pre-operative FNAC of a radiologically abnormal axillary lymph node were identified from two screening units, The axillary FNAC reports were correlated with sentinel node biopsy and AC reports, and sensitivity, specificity, positive (PPV) and negative (NPV) predictive values were calculated. RESULTS: FNAC had a moderate sensitivity (66.3%) and NPV (71.8%), and a high specificity (98.7%) and PPV (98.3%). Most patients (86%) had a single axillary operation. The sensitivity was highest in grade 3 (81.8%) and ductal type (77.8%) tumours. The sensitivity was lower in tumours of special type (34.8%), grade 1 tumours (50%) and those without lymphovascular invasion (LVI) (55.9%). The NPV was highest in pT1 (86.7%) and in grade 1 (84.5%) tumours, and lowest (44%) in tumours with LVI. The PPV was 100% in grade 1 and 3 tumours, stage pT2 and pT3 tumours and those without LVI, and was high (>96%) in all other groups. In lymph-node-positive patients, the mean number of lymph nodes involved was higher in the case of a positive (6.4) than negative FNAC (4.4). CONCLUSIONS: FNAC of ultrasonically abnormal axillary lymph nodes achieved surgical staging by a single operation in most patients with screen-detected invasive breast carcinoma, with moderate sensitivity and high specificity.

  17. Positron sources

    International Nuclear Information System (INIS)

    Chehab, R.

    1994-01-01

    A tentative survey of positron sources is given. Physical processes on which positron generation is based are indicated and analyzed. Explanation of the general features of electromagnetic interactions and nuclear β + decay makes it possible to predict the yield and emittance for a given optical matching system between the positron source and the accelerator. Some kinds of matching systems commonly used - mainly working with solenoidal field - are studied and the acceptance volume calculated. Such knowledge is helpful in comparing different matching systems. Since for large machines, a significant distance exists between the positron source and the experimental facility, positron emittance has to be preserved during beam transfer over large distances and methods used for that purpose are indicated. Comparison of existing positron sources leads to extrapolation to sources for future linear colliders. Some new ideas associated with these sources are also presented. (orig.)

  18. Slow positron beam production by a 14 MeV C.W. electron accelerator

    Science.gov (United States)

    Begemann, M.; Gräff, G.; Herminghaus, H.; Kalinowsky, H.; Ley, R.

    1982-10-01

    A 14 MeV c.w. electron accelerator is used for pair production in a tungsten target of 0.7 radiation lengths thickness. A small fraction of the positrons is thermalized and diffuses out of the surface ofsurface of a well annealed tungsten foil coated with MgO which is positioned immediately behind the target. The slow positrons are extracted from the target region and magnetically guided over a distance of 10 m onto a channelplate multiplier at the end of an S-shaped solenoid. The positrons are identified by their annihilation radiation using two NaI-detectors. The intensity of the slow positrons is proportional to the accelerator electron beam current. The maximum intensity of 2.2 × 10 5 slow positrons per second reaching thedetector at an accelerator current of 15 μA was limited by the power deposited in the uncooled target. The energy of the positrons is concentrated in a small region at about 1 eV and clearly demonstrates the emission of thermal positrons.

  19. Slow positron beam production by a 14 MeV c.w. electron accelerator

    International Nuclear Information System (INIS)

    Begemann, M.; Graeff, G.; Herminghaus, H.; Kalinowsky, H.; Ley, R.

    1982-01-01

    A 14 MeV c.w. electron accelerator is used for pair production in a tungsten target of 0.7 radiation lengths thickness. A small fraction of the positrons is thermalized and diffuses out of the surface of a well annealed tungsten foil coated with MgO which is positioned immediately behind the target. The slow positrons are extracted from the target region and magnetically guided over a distance of 10 m onto a channelplate multiplier at the end of an S-shaped solenoid. The positrons are identified by their annihilation radiation using two Nal-detectors. The intensity of the slow positrons is proportional to the accelerator electron beam current. The maximum intensity of 2.2 x 10 5 slow positrons per second reaching the detector at an accelerator current of 15 μA was limited by the power deposited in the uncooled target. The energy of the positrons is concentrated in a small region at about 1 eV and clearly demonstrates the emission of thermal positrons. (orig.)

  20. Development and growth potential of axillary buds in roses as affected by bud age.

    NARCIS (Netherlands)

    Marcelis-van Acker, C.A.M.

    1994-01-01

    The effect of axillary bud age on the development and potential for growth of the bud into a shoot was studied in roses. Age of the buds occupying a similar position on the plant varied from 'subtending leaf just unfolded' up to 1 year later. With increasing age of the axillary bud its dry mass,

  1. Transmission positron microscopes

    International Nuclear Information System (INIS)

    Doyama, Masao; Kogure, Yoshiaki; Inoue, Miyoshi; Kurihara, Toshikazu; Yoshiie, Toshimasa; Oshima, Ryuichiro; Matsuya, Miyuki

    2006-01-01

    Immediate and near-future plans for transmission positron microscopes being built at KEK, Tsukuba, Japan, are described. The characteristic feature of this project is remolding a commercial electron microscope to a positron microscope. A point source of electrons kept at a negative high voltage is changed to a point source of positrons kept at a high positive voltage. Positional resolution of transmission microscopes should be theoretically the same as electron microscopes. Positron microscopes utilizing trapping of positrons have always positional ambiguity due to the diffusion of positrons

  2. Paediatric regional anaesthesia:

    African Journals Online (AJOL)

    induced respiratory depression. The purpose ... regional blocks are usually performed under anaesthesia or .... brachial plexus, as well as the axillary, musculo-cutaneous, ulnar, ... of their use for continuous postoperative pain management or.

  3. The clinical value of 99mTc-MIBI imaging for axillary lymph node metastasis of breast cancer

    International Nuclear Information System (INIS)

    Song Bangkun; Yang Jisheng; Shen Dawei; Zuo Lei; Jiang Ling; Zhou Ya

    2001-01-01

    Objective: To observe the clinical value of 99m Tc-MIBI imaging for axillary lymph node metastasis of breast cancer. Methods: 56 patients with breast cancer proven by pathology were imaged with 99m Tc-MIBI. Images were taken at 5, 30, 60 minutes. The axillary area of affected side was included in imaging field. Results: The primary foci in 55 cases were positive and one case was negative in uptake. Of the 56 cases, 35 had histologically proven axillary lymph node metastases. MIBI uptake was seen in 30 cases and negative in 5 cases. The sensitivity was 85.7% (30/35 cases). In 21 cases who had no metastasis, 3 cases showed false positive uptake and 18 cases were true negative, making the specificity 85.7%. In the case who had negative imaging for primary focus, which was non-palpable, had an enlarged axillary lymphatic node. Positive MIBI uptake of the node area was seen in this case. Conclusion: 99m Tc-MIBI imaging is valuable for the diagnosis of axillary nodal metastasis of breast cancer. Even though there is no palpable primary focus, if there is an enlarged axillary lymphatic node and positive MIBI uptake, metastasis should be considered

  4. Regional myocardial metabolism in patients with acute myocardial infarction assessed by positron emission tomography

    International Nuclear Information System (INIS)

    Schwaiger, M.; Brunken, R.; Grover-McKay, M.; Krivokapich, J.; Child, J.; Tillisch, J.H.; Phelps, M.E.; Schelbert, H.R.

    1986-01-01

    Positron emission tomography has been shown to distinguish between reversible and irreversible ischemic tissue injury. Using this technique, 13 patients with acute myocardial infarction were studied within 72 hours of onset of symptoms to evaluate regional blood flow and glucose metabolism with nitrogen (N)-13 ammonia and fluorine (F)-18 deoxyglucose, respectively. Serial noninvasive assessment of wall motion was performed to determine the prognostic value of metabolic indexes for functional tissue recovery. Segmental blood flow and glucose utilization were evaluated using a circumferential profile technique and compared with previously established semiquantitative criteria. Relative N-13 ammonia uptake was depressed in 32 left ventricular segments. Sixteen segments demonstrated a concordant decrease in flow and glucose metabolism. Regional function did not change over time in these segments. In contrast, 16 other segments with reduced blood flow revealed maintained F-18 deoxyglucose uptake consistent with remaining viable tissue. The average wall motion score improved significantly in these segments (p less than 0.01), yet the degree of recovery varied considerably among patients. Coronary anatomy was defined in 9 of 13 patients: patent infarct vessels supplied 8 of 10 segments with F-18 deoxyglucose uptake, while 10 of 13 segments in the territory of an occluded vessel showed concordant decreases in flow and metabolism (p less than 0.01). Thus, positron emission tomography reveals a high incidence of residual tissue viability in ventricular segments with reduced flow and impaired function during the subacute phase of myocardial infarction. Absence of residual tissue metabolism is associated with irreversible injury, while preservation of metabolic activity identifies segments with a variable outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Positron emission tomography

    International Nuclear Information System (INIS)

    Bolwig, T.G.; Haunsoe, S.; Dahlgaard Hove, J.; Hesse, B.; Hoejgard, L.; Jensen, M.; Paulson, O.B.; Hastrup Svendsen, J.; Soelvsten Soerensen, S.

    1994-01-01

    Positron emission tomography (PET) is a method for quantitative imaging of regional physiological and biochemical parameters. Positron emitting radioactive isotopes can be produced by a cyclotron, eg. the biologically important carbon ( 11 C), oxygen ( 15 O), and nitrogen ( 13 N) elements. With the tomographic principles of the PET scanner the quantitative distribution of the administered isotopes can be determined and images can be provided as well as dynamic information on blood flow, metabolism and receptor function. In neurology PET has been used for investigations on numerous physiological processes in the brain: circulation, metabolism and receptor studies. In Parkinson's disease PET studies have been able to localize the pathology specifically, and in early stroke PET technique can outline focal areas with living but non-functioning cells, and this could make it possible to intervene in this early state. With positron emission tomography a quantitative evaluation of myocardial blood flow, glucose and fatty acid metabolism can be made as well as combined assessments of blood flow and metabolism. Combined studies of blood flow and metabolism can determine whether myocardial segments with abnormal motility consist of necrotic or viable tissue, thereby delineating effects of revascularisation. In the future it will probably be possible to characterize the myocardial receptor status in different cardiac diseases. The PET technique is used in oncology for clinical as well as more basic research on tumor perfusion and metabolism. Further, tumor uptake of positron labelled cytotoxic drugs might predict the clinical benefit of treatment. (au) (19 refs.)

  6. Topical niacinamide 4% and desonide 0.05% for treatment of axillary hyperpigmentation: a randomized, double-blind, placebo-controlled study

    Directory of Open Access Journals (Sweden)

    Castanedo-Cazares JP

    2013-01-01

    Full Text Available Juan Pablo Castanedo-Cazares,1 Gabryela Lárraga-Piñones,1 Adriana Ehnis-Pérez,1 Cornelia Fuentes-Ahumada,1 Cuauhtemoc Oros-Ovalle,2 Bruce R Smoller,3 Bertha Torres-Álvarez11Department of Dermatology, 2Department of Pathology, Hospital Central Dr Ignacio Morones Prieto, Universidad Autónoma de San Luis Potosí, México; 3Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, AK, USABackground: Axillary hyperpigmentation is a frequent cause of cosmetic consultations in dark-skinned women from tropical areas, including Latin America. Currently, there is no widely accepted treatment for the disorder, but it is usually treated with bleaching agents because it is considered a variant of inflammatory hyperpigmentation. The purpose of this study was to assess the efficacy of niacinamide 4% and desonide 0.05% emulsions compared with placebo in the treatment of axillary hyperpigmentation.Methods: Twenty-four women aged 19–27 years with hyperpigmented axillae (phototype III–V were randomly assigned to receive the study treatments in the axillary region. Improvement was assessed at baseline, then clinically and by colorimetry 9 weeks later. Quantitative evaluation including melanin, inflammatory infiltrates, NKI/Beteb, CD1a, CD68, and collagen type IV content was performed by histochemistry and immunohistochemistry, assisted by computerized morphometric analysis.Results: Both niacinamide and desonide induced significant colorimetric improvement compared with placebo; however, desonide showed a better depigmenting effect than niacinamide. A good to excellent response was achieved in 24% of cases for niacinamide, 30% for desonide, and 6% for placebo. We observed a marked disruption of the basal membrane in axillary hyperpigmentation and an inflammatory infiltrate that improved after treatment. Decreased pigmentation in the desonide-treated axillae was associated with recovery of disruption at the basal membrane

  7. Low-energy positron-argon collisions by using parameter-free positron correlation polarization potentials

    International Nuclear Information System (INIS)

    Jain, A.

    1990-01-01

    We report differential, integral, and momentum-transfer cross sections and the scattering length (A 0 ) for positron (e + )-argon scattering at low energies below the positronium formation threshold. An optical-potential approach is employed in which the repulsive Coulombic interaction is calculated exactly at the Hartree-Fock level and the attractive polarization and correlation effects are included approximately via a parameter-free positron correlation polarization (PCP) potential recently proposed by us. The PCP model is based on the correlation energy var-epsilon corr of one positron in a homogeneous electron gas; in the outside region, the var-epsilon corr is joined smoothly with the correct asymptotic form of the polarization interaction (-α 0 /2r 4 , where α 0 is the target polarizability) where they cross each other for the first time. The total optical potential of the e + -argon system is treated exactly in a partial-wave analysis to extract the scattering parameters. It is found that the PCP potential gives much better qualitative results, particularly for the differential cross sections and the scattering length, than the corresponding results obtained from an electron polarization potential used as such for the positron case. We also discuss the ''critical'' points (representing the minima in the differential scattering) in the low-energy e + -Ar scattering. The present results involve no fitting procedure

  8. Sentinel node biopsy before neoadjuvant chemotherapy spares breast cancer patients axillary lymph node dissection.

    Science.gov (United States)

    van Rijk, Maartje C; Nieweg, Omgo E; Rutgers, Emiel J T; Oldenburg, Hester S A; Olmos, Renato Valdés; Hoefnagel, Cornelis A; Kroon, Bin B R

    2006-04-01

    Neoadjuvant chemotherapy in breast cancer patients is a valuable method to determine the efficacy of chemotherapy and potentially downsize the primary tumor, which facilitates breast-conserving therapy. In 18 studies published about sentinel node biopsy after neoadjuvant chemotherapy, the sentinel node was identified in on average 89%, and the false-negative rate was on average 10%. Because of these mediocre results, no author dares to omit axillary clearance just yet. In our institute, sentinel lymph node biopsy is performed before neoadjuvant chemotherapy. The aim of this study was to evaluate our experience with this approach. Sentinel node biopsy was performed before neoadjuvant chemotherapy in 25 T2N0 patients by using lymphoscintigraphy, a gamma ray detection probe, and patent blue dye. Axillary lymph node dissection was performed after chemotherapy if the sentinel node contained metastases. Ten patients had a tumor-positive axillary sentinel node, and one patient had an involved lateral intramammary node. Four patients had additional involved nodes in the completion lymph node dissection specimen. The other 14 patients (56%) had a tumor-negative sentinel node and did not undergo axillary lymph node dissection. No recurrences have been observed after a median follow-up of 18 months. Fourteen (56%) of the 25 patients were spared axillary lymph node dissection when the sentinel node was found to be disease free. Performing sentinel node biopsy before neoadjuvant chemotherapy seems successful and reliable in patients with T2N0 breast cancer.

  9. Predicting axillary lymph node metastasis from kinetic statistics of DCE-MRI breast images

    Science.gov (United States)

    Ashraf, Ahmed B.; Lin, Lilie; Gavenonis, Sara C.; Mies, Carolyn; Xanthopoulos, Eric; Kontos, Despina

    2012-03-01

    The presence of axillary lymph node metastases is the most important prognostic factor in breast cancer and can influence the selection of adjuvant therapy, both chemotherapy and radiotherapy. In this work we present a set of kinetic statistics derived from DCE-MRI for predicting axillary node status. Breast DCE-MRI images from 69 women with known nodal status were analyzed retrospectively under HIPAA and IRB approval. Axillary lymph nodes were positive in 12 patients while 57 patients had no axillary lymph node involvement. Kinetic curves for each pixel were computed and a pixel-wise map of time-to-peak (TTP) was obtained. Pixels were first partitioned according to the similarity of their kinetic behavior, based on TTP values. For every kinetic curve, the following pixel-wise features were computed: peak enhancement (PE), wash-in-slope (WIS), wash-out-slope (WOS). Partition-wise statistics for every feature map were calculated, resulting in a total of 21 kinetic statistic features. ANOVA analysis was done to select features that differ significantly between node positive and node negative women. Using the computed kinetic statistic features a leave-one-out SVM classifier was learned that performs with AUC=0.77 under the ROC curve, outperforming the conventional kinetic measures, including maximum peak enhancement (MPE) and signal enhancement ratio (SER), (AUCs of 0.61 and 0.57 respectively). These findings suggest that our DCE-MRI kinetic statistic features can be used to improve the prediction of axillary node status in breast cancer patients. Such features could ultimately be used as imaging biomarkers to guide personalized treatment choices for women diagnosed with breast cancer.

  10. Low-Volume Brachial Plexus Block Providing Surgical Anesthesia for Distal Arm Surgery Comparing Supraclavicular, Infraclavicular, and Axillary Approach: A Randomized Observer Blind Trial

    Directory of Open Access Journals (Sweden)

    Mojgan Vazin

    2016-01-01

    Full Text Available Background. Distal arm surgery is widely performed under regional anesthesia with brachial plexus block. The preponderance of evidence for the efficacy relies upon injection of local anesthetic in excess of 30 mL. We aimed to compare three different ultrasound-guided brachial plexus block techniques restricting the total volume to 20 mL. Methods. 120 patients were prospectively randomized to ultrasound-guided brachial plexus block with 20 mL ropivacaine 0.75% at either the supraclavicular, infraclavicular, or axillary level. Multiinjection technique was performed with all three approaches. Primary outcome measure was performance time. Results. Performance time and procedural pain were similar between groups. Needle passes and injection numbers were significantly reduced in the infraclavicular group (P<0.01. Nerve visibility was significantly reduced in the axillary group (P=0.01. Success-rate was significantly increased in the supraclavicular versus the axillary group (P<0.025. Total anesthesia-related time was significantly reduced in the supraclavicular compared to the infraclavicular group (P<0.01. Block duration was significantly increased in the infraclavicular group (P<0.05. No early adverse effects occurred. Conclusion. Supraclavicular and infraclavicular blocks exhibited favorable characteristics compared to the axillary block. Supraclavicular brachial plexus block with the multiinjection intracluster technique exhibited significantly reduced total anesthesia-related time and higher success rate without any early adverse events.

  11. Secondary node analysis as an indicator for axillary lymphadenectomy in breast cancer patients.

    Science.gov (United States)

    Cremades, Manel; Torres, Mireia; Solà, Montse; Navinés, Jordi; Pascual, Icíar; Mariscal, Antonio; Caballero, Albert; Castellà, Eva; Luna, Miguel Ángel; Julián, Joan Francesc

    2017-11-01

    Currently, there is no agreement regarding if it would be necessary to perform an axillary lymph node dissection (ALND) in patients who have macrometastases in the sentinel lymph node (SLN). We studied the utility of the secondary node analysis (SN), defined as the following node after the SLN in an anatomical and lymphatic pathway, as a sign of malignant axillary involvement. An observational, retrospective and multicentre study was designed to assess the utility of the SN as a sign of axillary involvement. Among 2273 patients with breast cancer, a valid sample of 283 was obtained representing those who had the SN studied. Main endpoints of our study were: the SLN, the SN and the ALND histological pattern. Sensitivity, specificity and precision of the test were also calculated. SN test, in cases with positive SLN, has a sensitivity of 61.1%, a specificity of 78.7%, a positive predictive value of 45.8% and a negative predictive value of 87.3% with a precision of 74.7%. The study of the SN together with the technique of the SLN allows a more precise staging of the axillary involvement, in patients with breast cancer, than just the SLN technique. Copyright © 2017 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

  12. An estimation of the minimum effective anesthetic volume of 2% lidocaine in ultrasound-guided axillary brachial plexus block.

    LENUS (Irish Health Repository)

    O'Donnell, Brian D

    2009-07-01

    Ultrasound guidance facilitates precise needle and injectate placement, increasing axillary block success rates, reducing onset times, and permitting local anesthetic dose reduction. The minimum effective volume of local anesthetic in ultrasound-guided axillary brachial plexus block is unknown. The authors performed a study to estimate the minimum effective anesthetic volume of 2% lidocaine with 1:200,000 epinephrine (2% LidoEpi) in ultrasound-guided axillary brachial plexus block.

  13. Benefits of ambulatory axillary intra-aortic balloon pump for circulatory support as bridge to heart transplant.

    Science.gov (United States)

    Umakanthan, Ramanan; Hoff, Steven J; Solenkova, Natalia; Wigger, Mark A; Keebler, Mary E; Lenneman, Andrew; Leacche, Marzia; Disalvo, Thomas G; Ooi, Henry; Naftilan, Allen J; Byrne, John G; Ahmad, Rashid M

    2012-05-01

    Axillary intra-aortic balloon pump therapy has been described as a bridge to transplant. Advantages over femoral intra-aortic balloon pump therapy include reduced incidence of infection and enhanced patient mobility. We identified the patients who would benefit most from this therapy while awaiting heart transplantation. We conducted a single-center, retrospective observational study to evaluate outcomes from axillary intra-aortic balloon pump therapy. These included hemodynamic parameters, duration of support, and success in bridging to transplant. We selected patients on the basis of history of sternotomy, elevated panel-reactive antibody, and small body habitus. Patients were made to ambulate aggressively beginning on postoperative day 1. Between September 2007 and September 2010, 18 patients underwent axillary intra-aortic balloon pump therapy. All patients had the devices placed through the left axillary artery with a Hemashield side graft (Boston Scientific, Natick, Mass). Before axillary placement, patients underwent femoral placement to demonstrate hemodynamic benefit. Duration of support ranged from 5 to 63 days (median = 19 days). There was marked improvement in ambulatory potential and hemodynamic parameters, with minimal blood transfusion requirements. There were no device-related infections. Some 72% of the patients (13/18) were successfully bridged to transplantation. Axillary intra-aortic balloon pump therapy provides excellent support for selected patients as a bridge to transplant. The majority of the patients were successfully bridged to transplant and discharged. Although this therapy has been described in previous studies, this is the largest series to incorporate a regimen of aggressive ambulation with daily measurements of distances walked. Copyright © 2012. Published by Mosby, Inc.

  14. Lynch Syndrome Associated Colon Adenocarcinoma Resembling Lymphoma on Fluoro-Deoxyglucose-Positron Emission Tomography/Computed Tomography

    International Nuclear Information System (INIS)

    Aparici, Carina Mari; Win, Aung Zaw

    2015-01-01

    The patient was a 46-year-old Asian male diagnosed with lynch syndrome associated colon adenocarcinoma in the right ascending colon. A presurgical staging 18-fluoro-deoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) found increased metabolic activity in the cervical, axillary, mediastinal, supraclavicular, para-aortic and mesenteric lymph nodes. This pattern of metastasis was very unusual for lynch syndrome associated colon adenocarcinoma and the involvement of those lymph nodes resembles the pattern of spread of lymphoma. He underwent right hemicolectomy and he was subsequently treated with 12 cycles of folinic acid (leucovorin), fluorouracil (5-FU), irinotecan. A restaging FDG-PET/CT at the end of the chemotherapy showed interval decrease in size and metabolic activity in the affected lymph nodes. FDG-PET/CT is a useful imaging modality in following-up the treatment response in colon adenocarcinoma

  15. Basic principles of 18F-fluoro-deoxyglucose positron emission tomography

    International Nuclear Information System (INIS)

    Standke, R.

    2002-01-01

    Positron emission tomography uses photons to receive regional information about dynamic, physiologic, and biochemical processes in the living body. A positron decay is measured indirectly by the simultaneous registration of both gamma rays created by the annihilation. The event is counted, if two directly opposite located detectors register gamma rays in coincidence. Unfortunately the detectors of a positron emission tomography system do not register only true coincident events. There are also scattered and random coincidences. Different types of positron tomographs are presented and scintillation crystals, which are in use for positron emission tomography are discussed. The 2D- and 3D-acquisition methods are described as well as preprocessing methods, such as correction for attenuation, scatter and dead time. For quantification the relative parameter standard uptake value (SUV) is explained. Finally hybrid systems, such as combined positron emission tomography/computed tomography scanners and the use of computed tomography data for attenuation correction are introduced. (author)

  16. Technological evolution of axillary lymph nodes: Radiological visualisation in breast cancer patients

    International Nuclear Information System (INIS)

    Eglitis, J.; Krumins, V.; Stengrevics, A.; Berzins, A.; Vevere, I.; Storozenko, G.

    2004-01-01

    Full text: In patients with breast cancer, detection of axillary lymph node spread has a great prognostic significance. Visualisation of lymphatic glands is attracting attention of radiologists since long. Lymphogram usually shows 4-9 lymph glands as compared to 8 to 50 identified during surgical intervention. Lymphography is a laborious and complicated process requiring specific skills. Likewise, the evaluation and interpretation of results depends upon the experience of the specialist. We evaluated 234 breast cancer patients and found that lymphograms of these patients initially detected 1-2 central axillary lymph nodes followed by others. During surgical intervention, the total number of lymphatic glands removed from these patients was 3,241 of which only 2,693 (83.1%) were seen on lymphography. On further evaluation it was found that the largest groups of lymphatic nodes were seen in the following pattern (i) central axillary (ii) subclavicular (iii) lateral, with central axillary lymph nodes being the biggest (1.5 - 2 cm) and subclavicular the smallest (0.2 - 0.5 cm). Sternal lymph nodes receive lymph from medial quadrants of the breast and / or if the axillary lymph nodes are obstructed by metastases. The results of lymphography and post-operative examination matched in 71.7-75 % of cases. False positivity was seen in 19.2 % and false negative 9.1 % instances. As this method was not sufficiently selective and specific, its relative upsurge receded backwards and was forgotten. The last decade of the twentieth century saw a sentinel node (SN) concept. In advanced countries, the possibility to detect breast cancer of up to 1 cm diameter corresponding to T1A category, when the axillary lymph nodes still are not involved in malignant growth, accounts about 50%. Hence the search of lymphatic spread vis-a-vis sentinel node detection has gained more importance. Earlier, SN detection involved colour contrast methods, which was reasonably sensitive and specific in

  17. Traumatiske laesioner af a. axillaris og a. brachialis

    DEFF Research Database (Denmark)

    Bitsch, M; Hensler, M K; Schroeder, T V

    1994-01-01

    During af six year period 16 patients were treated for an axillary or brachial artery trauma. The vascular injury was caused by fracture in nine cases, contusion in four and penetrating injury in three. Concomitant nerve or tendon lesion occurred in five cases. Five of the 16 events were industri...

  18. Is axillary sonographic staging less accurate in invasive lobular breast cancer than in ductal breast cancer?

    Science.gov (United States)

    Sankaye, Prashant; Chhatani, Sharmila; Porter, Gareth; Steel, Jim; Doyle, Sarah

    2014-10-01

    The purpose of this study was to determine whether axillary sonography is less accurate in invasive lobular breast cancer than in ductal breast cancer. Patients with invasive breast cancer were retrospectively identified from histologic records from 2010 to 2012. Staging axillary sonograms from 96 patients with primary breast cancer in each of 2 subgroups, invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC), were reviewed. Preoperative sonographically guided 14-gauge core biopsy was performed on morphologically abnormal lymph nodes. Thirty-one of 96 patients (32%) in each subgroup were node positive on final postoperative histopathologic analysis. Axillary staging sensitivity was 17 of 31 patients (54%) in the IDC subgroup and 15 of 31(48%) in the ILC subgroup. Further analysis of the data showed no statistically significant differences between these subgroups. We found that there was no statistically significant difference in the accuracy of axillary sonographic staging between ILC and IDC. © 2014 by the American Institute of Ultrasound in Medicine.

  19. Development of an Electron-Positron Source for Positron Annihilation Lifetime Spectroscopy

    Science.gov (United States)

    2009-12-19

    REPORT Development of an electron- positron source for positron annihilation lifetime spectroscopy : FINAL REPORT 14. ABSTRACT 16. SECURITY...to generate radiation, to accelerate particles, and to produce electrons and positrons from vacuum. From applications using existing high-repetition...theoretical directions. This report reviews work directed toward the application of positron generation from laser interaction with matter 1. REPORT DATE

  20. Beam Collimation Studies for the ILC Positron Source

    Energy Technology Data Exchange (ETDEWEB)

    Drozhdin, A.; /Fermilab; Nosochkov, Y.; Zhou, F.; /SLAC

    2008-06-26

    Results of the collimation studies for the ILC positron source beam line are presented. The calculations of primary positron beam loss are done using the ELEGANT code. The secondary positron and electron beam loss, the synchrotron radiation along the beam line and the bremsstrahlung radiation in the collimators are simulated using the STRUCT code. The first part of the collimation system, located right after the positron source target (0.125 GeV), is used for protection of the RF Linac sections from heating and radiation. The second part of the system is used for final collimation before the beam injection into the Damping Ring at 5 GeV. The calculated power loss in the collimation region is within 100 W/m, with the loss in the collimators of 0.2-5 kW. The beam transfer efficiency from the target to the Damping Ring is 13.5%.

  1. Nomogram for prediction of level 2 axillary lymph node metastasis in proven level 1 node-positive breast cancer patients.

    Science.gov (United States)

    Jiang, Yanlin; Xu, Hong; Zhang, Hao; Ou, Xunyan; Xu, Zhen; Ai, Liping; Sun, Lisha; Liu, Caigang

    2017-09-22

    The current management of the axilla in level 1 node-positive breast cancer patients is axillary lymph node dissection regardless of the status of the level 2 axillary lymph nodes. The goal of this study was to develop a nomogram predicting the probability of level 2 axillary lymph node metastasis (L-2-ALNM) in patients with level 1 axillary node-positive breast cancer. We reviewed the records of 974 patients with pathology-confirmed level 1 node-positive breast cancer between 2010 and 2014 at the Liaoning Cancer Hospital and Institute. The patients were randomized 1:1 and divided into a modeling group and a validation group. Clinical and pathological features of the patients were assessed with uni- and multivariate logistic regression. A nomogram based on independent predictors for the L-2-ALNM identified by multivariate logistic regression was constructed. Independent predictors of L-2-ALNM by the multivariate logistic regression analysis included tumor size, Ki-67 status, histological grade, and number of positive level 1 axillary lymph nodes. The areas under the receiver operating characteristic curve of the modeling set and the validation set were 0.828 and 0.816, respectively. The false-negative rates of the L-2-ALNM nomogram were 1.82% and 7.41% for the predicted probability cut-off points of level 1 axillary lymph node metastasis. Patients with a low probability of L-2-ALNM could be spared level 2 axillary lymph node dissection, thereby reducing postoperative morbidity.

  2. Regional cerebral metabolic alterations in dementia of the Alzheimer type: positron emission tomography with [18F]fluorodeoxyglucose

    International Nuclear Information System (INIS)

    Friedland, R.P.; Budinger, T.F.; Ganz, E.; Yano, Y.; Mathis, C.A.; Koss, B.; Ober, B.A.; Huesman, R.H.; Derenzo, S.E.

    1983-01-01

    Alzheimer disease is the most common cause of dementia in adults. Despite recent advances in our understanding of its anatomy and chemistry, we remain largely ignorant of its pathogenesis, physiology, diagnosis, and treatment. Dynamic positron emission tomography using [ 18 F]fluorodeoxyglucose (FDG) was performed on the Donner 280-crystal ring in 10 subjects with dementia of the Alzheimer type and six healthy age-matched controls. Ratios comparing mean counts per resolution element in frontal, temporoparietal, and entire cortex regions in brain sections 10 mm thick obtained 40-70 min following FDG injection showed relatively less FDG uptake in the temporoparietal cortex bilaterally in all the Alzheimer subjects (p less than 0.01). Left-right alterations were less prominent than the anteroposterior changes. This diminished uptake was due to lowered rates of FDG use and suggests that the metabolic effects of Alzheimer disease are most concentrated in the temporoparietal cortex. Positron emission tomography is a most powerful tool for the noninvasive in vivo assessment of cerebral pathophysiology in dementia

  3. The PEP electron-positron ring

    International Nuclear Information System (INIS)

    Rees, J.R.

    1988-01-01

    The first stage of the positron-electron-proton (PEP) colliding-beam system which has been under joint study by a Lawrence Berkeley Laboratory-Stanford Linear Accelerator Center team for the past two years, will be the electron-positron storage ring. The physics justification for the e + e/sup minus/ ring is summarized briefly and the proposed facility is described. The ring will have six arcs having gross radii of about 220 m and six interaction regions located at the centers of straight sections about 130 m long. The longitudinal distance left free for experimental apparatus at the intersection regions will be 20 m. The range of operating beam energies will be from 5 GeV to 15 GeV. The design luminosity at 15 GeV will be 10 32 cm/sup minus 2/s/sup minus 1/, and the luminosity will vary approximately as the square of the beam energy. Alternative methods under consideration for adjusting the beam cross-section are discussed. The designs of the storage ring subsystems and of the conventional facilities including the experimental halls at the interaction regions are described

  4. A two-compartment description and kinetic procedure for measuring regional cerebral [11C]nomifensine uptake using positron emission tomography

    International Nuclear Information System (INIS)

    Salmon, E.; Brooks, D.J.; Leenders, K.L.; Turton, D.R.; Hume, S.P.; Cremer, J.E.; Jones, T.; Frackowiak, R.S.

    1990-01-01

    S-[11C]Nomifensine (S-[11C]NMF) is a positron-emitting tracer suitable for positron emission tomography, which binds to both dopaminergic and noradrenergic reuptake sites in the striatum and the thalamus. Modelling of the cerebral distribution of this drug has been hampered by the rapid appearance of glucuronide metabolites in the plasma, which do not cross the blood--brain barrier. To date, [11C]NMF uptake has simply been expressed as regional versus nonspecific cerebellar activity ratios. We have calculated a free NMF input curve from red cell activity curves, using the fact that the free drug rapidly equilibrates between red cells and plasma, while glucuronides do not enter red cells. With this free [11C]NMF input function, all regional cerebral uptake curves could be fitted to a conventional two-compartment model, defining tracer distribution in terms of [11C]NMF regional volume of distribution. Assuming that the cerebellar volume of distribution of [11C]NMF represents the nonspecific volume of distribution of the tracer in striatum and thalamus, we have calculated an equilibrium partition coefficient for [11C]NMF between freely exchanging specific and nonspecific compartments in these regions, representing its binding potential to dopaminergic or noradrenergic uptake sites (or complexes). This partition coefficient was lower in the striatum when the racemate rather than the active S-enantiomer of [11C]NMF was administered. In the striatum of patients suffering from Parkinson's disease and multiple-system atrophy, the specific compartmentation of S-[11C]NMF was significantly decreased compared with that of age-matched volunteers

  5. Manipulation of positron orbits in a dipole magnetic field with fluctuating electric fields

    Science.gov (United States)

    Saitoh, H.; Horn-Stanja, J.; Nißl, S.; Stenson, E. V.; Hergenhahn, U.; Pedersen, T. Sunn; Singer, M.; Dickmann, M.; Hugenschmidt, C.; Stoneking, M. R.; Danielson, J. R.; Surko, C. M.

    2018-01-01

    We report the manipulation of positron orbits in a toroidal dipole magnetic field configuration realized with electric fields generated by segmented electrodes. When the toroidal circulation motion of positrons in the dipole field is coupled with time-varying electric fields generated by azimuthally segmented outer electrodes, positrons undergo oscillations of their radial positions. This enables quick manipulation of the spatial profiles of positrons in a dipole field trap by choosing appropriate frequency, amplitude, phase, and gating time of the electric fields. According to numerical orbit analysis, we applied these electric fields to positrons injected from the NEPOMUC slow positron facility into a prototype dipole field trap experiment with a permanent magnet. Measurements with annihilation γ-rays clearly demonstrated the efficient compression effects of positrons into the strong magnetic field region of the dipole field configuration. This positron manipulation technique can be used as one of essential tools for future experiments on the formation of electron-positron plasmas.

  6. Production of slow positron beam with small diameter using electron linac in Osaka University

    Energy Technology Data Exchange (ETDEWEB)

    Honda, Yoshihide; Sawada, Junichi; Yamada, Masaki; Maekawa, Masaki; Okuda, Shuichi; Yoshida, Yoichi; Isoyama, Goro; Tagawa, Seiichi [Osaka Univ., Ibaraki (Japan). Inst. of Scientific and Industrial Research; Yamamoto, Takayoshi

    1997-03-01

    A slow positron facility using an electron linac was designed and constructed. The specifications were mainly decided by numerical calculations. The slow positrons are transported along magnetic field line. The cross sectional size of slow positron beam is 1-2cm and the maximum conversion rate from electron to positron is about 1.5 x 10{sup -6}. This value is about 1/4 of ideal case in our system. Extraction of slow positron beam from magnetic field region was made and preliminary brightness enhancement experiment was also performed. (author)

  7. Features and applications of positron emission tomography

    International Nuclear Information System (INIS)

    Fan Mingwu

    1997-01-01

    Positron emission tomography, the so-called world's smartest camera, is based on a NaI or BGO detector and imaging of positron-emitting radioisotopes which are introduced as a tracer into the regional tissue or organ of interest. With the aid of a computer visual images of a series of these distributions can be built into a picture of the functional status of the tissue or organ being imaged. This highly accurate imaging technique is already widely used for clinical diagnostics heart disease, brain disorder, tumors and so on

  8. Novel Axillary Approach for Brachial Plexus in Robotic Surgery: A Cadaveric Experiment

    Directory of Open Access Journals (Sweden)

    Cihangir Tetik

    2014-01-01

    Full Text Available Brachial plexus surgery using the da Vinci surgical robot is a new procedure. Although the supraclavicular approach is a well known described and used procedure for robotic surgery, axillary approach was unknown for brachial plexus surgery. A cadaveric study was planned to evaluate the robotic axillary approach for brachial plexus surgery. Our results showed that robotic surgery is a very useful method and should be used routinely for brachial plexus surgery and particularly for thoracic outlet syndrome. However, we emphasize that new instruments should be designed and further studies are needed to evaluate in vivo results.

  9. Potential bud bank responses to apical meristem damage and environmental variables: matching or complementing axillary meristems?

    Science.gov (United States)

    Klimešová, Jitka; Malíková, Lenka; Rosenthal, Jonathan; Šmilauer, Petr

    2014-01-01

    Soil nutrients, dormant axillary meristem availability, and competition can influence plant tolerance to damage. However, the role of potential bud banks (adventitious meristems initiated only after injury) is not known. Examining Central European field populations of 22 species of short-lived monocarpic herbs exposed to various sources of damage, we hypothesized that: (1) with increasing injury severity, the number of axillary branches would decrease, due to axillary meristem limitation, whereas the number of adventitious shoots (typically induced by severe injury) would increase; (2) favorable environmental conditions would allow intact plants to branch more, resulting in stronger axillary meristem limitation than in unfavorable conditions; and (3) consequently, adventitious sprouting would be better enabled in favorable than unfavorable conditions. We found strong support for the first hypothesis, only limited support for the second, and none for the third. Our results imply that whereas soil nutrients and competition marginally influence plant tolerance to damage, potential bud banks enable plants to overcome meristem limitation from severe damage, and therefore better tolerate it. All the significant effects were found in intraspecific comparisons, whereas interspecific differences were not found. Monocarpic plants with potential bud banks therefore represent a distinct strategy occupying a narrow environmental niche. The disturbance regime typical for this niche remains to be examined, as do the costs associated with the banks of adventitious and axillary reserve meristems.

  10. Potential bud bank responses to apical meristem damage and environmental variables: matching or complementing axillary meristems?

    Directory of Open Access Journals (Sweden)

    Jitka Klimešová

    Full Text Available Soil nutrients, dormant axillary meristem availability, and competition can influence plant tolerance to damage. However, the role of potential bud banks (adventitious meristems initiated only after injury is not known. Examining Central European field populations of 22 species of short-lived monocarpic herbs exposed to various sources of damage, we hypothesized that: (1 with increasing injury severity, the number of axillary branches would decrease, due to axillary meristem limitation, whereas the number of adventitious shoots (typically induced by severe injury would increase; (2 favorable environmental conditions would allow intact plants to branch more, resulting in stronger axillary meristem limitation than in unfavorable conditions; and (3 consequently, adventitious sprouting would be better enabled in favorable than unfavorable conditions. We found strong support for the first hypothesis, only limited support for the second, and none for the third. Our results imply that whereas soil nutrients and competition marginally influence plant tolerance to damage, potential bud banks enable plants to overcome meristem limitation from severe damage, and therefore better tolerate it. All the significant effects were found in intraspecific comparisons, whereas interspecific differences were not found. Monocarpic plants with potential bud banks therefore represent a distinct strategy occupying a narrow environmental niche. The disturbance regime typical for this niche remains to be examined, as do the costs associated with the banks of adventitious and axillary reserve meristems.

  11. Studies on topical antiperspirant control of axillary hyperhidrosis.

    Science.gov (United States)

    Shelley, W B; Hurley, H J

    1975-01-01

    Axillary hyperhidrotics is reviewed from the standpoint of anatomical factors, physiological mechanisms and the history of methods of control. Anhydrous aluminum chloride and anhydrous zirconium tetrachloride are shown to be superior topical agents for partial control of axillary sweating when applied as a powder or in anhydrous nonreactive vehicles. Complete anhidrosis as demonstrated by sustained garment armpit dryness could be achieved in hyperhidrotics within 48 hours by the following trinary antiperspirant system: (1) a saturated solution of aluminum chloride hexahydrate or zirconyl chloride in absolute ethanol or isopropyl alcohol, (2) application to the dry axilla at times of sleep or other prolonged non-sweating period, (3) water vapor occlusion of area for 6 to 8 hours by means of Saran wrap. The hypothesis is presented that metallic antiperspirants act by reflux entrance into the terminal intraepidermal eccrine duct, slowly combining with the intraductal keratin, to produce a fibrillar contraction (super contraction) of keratin and hence functional closure, not histologically evident. This altered keratin is shed weeks later, with the consequent return of ductal patency and sweating.

  12. Assessment of axillary temperature for the evaluation of normal body temperature of healthy young adults at rest in a thermoneutral environment.

    Science.gov (United States)

    Marui, Shuri; Misawa, Ayaka; Tanaka, Yuki; Nagashima, Kei

    2017-02-22

    The aims of this study were to (1) evaluate whether recently introduced methods of measuring axillary temperature are reliable, (2) examine if individuals know their baseline body temperature based on an actual measurement, and (3) assess the factors affecting axillary temperature and reevaluate the meaning of the axillary temperature. Subjects were healthy young men and women (n = 76 and n = 65, respectively). Three measurements were obtained: (1) axillary temperature using a digital thermometer in a predictive mode requiring 10 s (T ax-10 s ), (2) axillary temperature using a digital thermometer in a standard mode requiring 10 min (T ax-10 min ), and (3) tympanic membrane temperature continuously measured by infrared thermometry (T ty ). The subjects answered questions about eating and exercise habits, sleep and menstrual cycles, and thermoregulation and reported what they believed their regular body temperature to be (T reg ). T reg , T ax-10 s , T ax-10 min , and T ty were 36.2 ± 0.4, 36.4 ± 0.5, 36.5 ± 0.4, and 36.8 ± 0.3 °C (mean ± SD), respectively. There were correlations between T ty and T ax-10 min , T ty and T ax-10 s , and T ax-10 min and T ax-10 s (r = .62, r = .46, and r = .59, respectively, P body mass indices and irregular menstrual cycles. Modern devices for measuring axillary temperature may have changed the range of body temperature that is recognized as normal. Core body temperature variations estimated by tympanic measurements were smaller than those estimated by axillary measurements. This variation of axillary temperature may be due to changes in the measurement methods introduced by modern devices and techniques. However, axillary temperature values correlated well with those of tympanic measurements, suggesting that the technique may reliably report an individual's state of health. It is important for individuals to know their baseline axillary temperature to evaluate subsequent

  13. Positron emission tomography. Positronemisionstomografi

    Energy Technology Data Exchange (ETDEWEB)

    Bolwig, T G; Haunsoe, S; Dahlgaard Hove, J; Hesse, B; Hoejgard, L; Jensen, M; Paulson, O B; Hastrup Svendsen, J; Soelvsten Soerensen, S

    1994-10-01

    Positron emission tomography (PET) is a method for quantitative imaging of regional physiological and biochemical parameters. Positron emitting radioactive isotopes can be produced by a cyclotron, eg. the biologically important carbon ([sup 11]C), oxygen ([sup 15]O), and nitrogen ([sup 13]N) elements. With the tomographic principles of the PET scanner the quantitative distribution of the administered isotopes can be determined and images can be provided as well as dynamic information on blood flow, metabolism and receptor function. In neurology PET has been used for investigations on numerous physiological processes in the brain: circulation, metabolism and receptor studies. In Parkinson's disease PET studies have been able to localize the pathology specifically, and in early stroke PET technique can outline focal areas with living but non-functioning cells, and this could make it possible to intervene in this early state. With positron emission tomography a quantitative evaluation of myocardial blood flow, glucose and fatty acid metabolism can be made as well as combined assessments of blood flow and metabolism. Combined studies of blood flow and metabolism can determine whether myocardial segments with abnormal motility consist of necrotic or viable tissue, thereby delineating effects of revascularisation. In the future it will probably be possible to characterize the myocardial receptor status in different cardiac diseases. The PET technique is used in oncology for clinical as well as more basic research on tumor perfusion and metabolism. Further, tumor uptake of positron labelled cytotoxic drugs might predict the clinical benefit of treatment. (au) (19 refs.).

  14. Regional myocardial perfusion assessed by N-13 labeled ammonia and positron emission computerized axial tomography

    International Nuclear Information System (INIS)

    Schelbert, H.R.; Phelps, M.E.; Hoffman, E.J.; Huang, S.C.; Selin, C.E.; Kuhl, D.E.

    1978-01-01

    The usefulness of 13 NH 3 as an indicator of regional myocardial perfusion suitable for positron emission computerized axial tomography (PCT) has been suggested. However, the relationship between myocardial blood flow and uptake of 13 NH 3 has not been examined quantitatively. It was therefore the purpose of the current investigation to quantitate the relationship of myocardial 13 NH 3 tissue concentration to myocardial blood flow and to examine its suitability for PCT imaging. Twelve open chest dogs were studied. In 8 of the dogs 25 imaging procedures with 13 NH 3 and PCT were performed. In the remaining four dogs the relationship between flow and myocardial 13 NH 3 tissue concentration was assessed by in vitro techniques. The PCT technique provided high quality cross-sectional images of the distribution of 13 NH 3 in left ventricular myocardium. No significant redistribution of 13 NH 3 in myocardium occurred with time. Alterations in regional myocardial blood flow resulted in changes of the regional distribution of 13 NH 3 that were readily appreciated on the PCT images

  15. Role of Tulipa gesneriana TEOSINTE BRANCHED1 (TgTB1) in the control of axillary bud outgrowth in bulbs.

    Science.gov (United States)

    Moreno-Pachon, Natalia M; Mutimawurugo, Marie-Chantal; Heynen, Eveline; Sergeeva, Lidiya; Benders, Anne; Blilou, Ikram; Hilhorst, Henk W M; Immink, Richard G H

    2018-06-01

    Tulip vegetative reproduction. Tulips reproduce asexually by the outgrowth of their axillary meristems located in the axil of each bulb scale. The number of axillary meristems in one bulb is low, and not all of them grow out during the yearly growth cycle of the bulb. Since the degree of axillary bud outgrowth in tulip determines the success of their vegetative propagation, this study aimed at understanding the mechanism controlling the differential axillary bud activity. We used a combined physiological and "bottom-up" molecular approach to shed light on this process and found that first two inner located buds do not seem to experience dormancy during the growth cycle, while mid-located buds enter dormancy by the end of the growing season. Dormancy was assessed by weight increase and TgTB1 expression levels, a conserved TCP transcription factor and well-known master integrator of environmental and endogenous signals influencing axillary meristem outgrowth in plants. We showed that TgTB1 expression in tulip bulbs can be modulated by sucrose, cytokinin and strigolactone, just as it has been reported for other species. However, the limited growth of mid-located buds, even when their TgTB1 expression is downregulated, points at other factors, probably physical, inhibiting their growth. We conclude that the time of axillary bud initiation determines the degree of dormancy and the sink strength of the bud. Thus, development, apical dominance, sink strength, hormonal cross-talk, expression of TgTB1 and other possibly physical but unidentified players, all converge to determine the growth capacity of tulip axillary buds.

  16. Consumption of garlic positively affects hedonic perception of axillary body odour.

    Science.gov (United States)

    Fialová, Jitka; Roberts, S Craig; Havlíček, Jan

    2016-02-01

    Beneficial health properties of garlic, as well as its most common adverse effect - distinctive breath odour - are well-known. In contrast, analogous research on the effect of garlic on axillary odour is currently missing. Here, in three studies varying in the amount and nature of garlic provided (raw garlic in study 1 and 2, garlic capsules in study 3), we tested the effect of garlic consumption on the quality of axillary odour. A balanced within-subject experimental design was used. In total, 42 male odour donors were allocated to either a "garlic" or "non-garlic" condition, after which they wore axillary pads for 12 h to collect body odour. One week later, the conditions were reversed. Odour samples were then judged for their pleasantness, attractiveness, masculinity and intensity by 82 women. We found no significant differences in ratings of any characteristics in study 1. However, the odour of donors after an increased garlic dosage was assessed as significantly more pleasant, attractive and less intense (study 2), and more attractive and less intense in study 3. Our results indicate that garlic consumption may have positive effects on perceived body odour hedonicity, perhaps due to its health effects (e.g., antioxidant properties, antimicrobial activity). Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. New parameter-free polarization potentials in low-energy positron collisions

    Science.gov (United States)

    Jain, Ashok

    1990-01-01

    The polarization potential plays a decisive role in shaping up the cross sections in low energy positron collisions with atoms and molecules. However, its inclusion without involving any adjustable parameter, is still a challenge. Various other techniques employed so far for positron collisions are summarized, and a new, nonadjustable and very simple form of the polarization potential for positron-atom (molecule) collisions below the threshold of positronium formation is discussed. This new recently proposed potential is based on the correlation energy of a single positron in a homogeneous electron gas. The correlation energy was calculated by solving the Schrodinger equation of the positron-electron system and fitted to an analytical form in various ranges of the density parameter. In the outside region, the correlation energy is joined smoothly with the correct asymptotic form. This new positron correlation polarization (PCOP) potential was tested on several atomic and molecular targets such as the Ar, CO, and CH4. The results on the total and differential cross sections on these targets are shown along with the experimental data where available.

  18. Positron-annihilation studies on the YBa2Cu4O8 superconductor

    International Nuclear Information System (INIS)

    Sundar, C.S.; Bharathi, A.; Jean, Y.C.; Hor, P.H.; Meng, R.L.; Xue, Y.Y.; Huang, Z.J.; Chu, C.W.

    1990-01-01

    Positron-lifetime and Doppler-broadened annihilation-radiation line-shape parameter S in YBa 2 Cu 4 O 8 are observed to decrease with temperature below T c . The calculation of the positron-density distribution shows that the maximum of the positron density is in the region between the Cu-O double chains. The correlation between the temperature dependence of annihilation parameters and the positron-density distribution is discussed. The decrease in annihilation parameters below T c is understood in terms of a local electron transfer from the CuO 2 layers to the Cu-O chains in the superconducting state

  19. Clinical utility of routine pre-operative axillary ultrasound and fine needle aspiration cytology in patient selection for sentinel lymph node biopsy.

    Science.gov (United States)

    Rattay, T; Muttalib, M; Khalifa, E; Duncan, A; Parker, S J

    2012-04-01

    In patients with operable breast cancer, pre-operative evaluation of the axilla may be of use in the selection of appropriate axillary surgery. Pre-operative axillary ultrasound (US) and fine needle aspiration cytology (FNAC) assessments have become routine practice in many breast units, although the evidence base is still gathering. This study assessed the clinical utility of US+/-FNAC in patient selection for either axillary node clearance (ANC) or sentinel lymph node biopsy (SLNB) in patients undergoing surgery for operable breast cancer. Over a two-year period, 348 patients with a clinically negative axilla underwent axillary US. 67 patients with suspicious nodes on US also underwent FNAC. The sensitivity and specificity of axillary investigations to determine nodal involvement were 56% (confidence interval: 47-64%) and 90% (84-93%) for US alone, and 76% (61-87%) and 100% (65-100%) for FNAC combined with US, respectively. With a positive US, the post-test probability was 78%. A negative US carried a post-test probability of 25%. When FNAC was positive, the post-test probability was greater than unity. A negative FNAC yielded a post-test probability of 52%. All patients with positive FNAC and most patients with suspicious US were listed for axillary node clearance (ANC) after consideration at the multi-disciplinary team (MDT) meeting. With pre-operative axillary US+/-FNAC, 20% of patients were saved a potential second axillary procedure, facilitating a reduction in the overall re-operation rate to 12%. In this study, a positive pre-operative US+/-FNAC directs patients towards ANC. When the result is negative, other clinico-pathological factors need to be taken into account in the selection of the appropriate axillary procedure. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Computed tomography image of the mediastinal and axillary lymph nodes in clinically sound Rottweilers

    Directory of Open Access Journals (Sweden)

    Ana Carolina B. Fonseca Pinto

    2013-03-01

    Full Text Available Trough computed tomography (CT, it is possible to evaluate lymph nodes in detail and to detect changes in these structures earlier than with radiographs and ultrasound. Lack of information in the veterinary literature directed the focus of this report to normal aspects of the axillary and mediastinal lymph nodes of adult dogs on CT imaging. A CT scan of 15 normal adult male and female Rottweilers was done. To define them as clinically sound, anamnesis, physical examination, complete blood count, renal and hepatic biochemistry, ECG, and thoracic radiographs were performed. After the intravenous injection of hydrosoluble ionic iodine contrast medium contiguous 10mm in thickness thoracic transverse images were obtained with an axial scanner. In the obtained images mediastinal and axillary lymph nodes were sought and when found measured in their smallest diameter and their attenuation was compared to musculature. Mean and standard deviation of: age, weight, body length and the smallest diameter of the axillary and mediastinal lymph nodes were determined. Mean and standard deviation of parameters: age 3.87±2.03 years, weight 41.13±5.12, and body length 89.61±2.63cm. Axillary lymph nodes were seen in 60% of the animals, mean of the smallest diameter was 3.58mm with a standard deviation of 2.02 and a minimum value of 1mm and a maximum value of 7mm. From 13 observed lymph nodes 61.53% were hypopodense when compared with musculature, and 30.77% were isodense. Mediastinal lymph nodes were identified in 73.33% of the dogs; mean measure of the smallest diameter was 4.71mm with a standard deviation of 2.61mm and a minimum value of 1mm, and a maximum value of 8mm. From 14 observed lymph nodes 85.71% were isodense when compared with musculature and 14.28% were hypodense. The results show that it is possible to visualize axillary and mediastinal lymph nodes in adult clinically sound Rottweilers with CT using a slice thickness and interval of 10mm. The

  1. Investigation of positron moderator materials for electron-linac-based slow positron beamlines

    International Nuclear Information System (INIS)

    Suzuki, Ryoichi; Ohdaira, Toshiyuki; Uedono, Akira

    1998-01-01

    Positron re-emission properties were studied on moderator materials in order to improve the positron moderation system of electron-linac-based intense slow positron beamlines. The re-emitted positron fraction was measured on tungsten, SiC, GaN, SrTiO 3 , and hydrogen-terminated Si with a variable-energy pulsed positron beam. The results suggested that tungsten is the best material for the primary moderator of the positron beamlines while epitaxially grown n-type 6H-SiC is the best material for the secondary moderator. Defect characterization by monoenergetic positron beams and surface characterization by Auger electron spectroscopy were carried out to clarify the mechanism of tungsten moderator degradation induced by high-energy electron irradiation. The characterization experiments revealed that the degradation is due to both radiation-induced vacancy clusters and surface carbon impurities. For the restoration of degraded tungsten moderators, oxygen treatment at ∼900degC is effective. Furthermore, it was found that oxygen at the tungsten surface inhibits positronium formation; as a result, it can increase the positron re-emission fraction. (author)

  2. Partial axillary dissection in early breast cancer | El-Fayoumi ...

    African Journals Online (AJOL)

    ... of later clinical involvement of the axilla and at establishing a sound basis for adjuvant treatment planning axillary dissection is an important operative procedure. ... Methods: Eighteen patients underwent modified radical mastectomy, while the other two patients who were fulfilling the criteria for conservative breast surgery ...

  3. Successful Completion of the Pilot Phase of a Randomized Controlled Trial Comparing Sentinel Lymph Node Biopsy to No Further Axillary Staging in Patients with Clinical T1-T2 N0 Breast Cancer and Normal Axillary Ultrasound.

    Science.gov (United States)

    Cyr, Amy E; Tucker, Natalia; Ademuyiwa, Foluso; Margenthaler, Julie A; Aft, Rebecca L; Eberlein, Timothy J; Appleton, Catherine M; Zoberi, Imran; Thomas, Maria A; Gao, Feng; Gillanders, William E

    2016-08-01

    Axillary surgery is not considered therapeutic in patients with clinical T1-T2 N0 breast cancer. The importance of axillary staging is eroding in an era in which tumor biology, as defined by biomarker and gene expression profile, is increasingly important in medical decision making. We hypothesized that axillary ultrasound (AUS) is a noninvasive alternative to sentinel lymph node biopsy (SLNB), and AUS could replace SLNB without compromising patient care. Patients with clinical T1-T2 N0 breast cancer and normal AUS were eligible for enrollment. Subjects were randomized to no further axillary staging (arm 1) vs SLNB (arm 2). Descriptive statistics were used to describe the results of the pilot phase of the randomized controlled trial. Sixty-eight subjects were enrolled in the pilot phase of the trial (34 subjects in arm 1, no further staging; 32 subjects in arm 2, SLNB; and 2 subjects voluntarily withdrew from the trial). The median age was 61 years (range 40 to 80 years) in arm 1 and 59 years (range 31 to 81 years) in arm 2, and there were no significant clinical or pathologic differences between the arms. Median follow-up was 17 months (range 1 to 32 months). The negative predictive value (NPV) of AUS for identification of clinically significant axillary disease (>2.0 mm) was 96.9%. No axillary recurrences have been observed in either arm. Successful completion of the pilot phase of the randomized controlled trial confirms the feasibility of the study design, and provides prospective evidence supporting the ability of AUS to exclude clinically significant disease in the axilla. The results provide strong support for a phase 2 randomized controlled trial. Copyright © 2016 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  4. Comparison between minimal right vertical infra-axillary thoracotomy and standard median sternotomy for repair of atrial septal defects

    Directory of Open Access Journals (Sweden)

    Hafize Yaliniz

    2015-10-01

    Conclusion: Minimal right vertical infra-axillary thoracotomy can be performed with favorable cosmetic and clinical results for atrial septal defects closure. Infra-axillary thoracotomy provides a good alternative to standard median sternotomy for patients with atrial septal defects.

  5. Positron astrophysics and areas of relation to low-energy positron physics

    Science.gov (United States)

    Guessoum, Nidhal

    2014-05-01

    I briefly review our general knowledge of positron astrophysics, focusing mostly on the theoretical and modelling aspects. The experimental/observational aspects of the topic have recently been reviewed elsewhere [E. Churazov et al., Mon. Nat. R. Astron. Soc. 411, 1727 (2011); N. Prantazos et al., Rev. Mod. Phys. 83, 1001 (2011)]. In particular, I highlight the interactions and cross sections of the reactions that the positrons undergo in various cosmic media. Indeed, these must be of high interest to both the positron astrophysics community and the low-energy positron physics community in trying to find common areas of potential collaboration for the future or areas of research that will help the astrophysics community make further progress on the problem. The processes undergone by positrons from the moments of their birth to their annihilation (in the interstellar medium or other locations) are thus examined. The physics of the positron interactions with gases and solids (dust grains) and the physical conditions and characteristics of the environments where the processes of energy loss, positronium formation, and annihilation take place, are briefly reviewed. An explanation is given about how all the relevant physical information is taken into account in order to calculate annihilation rates and spectra of the 511 keV emission in the ISM; special attention is paid to positron interactions with dust and with polycyclic aromatic hydrocarbons. In particular, an attempt is made to show to what extent the interactions between positrons and interstellar dust grains are similar to laboratory experiments in which beams of low-energy positrons impinge upon solids and surfaces. Sample results are shown for the effect of dust grains on positron annihilation spectra in some phases of the ISM which, together with high resolution spectra measured by satellites, can be used to infer useful knowledge about the environment where the annihilation is predominantly taking place

  6. Defects investigation in neutron irradiated reactor steels by positron annihilation

    International Nuclear Information System (INIS)

    Slugen, V.

    2003-01-01

    Positron annihilation spectroscopy (PAS) based on positron lifetime measurements using the Pulsed Low Energy Positron System (PLEPS) was applied to the investigation of defects of irradiated and thermally treated reactor pressure vessel (RPV) steels. PLEPS results showed that the changes in microstructure of the RPV-steel properties caused by neutron irradiation and post-irradiation heat treatment can be well detected. From the lifetime measurements in the near-surface region (20-550 nm) the defect density in Russian types of RPV-steels was calculated using the diffusion trapping model. The post-irradiation heat treatment studies performed on non-irradiated specimens are also presented. (author)

  7. Positron-atom collisions

    International Nuclear Information System (INIS)

    Drachman, R.J.

    1984-01-01

    The past decade has seen the field of positron-atom collisions mature into an important sub-field of atomic physics. Increasingly intense positron sources are leading towards a situation in which electron and positron collision experiments will be on almost an equal footing, challenging theory to analyze their similarities and differences. The author reviews the advances made in theory, including dispersion theory, resonances, and inelastic processes. A survey of experimental progress and a brief discussion of astrophysical positronics is also included. (Auth.)

  8. Positron astrophysics and areas of relation to low-energy positron physics

    International Nuclear Information System (INIS)

    Guessoum, N.

    2014-01-01

    I briefly review our general knowledge of positron astrophysics, focusing mostly on the theoretical and modelling aspects. The experimental/observational aspects of the topic have recently been reviewed elsewhere [E. Churazov et al., Mon. Nat. R. Astron. Soc. 411, 1727 (2011); N. Prantazos et al., Rev. Mod. Phys. 83, 1001 (2011)]. In particular, I highlight the interactions and cross sections of the reactions that the positrons undergo in various cosmic media. Indeed, these must be of high interest to both the positron astrophysics community and the low-energy positron physics community in trying to find common areas of potential collaboration for the future or areas of research that will help the astrophysics community make further progress on the problem. The processes undergone by positrons from the moments of their birth to their annihilation (in the interstellar medium or other locations) are thus examined. The physics of the positron interactions with gases and solids (dust grains) and the physical conditions and characteristics of the environments where the processes of energy loss, positronium formation, and annihilation take place, are briefly reviewed. An explanation is given about how all the relevant physical information is taken into account in order to calculate annihilation rates and spectra of the 511 keV emission in the ISM; special attention is paid to positron interactions with dust and with polycyclic aromatic hydrocarbons. In particular, an attempt is made to show to what extent the interactions between positrons and interstellar dust grains are similar to laboratory experiments in which beams of low-energy positrons impinge upon solids and surfaces. Sample results are shown for the effect of dust grains on positron annihilation spectra in some phases of the ISM which, together with high resolution spectra measured by satellites, can be used to infer useful knowledge about the environment where the annihilation is predominantly taking place

  9. Correlation between obesity and fat-infiltrated axillary lymph nodes visualized on mammography.

    Science.gov (United States)

    diFlorio Alexander, Roberta M; Haider, Steffen J; MacKenzie, Todd; Goodrich, Martha E; Weiss, Julie; Onega, Tracy

    2018-01-05

    Using screening mammography, this study investigated the association between obesity and axillary lymph node (LN) size and morphology. We conducted a retrospective review of 188 females who underwent screening mammography at an academic medical centre. Length and width of the LN and hilum were measured in the largest, mammographically visible axillary node. The hilo-cortical ratio (HCR) was calculated as the hilar width divided by the cortical width. Measurements were performed by a board certified breast radiologist and a resident radiology physician. Inter-rater agreement was assessed with Pearson correlation coefficient. We performed multivariable regression analysis for associations of LN measurements with body mass index (BMI), breast density and age. There was a strong association between BMI and LN dimensions, hilum dimensions and HCR (p < 0.001 for all metrics). There was no significant change in cortex width with increasing BMI (p = 0.15). Increases in LN length and width were found with increasing BMI [0.6 mm increase in length per unit BMI, 95% CI (0.4-0.8), p < 0.001 and0.3 mm increase in width per unit BMI, 95% CI(0.2-0.4), p < 0.001, respectively]. Inter-rater reliability for lymph node and hilum measurements was 0.57-0.72. We found a highly significant association between increasing BMI and axillary LN dimensions independent of age and breast density with strong interobserver agreement. The increase in LN size was driven by expansion of the LN hilum secondary to fat infiltration. Advances in knowledge: This preliminary work determined a relationship between fat infiltrated axillary lymph nodes and obesity.

  10. The possibility of access to the kidneys from posterior axillary line in supine position for percutaneous nephrolithotomy

    Directory of Open Access Journals (Sweden)

    Ali Tabibi

    2013-11-01

    Full Text Available Please cite this article as: Tabibi A, Kashi AH, Mirjalili SAM, Mahmoudnejad N, Kashani P, Salavatipour B, Soltani MH. The possibility of access to the kidneys from posterior axillary line in supine position for percutaneous nephrolithotomy. Novel Biomed 2013;1(2:43-47.Objectives: To evaluate the possibility of access to the kidneys from posterior axillary line (PAL in supine position for percutaneous nephrolithotomy.Materials and Methods: 102 consecutive patients who were candidated for abdominal CT scan, enrolled in this study. In cases of impossible access, the point on the posterior surface of body which permitted safe access was determined and the percent of movement toward body midline (relative to PAL was calculated (M.PER.Results: Percutaneous access was simulated from upper and middle calyces of the kidney in 13% and 75% of cases, respectively. Access to the lower region was possible in 90% of right and 79% of left lower calyces, respectively (p=0.03. In cases with impossible access from PAL, the M.PER for a safe access was 46-47% for upper region and 34- 38% for middle and lower calyces of the kidney (P = 0.0001.Conclusions: Access to upper calyces from PAL was limited in some cases regarding to the presence of solid organs. Presence of colon made access impossible in the lower right and left calyces in about 10% and 20% of cases, respectively. In upper region, more deviation toward midline was necessary to establish a safe access compared with middle and lower calyces.

  11. Dynamic positron emission tomography for study of cerebral hemodynamics in a cross section of the head using positron-emitting 68Ga-EDTA and 77Kr

    International Nuclear Information System (INIS)

    Yamamoto, Y.L.; Thompson, C.J.; Meyer, E.; Robertson, J.S.; Feindel, W.

    1977-01-01

    Dynamic positron emission tomographic studies were performed on over 120 patients with occlusive cerebrovascular disease, arteriovenous malformations, and brain tumors, using the positron section scanner, consisting of a ring of 32 scintillation detectors. The radiopharmaceuticals were nondiffusible 68 Ga-EDTA for transit time and uptake studies and the diffusible tracer, 77 Kr, for quantitative regional cerebral blood flow studies in every square centimeter of the cross section of the head. The results of dynamic positron emission tomography in correlation with the results from the gamma scintillation camera dynamic studies and computed tomography (CT) scans are discussed

  12. Regional myocardial oxygen consumption estimated by carbon-11 acetate and positron emission tomography before and after repetitive ischemia

    DEFF Research Database (Denmark)

    Kofoed, K F; Hansen, P R; Holm, S

    2000-01-01

    alternating with 5 minutes of reperfusion. Before and after repetitive coronary occlusions, oxygen 15 water/oxygen 15 carbon monoxide (blood flow), and 11C-acetate (oxygen consumption) PET imaging were performed. Left ventricular regional systolic wall thickening was measured with sonomicrometry. Forty......BACKGROUND: Preserved myocardial oxygen consumption estimated by carbon 11-acetate and positron emission tomography (PET) in myocardial regions with chronic but reversibly depressed contractile function in patients with ischemic heart disease have been suggested to be caused by repeated short......-five minutes after the ischemic episodes, systolic ventricular wall thickening was decreased by 90%, whereas myocardial blood flow was reduced by 21% compared with baseline values (P consumption was unaltered compared with the baseline level...

  13. Positrons and positronium

    International Nuclear Information System (INIS)

    Jean, Y.C.; Lambrecht, R.M.

    1988-01-01

    This bibliography includes articles, proceedings, abstracts, reports and patents published between 1930 and 1984 on the subject of positrons, positron annihilation and positronium. The subject covers experimental and theoretical results in the areas of physics and chemistry of low and intermediate energy (< 0.6 MeV) positrons and positronium. The topics of interest are: fundamental properties, interactions with matter, nuclear technology, the history and philosophy of antimatter, the theory of the universe, and the applications of positrons in the chemical, physical, and biomedical sciences

  14. The proposed INEL intense slow positron source, beam line, and positron microscope facility

    International Nuclear Information System (INIS)

    Makowitz, H.; Denison, A.B.; Brown, B.

    1993-01-01

    A program is currently underway at the Idaho National Engineering Laboratory (INEL) to design and construct an Intense Slow Positron Beam Facility with an associated Positron Microscope. Positron beams have been shown to be valuable research tools and have potential application in industrial processing and nondestructive evaluation (microelectronics, etc.). The limit of resolution or overall usefulness of the technique has been limited because of lack of sufficient intensity. The goal of the INEL positron beam is ≥ 10 12 slow e+/s over a 0.03 cm diameter which represents a 10 3 to 10 4 advancement in beam current over existing beam facilities. The INEL is an ideal site for such a facility because of the nuclear reactors capable of producing intense positron sources and the personnel and facilities capable of handling high levels of radioactivity. A design using 58 Co with moderators and remoderators in conjunction with electrostatic positron beam optics has been reached after numerous computer code studies. Proof-of-principle electron tests have demonstrated the feasibility of the large area source focusing optics. The positron microscope development is occurring in conjunction with the University of Michigan positron microscope group. Such a Beam Facility and associated Intense Slow Positron Source (ISPS) can also be utilized for the generation and study of positron, and positron electron plasmas at ≤ 10 14 particles/cm 3 with plasma temperatures ranging from an eV to many keV, as well as an intense x-ray source via positron channeling radiation. The possibility of a tunable x-ray laser based on channeling positron radiation also exists. In this discussion the authors will present a progress report on various activities associated with the INEL ISPS

  15. Positron emission tomography for the assessment of myocardial viability

    International Nuclear Information System (INIS)

    Schelbert, H.R.

    1991-01-01

    The detection of viable myocardium or ischemically injured myocardium with a reversible impairment of contractile function remains clinically important but challenging. Detection of reversible dysfunction and distinction from irreversible tissue injury by positron emission tomography is based on identification of preserved or even enhanced glucose metabolism with F-18 2-fluoro 2-deoxyglucose. Regional patterns of myocardial glucose utilization and blood flow, defined as perfusion-metabolism mismatches or matches, on positron emission tomography in patients with chronic or even acute ischemic heart disease are highly accurate in predicting the functional outcome after interventional revascularization. Compared with thallium-201 redistribution scintigraphy, positron emission tomography appears to be diagnostically more accurate, especially in patients with severely impaired left ventricular function. While larger clinical trials are needed for further confirmation, positron emission tomography has already proved clinically useful for stratifying patients with poor left ventricular function to the most appropriate therapeutic approach

  16. Origin and distribution of the axillary nerve in the giant anteater (Myrmecophaga tridactyla

    Directory of Open Access Journals (Sweden)

    Daniela Cristina de Oliveira Silva

    2012-09-01

    Full Text Available The giant anteater (Myrmecophaga tridactyla, a mammal belonging to the order Xenarthra and family Myrmecophagidae, is an endangered species. For this reason, additional knowledge about its anatomy is of interest, especially the forelimb, which plays important roles in feeding and defense. The goal of this study was to learn more about the origin and distribution of the axillary nerve of Myrmecophaga tridactyla by studying two individuals (one male and one female that belong to the Research Laboratory of Wild Animals (UFU. The study material consisted of corpses fixed and preserved in 10% aqueous formalin solution. Dissection of the material followed standard procedures. In both animals, the axillary nerve was found in the ventral branch of the sixth cervical (C6 and seventh (C7 spinal nerve. This nerve showed symmetry in relation to its position in the two specimens and branched into the teres major, teres minor and deltoid muscles. In both specimens the axillary nerve originated in the cranial cutaneous branch of the lower leg.

  17. Simulation of tail distributions in electron-positron circular colliders

    International Nuclear Information System (INIS)

    Irwin, J.

    1992-02-01

    In addition to the Gaussian shaped core region, particle bunches in electron-positron circular colliders have a rarefied halo region of importance in determining beam lifetimes and backgrounds in particle detectors. A method is described which allows simulation of halo particle distributions

  18. presence of axillary bud and application of plant growth hormones

    African Journals Online (AJOL)

    D. alata)- were grown in pots in the greenhouse. Half the cuttings bore axillary buds and half had none. The cuttings were sprayed with a factorial combination of indole acetic acid (IAA), benzyladenine (BA) and giberellic acid (GA3). Cuttings ...

  19. Staging primary breast cancer. Are there tumour pathological features that correlate with a false-negative axillary ultrasound?

    International Nuclear Information System (INIS)

    Johnson, S.; Brown, S.; Porter, G.; Steel, J.; Paisley, K.; Watkins, R.; Holgate, C.

    2011-01-01

    Aim: To investigate whether the histopathological characteristics of primary breast cancer tumours could predict the likelihood of false-negative axillary ultrasound. Materials and methods: Screening and symptomatic patients were identified from pathology records and imaging and pathology records reviewed. True and false-negative axillary staging ultrasound groups were compared statistically in terms of tumour size, pathological type and grade, lymphovascular invasion, and oestrogen receptor (ER) status. Results: Of 155 women with normal ultrasounds, 45 (29%) were node positive at axillary surgery. Breast tumour size was significantly different with the average size smaller in the true-negative group: 21 versus 30 mm (p < 0.02). The histological type varied significantly between the groups, with more lobular carcinomas in the false-negative group [6/110 (5%) versus 6/45 (13%), p < 0.001]. The false-negative group was also more likely to show lymphovascular invasion in the breast [6/110 (5%) versus 14/45 (31%), p < 0.001]. There was no significant difference in tumour grade or ER status. Conclusion: The present study has found significant differences in tumour characteristics between women with true-negative and false-negative axillary staging ultrasound in terms of size, primary tumour histological type and presence of lymphovascular invasion. In particular, axillary ultrasound in primary lobular carcinoma may be less accurate and a negative result is more likely to be spurious than with primary ductal carcinomas.

  20. Positron emission tomography

    International Nuclear Information System (INIS)

    Reivich, M.; Alavi, A.

    1985-01-01

    This book contains 24 selections. Some of the titles are: Positron Emission Tomography Instrumentation, Generator Systems for Positron Emitters, Reconstruction Algorithms, Cerebral Glucose Consumption: Methodology and Validation, Cerebral Blood Flow Tomography Using Xenon-133 Inhalation: Methods and Clinical Applications, PET Studies of Stroke, Cardiac Positron Emission Tomography, and Use of PET in Oncology

  1. Cardiac positron emission tomography

    International Nuclear Information System (INIS)

    Eftekhari, M.; Ejmalian, G.

    2003-01-01

    Positron emission tomography is an intrinsically tool that provide a unique and unparalleled approach for clinicians and researchers to interrogate the heart noninvasively. The ability to label substances of physiological interest with positron-emitting radioisotopes has permitted insight into normal blood flow and metabolism and the alterations that occur with disease states. Positron emission tomography of the heart has evolved as a unique, noninvasive approach for the assessment of myocardial perfusion, metabolism, and function. Because of the intrinsic quantitative nature of positron emission tomography measurements as well as the diverse compounds that can be labeled with positron- emitting radioisotopes, studies with positron emission tomography have provided rich insight into the physiology of the heart under diverse conditions

  2. Local vacancies in optical modulation polymers studied by positron annihilation lifetime measurements

    International Nuclear Information System (INIS)

    Shimazu, Akira

    2009-01-01

    The ability of a slow positron beam to prove vacancies at the surface and in bulk regions of optical modulation polymers was demonstrated. A slow positron beam system was found to be a powerful tool to study the change in the microstructure driven by photopolymerization of novel optical modulation polymers. (author)

  3. BEPC II positron source

    International Nuclear Information System (INIS)

    Pei Guoxi; Sun Yaolin; Liu Jintong; Chi Yunlong; Liu Yucheng; Liu Nianzong

    2006-01-01

    BEPC II-an upgrade project of the Beijing Electron Positron Collider (BEPC) is a factory type of e + e - collider. The fundamental requirements for its injector linac are the beam energy of 1.89 GeV for on-energy injection and a 40 mA positron beam current at the linac end with a low beam emittance of 1.6 μm and a low energy spread of ±0.5% so as to guarantee a higher injection rate (≥50 mA/min) to the storage ring. Since the positron flux is proportional to the primary electron beam power on the target, the authors will increase the electron gun current from 4A to 10A by using a new electron gun system and increase the primary electron energy from 120 MeV to 240 MeV. The positron source itself is an extremely important system for producing more positrons, including a positron converter target chamber, a 12kA flux modulator, the 7m focusing module with DC power supplies and the support. The new positron production linac from the electron gun to the positron source has been installed into the tunnel. In what follows, the authors will emphasize the positron source design, manufacture and tests. (authors)

  4. Positron emission tomography (PET) and magnetic resonance imaging (MRI) for the assessment of axillary lymph node metastases in early breast cancer: systematic review and economic evaluation.

    Science.gov (United States)

    Cooper, K L; Meng, Y; Harnan, S; Ward, S E; Fitzgerald, P; Papaioannou, D; Wyld, L; Ingram, C; Wilkinson, I D; Lorenz, E

    2011-01-01

    Breast cancer is the most common type of cancer in women. Evaluation of axillary lymph node metastases is important for breast cancer staging and treatment planning. To evaluate the diagnostic accuracy, cost-effectiveness and effect on patient outcomes of positron emission tomography (PET), with or without computed tomography (CT), and magnetic resonance imaging (MRI) in the evaluation of axillary lymph node metastases in patients with newly diagnosed early-stage breast cancer. A systematic review of literature and an economic evaluation were carried out. Key databases (including MEDLINE, EMBASE and nine others) plus research registers and conference proceedings were searched for relevant studies up to April 2009. A decision-analytical model was developed to determine cost-effectiveness in the UK. One reviewer assessed titles and abstracts of studies identified by the search strategy, obtained the full text of relevant papers and screened them against inclusion criteria. Data from included studies were extracted by one reviewer using a standardised data extraction form and checked by a second reviewer. Discrepancies were resolved by discussion. Quality of included studies was assessed using the quality assessment of diagnostic accuracy studies (QUADAS) checklist, applied by one reviewer and checked by a second. Forty-five citations relating to 35 studies were included in the clinical effectiveness review: 26 studies of PET and nine studies of MRI. Two studies were included in the cost-effectiveness review: one of PET and one of MRI. Of the seven studies evaluating PET/CT (n = 862), the mean sensitivity was 56% [95% confidence interval (CI) 44% to 67%] and mean specificity 96% (95% CI 90% to 99%). Of the 19 studies evaluating PET only (n = 1729), the mean sensitivity was 66% (95% CI 50% to 79%) and mean specificity 93% (95% CI 89% to 96%). PET performed less well for small metastases; the mean sensitivity was 11% (95% CI 5% to 22%) for micrometastases (≤ 2 mm

  5. Regional cerebral glucose consumption measured by positron emission tomography in patients with Wilson's disease

    International Nuclear Information System (INIS)

    Kuwert, T.; Scholz, D.; Milz, M.; Herzog, H.; Feinendegen, L.E.; Hefter, H.; Weiss, P.; Arendt, G.; Loken, M.; Minnesota Univ., Minneapolis, MN; Hennerici, M.

    1992-01-01

    Using positron emission tomography (PET), the regional cerebral metabolic rate of glucose consumption (rCMRGlc) was measured in 14 patients with Wilson's disease (WD) and 23 normal subjects. In WD patients, cerebellar, striatal and - to a lesser extent - cortical and thalamic rCMRGlc were significantly decreased compared with controls. Striatal rCMRGlc was significantly reduced in those 4 patients who had recently started decoppering therapy as compared with striatal rCMRGlc measured in those 10 patients with longer duration of medication. Caudate rCMRGlc correlated significantly with various signs of extrapyramidal dysfunction. Cerebellar, thalamic and cortical rCMRGlc correlated significantly with the severity of pyramidal signs. These data indicate that the PET measurement of rCMRGlc may be a useful tool to evaluate cerebral involvement in WD and to monitor the response to treatment. (orig.)

  6. Harmonic focus versus electrocautery in axillary lymph node dissection for breast cancer: a randomized clinical study.

    Science.gov (United States)

    He, Qingqing; Zhuang, Dayong; Zheng, Luming; Fan, Ziyi; Zhou, Peng; Zhu, Jian; Lv, Zhen; Chai, Jixin; Cao, Lei

    2012-12-01

    Electrocautery has been proven to be associated with prolonged serous drainage that might result in several complications in patients requiring axillary lymph node dissection for breast cancer. We proposed that the Harmonic Focus might outperform electrocautery in axillary lymph node dissection, resulting in shorter operative times and reduced postoperative complications. One hundred twenty-eight women with confirmed T1-3 N1-2 breast cancer were randomly assigned to undergo mastectomy or breast-conserving surgery with axillary dissection by using Harmonic Focus or electrocautery. Sixty-four has surgery with Harmonic Focus (group A) and 64 with electrocautery (group B) by the same surgical team. Operative time, blood loss, total drainage volume and days, incidence of seroma, hematoma, pain score, and flap necrosis were recorded. Using Harmonic Focus significantly diminished operative time, blood loss, total drainage volume, days of stay, and visual analogue scale as compared with traditional electrocautery. There was no statistical difference between the 2 groups regarding seroma, hematoma, and flap necrosis. Axillary lymph node dissection using Harmonic Focus is feasible, safe, and a more comfortable design for the surgeon. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Positron CT findings of chronic schizophrenics

    International Nuclear Information System (INIS)

    Toyoda, Junzo; Miyazaki, Chihiro; Sugai, Yuichi; Iio, Masaaki.

    1983-01-01

    Positron CT images of 15 chronic schizophrenics (2 females and 13 males) were examined in contrast to 5 male controls. Average age of controls was 36 years and that of schizophrenics was 42 years. Schizophrenic cases were ill over 6 years, averaging 17 years. All were under antipsychotic drug therapy. Tracer compounds were 11 C-CO2 and 11 C-glucose photosynthesised, the former being inhalated once just before and the latter being administered orally 10-15 minutes before examinations. On positron CT images of all normal controls, hyper-radioactivities in frontal regions were observed. Some asymmetries of activities were observed but not remarkable. There wes no difference between the images with 11 C-CO2 and those with 11 C-glucose. In schizophrenic cases, (1) 7 out of 15 cases showed hypo-activities in the frontal regions both with 11 C-CO2 and 11 C-glucose. (2) With 11 C-glucose, relative activities in the brain were lower than those in the soft tissues around the scalp, suggesting the lowered selective uptake of 11 C-glucose by the brain. (3) With 11 C-CO 2, 4 cases showed higher activities in the right temporal regions and their subcortex than the left. By consideration of relationships between these positron CT findings and clinical data such as present age, age of onset of illness, duration of illness, psychiatric symptoms, present drug amount, summed drug amount from administration, EEG and X-ray CT findings, significant correlation was recognized only between low frontal radioactivities and apathy-abulia as main symptom. Limitation on the explanation of the findings with the image alone was discussed. (author)

  8. On the average luminosity of electron positron collider and positron-producing energy

    International Nuclear Information System (INIS)

    Xie Jialin

    1985-01-01

    In this paper, the average luminosity of linac injected electron positron collider is investigated from the positron-producing energy point of view. When the energy of the linac injector is fixed to be less than the operating energy of the storage ring, it has been found that there exists a positron-producing energy to give optimum average luminosity. Two cases have been studied, one for an ideal storage ring with no single-beam instability and the other for practical storage ring with fast head-tail instability. The result indicates that there is a positron-producing energy corresponding to the minimum injection time, but this does not correspond to the optimum average luminosity for the practical storage rings. For Beijing Electron Positron Collider (BEPC), the positron-producing energy corresponding to the optimum average luminosity is about one tenth of the total injector energy

  9. Numerical determination of elastic positron- and electron-atom scattering phaseshifts

    International Nuclear Information System (INIS)

    Page, B.A.P.

    1976-01-01

    Numerical investigations of both the positron- and electron-hydrogen systems in the elastic scattering energy region are presented. For the positron-hydrogen system, modifications of the Kohn variational method are used in which the quantities etasub(v) and etasub(Q) are related to the trial wavefunction PSIsub(t) through integral expressions using approximations to the target wavefunction psi. The quantities etasub(v) and etasub(Q) become the Kohn elastic phaseshifts when the exact target wavefunction is used. From the results obtained for the positron-hydrogen system it is conjectured that if the values of either etasub(v) or etasub(Q) display a local maximum when all the nonlinear parameters of PSIsub(t) are varied, then this local maximum value is a good approximation to the Kohn elastic phaseshifts that would be obtained by replacing the approximate psi with the exact psi in the particular PSIsub(t) used in the calculations. Application of this procedure to the positron-helium elastic scattering system is given using Hylleraas-type approximations to the helium ground-state wavefunction. Both the positron- and electron-hydrogen systems are analysed in the elastic scattering energy region using a modified optical potential method. The results suggest that the local maximum value of the modified optical potential phaseshift when all the nonlinear parameters of PSIsub(t) are varied, is reasonably close to the normal optical potential phaseshift obtained when the exact psi is used. (author)

  10. Positron emission tomography

    International Nuclear Information System (INIS)

    Paans, A.M.J.

    1981-01-01

    Positron emitting radiopharmaceuticals have special applications in in-vivo studies of biochemical processes. The combination of a cyclotron for the production of radionuclides and a positron emission tomograph for the registration of the distribution of radioactivity in the body enables the measurement of local radioactivity concentration in tissues, and opens up new possibilities in the diagnosis and examination of abnormalities in the metabolism. The principles and procedures of positron emission tomography are described and the necessary apparatus considered, with emphasis on the positron camera. The first clinical applications using 55 Co bloemycine for tumor detection are presented. (C.F.)

  11. [Isolated traumatic injuries of the axillary nerve. Radial nerve transfer in four cases and literatura review].

    Science.gov (United States)

    Domínguez-Páez, Miguel; Socolovsky, Mariano; Di Masi, Gilda; Arráez-Sánchez, Miguel Ángel

    2012-11-01

    To analyze the results of an initial series of four cases of traumatic injuries of the axillary nerve, treated by a nerve transfer from the triceps long branch of the radial nerve. An extensive analysis of the literature has also been made. Four patients aged between 21 and 42 years old presenting an isolated traumatic palsy of the axillary nerve were operated between January 2007 and June 2010. All cases were treated by nerve transfer six to eight months after the trauma. The results of these cases are analyzed, the same as the axillary nerve injuries series presented in the literature from 1982. One year after the surgery, all patients improved their abduction a mean of 70° (range 30 to 120°), showing a M4 in the British Medical Council Scale. No patient complained of triceps weakness after the procedure. These results are similar to those published employing primary grafting for the axillary nerve. Isolated injuries of the axillary nerve should be treated with surgery when spontaneous recovery is not verified 6 months after the trauma. Primary repair with grafts is the most popular surgical technique, with a rate of success of approximately 90%. The preliminary results of a nerve transfer employing the long triceps branch are similar, and a definite comparison of both techniques with a bigger number of cases should be done in the future. Copyright © 2012 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

  12. Evaluation of axillary dose coverage following whole breast radiotherapy: Variation with the breast volume and shape

    International Nuclear Information System (INIS)

    Aguiar, Artur; Gomes Pereira, Helena; Azevedo, Isabel; Gomes, Luciano

    2015-01-01

    Objective: To evaluate the axillary dose coverage in patients treated with tridimensional whole breast radiotherapy (3D-WBRT), according to the breast volume and shape in treatment position. Background: Several studies have demonstrated an insufficient dose contribution to the axillary levels, using 3D-WBRT, remaining unclear whether the breast volume and shape can influence it. Materials and methods: We retrospectively delineated the axillary levels on planning CT-images of 100 patients, treated with 3D-WBRT along 2012 in our institution. To estimate the shape we established an anatomic CT-based interval, defined as the Thoracic Extent (TE). The breast volume matched its CTV. Mean dose levels and V95 (volume receiving at least 95% of the prescribed dose) were evaluated. Results: Mean axillary level I (A1), II (A2) and III (A3) volume was 56.1 cc, 16.5 cc and 18.9 cc, respectively, and mean doses were 43.9 Gy, 38.6 Gy and 19.5 Gy. For breast volumes of <800 cc, 800–999 cc, 1000–1199 cc and >1200 cc, mean A1 V95 was 38%, 51%, 61.2% and 57.2% whereas median A2 V95 was 8.3%, 13.4%, 19.4% and 28% respectively. Regarding shape, where the breast relative position to the TE was categorized in intervals between 31% and 40%, 41% and 50%, 51% and 60%, and 61% and 70%, mean A1 V95 was 38.7%, 43.1%, 51.1% and 77.3% whereas mean A2 V95 was 6.1%, 11.2%, 17.1% and 37% respectively. Conclusions: We observed inadequate dose coverage to all axillary levels, even after applying a sub-analysis accounting for different breast volumes and shapes. Although higher doses were associated with the more voluminous and pendulous breasts, axillary coverage with 3D-WBRT seems to be inefficient, regardless of the breast morphology

  13. New techniques of positron annihilation

    International Nuclear Information System (INIS)

    1983-02-01

    Studies on new techniques of positron annihilation and its application to various fields are presented. First, production of slow positron and its characteristic features are described. The slow positron can be obtained from radioisotopes by using a positron moderator, proton beam bombardment on a boron target, and pair production by using an electron linear accelerator. Bright enhancement of the slow positron beam is studied. Polarized positron beam can be used for the study of the momentum distribution of an electron in ferromagnetic substances. Production of polarized positrons and measurements of polarization are discussed. Various phases of interaction between slow positrons and atoms (or molecules) are described. A comparative study of electron scavenging effects on luminescence and on positronium formation in cyclohexane is presented. The positron annihilation phenomena are applicable for the surface study. The microscopic information on the surface of porous material may be obtained. The slow positrons are also useful for the surface study. Production and application of slow muon (positive and negative) are presented in this report. (Kato, T.)

  14. Solvated Positron Chemistry - Positron Reactions with Pseudo-Halide Ions in Water

    DEFF Research Database (Denmark)

    Mogensen, O. E.; Pedersen, Niels Jørgen; Andersen, Jan Rud

    1982-01-01

    The hydrated positron e+aq reactions with SCN−, OCN−, CN−, S2− were studied by means of the angular correlation technique. The positron forms bound states with SCN−, CN−, and S2− but not with OCN−. Apparently, the e+aq reaction with SH− results in a positron bound state with S2−. It was difficult...

  15. Risk Factors for Regional Nodal Relapse in Breast Cancer Patients With One to Three Positive Axillary Nodes

    Energy Technology Data Exchange (ETDEWEB)

    Yates, Lucy, E-mail: lucy.yates@gstt.nhs.uk [Guy' s, King' s, St Thomas' Cancer Centre, Guy' s Hospital, London (United Kingdom); Kirby, Anna [Guy' s, King' s, St Thomas' Cancer Centre, Guy' s Hospital, London (United Kingdom); Department of Clinical Oncology, Royal Marsden Hospital, Sutton (United Kingdom); Crichton, Siobhan [Department of Statistics, Kings College London (United Kingdom); Gillett, Cheryl [Breast Pathology, Kings College London (United Kingdom); Cane, Paul [Department of Histopathology, Guy' s and St Thomas' Foundation Trust, London (United Kingdom); Fentiman, Ian; Sawyer, Elinor [Guy' s, King' s, St Thomas' Cancer Centre, Guy' s Hospital, London (United Kingdom)

    2012-04-01

    Purpose: In many centers, supraclavicular fossa radiotherapy (SCF RT) is not routinely offered to breast cancer patients with one to three positive lymph nodes. We aimed to identify a subgroup of these patients who are at high risk of supra or infraclavicular fossa relapse (SCFR) such that they can be offered SCFRT at the time of diagnosis to improve long term locoregional control. Methods and Materials: We performed a retrospective analysis of the pathological features of 1,065 cases of invasive breast cancer with one to three positive axillary lymph nodes. Patients underwent radical breast conserving surgery or mastectomy. A total of 45% of patients received adjuvant chest wall/breast RT. No patients received adjuvant SCFRT. The primary outcome was SCFR. Secondary outcomes were chest wall/breast recurrence, distant metastasis, all death, and breast-cancer specific death. Kaplan-Meier estimates were used to calculate actuarial event rates and survival functions compared using log-rank tests. Multivariate analyses (MVA) of factors associated with outcome were conducted using Cox proportional hazards models. Results: Median follow-up was 9.7 years. SCFR rate was 9.2%. Median time from primary diagnosis to SCFR was 3.4 years (range, 0.7-14.4 years). SCFR was associated with significantly lower 10-year survival (18% vs. 65%; p < 0.001). Higher grade and number of positive lymph nodes were the most significant predictors of SCFR on MVA (p < 0.001). 10 year SCFR rates were less than 1% in all patients with Grade 1 cancers compared with 30% in those having Grade 3 cancers with three positive lymph nodes. Additional factors associated with SCFR on univariate analysis but not on MVA included larger nodal deposits (p = 0.002) and proportion of positive nodes (p = 0.003). Conclusions: Breast cancer patients with one to three positive lymph nodes have a heterogenous risk of SCFR. Patients with two to three positive axillary nodes and/or high-grade disease may warrant

  16. Comparison of the diagnostic value of FDG-PET/CT and axillary ultrasound for the detection of lymph node metastases in breast cancer patients

    International Nuclear Information System (INIS)

    Riegger, Carolin; Heusner, Till A.; Koeninger, Angela; Kimmig, Rainer; Hartung, Verena; Bockisch, Andreas; Otterbach, Friedrich; Forsting, Michael; Antoch, Gerald

    2012-01-01

    Background. FDG-PET/CT is increasingly being used for breast cancer staging. Its diagnostic accuracy in comparison to ultrasound as the standard non-invasive imaging modality for the evaluation of axillary lymph nodes has yet not been evaluated. Purpose. To retrospectively compare the diagnostic value of full-dose, intravenously contrast-enhanced FDG-PET/CT and ultrasound for the detection of lymph node metastases in breast cancer patients. Material and Methods. Ninety patients (one patient with a bilateral carcinoma) (89 women, one man; mean age, 55.5 ± 16.6 years) suffering from primary breast cancer underwent whole-body FDG-PET/CT and axillary ultrasound. The ipsilateral axillary fossa (n = 91) was evaluated for metastatic spread. The sensitivity, specificity, the positive predictive value (PPV), negative predictive value (NPV), and accuracy of both methods were calculated. The sensitivity and accuracy were statistically compared using the McNemar Test (P <0.05). Analyses were made on a patient basis. The number of patients with extra-axillary locoregional lymph node metastases exclusively detected by FDG-PET/CT was evaluated. For axillary lymph node metastases histopathology served as the reference standard. Results. The sensitivity, specificity, PPV, NPV, and accuracy of FDG-PET/CT for the detection of axillary lymph node metastases were 54%, 89%, 77%, 74%, and 75%, respectively. For ultrasound it was 38%, 78%, 54%, 65%, and 62%, respectively. FDG-PET/CT was significantly more accurate than ultrasound for the detection of axillary lymph node metastases (P = 0.019). There was no statistically significant difference between the sensitivity of both modalities (P = 0.0578). FDG-PET/CT detected extra-axillary locoregional lymph node metastases in seven patients (8%) that had not been detected by another imaging modality. Conclusion. Though more accurate compared to ultrasound for evaluating the axillary lymph node status FDG-PET/CT is only as sensitive as

  17. Use of ropivacain and lidocaine for axillary plexus blockade ...

    African Journals Online (AJOL)

    Use of ropivacain and lidocaine for axillary plexus blockade. ... of the juvenile anatomy, psychological barriers, time constraints on block ... children in the age group of 2 to 10 years and undergoing short upper limb surgery. ... Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free To Read ...

  18. Feasibility study of axillary reverse mapping lymphoscintigraphy in carcinoma breast: A concept toward preventing lymphedema

    International Nuclear Information System (INIS)

    Gandhi, Sunny J.; Satish, C.; Sundaram, Palaniswamy Shanmuga; Subramanyam, Padma; Vijaykumar, D. K.

    2016-01-01

    In the surgery of breast cancer, axillary reverse mapping (ARM) is the identification and preservation of arm draining lymph node (ARM node) during an axillary dissection. The assumption is that the ARM node is different from node draining breast and is unlikely to be involved even in the patients with axillary nodal metastases. If we can identify and preserve ARM node using lymphoscintigraphy; morbidity of lymphedema, as seen with axillary dissection, may be avoided. Pathologically proven 50 breast cancer patients undergoing initial surgery (cTx-4, cN0-2, and Mx-0) were included in this study. Less than 37 MBq, 0.5 ml in equally divided doses of filtered 99mTc sulfur colloid was injected intradermally into the second and third web spaces. ARM nodes in the axilla were identified with the help of Gamma Probe intraoperatively; however, their location was noted with the reference to specific anatomical landmarks and sent for histopathological examination after excision. The ARM node was successfully identified in 47/50 cases (sensitivity - 94%). In 40 out of 47 cases (85%), the location of the ARM node was found to lateral to the subscapular pedicle, above the second intercostobrachial nerve and just below the axillary vein. Of the 47 patients in whom ARM node/s were identified, metastasis was noted in 5 of them (10%). Four out of these 5 patients had the pN3 disease. ARM node exists, and it is feasible to identify ARM node using radio isotope technique with an excellent sensitivity. ARM node seems to have a fairly constant location in more than 80% cases. It is involved with metastasis (10% cases) only when there are multiple lymph nodal metastases in the axilla

  19. Positron-Induced Luminescence

    Science.gov (United States)

    Stenson, E. V.; Hergenhahn, U.; Stoneking, M. R.; Pedersen, T. Sunn

    2018-04-01

    We report on the observation that low-energy positrons incident on a phosphor screen produce significantly more luminescence than electrons do. For two different wide-band-gap semiconductor phosphors (ZnS:Ag and ZnO:Zn), we compare the luminescent response to a positron beam with the response to an electron beam. For both phosphors, the positron response is significantly brighter than the electron response, by a factor that depends strongly on incident energy (0-5 keV). Positrons with just a few tens of electron-volts of energy (for ZnS:Ag) or less (for ZnO:Zn) produce as much luminescence as is produced by electrons with several kilo-electron-volts. We attribute this effect to valence band holes and excited electrons produced by positron annihilation and subsequent Auger processes. These results demonstrate a valuable approach for addressing long-standing questions about luminescent materials.

  20. Contemporary management of subclavian and axillary artery injuries-A Western Trauma Association multicenter review.

    Science.gov (United States)

    Waller, Christine J; Cogbill, Thomas H; Kallies, Kara J; Ramirez, Luis D; Cardenas, Justin M; Todd, S Rob; Chapman, Kayla J; Beckman, Marshall A; Sperry, Jason L; Anto, Vincent P; Eriksson, Evert A; Leon, Stuart M; Anand, Rahul J; Pearlstein, Maura; Capano-Wehrle, Lisa; Cothren Burlew, Clay; Fox, Charles J; Cullinane, Daniel C; Roberts, Jennifer C; Harrison, Paul B; Berg, Gina M; Haan, James M; Lightwine, Kelly

    2017-12-01

    Subclavian and axillary artery injuries are uncommon. In addition to many open vascular repairs, endovascular techniques are used for definitive repair or vascular control of these anatomically challenging injuries. The aim of this study was to determine the relative roles of endovascular and open techniques in the management of subclavian and axillary artery injuries comparing hospital outcomes, and long-term limb viability. A multicenter, retrospective review of patients with subclavian or axillary artery injuries from January 1, 2004, to December 31, 2014, was completed at 11 participating Western Trauma Association institutions. Statistical analysis included χ, t-tests, and Cochran-Armitage trend tests. A p value less than 0.05 was significant. Two hundred twenty-three patients were included; mean age was 36 years, 84% were men. An increase in computed tomography angiography and decrease in conventional angiography was observed over time (p = 0.018). There were 120 subclavian and 119 axillary artery injuries. Procedure type was associated with injury grade (p < 0.001). Open operations were performed in 135 (61%) patients, including 93% of greater than 50% circumference lacerations and 83% of vessel transections. Endovascular repairs were performed in 38 (17%) patients; most frequently for pseudoaneurysms. Fourteen (6%) patients underwent a hybrid procedure. Use of endovascular versus open procedures did not increase over the duration of the study (p = 0.248). In-hospital mortality rate was 10%. Graft or stent thrombosis occurred in 7% and graft or stent infection occurred in 3% of patients. Mean follow-up was 1.6 ± 2.4 years (n = 150). Limb salvage was achieved in 216 (97%) patients. The management of subclavian and axillary artery injuries still requires a wide variety of open exposures and procedures, especially for the control of active hemorrhage from more than 50% vessel lacerations and transections. Endovascular repairs were used most often for

  1. Role of [18F]fluorodeoxyglucose positron emission tomography-computed tomography, sonography, and sonographically guided fine-needle aspiration biopsy in the diagnosis of axillary lymph nodes in patients with breast cancer: comparison of diagnostic performance.

    Science.gov (United States)

    Sohn, Yu-Mee; Hong, Il Ki; Han, Kyunghwa

    2014-06-01

    The aim of this study was to compare the diagnostic performance of [(18)F]fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) with that of sonography and sonographically guided fine-needle aspiration (FNA) for determining the preoperative axillary lymph node (ALN) status and to evaluate the factors related to false-negative PET-CT, sonographic, and FNA results in ALN staging of invasive ductal carcinoma. From March 2009 to July 2012, 226 patients had a diagnosis of primary breast cancer. Among these patients, 107 constituted the study population after exclusion of transferred patients and patients with breast cancer other than invasive ductal carcinoma. The diagnostic performance of the modalities was compared with pathologic reports. Univariate and multivariate analyses were used to evaluate the relationship between clinicopathologic factors (symptoms, T stage, hormone receptors, and histologic grade), false-negative results, and true-negative results on PET-CT, sonography, and FNA. Of the 107 patients, 45 (42.1%) had positive results on final pathologic analysis of ALNs. Sonographically guided FNA had a significantly higher specificity, positive predictive value, accuracy, and area under the receiver operating characteristic curve than sonography and PET-CT (P < .01). When sonography and PET-CT were combined, the sensitivity was significantly improved (P = .019) compared with sonography alone. When FNA and PET-CT were combined, the sensitivity and negative predictive value were significantly increased compared with each modality (P < .01). Sonographically guided FNA was found to be an excellent diagnostic tool for preoperative evaluation of the ALN status. To obviate the step of sentinel lymph node biopsy for determining the ALN status, combined evaluation of ALNs by these modalities may be more complementary than the use of a single modality. © 2014 by the American Institute of Ultrasound in Medicine.

  2. Incidental head and neck findings on 18F-fluoro-deoxy-glucose positron emission tomography computed tomography.

    Science.gov (United States)

    Williams, S P; Kinshuck, A J; Williams, C; Dwivedi, R; Wieshmann, H; Jones, T M

    2015-09-01

    The overlapping risk factors for lung and head and neck cancer present a definite risk of synchronous malignant pathology. This is the first study to specifically review incidental positron emission tomography computed tomography findings in the head and neck region in lung carcinoma patients. A retrospective review was performed of all lung cancer patients who underwent positron emission tomography computed tomography imaging over a five-year period (January 2008 - December 2012), identified from the Liverpool thoracic multidisciplinary team database. Six hundred and nine patients underwent positron emission tomography computed tomography imaging over this period. In 76 (12.5 per cent) scans, incidental regions of avid 18F-fluoro-deoxy-glucose uptake were reported in the head and neck region. In the 28 patients who were fully investigated, there were 4 incidental findings of malignancy. In lung cancer patients undergoing investigative positron emission tomography computed tomography scanning, a significant number will also present with areas of clinically significant 18F-fluoro-deoxy-glucose uptake in the head and neck region. Of these, at least 5 per cent may have an undiagnosed malignancy.

  3. Positron emission tomography in the newborn: extensive impairment of regional cerebral blood flow with intraventricular hemorrhage and hemorrhagic intracerebral involvement

    International Nuclear Information System (INIS)

    Volpe, J.J.; Herscovitch, P.; Perlman, J.M.; Raichle, M.E.

    1983-01-01

    Positron emission tomography (PET) now provides the capability of measuring regional cerebral blood flow with high resolution and little risk. In this study, we utilized PET in six premature infants (920 to 1,200 g) with major intraventricular hemorrhage and hemorrhagic intracerebral involvement to measure regional cerebral blood flow during the acute period (5 to 17 days of age). Cerebral blood flow was determined after intravenous injection of H 2 O, labeled with the positron-emitting isotope, 15 O. Findings were similar and dramatic in all six infants. In the area of hemorrhagic intracerebral involvement, little or no cerebral blood flow was detected. However, in addition, surprisingly, a marked two- to fourfold reduction in cerebral blood flow was observed throughout the affected hemisphere, well posterior and lateral to the intracerebral hematoma, including cerebral white matter and, to a lesser extent, frontal, temporal, and parietal cortex. In the one infant studied a second time, ie, at 3 months of age, the extent and severity of the decreased cerebral blood flows in the affected hemisphere were similar to those observed on the study during the neonatal period. At the three autopsies, the affected left hemisphere showed extensive infarction, corroborating the PET scans. These observations, the first demonstration of the use of PET in the determination of regional cerebral blood flow in the newborn, show marked impairments in regional cerebral blood flow in the hemisphere containing an apparently restricted intracerebral hematoma, indicating that the hemorrhagic intracerebral involvement is only a component of a much larger lesion, ischemic in basic nature, ie, an infarction. This large ischemic lesion explains the poor neurologic outcome in infants with intraventricular hemorrhage and hemorrhagic intracerebral involvement

  4. Positron-annihilation-radiation transmission gauge

    International Nuclear Information System (INIS)

    Padawer, G.M.

    1984-01-01

    A radiographic method and apparatus for nondestructively monitoring a specimen for density variations are disclosed. A positron-annihilation-radiation-emitting point source is situated approximately midway along the axis separating two detectors sensitive to positron-annihilation (0.511-MeV photon) radiation. The outputs of the two detectors are fed to an electronic circuit that reckons only time-coincident events that are sensed simultaneously in the two detectors. The specimen to be measured is positioned between the source and one of the detectors such that the cone of detected, i.e., coincident, photons intercepts the region of interest. The number of coincidences that are counted in a preset time interval are recorded, or, alternatively, the coincidence count rate is monitored directly with a ratemeter. A linear scan of the region of interest is performed by the sequential displacing of the source/detectors axis with respect to the measured specimen, or the specimen with respect to the source/detectors axis. The number of coincidence counts accumulated within a preset time interval are recorded for each displacement. The spatial variation of density within the specimen is inferred from corresponding variations in the coincidence count rate

  5. Axillary artery to left anterior descending coronary artery bypass with an externally stented graft: a technical report

    Directory of Open Access Journals (Sweden)

    Salvador Loris

    2008-02-01

    Full Text Available Abstract With the proliferation of minimally invasive cardiac surgery a number of alternative inflow sites for coronary artery bypass grafting have been utilized, especially in higher risk patients. The use of axillary-coronary artery bypass is a safe and effective alternative especially in the case of patients requiring redo coronary revascularization. However, the length and convoluted course of the axillary-coronary vein graft makes is susceptible to twisting, trauma and neointimal hyperplasia. We therefore report a case of an axillary-coronary artery bypass in a high risk patient in which a Dacron conduit was used to externally support and protect the vein graft to the left anterior descending artery. Surgical technique and considerations are presented and discussed.

  6. Positron Factory project

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Sohei; Sunaga, Hiromi; Kaneko, Hirohisa; Kawasuso, Atsuo; Masuno, Shin-ichi; Takizawa, Haruki; Yotsumoto, Keiichi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    We have started drafting a construction program for the Positron Factory, in which linac-based intense monoenergetic positron beams are planned to be applied for materials science, biotechnology and basic physics and chemistry. A technical survey study confirmed the feasibility of manufacturing a dedicated electron linac of 100 kW class with a beam energy of 100 MeV, which will produce a world-highest monoenergetic positron beam of more than 10{sup 10}/sec in intensity. A self-driven rotating converter (electrons to positrons and photons) suitable for the high power electron beam was devised and successfully tested. The practicability of simultaneous extraction of multi-channel monoenergetic positron beams with multiple moderator assemblies, which had been originated on the basis of a Monte Carlo simulation, was demonstrated by an experiment using an electron linac. An efficient moderator structure, which is composed of honeycomb-like assembled moderator foils and reflectors, is also proposed. (author)

  7. Characterization of lacunar defects by positrons annihilation

    International Nuclear Information System (INIS)

    Barthe, M.F.; Corbel, C.; Blondiaux, G.

    2003-01-01

    Among the nondestructive methods for the study of matter, the positrons annihilation method allows to sound the electronic structure of materials by measuring the annihilation characteristics. These characteristics depend on the electronic density as seen by the positon, and on the electron momentums distribution which annihilate with the positon. The positon is sensible to the coulombian potential variations inside a material and sounds preferentially the regions away from nuclei which represent potential wells. The lacunar-type defects (lack of nuclei) represent deep potential wells which can trap the positon up to temperatures close to the melting. This article describes the principles of this method and its application to the characterization of lacunar defects: 1 - positrons: matter probes (annihilation of electron-positon pairs, annihilation characteristics, positrons sources); 2 - positrons interactions in solids (implantation profiles, annihilation states, diffusion and trapping, positon lifetime spectrum: evolution with the concentration of defects); 3 - measurement of annihilation characteristics with two gamma photons (lifetime spectroscopy with the β + 22 Na isotope, spectroscopy of Doppler enlargement of the annihilation line); 4 - determination of the free volume of defects inside or at the surface of materials (annihilation signature in lacunar defects, lacuna, lacunar clusters and cavities, acceptors nature in semiconductors: ionic or lacunar, interface defects, precipitates in alloys); 5 - conclusions. (J.S.)

  8. Quantifying the number of lymph nodes identified in one-stage versus two-stage axillary dissection in breast cancer

    DEFF Research Database (Denmark)

    Damgaard, Olaf E; Jensen, Maj-Britt; Kroman, Niels

    2013-01-01

    To establish whether a different number of lymph nodes is identified in a delayed versus an immediate axillary lymph node dissection (ALND) in breast cancer patients.......To establish whether a different number of lymph nodes is identified in a delayed versus an immediate axillary lymph node dissection (ALND) in breast cancer patients....

  9. KEK-IMSS Slow Positron Facility

    Energy Technology Data Exchange (ETDEWEB)

    Hyodo, T; Wada, K; Yagishita, A; Kosuge, T; Saito, Y; Kurihara, T; Kikuchi, T; Shirakawa, A; Sanami, T; Ikeda, M; Ohsawa, S; Kakihara, K; Shidara, T, E-mail: toshio.hyodo@kek.jp [High Energy Accelerator Research Organization (KEK) 1-1 Oho, Tsukuba, Ibaraki, 305-0801 (Japan)

    2011-12-01

    The Slow Positron Facility at the Institute of Material Structure Science (IMSS) of High Energy Accelerator Research Organization (KEK) is a user dedicated facility with an energy tunable (0.1 - 35 keV) slow positron beam produced by a dedicated 55MeV linac. The present beam line branches have been used for the positronium time-of-flight (Ps-TOF) measurements, the transmission positron microscope (TPM) and the photo-detachment of Ps negative ions (Ps{sup -}). During the year 2010, a reflection high-energy positron diffraction (RHEPD) measurement station is going to be installed. The slow positron generator (converter/ moderator) system will be modified to get a higher slow positron intensity, and a new user-friendly beam line power-supply control and vacuum monitoring system is being developed. Another plan for this year is the transfer of a {sup 22}Na-based slow positron beam from RIKEN. This machine will be used for the continuous slow positron beam applications and for the orientation training of those who are interested in beginning researches with a slow positron beam.

  10. Positron deposition in plasmas by positronium beam ionization and transport of positrons in tokamak plasmas

    International Nuclear Information System (INIS)

    Murphy, T.J.

    1986-11-01

    In a recently proposed positron transport experiment, positrons would be deposited in a fusion plasma by forming a positronium (Ps) beam and passing it through the plasma. Positrons would be deposited as the beam is ionized by plasma ions and electrons. Radial transport of the positrons to the limiter could then be measured by detecting the gamma radiation produced by annihilation of positrons with electrons in the limiter. This would allow measurements of the transport of electron-mass particles and might shed some light on the mechanisms of electron transport in fusion plasmas. In this paper, the deposition and transport of positrons in a tokamak are simulated and the annihilation signal determined for several transport models. Calculations of the expected signals are necessary for the optimal design of a positron transport experiment. There are several mechanisms for the loss of positrons besides transport to the limiter. Annihilation with plasma electrons and reformation of positronium in positron-hydrogen collisions are two such processes. These processes can alter the signal and place restrictions ons on the plasma conditions in which positron transport experiments can be effectively performed

  11. Sentinel Node Biopsy Alone versus Completion Axillary Node Dissection in Node Positive Breast Cancer: Systematic Review and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Rachna Ram

    2014-01-01

    Full Text Available Introduction. There has been recent interest in validity of completion axillary node dissection after a positive sentinel node. This systematic review aims to ascertain if sentinel lymph node dissection alone was noninferior to axillary lymph node dissection for breast cancer patients who have a positive sentinel node. Method. A systematic review of the electronic databases Embase, MEDLINE, and Cochrane Register of Controlled Trials was carried out. Only randomised trials that had patients with positive sentinel node as the study sample were included in the meta-analysis using the reported hazard ratios with a fixed effect model. Results. Three randomised controlled trials and five retrospective studies were identified. The pooled effect for overall survival was HR 0.94, 95% CI [0.79, 1.19], and for disease free survival was HR 0.83, 95% CI [0.60, 1.14]. The reported rates for locoregional recurrence were similar in both groups. The surgical morbidity was found to be significantly more in patients who had underwent axillary dissection. Conclusion. Amongst patients with micrometastasis in the sentinel node, no further axillary dissection is necessary. For patients with macrometastasis in the sentinel node, it is reasonable to consider omitting axillary dissection to avoid the morbidity of the procedure.

  12. Images to visualize the brain. PET: Positron Emission Tomography

    International Nuclear Information System (INIS)

    1992-01-01

    Diagnosis instrument and research tool, Positron Emission Tomography permits advanced technological developments on positron camera, on molecule labelling and principally on very complex 3D image processing. Cyceron Centre in Caen-France works on brain diseases and try to understand the mechanism of observed troubles and to assess the treatment efficiency with PET. Service Hospitalier Frederic Joliot of CEA-France establishes a mapping of cognitive functions in PET as vision areas, anxiety regions, brain organization of language, different attention forms, voluntary actions and motor functions

  13. Axillary silicone lymphadenopathy presenting with a lump and altered sensation in the breast: a case report

    Directory of Open Access Journals (Sweden)

    Adams Simon T

    2009-03-01

    Full Text Available Abstract Introduction Silicone lymphadenopathy is a rare but recognised complication of procedures involving the use of silicone. It has a poorly understood mechanism but is thought to occur following the transportation of silicone particles from silicone-containing prostheses to lymph nodes by macrophages. Case presentation We report of a case involving a 35-year-old woman who presented to the breast clinic with a breast lump and altered sensation below her left nipple 5 years after bilateral cosmetic breast augmentations. A small lump was detected inferior to the nipple but clinical examination and initial ultrasound investigation showed both implants to be intact. However, mammography and magnetic resonance imaging of both breasts revealed both intracapsular and extracapsular rupture of the left breast prosthesis. The patient went on to develop a flu-like illness and tender lumps in the left axilla and right mastoid regions. An excision biopsy of the left axillary lesion and replacement of the ruptured implant was performed. Subsequent histological analysis showed that the axillary lump was a lymph node containing large amounts of silicone. Conclusion The exclusion of malignancy remains the priority when dealing with lumps in the breast or axilla. Silicone lymphadenopathy should however be considered as a differential diagnosis in patients in whom silicone prostheses are present.

  14. The surgical importance of an axillary arch in sentinel node biopsy.

    LENUS (Irish Health Repository)

    Ridgway, P F

    2011-03-01

    When Carl Langer described the aberrant axillary arch in 1846 its relevance in sentinel node biopsy (SNB) surgery could not have been contemplated. The authors define an incidence and elucidate relevance of the arch in SNB of the axilla.

  15. Attenuation correction with region growing method used in the positron emission mammography imaging system

    Science.gov (United States)

    Gu, Xiao-Yue; Li, Lin; Yin, Peng-Fei; Yun, Ming-Kai; Chai, Pei; Huang, Xian-Chao; Sun, Xiao-Li; Wei, Long

    2015-10-01

    The Positron Emission Mammography imaging system (PEMi) provides a novel nuclear diagnosis method dedicated for breast imaging. With a better resolution than whole body PET, PEMi can detect millimeter-sized breast tumors. To address the requirement of semi-quantitative analysis with a radiotracer concentration map of the breast, a new attenuation correction method based on a three-dimensional seeded region growing image segmentation (3DSRG-AC) method has been developed. The method gives a 3D connected region as the segmentation result instead of image slices. The continuity property of the segmentation result makes this new method free of activity variation of breast tissues. The threshold value chosen is the key process for the segmentation method. The first valley in the grey level histogram of the reconstruction image is set as the lower threshold, which works well in clinical application. Results show that attenuation correction for PEMi improves the image quality and the quantitative accuracy of radioactivity distribution determination. Attenuation correction also improves the probability of detecting small and early breast tumors. Supported by Knowledge Innovation Project of The Chinese Academy of Sciences (KJCX2-EW-N06)

  16. Study of SiO2-Si and metal-oxide-semiconductor structures using positrons

    Science.gov (United States)

    Leung, T. C.; Asoka-Kumar, P.; Nielsen, B.; Lynn, K. G.

    1993-01-01

    Studies of SiO2-Si and metal-oxide-semiconductor (MOS) structures using positrons are summarized and a concise picture of the present understanding of positrons in these systems is provided. Positron annihilation line-shape S data are presented as a function of the positron incident energy, gate voltage, and annealing, and are described with a diffusion-annihilation equation for positrons. The data are compared with electrical measurements. Distinct annihilation characteristics were observed at the SiO2-Si interface and have been studied as a function of bias voltage and annealing conditions. The shift of the centroid (peak) of γ-ray energy distributions in the depletion region of the MOS structures was studied as a function of positron energy and gate voltage, and the shifts are explained by the corresponding variations in the strength of the electric field and thickness of the depletion layer. The potential role of the positron annihilation technique as a noncontact, nondestructive, and depth-sensitive characterization tool for the technologically important, deeply buried interface is shown.

  17. Study of SiO2-Si and metal-oxide-semiconductor structures using positrons

    International Nuclear Information System (INIS)

    Leung, T.C.; Asoka-Kumar, P.; Nielsen, B.; Lynn, K.G.

    1993-01-01

    Studies of SiO 2 -Si and metal-oxide-semiconductor (MOS) structures using positrons are summarized and a concise picture of the present understanding of positrons in these systems is provided. Positron annihilation line-shape S data are presented as a function of the positron incident energy, gate voltage, and annealing, and are described with a diffusion-annihilation equation for positrons. The data are compared with electrical measurements. Distinct annihilation characteristics were observed at the SiO 2 -Si interface and have been studied as a function of bias voltage and annealing conditions. The shift of the centroid (peak) of γ-ray energy distributions in the depletion region of the MOS structures was studied as a function of positron energy and gate voltage, and the shifts are explained by the corresponding variations in the strength of the electric field and thickness of the depletion layer. The potential role of the positron annihilation technique as a noncontact, nondestructive, and depth-sensitive characterization tool for the technologically important, deeply buried interface is shown

  18. A coincidental variation of the axillary artery: the brachioradial artery and the aberrant posterior humeral circumflex artery passing under the tendon of the latissimus dorsi muscle

    Directory of Open Access Journals (Sweden)

    Marek Konarik

    2014-09-01

    Full Text Available A case of anomalous terminal branching of the axillary artery was encountered and described in a left upper limb of a male cadaver. A series of 214 upper limbs of Caucasian race was dissected. A variant artery, stemming from the very end of the axillary artery followed a superficial course distally. It passed the cubital fossa, ran on the lateral side of the forearm as usual radial artery, crossed ventrally to the palm and terminated in the deep palmar arch. This vessel is a case of the brachioradial artery (incorrectly termed as the “radial artery with high origin”. Moreover, it was associated with another variation, concerning the aberrant posterior humeral circumflex artery passing under the tendon of the latissimus dorsi muscle. The anatomical knowledge of the axillary region is essential for radiodiagnostic, surgical and traumatologic procedures. The superficially located artery brings an elevated danger of heavy bleeding in all unexpected situations, its variant branching can cause problems in radial catheterization procedures and the anomalously coursing other arterial variant poses an elevated danger in surgical procedures concerning the surgical neck of humerus.

  19. Measurement of regional extravascular lung density and of pulmonary blood volume with positron emitting isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Larock, M.P.; Quaglia, L.; Lamotte, D.; De Landsheere, C.; Del Fiore, G.; Chevigne, M.; Peters, J.M.; Rigo, P. (Universite de Liege (Belgium))

    1982-01-01

    Studies of pulmonary blood volume changes with exercise can be performed after labelling of the blood pool by /sup 11/CO inhalation. Positron transaxial tomography permits the quantitative study of density distribution of the chest and of the pulmonary blood volume. This paper represents our preliminary experience with these techniques on models and control patients. We have first verified the linearity of transmission for density distribution below one. The tomographic examination first records a transmission image, then an emission image on the same section. We next normalize emission and transmission values on a region of unit density corresponding to blood: then we substract the emission from the transmission values to measure the extravascular pulmonary density. With crystal probes we record pulmonary blood volume variations before, during and after exercise. Peripheral hemodynamic variations explain the change recorded at the begining and at the end of exercise. Combination of these two techniques should help us to better study the importance of the acute changes in the ''formation'' of pulmonary oedema and its influence on regional pulmonary blood volume.

  20. The sensitivity of pre-operative axillary staging in breast cancer: comparison of invasive lobular and ductal carcinoma.

    Science.gov (United States)

    Topps, A; Clay, V; Absar, M; Howe, M; Lim, Y; Johnson, R; Bundred, N

    2014-07-01

    Axillary ultrasound (AUS) with fine-needle aspiration (FNA) biopsy of abnormal lymph nodes is important for pre-operative staging and planning the surgical management of the axilla. Invasive lobular carcinoma (ILC) metastases are thought to be difficult to detect because the cells are small and on cytology resemble lymphocytes. To investigate this we directly compared the sensitivity of pre-operative axillary staging between ILC and invasive ductal carcinoma (IDC). Consecutive patients that presented in a single breast unit with pure IDC between April 2005 and December 2006 and pure ILC between January 2008 and December 2012 were retrospectively identified from pathology records. Pre-operative axillary ultrasound and FNA biopsy results were compared with post-operative histopathology from the sentinel node biopsy (SNB) or axillary lymph node dissection (ALND). A total of 275 and 142 axillae were identified in the IDC and ILC groups respectively. In the node positive patients there was no significant difference in the sensitivity of AUS (IDC vs. ILC; 58.7% vs. 52.8%). However, there was a significant difference in the sensitivity of ultrasound-guided FNA biopsy of abnormal nodes (IDC vs. ILC; 98.4% vs. 53.6%; p < 0.001). AUS has comparative sensitivities between IDC and ILC populations. In contrast, FNA biopsy of abnormal axillary nodes is clearly less sensitive in the ILC group. In these patients, who have abnormal AUS, we suggest that a core biopsy is required to improve the pre-operative staging and prevent unnecessary surgical procedures. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Synthesis and characterization of magnesium oxide nanocrystallites and probing the vacancy-type defects through positron annihilation studies

    Science.gov (United States)

    Das, Anjan; Mandal, Atis Chandra; Roy, Soma; Prashanth, Pendem; Ahamed, Sk Izaz; Kar, Subhrasmita; Prasad, Mithun S.; Nambissan, P. M. G.

    2016-09-01

    Magnesium oxide nanocrystallites exhibit certain abnormal characteristics when compared to those of other wide band gap oxide semiconductors in the sense they are most prone to water absorption and formation of a hydroxide layer on the surface. The problem can be rectified by heating and pure nanocrystallites can be synthesized with controllable sizes. Inevitably the defect properties are distinctly divided between two stages, the one with the hydroxide layer (region I) and the other after the removal of the layer by annealing (region II). The lattice parameters, the optical band gap and even the positron annihilation characteristics are conspicuous by their distinct behavior in the two stages of the surface configurations of nanoparticles. While region I was specific with the formation of positronium-hydrogen complexes that drastically altered the defect-specific positron lifetimes, pick-off annihilation of orthopositronium atoms marked region II. The vacancy clusters within the nanocrystallites also trapped positrons. They agglomerated due to the effect of the higher temperatures and resulted in the growth of the nanocrystallites. The coincidence Doppler broadening spectroscopic measurements supported these findings and all the more indicated the trapping of positrons additionally into the neutral divacancies and negatively charged trivacancies. This is apart from the Mg2+ monovacancies which acted as the dominant trapping centers for positrons.

  2. Impact of axillary nodal metastases on lymphatic mapping and sentinel lymph node identification rate in patients with early stage breast cancer

    International Nuclear Information System (INIS)

    Pelosi, Ettore; Ala, Ada; Bussone, Riccardo; Bello, Marilena; Douroukas, Anastasios; Varetto, Teresio; Migliaretti, Giuseppe; Berardengo, Ester; Bisi, Gianni

    2005-01-01

    The aim of this study was to define the impact of the presence of axillary nodal metastases on lymphatic mapping and sentinel lymph node (SLN) identification rate in patients with early breast cancer. Two hundred and forty-six lymphatic mapping procedures were performed with both labelled nanocolloid and blue dye, followed by SLN biopsy and/or complete axillary dissection. The following parameters were recorded: patient's age, tumour laterality and location, tumour size, tumour histology, tumour stage, tumour grade, lymphovascular invasion, radiotracer injection site (subdermal-peritumoural/peri-areolar), SLN visualisation at lymphoscintigraphy, SLN metastases (presence/absence, size) and other axillary metastases (presence/absence, number). Discriminant analysis was used to analyse the data. SLNs were identified by labelled nanocolloid alone in 94.7% of tumours, by blue dye alone in 93.5% and by the combined technique in 99.2%. Discriminant analysis showed the gamma probe SLN identification rate to be significantly limited by the presence of axillary nodal metastases. In particular, the size of SLN metastases and the number of other axillary metastases were the most important variables in reducing the gamma probe SLN identification rate (p=0.004 and p=0.002, respectively). On the other hand, high tumour grade was the only parameter limiting the blue dye SLN identification rate. The accuracy of lymphatic mapping with labelled nanocolloid is limited by the presence of axillary nodal metastases, and particularly by the degree of SLN tumoural invasion and the presence and number of other axillary nodal metastases. Neither of these elements seems to interfere with the blue dye identification rate. The combination of the two tracers maximises the SLN identification rate. (orig.)

  3. Impact of axillary nodal metastases on lymphatic mapping and sentinel lymph node identification rate in patients with early stage breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Pelosi, Ettore [Ospedale S. Giovanni Battista, S.C.D.U. Medicina Nucleare 2, Turin (Italy); Universita Torino, Dottorato di Ricerca Radioimmunolocalizzazione dei Tumori Umani, Turin (Italy); Ala, Ada; Bussone, Riccardo [Ospedale S. Giovanni Battista, Reparto di Chirurgia Oncologica 10, Turin (Italy); Bello, Marilena; Douroukas, Anastasios; Varetto, Teresio [Ospedale S. Giovanni Battista, S.C.D.U. Medicina Nucleare 2, Turin (Italy); Migliaretti, Giuseppe [Universita di Torino, Dipartimento di Sanita Pubblica e Microbiologia, Turin (Italy); Berardengo, Ester [Ospedale S. Giovanni Battista, Servizio di Anatomia Patologica 4, Turin (Italy); Bisi, Gianni [Ospedale S. Giovanni Battista, S.C.D.U. Medicina Nucleare 2, Turin (Italy); Universita di Torino, Dipartimento di Medicina Interna, SCDU Medicina Nucleare 2, Turin (Italy)

    2005-08-01

    The aim of this study was to define the impact of the presence of axillary nodal metastases on lymphatic mapping and sentinel lymph node (SLN) identification rate in patients with early breast cancer. Two hundred and forty-six lymphatic mapping procedures were performed with both labelled nanocolloid and blue dye, followed by SLN biopsy and/or complete axillary dissection. The following parameters were recorded: patient's age, tumour laterality and location, tumour size, tumour histology, tumour stage, tumour grade, lymphovascular invasion, radiotracer injection site (subdermal-peritumoural/peri-areolar), SLN visualisation at lymphoscintigraphy, SLN metastases (presence/absence, size) and other axillary metastases (presence/absence, number). Discriminant analysis was used to analyse the data. SLNs were identified by labelled nanocolloid alone in 94.7% of tumours, by blue dye alone in 93.5% and by the combined technique in 99.2%. Discriminant analysis showed the gamma probe SLN identification rate to be significantly limited by the presence of axillary nodal metastases. In particular, the size of SLN metastases and the number of other axillary metastases were the most important variables in reducing the gamma probe SLN identification rate (p=0.004 and p=0.002, respectively). On the other hand, high tumour grade was the only parameter limiting the blue dye SLN identification rate. The accuracy of lymphatic mapping with labelled nanocolloid is limited by the presence of axillary nodal metastases, and particularly by the degree of SLN tumoural invasion and the presence and number of other axillary nodal metastases. Neither of these elements seems to interfere with the blue dye identification rate. The combination of the two tracers maximises the SLN identification rate. (orig.)

  4. A transmission positron microscope and a scanning positron microscope being built at KEK, Japan

    International Nuclear Information System (INIS)

    Doyama, M.; Inoue, M.; Kogure, Y.; Kurihara, T.; Yagishita, A.; Shidara, T.; Nakahara, K.; Hayashi, Y.; Yoshiie, T.

    2001-01-01

    This paper reports the plans of positron microscopes being built at KEK (High Energy Accelerator Research Organization), Tsukuba, Japan improving used electron microscopes. The kinetic energies of positron produced by accelerators or by nuclear decays have not a unique value but show a spread over in a wide range. Positron beam will be guided near electron microscopes, a transmission electron microscope (JEM100S) and a scanning electron microscope (JSM25S). Positrons are slowed down by a tungsten foil, accelerated and focused on a nickel sheet. The monochromatic focused beam will be injected into an electron microscope. The focusing of positrons and electrons is achieved by magnetic system of the electron microscopes. Imaging plates are used to record positron images for the transmission electron microscope. (orig.)

  5. Positron studies in catalysis research

    International Nuclear Information System (INIS)

    1994-01-01

    During the past eight months, the authors have made progress in several areas relevant to the eventual use of positron techniques in catalysis research. They have come closer to the completion of their positron microscope, and at the same time have performed several studies in their non-microscopic positron spectrometer which should ultimately be applicable to catalysis. The current status of the efforts in each of these areas is summarized in the following sections: Construction of the positron microscope (optical element construction, data collection software, and electronic sub-assemblies); Doppler broadening spectroscopy of metal silicide; Positron lifetime spectroscopy of glassy polymers; and Positron lifetime measurements of pore-sizes in zeolites

  6. 22 Na positron source for annihilation positron spectroscopy

    International Nuclear Information System (INIS)

    Cimpeanu, Catalina; Craciun, L.; Dragulescu, E.; Dudu, D.; Racolta, P. M.; Voiculescu, Dana; Miron, N.

    2003-01-01

    To extend the nuclear physics applications and to perform the study of vacancy - type defects in metals, semiconductors, polymers etc., we decided to promote positron annihilation techniques. In order to achieve this goal we started a project of dedicated positron sources produced at the IFIN-HH U-120 Cyclotron. We have used the nuclear reaction: 24 Mg(d,α) 22 Na with deuterons of 13 MeV energy. The paper presents the main characteristics of this procedure, as follows: general conditions asked for 22 NaCl sources, reactive chamber and characteristics of Mg target, parameters for the irradiation, radiochemical procedures for separating Na from Mg after the irradiation and geometrical or mechanical requirements for dedicated NaCl source for positron annihilation spectrometry. In the e + lifetime measurements, the e + end - start signals may be obtained from prompt γ -quanta emitted from the NaCl source (1. 275 MeV photons). The 22 NaCl stock solution obtained by radiochemical separation will be kept in quartz sealed ampoules in dry places and will be dropped between the study materials before the use in positron spectrometry. (authors)

  7. Breast-axillary complex in HIV/AIDS patients | Eni | Nigerian Journal ...

    African Journals Online (AJOL)

    This is a report of three cases seen and managed by the authors. : Three adult female patients presented with progressively increasing axillary and ipsilateral breast swellings. They also had associated fevers and weight loss. Their main concern had been development of breast cancer. One of the patients was a known ...

  8. Molecular Heterogeneity in Primary Breast Carcinomas and Axillary Lymph Node Metastases Assessed by Genomic Fingerprinting Analysis

    Science.gov (United States)

    Ellsworth, Rachel E; Toro, Allyson L; Blackburn, Heather L; Decewicz, Alisha; Deyarmin, Brenda; Mamula, Kimberly A; Costantino, Nicholas S; Hooke, Jeffrey A; Shriver, Craig D; Ellsworth, Darrell L

    2015-01-01

    Molecular heterogeneity within primary breast carcinomas and among axillary lymph node (LN) metastases may impact diagnosis and confound treatment. In this study, we used short tandem repeated sequences to assess genomic heterogeneity and to determine hereditary relationships among primary tumor areas and regional metastases from 30 breast cancer patients. We found that primary carcinomas were genetically heterogeneous and sampling multiple areas was necessary to adequately assess genomic variability. LN metastases appeared to originate at different time periods during disease progression from different sites of the primary tumor and the extent of genomic divergence among regional metastases was associated with a less favorable patient outcome (P = 0.009). In conclusion, metastasis is a complex process influenced by primary tumor heterogeneity and variability in the timing of dissemination. Genomic variation in primary breast tumors and regional metastases may negatively impact clinical diagnostics and contribute to therapeutic resistance. PMID:26279627

  9. Molecular Heterogeneity in Primary Breast Carcinomas and Axillary Lymph Node Metastases Assessed by Genomic Fingerprinting Analysis

    Directory of Open Access Journals (Sweden)

    Rachel E. Ellsworth

    2015-01-01

    Full Text Available Molecular heterogeneity within primary breast carcinomas and among axillary lymph node (LN metastases may impact diagnosis and confound treatment. In this study, we used short tandem repeated sequences to assess genomic heterogeneity and to determine hereditary relationships among primary tumor areas and regional metastases from 30 breast cancer patients. We found that primary carcinomas were genetically heterogeneous and sampling multiple areas was necessary to adequately assess genomic variability. LN metastases appeared to originate at different time periods during disease progression from different sites of the primary tumor and the extent of genomic divergence among regional metastases was associated with a less favorable patient outcome ( P = 0.009. In conclusion, metastasis is a complex process influenced by primary tumor heterogeneity and variability in the timing of dissemination. Genomic variation in primary breast tumors and regional metastases may negatively impact clinical diagnostics and contribute to therapeutic resistance.

  10. Slow positron applications at slow positron facility of institute of materials structure science, KEK

    Science.gov (United States)

    Hyodo, Toshio; Mochizuki, Izumi; Wada, Ken; Toge, Nobukazu; Shidara, Tetsuo

    2018-05-01

    Slow Positron Facility at High Energy Accelerator Research Organization (KEK) is a user dedicated facility with an energy-tunable (0.1 - 35 keV) slow positron beam created by a dedicated ˜ 50 MeV linac. It operates in a short pulse (width 1-12 ns, variable, 5×106 e+/s) and a long pulse (width 1.2 µs, 5×107 e+/s) modes of 50 Hz. High energy positrons from pair creation are moderated by reemission after thermalization in W foils. The reemitted positrons are then electrostatically accelerated to a desired energy up to 35 keV and magnetically transported. A pulse-stretching section (pulse stretcher) is installed in the middle of the beamline. It stretches the slow positron pulse for the experiments where too many positrons annihilating in the sample at the same time has to be avoided. Four experiment stations for TRHEPD (total-reflection high-energy positron diffraction), LEPD (low-energy positron diffraction), Ps- (positronium negative ion), and Ps-TOF (positronium time-of-flight) experiments are connected to the beamline branches, SPF-A3, SPF-A4, SPF-B1 and SPF-B2, respectively. Recent results of these stations are briefly described.

  11. Positronics of radiation-induced effects in chalcogenide glassy semiconductors

    International Nuclear Information System (INIS)

    Shpotyuk, O.; Kozyukhin, S. A.; Shpotyuk, M.; Ingram, A.; Szatanik, R.

    2015-01-01

    Using As 2 S 3 and AsS 2 glasses as an example, the principal possibility of using positron annihilation spectroscopy methods for studying the evolution of the free volume of hollow nanoobjects in chalcogenide glassy semiconductors exposed to radiation is shown. The results obtained by measurements of the positron annihilation lifetime and Doppler broadening of the annihilation line in reverse chronological order are in full agreement with the optical spectroscopy data in the region of the fundamental absorption edge, being adequately described within coordination defect-formation and physical-aging models

  12. Positronics of radiation-induced effects in chalcogenide glassy semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Shpotyuk, O. [Scientific Research Company “Carat” (Ukraine); Kozyukhin, S. A., E-mail: sergkoz@igic.ras.ru [Russian Academy of Sciences, Kurnakov Institute of General and Inorganic Chemistry (Russian Federation); Shpotyuk, M. [Scientific Research Company “Carat” (Ukraine); Ingram, A. [Opole Technical University (Poland); Szatanik, R. [Opole University (Poland)

    2015-03-15

    Using As{sub 2}S{sub 3} and AsS{sub 2} glasses as an example, the principal possibility of using positron annihilation spectroscopy methods for studying the evolution of the free volume of hollow nanoobjects in chalcogenide glassy semiconductors exposed to radiation is shown. The results obtained by measurements of the positron annihilation lifetime and Doppler broadening of the annihilation line in reverse chronological order are in full agreement with the optical spectroscopy data in the region of the fundamental absorption edge, being adequately described within coordination defect-formation and physical-aging models.

  13. Ion-acoustic nonlinear periodic waves in electron-positron-ion plasma

    International Nuclear Information System (INIS)

    Chawla, J. K.; Mishra, M. K.

    2010-01-01

    Ion-acoustic nonlinear periodic waves, namely, ion-acoustic cnoidal waves have been studied in electron-positron-ion plasma. Using reductive perturbation method and appropriate boundary condition for nonlinear periodic waves, the Korteweg-de Vries (KdV) equation is derived for the system. The cnoidal wave solution of the KdV equation is discussed in detail. It is found that the frequency of the cnoidal wave is a function of its amplitude. It is also found that the positron concentration modifies the properties of the ion-acoustic cnoidal waves. The existence regions for ion-acoustic cnoidal wave in the parameters space (p,σ), where p and σ are the positron concentration and temperature ratio of electron to positron, are discussed in detail. In the limiting case these ion-acoustic cnoidal waves reduce to the ion-acoustic soliton solutions. The effect of other parameters on the characteristics of the nonlinear periodic waves is also discussed.

  14. Positron effective mass in silicon

    International Nuclear Information System (INIS)

    Panda, B.K.; Shan, Y.Y.; Fung, S.; Beling, C.D.

    1995-01-01

    The positron effective mass in Si is obtained from the first-principles calculations along various crystallographic directions. The effect of electron-positron correlation on the band mass is examined in this work. A positron pseudopotential scheme is worked out to calculate the isotropic band mass without explicitly solving the band energy. The effective mass 1.46m obtained as a sum of band mass and the positron-plasmon interaction compares very well with 1.5m obtained from the positron mobility data

  15. Positron emission tomography

    International Nuclear Information System (INIS)

    Iio, Masahiro

    1982-01-01

    Utilization of positron emission tomography was reviewed in relation to construction and planned construction of small-size medical cyclotrons, planned construction of positron cameras and utilization of short-lived radionuclides. (Chiba, N.)

  16. Positron computed tomography studies: potential use in neuro-psychiatric disorders

    International Nuclear Information System (INIS)

    Yamasaki, T.; Tateno, Y.; Shishido, F.

    1982-01-01

    Since November 1979 positron computed tomography (PCT) have been performed to study subjects in a variety of states and varied disorders, using 13 NH 3 , 11 CO and 18 F-2-fluorodeoxyglucose ( 18 FDG) at the National Institute of Radiological Sciences, Japan. In neuro-psychiatric studies, normal volunteers and patients including schizophrenia, affective disorders, Alzheimer's disease, Huntigton's chorea were studied. Tomographic images were analyzed by visual observation and activity counting in regions selected. In degenerative disorder group, 18 FDG revealed decreased accumulation in target areas, whereas in functional psychosis group both in medicating patients and in non-medicated patients, positron images were basically similar to normal controls. Especially in a patient with Huntington's chorea, 18 FDG accumulation in striatal region was markedly decreased without significant change in the same region on X-ray CT and 13 NH 3 PCT

  17. Generation of a high-brightness pulsed positron beam for the Munich scanning positron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Piochacz, Christian

    2009-11-20

    Within the present work the prerequisites for the operation of the Munich scanning positron microscope (SPM) at the high intense neutron induced positron source Munich (NEPOMUC) were established. This was accomplished in two steps: Firstly, a re-moderation device was installed at the positron beam facility NEPOMUC, which enhances the brightness of the positron beam for all connected experiments. The second step was the design, set up and initial operation of the SPM interface for the high efficient conversion of the continuous beam into a bunched beam. The in-pile positron source NEPOMUC creates a positron beam with a diameter of typically 7 mm, a kinetic energy of 1 keV and an energy spread of 50 eV. The NEPOMUC re-moderator generates from this beam a low energy positron beam (20 - 200 eV) with a diameter of less than 2 mm and an energy spread well below 2.5 eV. This was achieved with an excellent total efficiency of 6.55{+-}0.25 %. The re-moderator was not only the rst step to implement the SPM at NEPOMUc, it enables also the operation of the pulsed low energy positron beam system (PLEPS). Within the present work, at this spectrometer rst positron lifetime measurements were performed, which revealed the defect types of an ion irradiated uranium molybdenum alloy. Moreover, the instruments which were already connected to the positron beam facility bene ts considerably of the high brightness enhancement. In the new SPM interface an additional re-moderation stage enhances the brightness of the beam even more and will enable positron lifetime measurements at the SPM with a lateral resolution below 1 {mu}m. The efficiency of the re-moderation process in this second stage was 24.5{+-}4.5 %. In order to convert high efficiently the continuous positron beam into a pulsed beam with a repetition rate of 50 MHz and a pulse duration of less than 50 ps, a sub-harmonic pre-bucher was combined with two sine wave bunchers. Furthermore, the additional re-moderation stage of the

  18. Generation of a high-brightness pulsed positron beam for the Munich scanning positron microscope

    International Nuclear Information System (INIS)

    Piochacz, Christian

    2009-01-01

    Within the present work the prerequisites for the operation of the Munich scanning positron microscope (SPM) at the high intense neutron induced positron source Munich (NEPOMUC) were established. This was accomplished in two steps: Firstly, a re-moderation device was installed at the positron beam facility NEPOMUC, which enhances the brightness of the positron beam for all connected experiments. The second step was the design, set up and initial operation of the SPM interface for the high efficient conversion of the continuous beam into a bunched beam. The in-pile positron source NEPOMUC creates a positron beam with a diameter of typically 7 mm, a kinetic energy of 1 keV and an energy spread of 50 eV. The NEPOMUC re-moderator generates from this beam a low energy positron beam (20 - 200 eV) with a diameter of less than 2 mm and an energy spread well below 2.5 eV. This was achieved with an excellent total efficiency of 6.55±0.25 %. The re-moderator was not only the rst step to implement the SPM at NEPOMUc, it enables also the operation of the pulsed low energy positron beam system (PLEPS). Within the present work, at this spectrometer rst positron lifetime measurements were performed, which revealed the defect types of an ion irradiated uranium molybdenum alloy. Moreover, the instruments which were already connected to the positron beam facility bene ts considerably of the high brightness enhancement. In the new SPM interface an additional re-moderation stage enhances the brightness of the beam even more and will enable positron lifetime measurements at the SPM with a lateral resolution below 1 μm. The efficiency of the re-moderation process in this second stage was 24.5±4.5 %. In order to convert high efficiently the continuous positron beam into a pulsed beam with a repetition rate of 50 MHz and a pulse duration of less than 50 ps, a sub-harmonic pre-bucher was combined with two sine wave bunchers. Furthermore, the additional re-moderation stage of the SPM

  19. Positron Annihilation Characteristics in Polymer Composites

    International Nuclear Information System (INIS)

    Ashry, A.; Hemdan, M.; Ismail, A.; Ismail, H.; Osman, H.

    2000-01-01

    The effect of incorporation of GPF-carbon black on the free volume properties as well as the Doppler broadening parameters has been investigated for Natural rubber/Styrene Butadiene rubber (NR/SBR) blends. It is seen that, the free volume decreases with increasing of the GPF-black. Besides, as the size of the free volume decreases, the W-parameter, which corresponds to high momentum region, decreases and the S-parameter, which corresponds to low momentum one, shows an opposite behaviour. Furthermore, the d.c.electrical conductivity, mechanical and swelling behavior have been also investigated. Positron Annihilation Lifetime (PAL) and Doppler Broadening of the Annihilation Radiation (DBAR) results are compared with the other physical parameters measured. The analysis of positron annihilation parameters introduces a trusted support for the interpretations of the other macroscopic physical properties

  20. A quantitative index of regional blood flow in canine myocardium derived noninvasively with N-13 ammonia and dynamic positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Nienaber, C.A.; Ratib, O.; Gambhir, S.S.; Krivokapich, J.; Huang, S.C.; Phelps, M.E.; Schelbert, H.R. (Univ. of California, Los Angeles School of Medicine (USA))

    1991-01-01

    To derive a quantitative index of regional myocardial blood flow, the arterial input function of the flow tracer N-13 ammonia and the regional myocardial N-13 activity concentrations were noninvasively determined in 29 experiments in eight dogs. N-13 ammonia was administered intravenously and cross-sectional images were acquired dynamically using an ECAT III positron emission tomograph with an effective in-plane resolution of 13.46 mm full-width half-maximum. Time-activity curves were derived from the serial images by assigning regions of interest to the left ventricular myocardium and left ventricular blood pool. Tracer net extractions were estimated from the myocardial time-activity concentrations at various times after tracer injection and the integral of the arterial input function. Myocardial blood flow was altered by intravenous dipyridamole, morphine, propranolol and partial or complete occlusion of the left anterior descending coronary artery, and ranged from 9 to 860 ml/min per 100 g. Estimates of tracer net extractions were most accurate when determined from the myocardial N-13 activity concentrations at 60 s divided by the integral of the arterial input function to that time. These estimates correlated with regional myocardial blood flows determined independently by the microsphere technique by y = x (1 - 0.64(e-114/x); SEE = 22.9; r = 0.94). First pass extraction fractions of N-13 ammonia determined noninvasively with this approach declined with higher flows in a nonlinear fashion and were similar to those determined invasively by direct intracoronary N-13 ammonia injections. The findings indicate that an accurate index of regional myocardial blood flow can be obtained noninvasively by high temporal sampling of arterial and myocardial tracer activity concentrations with positron emission tomography.

  1. Ultrasound-Guided Single-Injection Infraclavicular Block Versus Ultrasound-Guided Double-Injection Axillary Block: A Noninferiority Randomized Controlled Trial.

    Science.gov (United States)

    Boivin, Ariane; Nadeau, Marie-Josée; Dion, Nicolas; Lévesque, Simon; Nicole, Pierre C; Turgeon, Alexis F

    2016-01-01

    Single-injection ultrasound-guided infraclavicular block is a simple, reliable, and effective technique. A simplified double-injection ultrasound-guided axillary block technique with a high success rate recently has been described. It has the advantage of being performed in a superficial and compressible location, with a potentially improved safety profile. However, its effectiveness in comparison with single-injection infraclavicular block has not been established. We hypothesized that the double-injection ultrasound-guided axillary block would show rates of complete sensory block at 30 minutes noninferior to the single-injection ultrasound-guided infraclavicular block. After approval by our research ethics committee and written informed consent, adults undergoing distal upper arm surgery were randomized to either group I, ultrasound-guided single-injection infraclavicular block, or group A, ultrasound-guided double-injection axillary block. In group I, 30 mL of 1.5% mepivacaine was injected posterior to the axillary artery. In group A, 25 mL of 1.5% mepivacaine was injected posteromedial to the axillary artery, after which 5 mL was injected around the musculocutaneous nerve. Primary outcome was the rate of complete sensory block at 30 minutes. Secondary outcomes were the onset of sensory and motor blocks, surgical success rates, performance times, and incidence of complications. All outcomes were assessed by a blinded investigator. The noninferiority of the double-injection ultrasound-guided axillary block was considered if the limits of the 90% confidence intervals (CIs) were within a 10% margin of the rate of complete sensory block of the infraclavicular block. At 30 minutes, the rate of complete sensory block was 79% in group A (90% CI, 71%-85%) compared with 91% in group I (90% CI, 85%-95%); the upper limit of CI of group A is thus included in the established noninferiority margin of 10%. The rate of complete sensory block was lower in group A (proportion

  2. Comparison between 18F-Fluorodeoxyglucose Positron Emission Tomography and Sentinel Lymph Node Biopsy for Regional Lymph Nodal Staging in Patients with Melanoma: A Review of the Literature

    International Nuclear Information System (INIS)

    Mirk, Paoletta; Treglia, Giorgio; Salsano, Marco; Basile, Pietro; Giordano, Alessandro; Bonomo, Lorenzo

    2011-01-01

    Aim. to compare 18 F-Fluorodeoxyglucose positron emission tomography (FDG-PET) to sentinel lymph node biopsy (SLNB) for regional lymph nodal staging in patients with melanoma. Methods. We performed a literature review discussing original articles which compared FDG-PET to SLNB for regional lymph nodal staging in patients with melanoma. Results and Conclusions. There is consensus in the literature that FDG-PET cannot replace SLNB for regional lymph nodal staging in patients with melanoma

  3. Breast and Axillary Lymph Nodes Metastasis five years after Radical ...

    African Journals Online (AJOL)

    Breast is an uncommon and rare site for metastasis. Primary and secondary tumors of the breast need to be differentiated as management is different. We present a 67 year old female patient with two breast lumps and an axillary lymph node, 5 years after nephrectomy for Renal Cell Carcinoma (RCC). Mammogram report ...

  4. Origin and annihilation physics of positrons in the Galaxy

    International Nuclear Information System (INIS)

    Alexis, Anthony

    2014-01-01

    A gamma radiation at 511 keV is observed since the early 1970's toward the Galactic bulge region. This emission is the signature of a large number of electron-positron annihilations, the positron being the electron's antiparticle. Unfortunately, the origin of the positrons responsible for this emission is still a mystery. Many positron-source candidates have been suggested but none of them can account for the galactic annihilation emission. The spatial distribution of this emission is indeed very atypical. Since 2002, the SPI spectrometer onboard the INTEGRAL space laboratory revealed an emission strongly concentrated toward the galactic bulge and a weaker emission from the galactic disk. This morphology is unusual because it does not correspond to any of the known galactic astrophysical-object or interstellar-matter distributions. The assumption that positrons annihilate close to their sources (i.e. the spatial distribution of the annihilation emission reflects the spatial distribution of the sources) has consequently been called into question. Recent studies suggest that positrons could propagate far away from their sources before annihilating. This physical aspect could be the key point to solve the riddle of the galactic positron origin. This thesis is devoted to the modelling of the propagation and annihilation of positrons in the Galaxy, in order to compare simulated spatial models of the annihilation emission with recent measurements provided by SPI/INTEGRAL. This method allows to put constraints on the origin of galactic positrons. We therefore developed a propagation Monte-Carlo code of positrons within the Galaxy in which we implemented all the theoretical and observational knowledge about positron physics (sources, transport modes, energy losses, annihilation modes) and the interstellar medium of our Galaxy (interstellar gas distributions, galactic magnetic fields, structures of the gaseous phases). Due to uncertainties in several physical parameters

  5. Application of positron emission tomography in the lung

    International Nuclear Information System (INIS)

    Valind, S.O.; Wollmer, P.E.; Rhodes, C.G.

    1985-01-01

    The early application of positron emission tomography in the lung was mainly concerned with the investigation of the regional volume of the vascular and extravascular compartments, using measurements of fractional blood volume and lung density. However, in addition to its passive role in the exchange of oxygen and carbon dioxide, the lung exerts a number of active, metabolic functions such as the inactivation of circulating vasoactive compounds and the synthesis and release of biologically active substances. Furthermore, many of the pulmonary disorders originate at a cellular or metabolic level, or have metabolic consequences. Many of the substrates of biochemical reactions and the biologically active compounds, or their analogs, can be labeled with positron-emitting radioisotopes without disturbing their biological or biochemical characteristics. In combination with the development of the appropriate physiological and biochemical models, the quantitative measurements possible with PET provide a unique opportunity of regionally studying the metabolic processes of the lung of man in vivo. Hence, a range of different expressions of metabolism and of lung function can be evaluated and their interdependence can be studied regionally

  6. Positron sources for electron-positron colliders application to the ILC and CLIC

    CERN Multimedia

    CERN. Geneva

    2008-01-01

    The increased demanding qualities for positron sources dedicated to e+e- colliders pushed on investigations oriented on new kinds of e+ sources. The different kinds of positron sources polarized and no polarized are considered. Their main features (intensity, emittance) are described and analysed. Comparison between the different sources is worked out. The characteristics of the positron beam available in the collision point are greatly depending on the capture device and on the positron accelerator. Different kinds of capture systems are considered and their qualities, compared. Intense positron sources which are necessary for the colliders require intense incident beams (electrons or photons). The large number of pairs created in the targets leads to important energy deposition and so, thermal heating, which associated to temperature gradients provoke mechanical stresses often destructive. Moreover, the important Coulomb collisions, can affect the atomic structure in crystal targets and the radiation resist...

  7. Scattering of thermal photons by a 46 GeV positron beam at LEP

    International Nuclear Information System (INIS)

    Bini, C.; De Zorzi, G.; Diambrini-Palazzi, G.; Di Cosimo, G.; Di Domenico, A.; Gauzzi, P.; Zanello, D.

    1991-01-01

    The scattering of thermal photons present in the vacuum pipe of LEP against the high energy positron beam has been detected. The spectrum of the back-scattered photons is presented for a positron beam energy of 46.1 GeV. Measurements have been performed in the interaction region 1 with the LEP-5 experiment calorimeter. (orig.)

  8. High current pulsed positron microprobe

    International Nuclear Information System (INIS)

    Howell, R.H.; Stoeffl, W.; Kumar, A.; Sterne, P.A.; Cowan, T.E.; Hartley, J.

    1997-01-01

    We are developing a low energy, microscopically focused, pulsed positron beam for defect analysis by positron lifetime spectroscopy to provide a new defect analysis capability at the 10 10 e + s -l beam at the Lawrence Livermore National Laboratory electron linac. When completed, the pulsed positron microprobe will enable defect specific, 3-dimensional maps of defect concentrations with sub-micron resolution of defect location. By coupling these data with first principles calculations of defect specific positron lifetimes and positron implantation profiles we will both map the identity and concentration of defect distributions

  9. Efficient Cryosolid Positron Moderators

    Science.gov (United States)

    2012-08-01

    table layout Figure 21 shows the integration of the IR spectroscopy optics with the positron Moderation and Annihilation vacuum chambers on the...Characterization of Cryogenic Moderators The application of Matrix Isolation Spectroscopy (MIS) to characterizing cryogenic solid positron ...Matrix Isolation Spectroscopy capability into our Positron Moderation apparatus, which enables spectroscopic characterization of the cryogenic

  10. Positron annihilation in a metal-oxide semiconductor studied by using a pulsed monoenergetic positron beam

    Science.gov (United States)

    Uedono, A.; Wei, L.; Tanigawa, S.; Suzuki, R.; Ohgaki, H.; Mikado, T.; Ohji, Y.

    1993-12-01

    The positron annihilation in a metal-oxide semiconductor was studied by using a pulsed monoenergetic positron beam. Lifetime spectra of positrons were measured as a function of incident positron energy for a polycrystalline Si(100 nm)/SiO2(400 nm)/Si specimen. Applying a gate voltage between the polycrystalline Si film and the Si substrate, positrons implanted into the specimen were accumulated at the SiO2/Si interface. From the measurements, it was found that the annihilation probability of ortho-positronium (ortho-Ps) drastically decreased at the SiO2/Si interface. The observed inhibition of the Ps formation was attributed to an interaction between positrons and defects at the SiO2/Si interface.

  11. Positron lifetime studies of electron irradiated copper

    International Nuclear Information System (INIS)

    Hadnagy, T.D.

    1976-01-01

    Single-crystal copper was irradiated with 4.5-MeV electrons producing simple Frenkel defects as well as a significant concentration of divacancies. Mean positron lifetime characteristics, which are sensitive to the presence of vacancies and multivacancies in copper, was monitored after isochronal anneals between 80 and 800 0 K to determine the relative change of characteristic mean lifetimes and their associated intensities. Also a study of the dependence of the mean positron lifetime on the total electron fluence was made and compared with existing theories relating these lifetimes to vacancy or multivacancy concentrations. Numerical data from curve fitting procedures using a conventional trapping model for defect-induced changes in positron lifetimes indicate that upon irradiation with 4.5-MeV electrons at 80 0 K, about 8 percent of the defects produced are divacancy units. Divacancy units appear to be several times more effective in trapping positrons than are monovacancies. Further, the experimental data suggest that the stage III annealing processes in electron-irradiated copper most probably involve the motion and removal of both monovacancies and divacancies. A conglomerate (multivacancy) unit appears to exist as a stable entity even after annealing procedures are carried out at temperatures slightly above the stage III region. Such a stable unit could serve as a nucleation center for the appearance of voids

  12. [Selective biopsy of the sentinel lymph node in breast cancer: without axillary recurrences after a mean follow-up of 4.5 years].

    Science.gov (United States)

    Bañuelos Andrío, Luis; Rodríguez Caravaca, Gil; Argüelles Pintos, Miguel; Mitjavilla Casanova, Mercedes

    2014-01-01

    To analyze the rate of axillary recurrences (AR) in patients with early breast cancer who had not undergone an axillary node dissection (ALND) because of a negative sentinel lymph node biopsy (SLNB). The study includes 173 patients operated on for breast cancer and selective node biopsy. In 32 patients the SLNB was positive and undergone subsequent ALND. We followed up 141 patients with negative SLNB without LDN, with a median follow up of 55 months (range 74-36). The detection rate of SLN was of 99.42%. After a median follow-up of 4.5 years, there were no axillary recurrences. Two patients developed local recurrence, other two patients developed distant metastases and four patients developed a metachronous tumor. Four patients died, none of them because of breast cancer. The results obtained support the SLNB as an accurate technique in the axillary stratification of patients with breast cancer, offering in the cases of negative SLNB a safe axillary control after 4.5 year follow-up. Copyright © 2013 Elsevier España, S.L.U. and SEMNIM. All rights reserved.

  13. Comparison of peripheral nerve stimulator versus ultrasonography guided axillary block using multiple injection technique.

    Science.gov (United States)

    Kumar, Alok; Sharma, Dk; Sibi, Maj E; Datta, Barun; Gogoi, Biraj

    2014-01-01

    The established methods of nerve location were based on either proper motor response on nerve stimulation (NS) or ultrasound guidance. In this prospective, randomised, observer-blinded study, we compared ultrasound guidance with NS for axillary brachial plexus block using 0.5% bupivacaine with the multiple injection techniques. A total of 120 patients receiving axillary brachial plexus block with 0.5% bupivacaine, using a multiple injection technique, were randomly allocated to receive either NS (group NS, n = 60), or ultrasound guidance (group US, n = 60) for nerve location. A blinded observer recorded the onset of sensory and motor blocks, skin punctures, needle redirections, procedure-related pain and patient satisfaction. The median (range) number of skin punctures were 2 (2-4) in group US and 3 (2-5) in group NS (P =0.27). Insufficient block was observed in three patient (5%) of group US and four patients (6.67%) of group NS (P > =0.35). Patient acceptance was similarly good in the two groups. Multiple injection axillary blocks with ultrasound guidance provided similar success rates and comparable incidence of complications as compared with NS guidance with 20 ml 0.5% bupivacaine.

  14. Comparison of peripheral nerve stimulator versus ultrasonography guided axillary block using multiple injection technique

    Directory of Open Access Journals (Sweden)

    Alok Kumar

    2014-01-01

    Full Text Available Background: The established methods of nerve location were based on either proper motor response on nerve stimulation (NS or ultrasound guidance. In this prospective, randomised, observer-blinded study, we compared ultrasound guidance with NS for axillary brachial plexus block using 0.5% bupivacaine with the multiple injection techniques. Methods : A total of 120 patients receiving axillary brachial plexus block with 0.5% bupivacaine, using a multiple injection technique, were randomly allocated to receive either NS (group NS, n = 60, or ultrasound guidance (group US, n = 60 for nerve location. A blinded observer recorded the onset of sensory and motor blocks, skin punctures, needle redirections, procedure-related pain and patient satisfaction. Results: The median (range number of skin punctures were 2 (2-4 in group US and 3 (2-5 in group NS (P =0.27. Insufficient block was observed in three patient (5% of group US and four patients (6.67% of group NS (P > =0.35. Patient acceptance was similarly good in the two groups. Conclusion: Multiple injection axillary blocks with ultrasound guidance provided similar success rates and comparable incidence of complications as compared with NS guidance with 20 ml 0.5% bupivacaine.

  15. Characterization of the melting process of PTFE using positron annihilation spectroscopy

    International Nuclear Information System (INIS)

    Honda, Y; Nishijima, S

    2015-01-01

    Poly(tetrafluoroethylene) (PTFE) is a semi-crystalline polymer and the lifetime of ortho-positronium(o-Ps) is known to be able to be separated into two components due to annihilation in the crystal region and in the amorphous region. The melting process of PTFE was investigated using positron annihilation spectroscopy and X-ray diffraction. The results indicated that volume expansion with an increase of temperature is dominantly due to the expansion of the amorphous region and a Ps bubble is formed at melting in both regions. The o-Ps relating to the crystal region definitely remains on the surface of crystal at the time of annihilation. The production of lower energy electrons at melting was deduced by the analysis of the Doppler broadened annihilation photopeak, and the increase in the number of such electrons was found to have great influence on the formation of the o-Ps and annihilation processes of positron and o-Ps. (paper)

  16. 22 Na positron source for annihilation positron spectroscopy

    International Nuclear Information System (INIS)

    Cimpeanu, Catalina; Craciun, L.; Dragulescu, E.; Dudu, D.; Racolta, P.M.; Voiculescu, Dana; Miron, N.

    2002-01-01

    To extend the nuclear physics applications and to perform the study of vacancy - type defects in metals, semiconductors, polymers etc., we decided to promote positron annihilation techniques. In order to achieve this goal we started a project of dedicated positron sources produced at the IFIN-HH U-120 Cyclotron. We have used the nuclear reaction 24 Mg(d,α) 22 Na and deuterons of 13 MeV energy. The paper presents the main steps of this procedure like: general conditions required for 22 NaCl sources, reactive chamber and characteristics of Mg target, parameters for the irradiation, radiochemical procedures to separate Na from Mg after the irradiation and geometrical or mechanical requirements for dedicated NaCl source for positron annihilation spectrometry. In the e + lifetime measurements the e + 'death - stop' signals are always provided by γ - quanta generated by the e + e - annihilation and the 'birth - start' signals may be obtained from 'prompt' γ - quanta emitted from the NaCl source (the 1.275 MeV photons). The 22 NaCl stock solution obtained by radiochemical separation will be kept in the sealed quartz vials in dry places and will be dropped between the studied materials before use in positron spectrometry. (authors)

  17. Performance of a slow positron beam using a hybrid lens design

    International Nuclear Information System (INIS)

    Cheung, C.K.; Naik, P.S.; Beling, C.D.; Fung, S.; Weng, H.M.

    2006-01-01

    The University of Hong Kong positron beam employs conventional magnetic field transport to the target, but has a special hybrid lens design around the positron moderator that allows the beam to be focused to millimeter spot sizes at the target. The good focusing capabilities of the beam are made possible by extracting work-function positrons from the moderator in a magnetic field free region using a conventional Soa lens thus minimizing beam canonical angular momentum. An Einzel lens is used to focus the positrons into the magnetic funnel at the end of transportation magnetic field while at the same time bringing up the beam energy to the intermediate value of 7.5 keV. The beam is E x B filtered at this intermediate energy. The final beam energy is obtained by floating the Soa-Einzel system, E x B filter and flight tube, and accelerating the positrons just before the target. External beam steering saddle coils fine tune the position, and the magnetic field around the target chamber is adjusted so as to keep one of the beam foci always on the target. The system is fully computer controlled. Variable energy-Doppler broadened annihilation radiation (VEDBAR) data for a GaN sample are shown which demonstrate the performance of the positron beam system

  18. A case study of an axillary artery pseudoaneurysm following anterior dislocation of the glenohumeral joint: A rare presentation on plain film radiographs

    International Nuclear Information System (INIS)

    Whittam, Katie; Hardy, Maryann

    2007-01-01

    Axillary pseudoaneurysm is a rare but important complication of anterior glenohumeral joint dislocation. Diagnosis of axillary pseudoaneurysm is predominantly undertaken following clinical examination but where diagnosis is uncertain, Doppler ultrasound is the imaging examination of choice to confirm diagnosis. In this case study, the initial clinical signs of axillary pseudoaneurysm were masked by the presenting trauma and, although findings indicative of pseudoaneurysm were present on late plain film images, they were not immediately recognised. Misdiagnosis or delayed diagnosis of axillary pseudoaneurysm may result in upper limb morbidity or patient mortality. Consequently, the prompt and accurate identification of an axillary pseudoaneurysm on plain film radiographs, although rare, is essential. Yet for inexperienced film readers, correctly identifying an axillary pseudoaneurysm can be difficult due to its apparent similarity to other pathologies. This article will highlight the differences in radiological appearances between a pseudoaneurysm and a gleno-humeral joint effusion to raise radiographer awareness of the risks and clinical signs of an axillary pseudoaneurysm post gleno-humeral joint dislocation and discuss the difficulties encountered in its diagnosis. Finally, this review will evaluate current diagnostic practices in comparison with best practice, as identified in the literature [Fitzgerald JF, Keates J. False aneurysm as a late complication of anterior shoulder dislocation. Ann Surg 1975;6:785-6; Drury JK, Scullion JE. Vascular complications of anterior dislocation of the shoulder. Br J Surg 1980;67(8):579-81. Waxman DL, France MP, Douglas T, Harryman I. Late lateral displacement of the humeral head after closed reduction of dislocation: a sign of vascular injury. J Bone Joint Surg 1996;78(6):907-10

  19. Positron Beam Characteristics at NEPOMUC Upgrade

    Science.gov (United States)

    Hugenschmidt, C.; Ceeh, H.; Gigl, T.; Lippert, F.; Piochacz, C.; Reiner, M.; Schreckenbach, K.; Vohburger, S.; Weber, J.; Zimnik, S.

    2014-04-01

    In 2012, the new neutron induced positron source NEPOMUC upgrade was put into operation at FRMII. Major changes have been made to the source which consists of a neutron-γ-converter out of Cd and a Pt foil structure for electron positron pair production and positron moderation. The new design leads to an improvement of both intensity and brightness of the mono-energetic positron beam. In addition, the application of highly enriched 113Cd as neutron-γ-converter extends the lifetime of the positron source to 25 years. A new switching and remoderation device has been installed in order to allow toggling from the high-intensity primary beam to a brightness enhanced remoderated positron beam. At present, an intensity of more than 109 moderated positrons per second is achieved at NEPOMUC upgrade. The main characteristics are presented which comprise positron yield and beam profile of both the primary and the remoderated positron beam.

  20. Electron–Positron Pair Flow and Current Composition in the Pulsar Magnetosphere

    Science.gov (United States)

    Brambilla, Gabriele; Kalapotharakos, Constantinos; Timokhin, Andrey N.; Harding, Alice K.; Kazanas, Demosthenes

    2018-05-01

    We perform ab initio particle-in-cell (PIC) simulations of a pulsar magnetosphere with electron–positron plasma produced only in the regions close to the neutron star surface. We study how the magnetosphere transitions from the vacuum to a nearly force-free configuration. We compare the resulting force-free-like configuration with those obtained in a PIC simulation where particles are injected everywhere as well as with macroscopic force-free simulations. We find that, although both PIC solutions have similar structure of electromagnetic fields and current density distributions, they have different particle density distributions. In fact, in the injection from the surface solution, electrons and positrons counterstream only along parts of the return current regions and most of the particles leave the magnetosphere without returning to the star. We also find that pair production in the outer magnetosphere is not critical for filling the whole magnetosphere with plasma. We study how the current density distribution supporting the global electromagnetic configuration is formed by analyzing particle trajectories. We find that electrons precipitate to the return current layer inside the light cylinder and positrons precipitate to the current sheet outside the light cylinder by crossing magnetic field lines, contributing to the charge density distribution required by the global electrodynamics. Moreover, there is a population of electrons trapped in the region close to the Y-point. On the other hand, the most energetic positrons are accelerated close to the Y-point. These processes can have observational signatures that, with further modeling effort, would help to distinguish this particular magnetosphere configuration from others.

  1. Permanent pace maker implantation through axillary vein approach

    International Nuclear Information System (INIS)

    Shah, B.; Hussain, C.; Awan, Z.A.

    2017-01-01

    Device implantation is an integral part of interventional cardiology particularly electrophysiology. In this study, we are going to share our experience of device implantation technique at electrophysiology department Hayatabad Medical Complex, Peshawar. Methods: the study was conducted from June 2011 to December 2015. Axillary vein was used to implant the devices but in some cases when this rout was not convenient due to any reason then subclavian vein was entered through the Seldinger technique. Fluoroscopy time was less than 10 minutes and total procedure time was not more than 45 minutes. Electric cautery was used only in two cases. Pressure dressing was used in a few cases. Results: Total numbers of permanent pacemakers (PPM) remain 800 during the study period. There were 450 single chamber pacemakers and 350 dual chambers pacemakers. No case of any major bleeding was documented and in very few cases there was mild ooze from the procedure site after the operation which was tackled with pressure dressing. Four cases of pneumothorax were noted during the study period and in three cases chest intubation were done and one patient was kept on conservative management. Patient were followed after one month of discharge from the hospital and then yearly. Eight cases of lead dislodgment were documented during the study period. Conclusion: Axillary vein approach for implantation of permanent pacemakers is a safe and less time-consuming technique. (author)

  2. Positron emission tomography

    International Nuclear Information System (INIS)

    Wienhard, K.; Heiss, W.D.

    1984-01-01

    The principles and selected clinical applications of positron emission tomography are described. In this technique a chemical compound is labeled with a positron emitting isotope and its biochemical pathway is traced by coincidence detection of the two annihilation photons. The application of the techniques of computed tomography allows to reconstruct the spatial distribution of the radioactivity within a subject. The 18 F-deoxyglucose method for quantitative measurement of local glucose metabolism is discussed in order to illustrate the possibilities of positron emission tomography to record physiological processes in vivo. (orig.) [de

  3. Diversification in the South American Pampas: the genetic and morphological variation of the widespread Petunia axillaris complex (Solanaceae).

    Science.gov (United States)

    Turchetto, Caroline; Fagundes, Nelson J R; Segatto, Ana L A; Kuhlemeier, Cris; Solís Neffa, Viviana G; Speranza, Pablo R; Bonatto, Sandro L; Freitas, Loreta B

    2014-02-01

    Understanding the spatiotemporal distribution of genetic variation and the ways in which this distribution is connected to the ecological context of natural populations is fundamental for understanding the nature and mode of intraspecific and, ultimately, interspecific differentiation. The Petunia axillaris complex is endemic to the grasslands of southern South America and includes three subspecies: P. a. axillaris, P. a. parodii and P. a. subandina. These subspecies are traditionally delimited based on both geography and floral morphology, although the latter is highly variable. Here, we determined the patterns of genetic (nuclear and cpDNA), morphological and ecological (bioclimatic) variation of a large number of P. axillaris populations and found that they are mostly coincident with subspecies delimitation. The nuclear data suggest that the subspecies are likely independent evolutionary units, and their morphological differences may be associated with local adaptations to diverse climatic and/or edaphic conditions and population isolation. The demographic dynamics over time estimated by skyline plot analyses showed different patterns for each subspecies in the last 100 000 years, which is compatible with a divergence time between 35 000 and 107 000 years ago between P. a. axillaris and P. a. parodii, as estimated with the IMa program. Coalescent simulation tests using Approximate Bayesian Computation do not support previous suggestions of extensive gene flow between P. a. axillaris and P. a. parodii in their contact zone. © 2013 John Wiley & Sons Ltd.

  4. Application of mathematical removal of positron range blurring in positron emission tomography

    International Nuclear Information System (INIS)

    Haber, S.F.; Derenzo, S.E.; Uber, D.

    1990-01-01

    The range of positrons in tissue is an important limitation to the ultimate spatial resolution achievable in positron emission tomography. In this work the authors have applied a Fourier deconvolution technique to remove range blurring in images taken by the Donner 600-crystal positron tomograph. Using phantom data, the authors have found significant improvement in the image quality and the FWHM for both 68 Ga and 82 Rb. These were successfully corrected so that the images and FWHM almost matched those of 18 F which has negligible positron range. However, statistical noise was increased by the deconvolution process and it was not practical to recover the full spatial resolution of the tomograph

  5. Studies of high coverage oxidation of the Cu(100) surface using low energy positrons

    Science.gov (United States)

    Fazleev, N. G.; Maddox, W. B.; Weiss, A. H.

    2012-02-01

    The study of oxidation of single crystal metal surfaces is important in understanding the corrosive and catalytic processes associated with thin film metal oxides. The structures formed on oxidized transition metal surfaces vary from simple adlayers of chemisorbed oxygen to more complex structures which result from the diffusion of oxygen into subsurface regions. In this work we present the results of theoretical studies of positron surface and bulk states and annihilation probabilities of surface-trapped positrons with relevant core electrons at the oxidized Cu(100) surface under conditions of high oxygen coverage. Calculations are performed for various high coverage missing row structures ranging between 0.50 and 1.50 ML oxygen coverage. The results of calculations of positron binding energy, positron work function, and annihilation characteristics of surface trapped positrons with relevant core electrons as function of oxygen coverage are compared with experimental data obtained from studies of oxidation of the Cu(100) surface using positron annihilation induced Auger electron spectroscopy (PAES).

  6. Positron Annihilation in Insulating Materials

    International Nuclear Information System (INIS)

    Asoka-Kumar, P; Sterne, PA

    2002-01-01

    We describe positron results from a wide range of insulating materials. We have completed positron experiments on a range of zeolite-y samples, KDP crystals, alkali halides and laser damaged SiO 2 . Present theoretical understanding of positron behavior in insulators is incomplete and our combined theoretical and experimental approach is aimed at developing a predictive understanding of positrons and positronium annihilation characteristics in insulators. Results from alkali halides and alkaline-earth halides show that positrons annihilate with only the halide ions, with no apparent contribution from the alkali or alkaline-earth cations. This contradicts the results of our existing theory for metals, which predicts roughly equal annihilation contributions from cation and anion. We also present result obtained using Munich positron microprobe on laser damaged SiO 2 samples

  7. A rare case of breast carcinoma co-existing with axillary mantle cell lymphoma

    Directory of Open Access Journals (Sweden)

    Scally John

    2003-12-01

    Full Text Available Abstract Background Mantle cell lymphoma (MCL is a rare variety of non-Hodgkin's lymphoma which originates from CD5+ B-cell population in the mantle zones of lymphoid follicles. Coexistence of such tumours in the axillary lymph nodes with invasive breast cancers without prior history of adjuvant chemotherapy or radiotherapy has not been previously reported in literature. Case report We report a rare case of breast cancer co-existing with stage I mantle cell lymphoma of the ipsilateral axillary lymph node detected fortuitously by population screening. Conclusion Though some studies have tried to prove breast carcinomas and lymphomas to share a common molecular or viral link, more research needs to be done to establish whether such a link truly exists.

  8. Topics in electron-positron interactions

    International Nuclear Information System (INIS)

    Soeding, P.

    1983-01-01

    This chapter investigates the collision of an electron and a positron in a high energy storage ring in which a large energy Q=W=√s=2 E /SUB beam/ is dumped into a tiny region of space-time. If the electron and positron annihilate each other almost all of this energy becomes concentrated in a single field quantum. Points out 3 consequences: 1) all flavored particles existing in nature are expected to be pair-produced provided their mass is not larger than W/2; 2) the pair production process acts as an effective ''filter'' for fundamental (i.e. pointlike) particles; and 3) particles without flavor (i.e. the gluons) are not directly pair-produced in e - e + interactions. Discusses basic processes; probing QED and lepton structure; hadron production at high energies; resonances; e - e + storage rings; detectors; electroweak interaction and new particles (leptons, quarks); restrictions on a more general weak interaction scenario; limits on pair production of scalar particles; and jets and QCD tests

  9. Applications of slow positrons to cancer research: Search for selectivity of positron annihilation to skin cancer

    International Nuclear Information System (INIS)

    Jean, Y.C.; Li Ying; Liu Gaung; Chen, Hongmin; Zhang Junjie; Gadzia, Joseph E.

    2006-01-01

    Slow positrons and positron annihilation spectroscopy (PAS) have been applied to medical research in searching for positron annihilation selectivity to cancer cells. We report the results of positron lifetime and Doppler broadening energy spectroscopies in human skin samples with and without cancer as a function of positron incident energy (up to 8 μm depth) and found that the positronium annihilates at a significantly lower rate and forms at a lower probability in the samples having either basal cell carcinoma (BCC) or squamous cell carcinoma (SCC) than in the normal skin. The significant selectivity of positron annihilation to skin cancer may open a new research area of developing positron annihilation spectroscopy as a novel medical tool to detect cancer formation externally and non-invasively at the early stages

  10. Applications of slow positrons to cancer research: Search for selectivity of positron annihilation to skin cancer

    Energy Technology Data Exchange (ETDEWEB)

    Jean, Y.C. [Department of Chemistry, University of Missouri-Kansas City, 205 Spenscer Chemistry Building, 5009 Rockhill Road, Kansas City, MO 64110 (United States)]. E-mail: jeany@umkc.edu; Li Ying [Department of Chemistry, University of Missouri-Kansas City, 205 Spenscer Chemistry Building, 5009 Rockhill Road, Kansas City, MO 64110 (United States); Liu Gaung [Department of Chemistry, University of Missouri-Kansas City, 205 Spenscer Chemistry Building, 5009 Rockhill Road, Kansas City, MO 64110 (United States); Chen, Hongmin [Department of Chemistry, University of Missouri-Kansas City, 205 Spenscer Chemistry Building, 5009 Rockhill Road, Kansas City, MO 64110 (United States); Zhang Junjie [Department of Chemistry, University of Missouri-Kansas City, 205 Spenscer Chemistry Building, 5009 Rockhill Road, Kansas City, MO 64110 (United States); Gadzia, Joseph E. [Dermatology, Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS 66103 (United States); Kansas Medical Clinic, Topeka, KS 66614 (United States)

    2006-02-28

    Slow positrons and positron annihilation spectroscopy (PAS) have been applied to medical research in searching for positron annihilation selectivity to cancer cells. We report the results of positron lifetime and Doppler broadening energy spectroscopies in human skin samples with and without cancer as a function of positron incident energy (up to 8 {mu}m depth) and found that the positronium annihilates at a significantly lower rate and forms at a lower probability in the samples having either basal cell carcinoma (BCC) or squamous cell carcinoma (SCC) than in the normal skin. The significant selectivity of positron annihilation to skin cancer may open a new research area of developing positron annihilation spectroscopy as a novel medical tool to detect cancer formation externally and non-invasively at the early stages.

  11. The Effect of Ketamine and Dexamethasone in Combination with Lidocaine on the Onset and Duration of Axillary Block in Hand and Forearm Soft Tissue Surgery.

    Science.gov (United States)

    Zaman, Behrooz; Hojjati Ashrafi, Siavash; Seyed Siamdoust, Seyedalireza; Hassani, Valiollah; Mohamad Taheri, Siavash; Noorizad, Samad

    2017-10-01

    Using peripheral nerve block compared to general anesthesia has gained more popularity due to reduced postoperative pain, less need for post-surgery analgesic drugs, reduced incidence of nausea, shortness of PACU time, and increased patient satisfaction. The aim of this study was to compare the effect of ketamine and dexamethasone as additives to lidocaine on duration and onset of axillary block action. In this clinical trial, all patients who referred to Hazrat-e-Fatemeh hospital for forearm and hand soft tissue surgery with informed consent were randomly divided into three groups in order to examine the onset and duration of axillary block: lidocaine + ketamine, lidocaine + dexamethasone in axillary block, and lidocaine alone (control). Then, the onset and duration of sensory and motor blocks were measured and recorded every three minutes and after the surgery. Quantitative and qualitative variables were analyzed using ANOVA or Kruskal-Wallis test and Chi-square or Fisher exact test in SPSS v.22. Duration of sensory and motor block axillary was significantly higher in lidocaine + dexamethasone group than in lidocaine + ketamine group (P block axillary between the three groups (P > 0.05). According to the results of our study, we can conclude that adding dexamethasone or ketamine to lidocaine could improve duration of sensory and motor axillary block in patients undergoing forearm and hand soft tissue surgery. However, dexamethasone had the highest effect on duration of block axillary. We proved that dexamethasone or ketamine added to lidocaine had no effect on the onset of block axillary.

  12. Positron lifetime measurements and positron-annihilation induced auger electron spectroscpy using slow positron beams; Teisoku yodenshi bimu wo mochiita yodenshi jumyo sokutei oyobi yodenshi shometsu reiki oje denshi bunko

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, R. [Electrotechnical Lab., Tsukuba (Japan)

    1996-02-20

    Slow positron beam with less than several eV can be controlled freely such as accelerating, throttling the beam size, shortening the pulse or making pulse with short time width and so forth. These low positron beams are applied to various measurements like Doppler broadening measurement of annihilation {gamma} rays or lifetime measurement of positron, and secondary particle measurements using positron microscope, positron electron ray diffraction, flight time method and so forth. In particular, these recent years, high intensity slow positron beams were possible using accelerators like electron linac and its application is increasing. In this report, pulse shortening method for high intensity slow positron beam, and incidence energy variable positron lifetime measurement method using this slow pulsed beam and flight time type positron-annihilation-induced auger electron spectroscopy are outlined. In future, these measurements can be possible to carry out with high resolution and also with high counting rate if higher intensity monochromatic excellent positron beam than present one is produced. 31 refs., 5 figs.

  13. LLNL pure positron plasma program

    International Nuclear Information System (INIS)

    Hartley, J.H.; Beck, B.R.; Cowan, T.E.; Howell, R.H.; McDonald, J.L.; Rohatgi, R.R.; Fajans, J.; Gopalan, R.

    1995-01-01

    Assembly and initial testing of the Positron Time-of-Flight Trap at the Lawrence Livermore National Laboratory (LLNL) Increase Pulsed Positron Facility has been completed. The goal of the project is to accumulate at high-density positron plasma in only a few seconds., in order to facilitate study that may require destructive diagnostics. To date, densities of at least 6 x 10 6 positrons per cm 3 have been achieved

  14. Readiness for surgery after axillary block

    DEFF Research Database (Denmark)

    Koscielniak-Nielsen, Z J; Stens-Pedersen, H L; Lippert, F K

    1997-01-01

    required less time for block performance (mean 5.5 min) than multiple injections (mean 9.5 min), P requirement for supplemental nerve blocks was greater, after single injections (33 min and 57%) than after multiple injections (15.5 min and 7......We have assessed prospectively the time to readiness for surgery following axillary block (sum of block performance and latency times) in 80 patients. The brachial plexus was identified using a nerve stimulator, and anaesthetized with 45 mL of mepivacaine 1% with adrenaline 5 micrograms mL-1......%, respectively), P effectiveness was 100% in group 1 and 98% in group 2 (NS). The frequency of adverse effects (vessel puncture or paraesthesia) was similar...

  15. Repair of Multiple Subclavian and Axillary Artery Aneurysms in a 58-Year-Old Man with Marfan Syndrome

    OpenAIRE

    Dolapoglu, Ahmet; de la Cruz, Kim I.; Preventza, Ourania; Coselli, Joseph S.

    2016-01-01

    Dilation of the ascending aorta and aortic dissections are often seen in Marfan syndrome; however, true aneurysms of the subclavian and axillary arteries rarely seem to develop in patients who have this disease. We present the case of a 58-year-old man with Marfan syndrome who had undergone a Bentall procedure and thoracoabdominal aortic repair for an aortic dissection and who later developed multiple aneurysmal dilations of his right subclavian and axillary arteries. The aneurysms were succe...

  16. In vitro Proliferation Ability of Axillary Buds in Musa spp | Youmbi ...

    African Journals Online (AJOL)

    from : Pisang Mas (AA), Grande Naine (AAA), Batard and French Clair (AAB), CRBP 39 (AAAB) and Pelipita (ABB) varieties were used as explants. The proliferation rate of Axillary and apical buds and other growth parameters were measured. Results showed that no significant differences were observed between the two ...

  17. High resolution positron tomography

    International Nuclear Information System (INIS)

    Brownell, G.L.; Burnham, C.A.

    1982-01-01

    The limits of spatial resolution in practical positron tomography are examined. The four factors that limit spatial resolution are: positron range; small angle deviation; detector dimensions and properties; statistics. Of these factors, positron range may be considered the fundamental physical limitation since it is independent of instrument properties. The other factors are to a greater or lesser extent dependent on the design of the tomograph

  18. The role of sonography in patients with breast cancer presenting as an axillary mass

    International Nuclear Information System (INIS)

    Park, Sun Young; Kim, Eun Kyung; Oh, Ki Keun; Lee, Kyong Sik; Park, Byeong Woo

    2002-01-01

    To compare sonography and mammography in terms of their diagnostic value in breast cancer cases which initially presented as an axillary mass without a palpable mass or other clinical symptoms. Seven patients with enlarged axillary lymph nodes who first presented with no evidence of palpable breast lesions and who underwent both mammography and sonography were enrolled in this study. In six of the seven, the presence of metastatic adenocarcinoma was confirmed preoperatively by axillary needle aspiration biopsy; in four, subsequent sonographically guided breast core biopsy performed after careful examination of the primary site indicated that primary breast cancer was present. In each case, the radiologic findings were evaluated by both breast sonography and mammography. Breast lesions were detected mammographically in four of seven cases (57%); in three of the four, the lesion presented as a mass, and in one as microcalcification. In three of these four detected cases, fatty or scattered fibroglandular breast parenchyma was present; in one, the parenchyma was dense. In the three cases in which lesions were not detected, mammography revealed the presence of heterogeneously dense parenchyma. Breast sonography showed that lesions were present in six of seven cases (86%); in the remaining patient, malignant microcalcification was detected at mammography. Final pathologic examination indicated that all breast lesions except one, which was a ductal carcinoma in situ, with microinvasion, were infiltrating ductal carcinomas whose size ranged from microscopic to greater than 3 cm. At the time of this study, all seven patients were alive and well, having been disease free for up to 61 months after surgery. In women with a palpable axillary mass confirmed as metastatic adenocarcinoma, breast sonography may be a valuable adjunct to mammography

  19. Positron lifetime calculation for defects and defect clusters in graphite

    International Nuclear Information System (INIS)

    Onitsuka, T.; Ohkubo, H.; Takenaka, M.; Tsukuda, N.; Kuramoto, E.

    2000-01-01

    Calculations of positron lifetime have been made for vacancy type defects in graphite and compared with experimental results. Defect structures were obtained in a model graphite lattice after including relaxation of whole lattice as determined by the molecular dynamics method, where the interatomic potential given by Pablo Andribet, Dominguez-Vazguez, Mari Carmen Perez-Martin, Alonso, Jimenez-Rodriguez [Nucl. Instrum. and Meth. 115 (1996) 501] was used. For the defect structures obtained via lattice relaxation positron lifetime was calculated under the so-called atomic superposition method. Positron lifetimes 204 and 222 ps were obtained for the graphite matrix and a single vacancy, respectively, which can be compared with the experimental results 208 and 233 ps. For planar vacancy clusters, e.g., vacancy loops, lifetime calculation was also made and indicated that lifetime increases with the number of vacancies in a cluster. This is consistent with the experimental result in the region of higher annealing temperature (above 1200 deg. C), where the increase of positron lifetime is seen, probably corresponding to the clustering of mobile vacancies

  20. Positron transport studies at the Au - (InP:Fe) interface

    Science.gov (United States)

    Au, H. L.; Lee, T. C.; Beling, C. D.; Fung, S.

    1996-03-01

    Positron mobility and lifetime measurements have been carried out on semi-insulating Fe-doped InP samples with Au contacts used for electric field application. The lifetime measurements, with electric fields directed towards the Au - InP:Fe interface, reveal no component associated with interfacial open-volume sites and thus give no evidence of any positron mobility. The mobility measurements, made using the Doppler-shifted annihilation radiation technique, however, reveal a temperature independent positron mobility of about 0953-8984/8/10/012/img1 in the range 150 - 300 K. These observations, together with results from I - V analysis, are discussed with reference to two possible band-bending schemes. The first, which requires an ionized shallow donor region adjacent to the Au - InP interface, seems less plausible on a number of grounds. In the second, however, an 0953-8984/8/10/012/img2 negative space charge produces an adverse diffusion barrier for positrons approaching the interface together with a non-uniform electric field in the samples capable of explaining the observed mobility results.

  1. Association between US features of primary tumor and axillary lymph node metastasis in patients with clinical T1-T2N0 breast cancer.

    Science.gov (United States)

    Bae, Min Sun; Shin, Sung Ui; Song, Sung Eun; Ryu, Han Suk; Han, Wonshik; Moon, Woo Kyung

    2018-04-01

    Background Most patients with early-stage breast cancer have clinically negative lymph nodes (LNs). However, 15-20% of patients have axillary nodal metastasis based on the sentinel LN biopsy. Purpose To assess whether ultrasound (US) features of a primary tumor are associated with axillary LN metastasis in patients with clinical T1-T2N0 breast cancer. Material and Methods This retrospective study included 138 consecutive patients (median age = 51 years; age range = 27-78 years) who underwent breast surgery with axillary LN evaluation for clinically node-negative T1-T2 breast cancer. Three radiologists blinded to the axillary surgery results independently reviewed the US images. Tumor distance from the skin and distance from the nipple were determined based on the US report. Association between US features of a breast tumor and axillary LN metastasis was assessed using a multivariate logistic regression model after controlling for clinicopathologic variables. Results Of the 138 patients, 28 (20.3%) had nodal metastasis. At univariate analysis, tumor distance from the skin ( P = 0.019), tumor size on US ( P = 0.023), calcifications ( P = 0.036), architectural distortion ( P = 0.001), and lymphovascular invasion ( P = 0.049) were associated with axillary LN metastasis. At multivariate analysis, shorter skin-to-tumor distance (odds ratio [OR] = 4.15; 95% confidence interval [CI] = 1.01-16.19; P = 0.040) and masses with associated architectural distortion (OR = 3.80; 95% CI = 1.57-9.19; P = 0.003) were independent predictors of axillary LN metastasis. Conclusion US features of breast cancer can be promising factors associated with axillary LN metastasis in patients with clinically node-negative early-stage breast cancer.

  2. Positron emission tomography

    NARCIS (Netherlands)

    Paans, AMJ

    Positron Emission Tomography (PET) is a method for determining biochemical and physiological processes in vivo in a quantitative way by using radiopharmaceuticals labelled with positron emitting radionuclides as C-11, N-13, O-15 and F-18 and by measuring the annihilation radiation using a

  3. Positron confinement in embedded lithium nanoclusters

    Science.gov (United States)

    van Huis, M. A.; van Veen, A.; Schut, H.; Falub, C. V.; Eijt, S. W.; Mijnarends, P. E.; Kuriplach, J.

    2002-02-01

    Quantum confinement of positrons in nanoclusters offers the opportunity to obtain detailed information on the electronic structure of nanoclusters by application of positron annihilation spectroscopy techniques. In this work, positron confinement is investigated in lithium nanoclusters embedded in monocrystalline MgO. These nanoclusters were created by means of ion implantation and subsequent annealing. It was found from the results of Doppler broadening positron beam analysis that approximately 92% of the implanted positrons annihilate in lithium nanoclusters rather than in the embedding MgO, while the local fraction of lithium at the implantation depth is only 1.3 at. %. The results of two-dimensional angular correlation of annihilation radiation confirm the presence of crystalline bulk lithium. The confinement of positrons is ascribed to the difference in positron affinity between lithium and MgO. The nanocluster acts as a potential well for positrons, where the depth of the potential well is equal to the difference in the positron affinities of lithium and MgO. These affinities were calculated using the linear muffin-tin orbital atomic sphere approximation method. This yields a positronic potential step at the MgO||Li interface of 1.8 eV using the generalized gradient approximation and 2.8 eV using the insulator model.

  4. Extranodal extension of axillary metastasis of invasive breast carcinoma as a possible predictor for the total number of positive lymph nodes

    NARCIS (Netherlands)

    Palamba, H. W.; Rombouts, M. C.; Ruers, T. J.; Klinkenbijl, J. H.; Wobbes, T.

    2001-01-01

    By the implementation of the sentinel node procedure in the treatment of breast carcinoma routine axillary lymph node, dissection can be abandoned in patients with a tumour-negative sentinel node. When the sentinel node is positive there are two options; an axillary dissection or radiotherapy of the

  5. A clinical assessment tool for ultrasound-guided axillary brachial plexus block.

    LENUS (Irish Health Repository)

    Sultan, S F

    2012-05-01

    Competency in anesthesia traditionally has been determined subjectively in practice. Optimal training in procedural skills requires valid and reliable forms of assessment. The objective was to examine a procedure-specific clinical assessment tool for ultrasound-guided axillary brachial plexus block for inter-rater reliability and construct validity in a clinical setting.

  6. Duration of 18F-FDG avidity in lymph nodes after pandemic H1N1v and seasonal influenza vaccination

    International Nuclear Information System (INIS)

    Thomassen, Anders; Lerberg Nielsen, Anne; Gerke, Oke; Johansen, Allan; Petersen, Henrik

    2011-01-01

    The aim of our study was to investigate the occurrence of fluorodeoxyglucose (FDG) avidity in draining axillary lymph nodes after vaccination against influenza (H1N1v pandemic and seasonal) and to determine the period of increased FDG uptake. During December 2009, patients referred for 18 F-FDG positron emission tomography (PET)/CT scans (n = 293) filled in a questionnaire concerning vaccination type (seasonal and/or H1N1v), time and anatomical localization of vaccination. Only injections in deltoid regions were evaluated, thus ensuring that draining lymph nodes were axillary. If more vaccinations had been given, only the latest vaccination was evaluated in each deltoid region. Of all patients who underwent PET/CT scans during December 2009, 26% had been vaccinated with at least one influenza vaccination in the deltoid region. A total of 92 'draining' and 60 'reference' (i.e. contralateral, non-vaccinated) axillary lymph nodes were evaluated in 61 patients (19 of 61 patients were scanned twice). The maximal intensity in FDG uptake (SUV max ) in draining lymph nodes was 5 g/ml body weight (BW), whereas the maximal intensity in reference lymph nodes was 1.9 g/ml BW. The SUV max was normalized approximately 40 days after vaccination. No significant enlargement of metabolically active draining lymph nodes could be demonstrated on CT scan. Chemotherapy or immunosuppressive drugs given within 2 weeks from vaccination did not affect SUV max in the axillary lymph nodes. Influenza vaccination may lead to FDG-avid draining lymph nodes beyond 1 month. (orig.)

  7. Duration of {sup 18}F-FDG avidity in lymph nodes after pandemic H1N1v and seasonal influenza vaccination

    Energy Technology Data Exchange (ETDEWEB)

    Thomassen, Anders; Lerberg Nielsen, Anne; Gerke, Oke; Johansen, Allan; Petersen, Henrik [OUH, Odense University Hospital, Department of Nuclear Medicine, Odense C (Denmark)

    2011-05-15

    The aim of our study was to investigate the occurrence of fluorodeoxyglucose (FDG) avidity in draining axillary lymph nodes after vaccination against influenza (H1N1v pandemic and seasonal) and to determine the period of increased FDG uptake. During December 2009, patients referred for {sup 18}F-FDG positron emission tomography (PET)/CT scans (n = 293) filled in a questionnaire concerning vaccination type (seasonal and/or H1N1v), time and anatomical localization of vaccination. Only injections in deltoid regions were evaluated, thus ensuring that draining lymph nodes were axillary. If more vaccinations had been given, only the latest vaccination was evaluated in each deltoid region. Of all patients who underwent PET/CT scans during December 2009, 26% had been vaccinated with at least one influenza vaccination in the deltoid region. A total of 92 'draining' and 60 'reference' (i.e. contralateral, non-vaccinated) axillary lymph nodes were evaluated in 61 patients (19 of 61 patients were scanned twice). The maximal intensity in FDG uptake (SUV{sub max}) in draining lymph nodes was 5 g/ml body weight (BW), whereas the maximal intensity in reference lymph nodes was 1.9 g/ml BW. The SUV{sub max} was normalized approximately 40 days after vaccination. No significant enlargement of metabolically active draining lymph nodes could be demonstrated on CT scan. Chemotherapy or immunosuppressive drugs given within 2 weeks from vaccination did not affect SUV{sub max} in the axillary lymph nodes. Influenza vaccination may lead to FDG-avid draining lymph nodes beyond 1 month. (orig.)

  8. Mycosis fungoides: Positron emission tomography/computed tomography in staging and monitoring the effect of therapy

    International Nuclear Information System (INIS)

    D’Souza, Maria Mathew; D’Souza, Paschal; Sharma, Rajnish; Jaimini, Abhinav; Mondal, Anupam

    2015-01-01

    A 58-year-old woman, diagnosed as a case of mycosis fungoides (MF), underwent [18F]-fluoro-D-glucose positron emission tomography/computed tomography (FDG PET/CT) examination. The study revealed intense FDG uptake in a large ulceroproliferative right thigh lesion, indurated plaques in the chest wall and left thigh, along with multiple sites of cutaneous involvement, axillary and inguinal lymphadenopathy. The patient underwent chemotherapy with CHOP regimen, radiotherapy for the right thigh lesion, along with topical corticosteroids and emollients for the disseminated cutaneous involvement. Repeat [18F]-FDG PET/CT study performed a year later, showed near complete disease regression specifically of the ulceroproliferative lesion and indurated cutaneous plaques, no change in lymphadenopathy, and a subtle diffuse progression of the remaining cutaneous lesions. A multidisciplinary approach to the diagnosis, staging and treatment of MF has long been suggested for optimizing outcomes from management of patients with this disease. This case highlights the potential role of incorporating PET/CT as a single modality imaging technique in the staging and assessment of response to therapy

  9. Positrons annihilation and the Galactic center

    International Nuclear Information System (INIS)

    Wallyn, Pierre

    1992-01-01

    The Galactic center has been observed in gamma rays, many times since more than two decades and we do not still have a full comprehensive picture of this region. It is fairly well established that the 511 keV annihilation line has two origins: a steady diffuse emission, which follows more or less the type I supernovae distribution along the Galactic plane and a variable emission coming from the positrons emitted by (at least) one compact object and annihilating in a nearby cold molecular cloud. We present here an analysis of the profiles and intensifies of the 511 keV annihilation line observed in the direction of the Galactic center. We find that a warm medium (temperature of 8000 K) can describe the annihilation of positrons from the diffuse component of the line. The high state observations of the 511 keV line can be explained if the time-variable component is coming from the annihilation of the positrons in a cold medium (temperature around 80 K). This constraint on the annihilation medium temperature supports the association with the molecular cloud G-0.86-0.08 in the direction of 1E1740.7-2942. On may 22, 1989, HEXAGONE detected a narrow 511 keV line and also a broad emission around 170 keV in the direction of the Galactic center. Two weeks before, EXITE observed in the same direction a new transient source EXS 1737.9-2952 which showed a bump around 102 keV. We propose a simple semi-quantitative model which can mimic the bumps as well as its time variations and emphasize the strong similarities between EXS1737.9-2952 and Nova Muscae. We study the behaviour of positron annihilation by charge exchange in the cold phase of the interstellar medium. We calculate formula for the slowing-down time before thermalization of positrons of a given initial energy, for different medium densities. Our scenario explains the lack of detection of the recombination lines from positronium and gives new constraints on their possible observation. (author) [fr

  10. Mining the bulk positron lifetime

    International Nuclear Information System (INIS)

    Aourag, H.; Guittom, A.

    2009-01-01

    We introduce a new approach to investigate the bulk positron lifetimes of new systems based on data-mining techniques. Through data mining of bulk positron lifetimes, we demonstrate the ability to predict the positron lifetimes of new semiconductors on the basis of available semiconductor data already studied. Informatics techniques have been applied to bulk positron lifetimes for different tetrahedrally bounded semiconductors in order to discover computational design rules. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Detection of axillary lymph node metastases in breast carcinoma by technetium-99m sestamibi breast scintigraphy, ultrasound and conventional mammography

    International Nuclear Information System (INIS)

    Lam, W.W.M.; Yang, W.T.; Chan, Y.L.; Stewart, I.E.T.; Metreweli, C.; King, W.

    1996-01-01

    Axillary lymph node status is important in the staging of breast carcinoma. To evaluate the accuracy of technetium-99m sestamibi breast scintigraphy in detecting metastatic axillary lymph nodes as compared with other accepted imaging modalities, we performed 99m Tc-sestamibi breast scintigraphy, conventional mammography and ultrasound in 36 patients with primary untreated breast cardinoma. With histopathology as the gold standard, 99m Tc-sestamibi breast scintigraphy was found to yield true-positive results in 7 of 11 cases (64%) of axillary lymph nodes metastases and true-negative results in 18 of 20 cases (90%); it has an accuracy of 81%, a positive predictive value of 77.8% and a negative predicive value of 81.8%. (orig.)

  12. Solvated Positron Chemistry. Competitive Positron Reactions with Halide Ions in Water

    DEFF Research Database (Denmark)

    Christensen, Palle; Pedersen, Niels Jørgen; Andersen, J. R.

    1979-01-01

    It is shown by means of the angular correlation technique that the binding of positrons to halides is strongly influenced by solvation effects. For aqueous solutions we find increasing values for the binding energies between the halide and the positron with increasing mass of the halide...

  13. Positron annihilation studies in ZnO nanoparticles

    Science.gov (United States)

    Sharma, S. K.; Pujari, P. K.; Sudarshan, K.; Dutta, D.; Mahapatra, M.; Godbole, S. V.; Jayakumar, O. D.; Tyagi, A. K.

    2009-04-01

    We report results on positron annihilation spectroscopic (PAS) studies using lifetime and coincidence Doppler broadening techniques in zinc oxide (ZnO) nanoparticles (4 to 40 nm) synthesized by solid state pyrolytic reaction followed by annealing in the temperature range of 200 ∘C to 800 ∘C. Positron lifetime in the nanoparticles are observed to be higher than bulk lifetime in all the cases. Theoretical calculation of lifetime indicates the presence of either Zn or (Zn, O) vacancy clusters which migrate and anneal out at high temperature. Comparison of ratio spectra from coincidence Doppler broadening measurement and calculated electron momentum distribution indicates the presence of either Zn or (Zn, O) vacancies. In addition, photoluminescence (PL) measurements have been carried out to examine the role of defects on the intensity of emission in the visible region.

  14. Slow positrons in single-crystal samples of Al and Al-AlxOy

    Science.gov (United States)

    Lynn, K. G.; Lutz, H.

    1980-11-01

    Well-characterized Al(111) and Al(100) samples were studied with monoenergetic positrons before and after exposure to oxygen. Both positronium-formation and positron-emission curves were obtained for various incident positron energies at sample temperatures ranging from 160-900 K. The orthopositronium decay signal provides a unique signature that the positron has emerged from the surface region of a clean metal. In the clean Al crystals part of the positronium formed near the surface is found to be associated with a temperature-activated process described as the thermally activated detrapping of a positron from a surface state. A simple positron diffusion model, including surface and vacancy trapping, is fitted to the positronium data and an estimate of the binding energy of the positron in this trap is made. The positron diffusion constant is found to have a negative temperature dependence before the onset of positron trapping at thermally generated monovacancies (>500 K), in reasonable agreement with theoretical predictions. The depth of the positron surface state is reduced or positronium is formed in the chemisorbed layer as oxygen is adsorbed on both Al sample surfaces, thus increasing the positronium fraction and decreasing the positron emission. At higher oxygen exposures [>500 L (1 L = 10-6 torr sec)] positron or positronium traps are generated in the overlayer and the positronium fraction is reduced. The amorphous-to-crystalline surface transition of AlxOy on Al is observed between 650 and 800 K by the change in the positronium fraction and is interpreted as the removal of trapping centers in the metal-oxide overlayer. At the higher temperatures and incident energies vacancy trapping is observed by the decrease in the positron diffusion length in both the clean and the underlying Al of the oxygen-exposed samples. Similar vacancy formation enthalpies for Al are extracted in both the clean and oxygen-covered samples by a simple model and are in good

  15. Development of a transmission positron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Matsuya, M., E-mail: matsuya@jeol.co.jp [JEOL Ltd., 1-2 Musashino, 3-Chome, Akishima, Tokyo 196-8558 (Japan); Jinno, S. [Department of Applied Chemistry, Chiba University, Yayoi, Inage, Chiba, Chiba 263-8552 (Japan); Ootsuka, T.; Inoue, M. [JEOL Ltd., 1-2 Musashino, 3-Chome, Akishima, Tokyo 196-8558 (Japan); Kurihara, T. [High Energy Accelerator Research Organization, Oho, Tsukuba, Ibaraki 305-0801 (Japan); Doyama, M.; Inoue, M. [Teikyo University of Science and Technology, Uenohara, Yamanashi 409-0913 (Japan); Fujinami, M. [Department of Applied Chemistry, Chiba University, Yayoi, Inage, Chiba, Chiba 263-8552 (Japan)

    2011-07-21

    A practical transmission positron microscope (TPM) JEM-1011B has been developed to survey differences in the interaction of positron and electron beams with materials, and is installed in the Slow Positron Facility of High Energy Accelerator Research Organization (KEK). The TPM can share positron and electron beams, and can also be used as a transmission electron microscope (TEM). Positron transmission images up to magnification 10,000x (resolution: 50 nm) and positron diffraction patterns up to 044 family were successfully obtained by the TPM comparing them with those of electrons. The differences in material transmittances for both beams have been measured, and can be explained by the calculated results of the Monte Carlo simulation code PENELOPE-2008.

  16. Intramedullary fixation of proximal humerus fractures: do locking bolts endanger the axillary nerve or the ascending branch of the anterior circumflex artery? A cadaveric study

    Directory of Open Access Journals (Sweden)

    Sermon An

    2008-12-01

    Full Text Available Abstract Background Proximal humerus fractures are one of the most common fractures. Intramedullary locked nailing is becoming a popular alternative treatment, especially for easier fracture patterns. Although axillary nerve injury has been reported, no study has compared the safety of the proximal locking options relative to the axillary nerve and the ascending branch of the anterior circumflex artery. Method Six different commercially available proximal humeral nails were implanted in 30 shoulders of 18 cadavers. After fluoroscopically guided implantation the shoulders were carefully dissected and the distance between the locking screws, the axillary nerve and the ascending branch of the anterior circumflex artery was measured. Results The course of the axillary nerve varies. A mean distance of 55.8 mm (SD = 5.3 between the lateral edge of the acromions and the axillary nerve at the middle of the humerus in a neutrally rotated position was observed. The minimum distance was 43.4 mm, the maximum 63.9 mm. Bent nails with oblique head interlocking bolts appeared to be the most dangerous in relation to the axillary nerve. The two designs featuring such a bend and oblique bolt showed a mean distance of the locking screw to the axillary nerve of 1 mm and 2.7 mm respectively Sirus (Zimmer® and (Stryker® T2 PHN (Proximal Humeral Nail. Regarding the ascending branch of the anterior circumflex artery, there was no difference between the nails which have an anteroposterior locking option. Conclusion It is of great importance for surgeons treating proximal humerus fractures to understand the relative risk of any procedure they perform. Since the designs of different nailing systems risk damaging the axillary nerve and ascending branch, blunt dissection, the use of protection sleeves during drilling and screw insertion, and individual risk evaluation prior to the use of a proximal humeral nail are advocated.

  17. Positron annihilation microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Canter, K F [Brandeis Univ., Waltham, MA (United States)

    1997-03-01

    Advances in positron annihilation microprobe development are reviewed. The present resolution achievable is 3 {mu}m. The ultimate resolution is expected to be 0.1 {mu}m which will enable the positron microprobe to be a valuable tool in the development of 0.1 {mu}m scale electronic devices in the future. (author)

  18. Positron lifetimes in deformed copper

    International Nuclear Information System (INIS)

    Hinode, Kenji; Tanigawa, Shoichiro; Doyama, Masao

    1976-01-01

    Positron lifetime measurements were performed for Cu samples with different densities of lattice defects. The lifetime spectra were successfully resolved into two components with the help of the well established analysis program. Obtained results were quite consistent with those expected from the trapping model. The positron trapping mechanism from free to trapped states and the initial condition of the model were especially checked. Deduced values obtained for tau sub(c) (lifetime of free positrons) and tau sub(t) (lifetime of trapped positrons) were 122+-5 psec and 176+-5 psec, respectively. (auth.)

  19. Case Report and Dosimetric Analysis of an Axillary Recurrence After Partial Breast Irradiation with Mammosite Catheter

    International Nuclear Information System (INIS)

    Shah, Anand P.; Dickler, Adam; Kirk, Michael C.; Chen, Sea S.; Strauss, Jonathan B.; Coon, Alan B.; Turian, Julius V.; Siziopikou, Kalliopi; Dowlat, Kambiz; Griem, Katherine L.

    2008-01-01

    Partial breast irradiation (PBI) was designed in part to decrease overall treatment times associated with whole breast radiation therapy (WBRT). WBRT treats the entire breast and usually portions of the axilla. The goal of PBI is to treat a smaller volume of breast tissue in less time, focusing the dose around the lumpectomy cavity. The following is a case of a 64-year-old woman with early-stage breast cancer treated with PBI who failed regionally in the ipsilateral axilla. With our dosimetric analysis, we found that the entire area of this axillary failure would have likely received at least 45 Gy if WBRT had been used, enough to sterilize microscopic disease. With PBI, this area received a mean dose of only 2.8 Gy, which raises the possibility that this regional failure may have been prevented had WBRT been used instead of PBI

  20. Positron annihilation study of Pd contacts on impurity-doped GaN

    International Nuclear Information System (INIS)

    Lee, Jong-Lam; Kim, Jong Kyu; Weber, Marc H.; Lynn, Kelvin G.

    2001-01-01

    Pd contacts on both n-type and p-type GaN were studied using positron annihilation spectroscopy, and the results were used to interpret the role of Ga vacancies on the band bending below the contacts. The concentration of Ga vacancy in Si-doped GaN was higher than that in the Mg-doped one. In Si-doped GaN, implanted positrons were annihilated at the nearer surface region and the interface of Pd/n-type GaN was detected by positrons clearly shifted toward the surface of Pd. This suggests that Ga vacancies could act as an interface state, pinning the Fermi level at the interface of Pd with GaN, leading to the production of a negative electric field below the interface. [copyright] 2001 American Institute of Physics

  1. Exploring of defects in He+ implanted Si(100) by slow positron beam

    International Nuclear Information System (INIS)

    Zhang Tianhao; Weng Huimin; Fan Yangmei; Du Jiangfeng; Zhou Xianyi; Han Rongdian; Zhang Miao; Lin Chenglu

    2001-01-01

    Si(100) crystal implanted by 5 x 10 16 cm -2 , 140 keV He + was probed by slow positron beam, and defect distribution along depth was obtained from the relation between S parameter and positron incidence energy. The near surface region of implanted sample was only slightly damaged. Small vacancies and vacancy clusters less than 1 nm in diameter were the dominant defects, while the deeper region around the He + projected range was heavily damaged and had dense larger helium micro-bubbles and microvoids. Thermal anneal study at different temperatures showed that low temperature annealing could remove most vacancy-type defects effectively. However, annealing at high temperature enlarged the diameters of micro-bubbles and microvoids

  2. CLINICOPATHOLOGICAL FACTORS ASSOCIATED WITH POSITIVE PREOPERATIVE AXILLARY ULTRASOUND SCANNING IN BREAST CANCER PATIENTS

    Directory of Open Access Journals (Sweden)

    Lona Jalini

    2016-01-01

    Full Text Available Background: Axillary lymph node status is the most important breast cancer prognostic factor. Preoperative axillary ultrasound examination (PAUS is used to triage patients for sentinel lymph node biopsy (SLNB or axillary lymph node dissection (ALND. We assessed the detection rate of lymph node metastases by PAUS in a screening unit and evaluated associations between clinicopathological factors and PAUS positivity. Patients and Methods: This was a single-centre retrospective analysis of data extracted from a hospital breast cancer database and clinical records. Clinical, radiological, and pathological and prognostic indices were compared between PAUS-positive and PAUS-negative patients subsequently found to have lymph node metastases on histopathological analysis. Results: Two hundred and two patients were eligible for analysis. 50.5% of lymph node-positive patients were correctly identified as PAUS positive. Patients with PAUS-positive lymph nodes had less favorable disease characteristics, namely clinically palpable lymph nodes, higher Nottingham prognostic (NPI index, high lymph node burden according to the European Society of Medical Oncology (ESMO group classification, and larger, grade 3 tumors with lymphovascular invasion and extranodal spread. Moreover, PAUS-positive patients had more macrometastases and lymph node involvement than PAUS-negative patients. Conclusion: PAUS-positive patients and PAUS-negative (SLNB-positive patients have different clinicopathological characteristics. The presence of LVI, extranodal spread, grade 3 histology, or large tumors with poor prognostic indices in PAUS-negative patients should be regarded with caution and perhaps prompt second-look ultrasound examination.

  3. Positron spectroscopy as an analytical tool in material sciences

    International Nuclear Information System (INIS)

    Pujari, P.K.

    2010-01-01

    Full text: Positron annihilation spectroscopy has emerged as a powerful tool in material sciences due to its ability to provide information about the electron momentum distribution and electron density in a given medium. These features help in identifying altered state of electronic rearrangements as one encounters in phase transitions. In addition, positrons prefer regions of lower electron density such as open volume defects i.e. vacancies or vacancy clusters in metals, alloys and semiconductors or free-volumes in molecular solids. Its sensitivity to defects is extremely high e.g. it can detect as small a defect as monovacancy to concentration as low as parts per million(ppm). Innovative nuclear instrumentation has helped in getting chemical specificity at the annihilation site. For example, precipitates, embedded, nanoparticles or element decorated vacancies can now be easily identified. This presentation is structured to introduce the technique and provide a global perspective on area of applications. Specific examples on defect characterization, nanostructure-property correlations in polymers, advantages of elemental specificity by indexing the core electron momentum will be given. In addition, slow positron beam based studies on nanostructured materials as well as particle accelerator based positron spectroscopy for volumetric assay of defects in large engineering samples will be presented

  4. Characterization of defects in metals by positron-annihilation spectroscopy

    International Nuclear Information System (INIS)

    Siegel, R.W.

    1981-10-01

    The application of positron-annihilation spectroscopy (PAS) to the characterization and study of defects in metals has grown rapidly and increasingly useful in recent years. Owing to the ability of the positron to annihilate from a variety of defect-trapped states in metals, PAS can yield defect-specific information which, by itself or in conjunction with more traditional experimental techniques, has already made a significant impact upon our knowledge regarding lattice defect properties in metals. This has been especially true for vacancy defets, as a result of the positron's affinity for lower-than-average electron-density regions in the metal. The physical basis for the positron annihilation techniques is presented in this paper; and the experimental techniques, lifetime, Doppler broadening, and angular correlation, are briefly described and compared with respect to the information that can be obtained from each of them. A number of examples of the application of PAS to the characterization of atomic defects and their agglomerates are presented. The particular examples, chosen from the areas of equilibrium vacancy formation and atomic-defect recovery, were selected with a view toward elucidating the particular advantages of PAS over more traditional defect-characterization techniques. Limitations of PAS are also pointed out. 98 references

  5. High energy positron imaging

    International Nuclear Information System (INIS)

    Chen Shengzu

    2003-01-01

    The technique of High Energy Positron Imaging (HEPI) is the new development and extension of Positron Emission Tomography (PET). It consists of High Energy Collimation Imaging (HECI), Dual Head Coincidence Detection Imaging (DHCDI) and Positron Emission Tomography (PET). We describe the history of the development and the basic principle of the imaging methods of HEPI in details in this paper. Finally, the new technique of the imaging fusion, which combined the anatomical image and the functional image together are also introduced briefly

  6. Electrical properties of MOS structures on nitrogen-doped Czochralski-grown silicon: A positron annihilation study

    International Nuclear Information System (INIS)

    Slugen, V.; Harmatha, L.; Tapajna, M.; Ballo, P.; Pisecny, P.; Sik, J.; Koegel, G.; Krsjak, V.

    2006-01-01

    Measurements of interface trap density, effective generation lifetime (GL) and effective surface generation velocity have been performed using different methods on selected MOS structures prepared on nitrogen-doped Czochralski-grown (NCz) silicon. The application of the positron annihilation technique using a pulsed low energy positron system (PLEPS) focused on the detection of nitrogen-related defects in NCz silicon in the near surface region. In the case of p-type Cz silicon, all the results could be used for the testing of homogeneity. In n-type Cz silicon, positron annihilation was found insensitive to nitrogen doping

  7. Positron emission tomography (PET) in psychiatry

    International Nuclear Information System (INIS)

    Buchsbaum, M.S.

    1984-01-01

    In the past the approach to the brain has been necessarily indirect, employing peripheral fluids to assess central and regional neurochemical processes. Blood, urine, skin and muscle biopsy, and cerebrospinal fluid are valuable reflectors of the neurochemical and neuropharmacological activity of the brain, but are removed in time and place from disordered thought processes and diluted by the products of both functional and dysfunctional brain systems. Biopsy studies have helped in studying the functional disorders of organs like the liver, but they are destructive to the brain and less useful because unlike these organs, the brain has a regional variation in its chemistry. The experimental insights from animal studies focusing on the pharmacology of individual cell groups - in striatum or locus coeruleus, for example - cannot easily or unambigiously be applied to clinical populations. Positron emission tomography (PET) is a versatile approach utilizing the mathematics of x-ray transmission scanning (CT scanning) to produce slice images of radioisotope distribution. PET makes possible a wide range of metabolic studies. Positron emitters such as carbon-11 or fluorine-18 can be used to label glucose, amino acids, drugs, neurotransmitter precursors, and many other molecules and examine their distribution and fate in discrete cell groups

  8. High intensity positron program at LLNL

    International Nuclear Information System (INIS)

    Asoka-Kumar, P.; Howell, R.; Stoeffl, W.; Carter, D.

    1999-01-01

    Lawrence Livermore National Laboratory (LLNL) is the home of the world's highest current beam of keV positrons. The potential for establishing a national center for materials analysis using positron annihilation techniques around this capability is being actively pursued. The high LLNL beam current will enable investigations in several new areas. We are developing a positron microprobe that will produce a pulsed, focused positron beam for 3-dimensional scans of defect size and concentration with submicron resolution. Below we summarize the important design features of this microprobe. Several experimental end stations will be available that can utilize the high current beam with a time distribution determined by the electron linac pulse structure, quasi-continuous, or bunched at 20 MHz, and can operate in an electrostatic or (and) magnetostatic environment. Some of the planned early experiments are: two-dimensional angular correlation of annihilation radiation of thin films and buried interfaces, positron diffraction holography, positron induced desorption, and positron induced Auger spectroscopy

  9. High intensity positron program at LLNL

    International Nuclear Information System (INIS)

    Asoka-Kumar, P.; Howell, R.H.; Stoeffl, W.

    1998-01-01

    Lawrence Livermore National Laboratory (LLNL) is the home of the world's highest current beam of keV positrons. The potential for establishing a national center for materials analysis using positron annihilation techniques around this capability is being actively pursued. The high LLNL beam current will enable investigations in several new areas. We are developing a positron microprobe that will produce a pulsed, focused positron beam for 3-dimensional scans of defect size and concentration with submicron resolution. Below we summarize the important design features of this microprobe. Several experimental end stations will be available that can utilize the high current beam with a time distribution determined by the electron linac pulse structure, quasi-continuous, or bunched at 20 MHz, and can operate in an electrostatic or (and) magnetostatic environment. Some of the planned early experiments are: two-dimensional angular correlation of annihilation radiation of thin films and buried interfaces, positron diffraction holography, positron induced desorption, and positron induced Auger spectra

  10. Positron and positronium annihilation in silica-based thin films studied by a pulsed positron beam

    International Nuclear Information System (INIS)

    Suzuki, R.; Ohdaira, T.; Kobayashi, Y.; Ito, K.; Shioya, Y.; Ishimaru, T.

    2003-01-01

    Positron and positronium annihilation in silica-based thin films has been investigated by means of measurement techniques with a monoenergetic pulsed positron beam. The age-momentum correlation study revealed that positron annihilation in thermally grown SiO 2 is basically the same as that in bulk amorphous SiO 2 while o-Ps in the PECVD grown SiCOH film predominantly annihilate with electrons of C and H at the microvoid surfaces. We also discuss time-dependent three-gamma annihilation in porous low-k films by two-dimensional positron annihilation lifetime spectroscopy

  11. Ultrasound-guided approach for axillary brachial plexus, femoral nerve, and sciatic nerve blocks in dogs.

    Science.gov (United States)

    Campoy, Luis; Bezuidenhout, Abraham J; Gleed, Robin D; Martin-Flores, Manuel; Raw, Robert M; Santare, Carrie L; Jay, Ariane R; Wang, Annie L

    2010-03-01

    To describe an ultrasound-guided technique and the anatomical basis for three clinically useful nerve blocks in dogs. Prospective experimental trial. Four hound-cross dogs aged 2 +/- 0 years (mean +/- SD) weighing 30 +/- 5 kg and four Beagles aged 2 +/- 0 years and weighing 8.5 +/- 0.5 kg. Axillary brachial plexus, femoral, and sciatic combined ultrasound/electrolocation-guided nerve blocks were performed sequentially and bilaterally using a lidocaine solution mixed with methylene blue. Sciatic nerve blocks were not performed in the hounds. After the blocks, the dogs were euthanatized and each relevant site dissected. Axillary brachial plexus block Landmark blood vessels and the roots of the brachial plexus were identified by ultrasound in all eight dogs. Anatomical examination confirmed the relationship between the four ventral nerve roots (C6, C7, C8, and T1) and the axillary vessels. Three roots (C7, C8, and T1) were adequately stained bilaterally in all dogs. Femoral nerve block Landmark blood vessels (femoral artery and femoral vein), the femoral and saphenous nerves and the medial portion of the rectus femoris muscle were identified by ultrasound in all dogs. Anatomical examination confirmed the relationship between the femoral vessels, femoral nerve, and the rectus femoris muscle. The femoral nerves were adequately stained bilaterally in all dogs. Sciatic nerve block. Ultrasound landmarks (semimembranosus muscle, the fascia of the biceps femoris muscle and the sciatic nerve) could be identified in all of the dogs. In the four Beagles, anatomical examination confirmed the relationship between the biceps femoris muscle, the semimembranosus muscle, and the sciatic nerve. In the Beagles, all but one of the sciatic nerves were stained adequately. Ultrasound-guided needle insertion is an accurate method for depositing local anesthetic for axillary brachial plexus, femoral, and sciatic nerve blocks.

  12. Positron emission tomography of FDG in schizophrenia

    International Nuclear Information System (INIS)

    Sargent, T. III; Kusubov, N.

    1986-01-01

    The use of the Donner dynamic positron emission tomograph to study fluorodeoxyglucose labelled 18 F uptake in the brain of six patients with schizophrenia is reported. The glucose metabolic rate and the local cerebral metabolic rate were calculated. The dynamic brain uptake data and the blood input function were used to calculate rate constants by an iterative least squares fitting program for all regions of interest chosen in the brain. Although the number of patients was small, differences in k3 were statistically significant in several brain regions compared with normal controls

  13. Regional Cerebral Glucose Metabolism in Novelty Seeking and Antisocial Personality: A Positron Emission Tomography Study.

    Science.gov (United States)

    Park, So Hyeon; Park, Hyun Soo; Kim, Sang Eun

    2016-08-01

    Novelty seeking (NS) and antisocial personality (ASP) are commonly exhibited by those who suffer from addictions, such as substance abuse. NS has been suggested to be a fundamental aspect of ASP. To investigate the neurobiological substrate of NS and ASP, we tested the relationship between regional cerebral glucose metabolism and the level of NS, determining the differences between individuals with and without ASP. Seventy-two healthy adults (43 males, mean age±SD=38.8±16.6 years, range=20~70 years; 29 females, 44.2±20.1 years, range=19~72 years) underwent resting-state brain positron emission tomography (PET) 40 minutes after (18)F-fluorodeoxyglucose (FDG) injection. Within 10 days of the FDG PET study, participants completed Cloninger's 240-item Temperament and Character Inventory (TCI) to determine NS scores. Participants with and without ASP were grouped according to their TCI profiles. Statistical parametric mapping analysis was performed using the FDG PET and TCI profile data. NS scores positively correlated with metabolism in the left anterior cingulate gyrus and the insula on both sides of the brain and negatively correlated with metabolism in the right pallidum and putamen. Participants with ASP showed differences in cerebral glucose metabolism across various cortical and subcortical regions, mainly in the frontal and prefrontal areas. These data demonstrate altered regional cerebral glucose metabolism in individuals with NS and ASP and inform our understanding of the neurobiological substrates of problematic behaviors and personality disorders.

  14. Axillary node metastasis from differentiated thyroid carcinoma with hürthle and signet ring cell differentiation. A case of disseminated thyroid cancer with peculiar histologic findings

    International Nuclear Information System (INIS)

    Chiofalo, Maria Grazia; Losito, Nunzia Simona; Fulciniti, Franco; Setola, Sergio Venanzio; Tommaselli, Antonio; Marone, Ugo; Di Cecilia, Maria Luisa; Pezzullo, Luciano

    2012-01-01

    Differentiated thyroid cancer is usually associated with an excellent prognosis and indolent course. Distant metastases are rare events at the onset of thyroid cancer. Among these presentations, metastasis to the axillary lymph nodes is even more unusual: only few cases were previously reported in the literature; there has been no report of axillary lymph node metastasis from follicular thyroid carcinoma. Axillary lymph node metastasis generally arises in the context of disseminated disease and carries an ominous prognosis. Here we present a case of axillary lymph node metastasis in the context of disseminated differentiated thyroid cancer. The patient underwent near total thyroidectomy and neck and axillary lymph node dissection. A histopathological diagnosis of poorly differentiated follicular carcinoma with 'signet ring cells' and Hürthle cell features was established. The patient received radioactive iodine therapy and TSH suppression therapy. Subsequently his serum thyroglobulin level decreased to 44.000 ng/ml from over 100.000 ng/ml. Currently there are only few reported cases of axillary node metastases from thyroid cancer, and to our knowledge, this is the first report on axillary lymph node metastasis from follicular thyroid carcinoma. 'Signet ring cell' is a morphologic feature shared by both benign and, more rarely, malignant follicular thyroid neoplasm, and it generally correlates with an arrest in folliculogenesis. Our case is one of the rare 'signet ring cells' carcinomas so far described

  15. Tangential vs. defined radiotherapy in early breast cancer treatment without axillary lymph node dissection. A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Nitsche, Mirko [Zentrum fuer Strahlentherapie und Radioonkologie, Bremen (Germany); Universitaet Kiel, Klinik fuer Strahlentherapie, Karl-Lennert-Krebscentrum, Kiel (Germany); Temme, Nils; Foerster, Manuela; Reible, Michael [Zentrum fuer Strahlentherapie und Radioonkologie, Bremen (Germany); Hermann, Robert Michael [Zentrum fuer Strahlentherapie und Radioonkologie, Bremen (Germany); Medizinische Hochschule Hannover, Abteilung Strahlentherapie und Spezielle Onkologie, Hannover (Germany)

    2014-08-15

    Recent studies have demonstrated low regional recurrence rates in early-stage breast cancer omitting axillary lymph node dissection (ALND) in patients who have positive nodes in sentinel lymph node dissection (SLND). This finding has triggered an active discussion about the effect of radiotherapy within this approach. The purpose of this study was to analyze the dose distribution in the axilla in standard tangential radiotherapy (SRT) for breast cancer and the effects on normal tissue exposure when anatomic level I-III axillary lymph node areas are included in the tangential radiotherapy field configuration. We prospectively analyzed the dosimetric treatment plans from 51 consecutive women with early-stage breast cancer undergoing radiotherapy. We compared and analyzed the SRT and the defined radiotherapy (DRT) methods for each patient. The clinical target volume (CTV) of SRT included the breast tissue without specific contouring of lymph node areas, whereas the CTV of DRT included the level I-III lymph node areas. We evaluated the dose given in SRT covering the axillary lymph node areas of level I-III as contoured in DRT. The mean V{sub D95} {sub %} of the entire level I-III lymph node area in SRT was 50.28 % (range, 37.31-63.24 %), V{sub D45} {sub Gy} was 70.1 % (54.8-85.4 %), and V{sub D40} {sub Gy} was 83.5 % (72.3-94.8 %). A significant difference was observed between lung dose and heart toxicity in SRT vs. DRT. The V{sub 20} {sub Gy} and V{sub 30} {sub Gy} of the right and the left lung in DRT were significantly higher in DRT than in SRT (p < 0.001). The mean heart dose in SRT was significantly lower (3.93 vs. 4.72 Gy, p = 0.005). We demonstrated a relevant dose exposure of the axilla in SRT that should substantially reduce local recurrences. Furthermore, we demonstrated a significant increase in lung and heart exposure when including the axillary lymph nodes regions in the tangential radiotherapy field set-up. (orig.) [German] Aktuelle Studien zeigen

  16. Positron implantation profile in kapton

    International Nuclear Information System (INIS)

    Plotkowski, K.; Panek, T.J.; Kansj, J.

    1988-01-01

    Measurements of positrons' implantation profile were made with geometry as in the majority of PAT experiments, making use of the difference in values of mean lifetimes of positrons in the absorber and in the detector. The function describing the absorption of positrons in the absorber taking into account measurement geometry was fitted to the experimental data. The correction to the exponential relation occurring in this function is the dominating factor for small thicknesses of the absorber. In this analysis various values of positrons' backscatter coefficients of the nickel and of the kapton were also taken into account

  17. The Positron-Electron Correlation Energy In ZnO Calculated With The Modified Single Wave Function Of Positron

    International Nuclear Information System (INIS)

    Chau Van Tao; Trinh Hoa Lang; Le Hoang Chien; Nguyen Huu Loc; Nguyen Anh Tuan

    2011-01-01

    Positron-electron correlation energy of the ZnO - positron system is studied on assumption that positron binds with the outer shell electrons of Zinc and Oxygen to form the pseudo ZnO - positron molecule before it annihilates with one of these electrons. In this work, the single wave function for positron is form by LCAO approximation and is modified according to the principle of linear superposition, and by using Variational Quantum Monte Carlo method (VQMC) [7] the correlation energy of this system is estimated with the value E c e-p = - 9.3 ± 1.1 eV. In the theoretical aspect it turns out that this result is more reasonable and closer to those of other methods [3] than the one which is done without modifying the wave function of positron [1]. To confirm this legitimate approach, however, the further calculations of positron annihilation rate in ZnO have to be carried out in our next work. (author)

  18. Positron emission tomography in movement disorders

    International Nuclear Information System (INIS)

    Martin, W.R.W.

    1985-01-01

    Positron emission tomography provides a method for the quantitation of regional function within the living human brain. Studies of cerebral metabolism and blood flow in patients with Huntington's disease, Parkinson's disease and focal dystonia have revealed functional abnormalities within substructures of the basal ganglia. Recent developments permit assessment of both pre-synaptic and post-synaptic function ion dopaminergic pathways. These techniques are now being applied to studies of movement disorders in human subjects

  19. Positron emission tomography in movement disorders

    Energy Technology Data Exchange (ETDEWEB)

    Martin, W R.W.

    1985-02-01

    Positron emission tomography provides a method for the quantitation of regional function within the living human brain. Studies of cerebral metabolism and blood flow in patients with Huntington's disease, Parkinson's disease and focal dystonia have revealed functional abnormalities within substructures of the basal ganglia. Recent developments permit assessment of both pre-synaptic and post-synaptic function in dopaminergic pathways. These techniques are now being applied to studies of movement disorders in human subjects.

  20. A Southern African positron beam

    International Nuclear Information System (INIS)

    Britton, D.T.; Haerting, M.; Teemane, M.R.B.; Mills, S.; Nortier, F.M.; Van der Walt, T.N.

    1997-01-01

    The first stage of a state of the art positron beam, being constructed at the University of Cape Town, is currently being brought into operation. This is the first positron beam on the African continent, as well as being the first positron beam dedicated to solid and surface studies in the southern hemisphere. The project also contains a high proportion of local development, including the encapsulated 22 Na positron source developed by our collaboration. Novel features in the design include a purely magnetic in-line deflector, working in the solenoidal guiding field, to eliminate unmoderated positrons and block the direct line of sight to the source. A combined magnetic projector and single pole probe forming lens is being implemented in the second phase of construction to achieve a spot size of 10 μm without remoderation

  1. Positron Transport and Annihilation in the Galactic Bulge

    Directory of Open Access Journals (Sweden)

    Fiona Helen Panther

    2018-03-01

    Full Text Available The annihilation of positrons in the Milky Way Galaxy has been observed for ∼50 years; however, the production sites of these positrons remains hard to identify. The observed morphology of positron annihilation gamma-rays provides information on the annihilation sites of these Galactic positrons. It is understood that the positrons responsible for the annihilation signal originate at MeV energies. The majority of sources of MeV positrons occupy the star-forming thin disk of the Milky Way. If positrons propagate far from their sources, we must develop accurate models of positron propagation through all interstellar medium (ISM phases in order to reveal the currently uncertain origin of these Galactic positrons. On the other hand, if positrons annihilate close to their sources, an alternative source of MeV positrons with a distribution that matches the annihilation morphology must be identified. In this work, I discuss the various models that have been developed to understand the origin of the 511 keV line from the direction of the Galactic bulge, and the propagation of positrons in the ISM.

  2. Brain metabolism in autism. Resting cerebral glucose utilization rates as measured with positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Rumsey, J.M.; Duara, R.; Grady, C.; Rapoport, J.L.; Margolin, R.A.; Rapoport, S.I.; Cutler, N.R.

    1985-05-01

    The cerebral metabolic rate for glucose was studied in ten men (mean age = 26 years) with well-documented histories of infantile autism and in 15 age-matched normal male controls using positron emission tomography and (F-18) 2-fluoro-2-deoxy-D-glucose. Positron emission tomography was completed during rest, with reduced visual and auditory stimulation. While the autistic group as a whole showed significantly elevated glucose utilization in widespread regions of the brain, there was considerable overlap between the two groups. No brain region showed a reduced metabolic rate in the autistic group. Significantly more autistic, as compared with control, subjects showed extreme relative metabolic rates (ratios of regional metabolic rates to whole brain rates and asymmetries) in one or more brain regions.

  3. Brain metabolism in autism. Resting cerebral glucose utilization rates as measured with positron emission tomography

    International Nuclear Information System (INIS)

    Rumsey, J.M.; Duara, R.; Grady, C.; Rapoport, J.L.; Margolin, R.A.; Rapoport, S.I.; Cutler, N.R.

    1985-01-01

    The cerebral metabolic rate for glucose was studied in ten men (mean age = 26 years) with well-documented histories of infantile autism and in 15 age-matched normal male controls using positron emission tomography and (F-18) 2-fluoro-2-deoxy-D-glucose. Positron emission tomography was completed during rest, with reduced visual and auditory stimulation. While the autistic group as a whole showed significantly elevated glucose utilization in widespread regions of the brain, there was considerable overlap between the two groups. No brain region showed a reduced metabolic rate in the autistic group. Significantly more autistic, as compared with control, subjects showed extreme relative metabolic rates (ratios of regional metabolic rates to whole brain rates and asymmetries) in one or more brain regions

  4. The Use of Ultrasound to Improve Axillary Vein Access and Minimize Complications during Pacemaker Implantation.

    Science.gov (United States)

    Esmaiel, Abdullah; Hassan, Jeremy; Blenkhorn, Fay; Mardigyan, Vartan

    2016-05-01

    The Agency for Healthcare Research and Quality in the United States recommends the use of ultrasound (US) for central venous access to improve patient outcomes. However, in a recent publication, US is still underutilized for axillary vein access during pacemaker implantation. We sought to describe a technique for US-guided axillary vein access during pacemaker implantation and to report complication rates and success rate. Retrospective data collection included success rate and complications on all pacemaker implants by one operator since implementing the systematic use of US at our institution, from November 2012 to January 2015. For the last 59 cases, data were collected prospectively to include time of venous access and number of attempts. A total of 403 consecutive patients were included in the analysis. Two leads were implanted in 255 cases and one lead was implanted in 148 cases. The rate of successful US-guided access was 99.25%. There were no access-related complications. The average number of venipuncture attempts was 1.18 per patient. The average time to obtain venous access was 2.24 minutes including the time to apply the sterile US sleeve. The described technique has the potential to improve the success rate of axillary vein access and minimize complications during pacemaker implantation. ©2016 Wiley Periodicals, Inc.

  5. Comparison of the effect of diode laser versus intense pulsed light in axillary hair removal.

    Science.gov (United States)

    Ormiga, Patricia; Ishida, Cleide Eiko; Boechat, Alvaro; Ramos-E-Silva, Marcia

    2014-10-01

    Devices such as diode laser and intense pulsed light (IPL) are in constant development aiming at permanent hair removal, but there are few comparative studies between these technologies. The objective was to comparatively assess axillary hair removal performed by diode laser and IPL and to obtain parameters of referred pain and evolution response for each method. A comparative prospective, double-blind, and randomized study of axillary hair removal performed by the diode laser and IPL was conducted in 21 females. Six sessions were held with application of the diode laser in one axilla and the IPL in the other, with intervals of 30 days and follow-up of 6 months after the last session. Clinical photographs and digital dermoscopy for hair counts in predefined and fixed fields of the treated areas were performed before, 2 weeks after the sixth session, and 6 months after the end of treatment. A questionnaire to assess the pain was applied. The number of hair shafts was significantly reduced with the diode laser and IPL. The diode laser was more effective, although more painful than the IPL. No serious, adverse, or permanent effects were observed with both technologies. Both diode laser and the IPL are effective, safe, and able to produce lasting results in axillary hair removal.

  6. Positron emission tomography

    International Nuclear Information System (INIS)

    Yamamoto, Y.L.; Thompson, C.J.; Diksic, M.; Meyer, E.; Feindel, W.H.

    1984-01-01

    One of the most exciting new technologies introduced in the last 10 yr is positron emission tomography (PET). PET provides quantitative, three-dimensional images for the study of specific biochemical and physiological processes in the human body. This approach is analogous to quantitative in-vivo autoradiography but has the added advantage of permitting non-invasive in vivo studies. PET scanning requires a small cyclotron to produce short-lived positron emitting isotopes such as oxygen-15, carbon-11, nitrogen-13 and fluorine-18. Proper radiochemical facilities and advanced computer equipment are also needed. Most important, PET requires a multidisciplinary scientific team of physicists, radiochemists, mathematicians, biochemists and physicians. The most recent trends are reviewed in the imaging technology, radiochemistry, methodology and clinical applications of positron emission tomography. (author)

  7. Locoregional Recurrence After Sentinel Lymph Node Dissection With or Without Axillary Dissection in Patients With Sentinel Lymph Node Metastases: Long-term Follow-up From the American College of Surgeons Oncology Group (Alliance) ACOSOG Z0011 Randomized Trial.

    Science.gov (United States)

    Giuliano, Armando E; Ballman, Karla; McCall, Linda; Beitsch, Peter; Whitworth, Pat W; Blumencranz, Peter; Leitch, A Marilyn; Saha, Sukamal; Morrow, Monica; Hunt, Kelly K

    2016-09-01

    The early results of the American College of Surgeons Oncology Group (ACOSOG) Z0011 trial demonstrated no difference in locoregional recurrence for patients with positive sentinel lymph nodes (SLNs) randomized either to axillary lymph node dissection (ALND) or sentinel lymph node dissection (SLND) alone. We now report long-term locoregional recurrence results. ACOSOG Z0011 prospectively examined overall survival of patients with SLN metastases undergoing breast-conserving therapy randomized to undergo ALND after SLND or no further axillary specific treatment. Locoregional recurrence was prospectively evaluated and compared between the groups. Four hundred forty-six patients were randomized to SLND alone and 445 to SLND and ALND. Both groups were similar with respect to age, Bloom-Richardson score, Estrogen Receptor status, adjuvant systemic therapy, histology, and tumor size. Patients randomized to ALND had a median of 17 axillary nodes removed compared with a median of only 2 SLNs removed with SLND alone (P alone arm (P = 0.28). Ten-year cumulative locoregional recurrence was 6.2% with ALND and 5.3% with SLND alone (P = 0.36). Despite the potential for residual axillary disease after SLND, SLND without ALND offers excellent regional control for selected patients with early metastatic breast cancer treated with breast-conserving therapy and adjuvant systemic therapy.

  8. High intensity positron program at LLNL

    International Nuclear Information System (INIS)

    Asoka-Kumar, P.; Howell, R.; Stoeffl, W.; Carter, D.

    1999-01-01

    Lawrence Livermore National Laboratory (LLNL) is the home of the world close-quote s highest current beam of keV positrons. The potential for establishing a national center for materials analysis using positron annihilation techniques around this capability is being actively pursued. The high LLNL beam current will enable investigations in several new areas. We are developing a positron microprobe that will produce a pulsed, focused positron beam for 3-dimensional scans of defect size and concentration with submicron resolution. Below we summarize the important design features of this microprobe. Several experimental end stations will be available that can utilize the high current beam with a time distribution determined by the electron linac pulse structure, quasi-continuous, or bunched at 20 MHz, and can operate in an electrostatic or (and) magnetostatic environment. Some of the planned early experiments are: two-dimensional angular correlation of annihilation radiation of thin films and buried interfaces, positron diffraction holography, positron induced desorption, and positron induced Auger spectroscopy. copyright 1999 American Institute of Physics

  9. Prognostic significance of pathological response of primary tumor and metastatic axillary lymph nodes after neoadjuvant chemotherapy for locally advanced breast carcinoma.

    Science.gov (United States)

    Machiavelli, M R; Romero, A O; Pérez, J E; Lacava, J A; Domínguez, M E; Rodríguez, R; Barbieri, M R; Romero Acuña, L A; Romero Acuña, J M; Langhi, M J; Amato, S; Ortiz, E H; Vallejo, C T; Leone, B A

    1998-01-01

    The prognostic significance of pathological response of primary tumor and metastatic axillary lymph nodes after neoadjuvant chemotherapy was assessed in patients with noninflammatory locally advanced breast carcinoma. Between January 1989 and April 1995, 148 consecutive patients with locally advanced breast carcinoma participated in the study. Of these, 140 fully evaluable patients (67, stage IIIA; 73, stage IIIB) were treated with three courses of 5-fluorouracil, doxorubicin, and cyclophosphamide (FAC), followed by modified radical mastectomy when technically feasible or definitive radiation therapy. The median age was 53 years (range, 26 to 75 years); 55% of patients were postmenopausal. Objective response was recorded in 99 of 140 patients (71%; 95% confidence interval, 63% to 79%). Complete response occurred in 11 patients (8%), and partial response occurred in 88 patients (63%). No change was recorded in 37 patients (26%), and progressive disease occurred in 4 patients (3%). One hundred and thirty-six patients underwent the planned surgery. Maximal pathological response of the primary tumor (in situ carcinoma or minimal microscopic residual tumor) was observed in 24 (18%); 112 patients (82%) presented minimal pathological response of the primary tumor (gross residual tumor). The number of metastatic axillary nodes after neoadjuvant chemotherapy was as follows: N0, 39 patients (29%); N1-N3, 35 patients (26%); > N3, 62 patients (45%). Considering the initial TNM status, 75% of the patients had decreases in tumor compartment after neoadjuvant chemotherapy. Also, 31% and 23% of patients with clinical N1 and N2, respectively, showed uninvolved axillary lymph nodes. A significant correlation was noted between pathological response of primary tumor and the number of metastatic axillary lymph nodes. Median disease-free survival was 34 months, whereas median overall survival was 66 months. Pathological responses of both primary tumor and metastatic axillary lymph nodes

  10. PF slow positron source

    International Nuclear Information System (INIS)

    Shirakawa, A.; Enomoto, A.; Kurihara, T.

    1993-01-01

    A new slow-positron source is under construction at the Photon Factory. Positrons are produced by bombarding a tantalum rod with high-energy electrons; they are moderated in multiple tungsten vanes. We report here the present status of this project. (author)

  11. Positron spectroscopy of 2D materials using an advanced high intensity positron beam

    Science.gov (United States)

    McDonald, A.; Chirayath, V.; Lim, Z.; Gladen, R.; Chrysler, M.; Fairchild, A.; Koymen, A.; Weiss, A.

    An advanced high intensity variable energy positron beam(~1eV to 20keV) has been designed, tested and utilized for the first coincidence Doppler broadening (CDB) measurements on 6-8 layers graphene on polycrystalline Cu sample. The system is capable of simultaneous Positron annihilation induced Auger electron Spectroscopy (PAES) and CDB measurements giving it unparalleled sensitivity to chemical structure at external surfaces, interfaces and internal pore surfaces. The system has a 3m flight path up to a micro channel plate (MCP) for the Auger electrons emitted from the sample. This gives a superior energy resolution for PAES. A solid rare gas(Neon) moderator was used for the generation of the monoenergetic positron beam. The positrons were successfully transported to the sample chamber using axial magnetic field generated with a series of Helmholtz coils. We will discuss the PAES and coincidence Doppler broadening measurements on graphene -Cu sample and present an analysis of the gamma spectra which indicates that a fraction of the positrons implanted at energies 7-60eV can become trapped at the graphene/metal interface. This work was supported by NSF Grant No. DMR 1508719 and DMR 1338130.

  12. Successful ablation of a right atrium-axillary ventricular accessory pathway associated with Wolff-Parkinson-White syndrome.

    Science.gov (United States)

    Yuan, Yuan; Long, Deyong; Dong, Jianzeng; Tao, Ling; Ma, Changsheng

    2017-12-01

    We report a case of a patient with right axillary ventricular. Similar congenital anomaly of the right atrium was reported as "right appendage diverticulum or right atrial diverticulum." However, this independent chamber has its own annulus, synchronizes with the right ventricular, and generates large ventricular potential. Under the guidance of the CARTO mapping system (Biosense Webster, Diamond Bar, CA, USA), a right atrioventricular accessory pathway associated with type B Wolff-Parkinson-White syndrome was ablated successfully. This pathway was close to the annulus of the axillary ventricular. The patient remained free of arrhythmia at 1-year follow-up. © 2017 Wiley Periodicals, Inc.

  13. Positron depth profiling

    International Nuclear Information System (INIS)

    Coleman, P.

    2001-01-01

    Wide-ranging studies of defects below the surface of semiconductor structures have been performed at the University of Bath, in collaboration with the University of Surrey Centre for Ion Beam Applications and with members of research teams at a number of UK universities. Positron implantation has been used in conjunction with other spectroscopies such as RBS-channeling and SIMS, and electrical characterisation methods. Research has ranged from the development of a positron-based technique to monitor the in situ annealing of near-surface open-volume defects to the provision of information on defects to comprehensive diagnostic investigations of specific device structures. We have studied Si primarily but not exclusively; e.g., we have investigated ion-implanted SiC and SiO 2 /GaAs structures. Of particular interest are the applications of positron annihilation spectroscopy to ion-implanted semiconductors, where by linking ion dose to vacancy-type defect concentration one can obtain information on ion dose and uniformity with a sensitivity not achievable by standard techniques. A compact, user-friendly positron beam system is currently being developed at Bath, in collaboration with SCRIBA, with the intention of application in an industrial environment. (orig.)

  14. Positron annihilation induced Auger electron spectroscopy and its implementation at accelerator based low energy positron factories

    International Nuclear Information System (INIS)

    Weiss, A.; Koeymen, A.R.; Mehl, D.; Lee, K.H.; Yang Gimo; Jensen, K.

    1991-01-01

    Positron annihilation induced auger electron spectroscopy (PAES) makes use of a beam of low energy positrons to excite Auger transitions by annihilating core electrons. The large secondary electron background usually present in Auger spectra can be eliminated by setting the positron beam energy well below the Auger electron energy. This allows true Auger lineshapes to be obtained. Further, because the positron is localized just outside the surface before it annihilates, PAES is extremely sensitive to the topmost atomic layer. Recent PAES results obtained at the University of Texas at Arlington will be presented. In addition, the use of high resolution energy analyzers with multichannel particle detection schemes to prevent problems due to the high data rates associated with accelerator based positron beams will be discussed. (orig.)

  15. Nonlinear positron acoustic solitary waves

    International Nuclear Information System (INIS)

    Tribeche, Mouloud; Aoutou, Kamel; Younsi, Smain; Amour, Rabia

    2009-01-01

    The problem of nonlinear positron acoustic solitary waves involving the dynamics of mobile cold positrons is addressed. A theoretical work is presented to show their existence and possible realization in a simple four-component plasma model. The results should be useful for the understanding of the localized structures that may occur in space and laboratory plasmas as new sources of cold positrons are now well developed.

  16. Positron emission tomography. Basic principles

    International Nuclear Information System (INIS)

    Rodriguez, Jose Luis; Massardo, Teresa; Gonzalez, Patricio

    2001-01-01

    The basic principles of positron emission tomography (PET) technique are reviewed. lt allows to obtain functional images from gamma rays produced by annihilation of a positron, a positive beta particle. This paper analyzes positron emitters production in a cyclotron, its general mechanisms, and the various detection systems. The most important clinical applications are also mentioned, related to oncological uses of fluor-l8-deoxyglucose

  17. Compressive effect of the magnetic field on the positron range in commonly used positron emitters simulated using Geant4

    Science.gov (United States)

    Li, Chong; Cao, Xingzhong; Liu, Fuyan; Tang, Haohui; Zhang, Zhiming; Wang, Baoyi; Wei, Long

    2017-11-01

    The compressive effect of a magnetic field on the positron range from commonly used positron emitters in PET (Positron Emission Tomography) was simulated using the Geant4 toolkit with H2O as the environmental material. The compression of the positron range, which was different in the directions parallel and perpendicular to the magnetic field, showed finite final variation of relative change rate versus the magnetic field. The variation greatly depended on the positron-emission energy spectrum in the same medium. Furthermore, the volume of the positron annihilation point was dramatically compressed as the magnetic field was set in the range of 3-6T. It was more prominent for 82Rb , which is generally used as a positron source in PET technology.

  18. Positron annihilation studies of mesoporous silica films using a slow positron beam

    International Nuclear Information System (INIS)

    He Chunqing; Muramatsu, Makoto; Ohdaira, Toshiyuki; Kinomura, Atsushi; Suzuki, Ryoichi; Ito, Kenji; Kabayashi, Yoshinori

    2006-01-01

    Positron annihilation lifetime spectra were measured for mesoporous silica films, which were synthesized using triblock copolymer (EO 106 PO 70 EO 106 ) as a structure-directing agent. Different positron lifetime spectra for the deposited and calcined films indicated the formation of meso-structure after calcination, which was confirmed by Fourier transform infrared (FTIR) spectra and field emission-scanning electron microscopy (FE-SEM) observation. Open porosity or pore interconnectivity of a silica film might be evaluated by a two-dimensional positron annihilation lifetime spectrum of an uncapped film. Pore sizes and their distributions in the silica films were found to be affected by thermal treatments

  19. Minimum effective concentration of bupivacaine for axillary brachial plexus block guided by ultrasound

    Directory of Open Access Journals (Sweden)

    Alexandre Takeda

    2015-05-01

    Full Text Available Introduction: The use of ultrasound in regional anesthesia allows reducing the dose of local anesthetic used for peripheral nerve block. The present study was performed to determine the minimum effective concentration (MEC90 of bupivacaine for axillary brachial plexus block. Methods: Patients undergoing hand surgery were recruited. To estimate the MEC90, a sequential up-down biased coin method of allocation was used. The bupivacaine dose was 5 mL for each nerve (radial, ulnar, median, and musculocutaneous. The initial concentration was 0.35%. This concentration was changed by 0.05% depending on the previous block; a blockade failure resulted in increased concentration for the next patient; in case of success, the next patient could receive or reduction (0.1 probability or the same concentration (0.9 probability. Surgical anesthesia was defined as driving force ≤2 according to the modified Bromage scale, lack of thermal sensitivity and response to pinprick. Postoperative analgesia was assessed in the recovery room with numeric pain scale and the amount of drugs used within 4 h after the blockade. Results: MEC90 was 0.241% [R2: 0.978, confidence interval: 0.20–0.34%]. No patient, with successful block, reported pain after 4 h. Conclusion: This study demonstrated that ultrasound guided axillary brachial plexus block can be performed with the use of low concentration of local anesthetics, increasing the safety of the procedure. Further studies should be conducted to assess blockade duration at low concentrations. Resumo: Introdução: O uso do ultrassom na anestesia regional permite a redução da dose de anestésico local utilizada para o bloqueio de nervos periféricos. O presente estudo foi conduzido com o objetivo de determinar a concentração mínima efetiva (CME90 de bupivacaína para o bloqueio do plexo braquial via axilar (BPVA. Métodos: Pacientes submetidos a cirurgias da mão foram recrutados. Foi usado um método de alocação

  20. Positron annihilation spectroscopy

    International Nuclear Information System (INIS)

    Sundar, C.S.; Viswanathan, B.

    1996-01-01

    An overview of positron annihilation spectroscopy, the experimental techniques and its application to studies on defects and electronic structure of materials is presented. The scope of this paper is to present the requisite introductory material, that will enable a better appreciation of the subsequent specialized articles on the applications of positron annihilation spectroscopy to investigate various problems in materials science. (author). 31 refs., 3 figs

  1. Positron Studies of Oxide-Semiconductor Structures

    OpenAIRE

    Uedono , A.; Wei , L.; Kawano , T.; Tanigawa , S.; Suzuki , R.; Ohgaki , H.; Mikado , T.

    1995-01-01

    The annihilation characteristics of positrons in SiO2 films grown on Si substrates were studied by using monoenergetic positron beams. Doppler broadening profiles of the annihilation radiation and lifetime spectra of positrons were measured as a function of incident positron energy for SiO2/Si structures fabricated by various oxidation techniques. From the measurements, it was found that the formation probability of positronium (Ps) atoms in SiO2 films strongly depends on the growth condition...

  2. Positron-annihilation study of oxygen-deficient YBa2Cu3Ox (6.3

    International Nuclear Information System (INIS)

    Tang, C.Q.; Li, B.R.; Chen, A.

    1990-01-01

    We have measured the positron-lifetime spectra of oxygen-deficient YBa 2 Cu 3 O x for 6.3 m , τ 1 , τ 2 , and I 2 have a significant oxygen-content dependence. It is suggested that there are many kinds of positron states in polycrystalline YBa 2 Cu 3 O x , the disordering of O(1) vacancies strongly affects positron lifetime, and with gradually decreasing x the average electronic density decreases and the configuration and/or the charge states of the oxygen vacancies change in the region containing Cu(1)-O(1) chains

  3. Axillary Temperature, as Recorded by the iThermonitor WT701, Well Represents Core Temperature in Adults Having Noncardiac Surgery.

    Science.gov (United States)

    Pei, Lijian; Huang, Yuguang; Mao, Guangmei; Sessler, Daniel I

    2018-03-01

    Core temperature can be accurately measured from the esophagus or nasopharynx during general anesthesia, but neither site is suitable for neuraxial anesthesia. We therefore determined the precision and accuracy of a novel wireless axillary thermometer, the iThermonitor, to determine its suitability for use during neuraxial anesthesia and in other patients who are not intubated. We enrolled 80 adults having upper abdominal surgery with endotracheal intubation. Intraoperative core temperature was measured in distal esophagus and was estimated at the axilla with a wireless iThermonitor WT701 (Raiing Medical, Boston MA) at 5-minute intervals. Pairs of axillary and reference distal esophageal temperatures were compared and summarized using linear regression and repeated-measured Bland-Altman methods. We a priori determined that the iThermonitor would have clinically acceptable accuracy if most estimates were within ±0.5°C of the esophageal reference, and suitable precision if the limits of agreement were within ±0.5°C. There were 3339 sets of paired temperatures. Axillary and esophageal temperatures were similar, with a mean difference (esophageal minus axillary) of only 0.14°C ± 0.26°C (standard deviation). The Bland-Altman 95% limits of agreement were reasonably narrow, with the estimated upper limit at 0.66°C and the lower limit at -0.38°C, thus ±0.52°C, indicating good agreement across the range of mean temperatures from 34.9°C to 38.1°C. The absolute difference was within 0.5°C in 91% of the measurements (95% confidence interval, 88%-93%). Axillary temperature, as recorded by the iThermonitor WT701, well represents core temperature in adults having noncardiac surgery and thus appears suitable for clinical use.

  4. Depth-dependent positron annihilation in different polymers

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J.; Zhang, P.; Cheng, G.D.; Li, D.X.; Wu, H.B.; Li, Z.X.; Cao, X.Z. [Key Laboratory of Nuclear Analysis Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, No. 19 Yuquan Lu, Beijing 100049 (China); Jia, Q.J. [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, No. 19 Yuquan Lu, Beijing 100049 (China); Yu, R.S. [Key Laboratory of Nuclear Analysis Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, No. 19 Yuquan Lu, Beijing 100049 (China); Wang, B.Y., E-mail: wangboy@ihep.ac.cn [Key Laboratory of Nuclear Analysis Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, No. 19 Yuquan Lu, Beijing 100049 (China)

    2013-09-01

    Depth-dependent positron annihilation Doppler broadening measurements were conducted for polymers with different chemical compositions. Variations of the S parameter with respect to incident positron energy were observed. For pure hydrocarbons PP, HDPE and oxygen-containing polymer PC, S parameter rises with increasing positron implantation depth. While for PI and fluoropolymers like PTFE, ETFE and PVF, S parameter decreases with higher positron energy. For chlorine-containing polymer PVDC, S parameter remains nearly constant at all incident positron energies. It is suggested that these three variation trends are resulted from a competitive effect between the depth-dependent positronium formation and the influence of highly electronegative atoms on positron annihilation characteristics.

  5. Positron Annihilation in Thunderstorms Observed by ILDAS.

    Science.gov (United States)

    Kochkin, P.; Sarria, D., Sr.; Van Deursen, A.; de Boer, A.; Bardet, M.; Allasia, C.; Flourens, F.; Østgaard, N.

    2017-12-01

    Positron clouds within thunderstorms were for the first time reported in 2015 [Dwyer et al. 2015]. The observation was made by the Airborne Detector for Energetic Lightning Emissions (ADELE) in 2009 at 14.1 km altitude. Strong 511 keV line enhancement was recorded synchronously with nearby electrical activity. It lasted at least 0.2 s and was modeled as annihilation from disperse positron cloud more than a kilometer across. Different positron generation mechanisms were proposed in the paper. In January 2016 an Airbus A340 factory test aircraft was intentionally flying through thunderstorms over Northern Australia. The aircraft was equipped with a dedicated in-flight lightning detection system ILDAS (http://ildas.nlr.nl). The system contains two gamma-ray scintillation detectors each with 38x38 mm cylinder LaBr3 crystals. Total 9 video cameras were installed on-board to monitor the outer surfaces. When the aircraft flew at 12 km inside an active thundercloud, the ambient electric field was strong enough to trigger electrical discharges from the sharp edges. One sequence of such discharges was accompanied with enhancements of 511 keV line, each lasted for 0.5 - 1.0 s and total duration over 15 s. The video cameras recorded electrical discharges attached to the aircraft during this process. ILDAS reported brief 100 A current pulses in association with these discharges. Ground-based lightning location networks, i.e. WWLLN and local Australian LIAS, have not detected any sferics from this region. A detailed Geant4 model of the aircraft was created. The model was used to test different production mechanisms for the observed emission. In this presentation we will show a detailed reconstruction ofthe events with precise mapping on infrared cloud snapshot. Videos from the cameras at the positron detection moment will be shown. The results of the Geant4 simulation will be presented and discussed. References: 1. Dwyer, Joseph R., et al. "Positron clouds within thunderstorms

  6. Experimentation with low-energy positron beams

    International Nuclear Information System (INIS)

    Mills, A.P. Jr.

    1983-01-01

    The capability of studying the interactions of positrons with surfaces has recently been exploited by using ultra-high-vacuum techniques. The result has been a new understanding of how positrons interact with surfaces and because of this we are now able to make much stronger fluxes of slow positrons. The higher beam strengths in turn are opening up new possibilities for experimentation on surfaces and solids and for studying the atomic physics of positronium and positron-molecule scattering at low energies. The lectures are intended to review some of the history of this subject and to outline the present state of our knowledge of experimentation with low-energy positron beams. (orig./TW)

  7. Positron annihilation in vitreous silica glasses

    International Nuclear Information System (INIS)

    Uedono, Akira; Tanigawa, Shoichiro

    1993-01-01

    The annihilation characteristics of positrons in vitreous silica glasses (v-SiO 2 ) were studied by measurements of two-dimensional angular correlation of positron annihilation radiations and positron lifetime spectra. From the measurements, it was found that positrons and positronium (Ps) atoms mainly annihilate from trapped states by vacancy-type defects in v-SiO 2 . For v-SiO 2 specimens with cylindrical porous structures, annihilations of Ps with anisotropic momentum distributions were observed. This fact was attributed to the momentum uncertainty due to localization of Ps in a finite dimension of pores. This investigation showed possibilities for the detection of microstructures in v-SiO 2 by the positron annihilation technique. (author)

  8. Positrons in ionic crystals

    International Nuclear Information System (INIS)

    Pareja, R.

    1988-01-01

    Positron annihilation experiments in ionic crystals are reviewed and their results are arranged. A discussion about the positron states in these materials is made in the light of these results and the different proposed models. The positronium in alkali halides is specially considered. (Author)

  9. Positron annihilation studies of zirconia doped with metal cations of different valence

    Science.gov (United States)

    Prochazka, I.; Cizek, J.; Melikhova, O.; Konstantinova, T. E.; Danilenko, I. A.; Yashchishyn, I. A.; Anwand, W.; Brauer, G.

    2013-06-01

    New results obtained by applying positron annihilation spectroscopy to the investigation of zirconia-based nanomaterials doped with metal cations of different valence are reported. The slow-positron implantation spectroscopy combined with Doppler broadening measurements was employed to study the sintering of pressure-compacted nanopowders of tetragonal yttria-stabilised zirconia (t-YSZ) and t-YSZ with chromia additive. Positronium (Ps) formation in t-YSZ was proven by detecting 3γ-annihilations of ortho-Ps and was found to gradually decrease with increasing sintering temperature. A subsurface layer with enhanced 3γ-annihilations, compared to the deeper regions, could be identified. Addition of chromia was found to inhibit Ps formation. In addition, first results of positron lifetime measurements on nanopowders of zirconia phase-stabilised with MgO and CeO2 are presented.

  10. Positron annihilation in SiO 2-Si studied by a pulsed slow positron beam

    Science.gov (United States)

    Suzuki, R.; Ohdaira, T.; Uedono, A.; Kobayashi, Y.

    2002-06-01

    Positron and positronium (Ps) behavior in SiO 2-Si have been studied by means of positron annihilation lifetime spectroscopy (PALS) and age-momentum correlation (AMOC) spectroscopy with a pulsed slow positron beam. The PALS study of SiO 2-Si samples, which were prepared by a dry-oxygen thermal process, revealed that the positrons implanted in the Si substrate and diffused back to the interface do not contribute to the ortho-Ps long-lived component, and the lifetime spectrum of the interface has at least two components. From the AMOC study, the momentum distribution of the ortho-Ps pick-off annihilation in SiO 2, which shows broader momentum distribution than that of crystalline Si, was found to be almost the same as that of free positron annihilation in SiO 2. A varied interface model was proposed to interpret the results of the metal-oxide-semiconductor (MOS) experiments. The narrow momentum distribution found in the n-type MOS with a negative gate bias voltage could be attributed to Ps formation and rapid spin exchange in the SiO 2-Si interface. We have developed a two-dimensional positron lifetime technique, which measures annihilation time and pulse height of the scintillation gamma-ray detector for each event. Using this technique, the positronium behavior in a porous SiO 2 film, grown by a sputtering method, has been studied.

  11. Theoretical calculations of positron lifetimes for metal oxides

    International Nuclear Information System (INIS)

    Mizuno, Masataka; Araki, Hideki; Shirai, Yasuharu

    2004-01-01

    Our recent positron lifetime measurements for metal oxides suggest that positron lifetimes of bulk state in metal oxides are shorter than previously reported values. We have performed theoretical calculations of positron lifetimes for bulk and vacancy states in MgO and ZnO using first-principles electronic structure calculations and discuss the validity of positron lifetime calculations for insulators. By comparing the calculated positron lifetimes to the experimental values, it wa found that the semiconductor model well reproduces the experimental positron lifetime. The longer positron lifetime previously reported can be considered to arise from not only the bulk but also from the vacancy induced by impurities. In the case of cation vacancy, the calculated positron lifetime based on semiconductor model is shorter than the experimental value, which suggests that the inward relaxation occurs around the cation vacancy trapping the positron. (author)

  12. Concurrent Rotator Cuff Tear and Axillary Nerve Palsy Associated with Anterior Dislocation of the Shoulder and Large Glenoid Rim Fracture: A “Terrible Tetrad”

    Directory of Open Access Journals (Sweden)

    Fumiaki Takase

    2014-01-01

    Full Text Available We present a case of concurrent rotator cuff tear and axillary nerve palsy resulting from anterior dislocation of the shoulder and a large glenoid rim fracture—a “terrible tetrad.” A 61-year-old woman fell on her right shoulder. Radiographs showed anterior dislocation of the shoulder with a glenoid rim fracture, and an MRI two months after injury revealed a rotator cuff tear. Upon referral to our hospital, physical and electrophysiological examinations revealed axillary nerve palsy. The axillary nerve palsy was incomplete and recovering, and displacement of the glenoid rim fracture was minimal and already united; therefore, we surgically repaired only the rotator cuff tear three months after injury. The patient recovered satisfactorily following the operation. In patients whose axillary nerve palsy is recovering, surgeons should consider operating on rotator cuff tears in an attempt to prevent rotator cuff degeneration.

  13. Production and applications of positron microbeams

    International Nuclear Information System (INIS)

    Brandes, G.R.; Canter, K.F.; Horsky, T.N.; Lippel, P.H.; Mills, A.P. Jr.

    1989-01-01

    The production of a positron microbeam using the high-brightness beam developed at Brandeis University and possible applications of this microbeam to spatially resolved defect studies and positron microscopy are reviewed. The high-brightness beam consists of a W(110) primary moderator and two remoderation stages which provide a 500-fold increase in brightness. With this brightness increase and microbeam optics, we are able to form a 12 μm FWHM beam (48 mrad pencil half-angle) at 5 keV beam energy. The well characterised small-diameter beam is particularly adaptable for determining defect concentration and structure, both laterally and in a depth-profiling mode. In the case of a transmission positron microscope or a positron re-emission microscope operating in a high-magnification mode, efficient image formation requires the use of a microbeam to maximise the number of positrons in the area being imaged. Results of the scanning microbeam tests and the application of a microbeam to positron microscopy and defect studies are reviewed. (author)

  14. Detection of tokamak plasma positrons using annihilation photons

    Energy Technology Data Exchange (ETDEWEB)

    Guanying, Yu; Liu, Jian; Xie, Jinlin [University of Science and Technology, Hefei, Anhui, 230027 (China); Li, Jiangang, E-mail: j_li@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China)

    2017-05-15

    Highlights: • A design for detection of tokamak plasma positrons is given. • Identify the main obstacle toward experimental confirmation of fusion plasma positrons. • Signal to noise ratio in a plasma disruption is estimated. • Unique potential applications of fusion plasma positrons are discussed. - Abstract: A massive amount of positrons (plasma positrons), produced by the collision between runaway electrons and nuclei during fusion plasma disruption, was first predicted theoretically in 2003. To help confirm this prediction, we report here the design of an experimental system to detect tokamak plasma positrons. Because a substantial amount of positrons (material positrons) are produced when runaway electrons impact plasma-facing materials, we proposed maximizing the ratio of plasma to material positrons by inserting a thin carbon target at the plasma edge as a plasma positron bombing target and producing a plasma disruption scenario triggered by massive gas injection. Meanwhile, the coincidence detection of positron annihilation photons was used to filter out the noise of annihilation photons from locations other than the carbon target and that of bremsstrahlung photons near 511 keV. According to our simulation, the overall signal-to-noise ratio should be more than 10:1.

  15. Time-dependent behavior of positrons in noble gases

    International Nuclear Information System (INIS)

    Wadehra, J.M.

    1990-01-01

    Both equilibrium and nonequilibrium behaviors of positrons in several noble gases are reviewed. Our novel procedure for obtaining the time-dependent behavior of various swarm parameters -- such as the positron drift velocity, average positron energy, positron annihilation rate (or equivalently Z eff ) etc. -- for positrons in pure ambient gases subjected to external electrostatic fields is described. Summaries of time-dependent as well as electric field-dependent results for positron swarms in various noble gases are presented. New time-dependent results for positron swarms in neon are also described in detail. 36 refs., 4 figs., 3 tabs

  16. Impact of axillary ultrasound and core needle biopsy on the utility of intraoperative frozen section analysis and treatment decision making in women with invasive breast cancer.

    Science.gov (United States)

    Caretta-Weyer, Holly; Sisney, Gale A; Beckman, Catherine; Burnside, Elizabeth S; Salkowsi, Lonie R; Strigel, Roberta M; Wilke, Lee G; Neuman, Heather B

    2012-09-01

    Our objective was to evaluate the impact of preoperative axillary ultrasound and core needle biopsy (CNB) on breast cancer treatment decision making. A secondary aim was to evaluate the impact on the utility of intraoperative sentinel lymph node (SLN) frozen section. A review of 84 patients with clinically negative axilla who underwent axillary ultrasound was performed. Sensitivity, specificity, and positive/negative predictive value for axillary ultrasound with CNB was calculated. Thirty-one (37%) had suspicious nodes. Of 27 amenable to CNB, 12 (14%) were malignant, changing treatment plans. The sensitivity of ultrasound and CNB was 54% and specificity 100%; the positive and negative predictive values were 100% and 80%, respectively. In 41 patients with normal ultrasounds who underwent SLN frozen section, 10 (24%) were positive. Preoperative axillary ultrasound impacts treatment decision making in 14%. With a sensitivity of 54%, it is a useful adjunct to, but not replacement for, SLN biopsy. Frozen section remains of utility even after a negative axillary ultrasound. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Solvated Positron Chemistry. II

    DEFF Research Database (Denmark)

    Mogensen, O. E.

    1979-01-01

    The reaction of the hydrated positron, eaq+ with Cl−, Br−, and I− ions in aqueous solutions was studied by means of positron The measured angular correlation curves for [Cl−, e+], [Br−, e+, and [I−, e+] bound states were in good agreement with th Because of this agreement and the fact...... that the calculated positron wavefunctions penetrate far outside the X− ions in the [X−, e+] sta propose that a bubble is formed around the [X−, e+] state, similar to the Ps bubble found in nearly all liquids. F−ions did not react w Preliminary results showed that CN− ions react with eaq+ while OH−ions are non...... in the Cl− case) at higher concentrations. This saturation and the high-concentration effects-in the angular correlation results were interpreted as caused by rather complicated spur effects, wh It is proposed that spur electrons may pick off the positron from the [X−, e+ states with an efficiency which...

  18. Intraductal papilloma in an axillary lymph node of a patient with human immunodeficiency virus: a case report and review of the literature.

    Science.gov (United States)

    Cottom, Hannah; Rengabashyam, Bhavani; Turton, Philip E; Shaaban, Abeer M

    2014-05-23

    Inclusions of ectopic breast tissue in axillary lymph nodes are reported very infrequently and typically are only identified microscopically as an incidental finding. Furthermore the development of a benign proliferative lesion in the form of an intraductal papilloma from intranodal ectopic breast tissue is an extremely rare phenomenon with only three previous cases reported. This report describes an unusual and rare case of an intraductal papilloma arising in an axillary lymph node of a patient known to have the human immunodeficiency virus. A 40-year-old Black African woman underwent excision of an enlarged palpable axillary lymph node. In the preceding 7 years she had received at least six separate surgical excisions to her ipsilateral breast for papillomatosis. The last surgical intervention was performed 1 year prior to presentation with an enlarged axillary lymph node. Histological examination of her axillary lymph node revealed a papillomatous proliferative epithelial lesion within an apparent encompassing duct, resembling a mammary intraductal papilloma. In the surrounding lymphoid tissue small groups of duct-like structures were additionally noted. Immunostaining with a panel of myoepithelial markers in conjunction with oestrogen receptor produced a mixed heterogeneous staining pattern in both the papillomatous lesion and the peripheral duct-like structures. This confirmed the diagnosis of a benign intraductal papilloma within an axillary lymph node, considered to have arisen from ectopic breast tissue. This case demonstrates that intranodal ectopic breast tissue has the potential to undergo benign proliferative change albeit extremely rarely. Therefore this possibility must be considered to ensure the correct diagnosis is made. In addition, to the best of our knowledge, this is the first case report which has described recurrent intraductal papillomas and the subsequent development of an intraductal papilloma within an ipsilateral axillary lymph node, in

  19. Radiation damage of polymers studied by positron annihilation. Positron and gamma-ray irradiation effects

    International Nuclear Information System (INIS)

    Suzuki, T.; Oki, Y.; Numajiri, M.; Miura, T.; Kondo, K.; Ito, Y.

    1995-01-01

    Positron irradiation effects on polypropylene (PP) have been studied using positron sources ( 22 Na) during positron annihilation (PA) experiments. The irradiation effect was measured by the intensity (I 3 ) of the long-lived component of positronium (Ps). At a low temperature of around 100 K, I 3 for unirradiated PP samples increased due to a termination of the thermal motion of the -CH 3 groups. However, the increase in I 3 for γ-ray irradiated samples was reduced in inverse proportion to the amount of irradiation. Although no increase in I 3 was observed for 1 MGy-irradiated PP with γ-rays, an increase was observed again after a 48 h irradiation by positrons emitted from 22 Na. This may be due to a reconstructing of the polymer chains. (author)

  20. Importance of non-local electron-positron correlations for positron annihilation characteristics in solids

    International Nuclear Information System (INIS)

    Rubaszek, A.

    2001-01-01

    Several methods to describe the electron-positron (e-p) correlation effects are used in calculations of positron annihilation characteristics in solids. The weighted density approximation (WDA), giving rise to the non-local, state-selective e-p correlation functions, is applied to calculate positron annihilation rates and e-p momentum densities in a variety of metals and silicon. The WDA results are compared to the results of other methods such as the independent particle model, local density approximation, generalised gradient approximation, and also to experiments. The importance of non-locality and state-dependence of the e-p correlation functions is discussed. (orig.)

  1. Positron source based on the 48V isotope dedicated to positron lifetime spectroscopy

    International Nuclear Information System (INIS)

    Dryzek, Jerzy

    2009-01-01

    In the paper we consider application of the 48 V isotope as a source in the positron lifetime spectroscopy. The isotope was produced in the 48 Ti(p,n) 48 V reaction using 15 MeV proton beam. As a target the natural titanium thin plate was used. The measurements using the typical positron lifetime spectrometer have shown the usefulness of the source obtained for this application. Due to its properties, the source may be used for measurements of positron annihilation characteristics in high temperature or aggressive environments. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Frequency and associated factors of axillary web syndrome in women who had undergone breast cancer surgery: a transversal and retrospective study.

    Science.gov (United States)

    Fukushima, Kassandra Ferreira Pessoa; Carmo, Luana Aroucha; Borinelli, Adriana Carvalho; Ferreira, Caroline Wanderley Souto

    2015-01-01

    Breast cancer is the most common malignancy among women. Surgical treatment is an essential part of therapy, which still includes chemotherapy, radiotherapy and hormone therapy. The increase in early cancer detection and less aggressive treatment has made longer survival rates possible for women with this neoplasia. Morbidities after treatment have subsequently aroused particular interest in the scientific community in order to minimize their effects and provide increased quality-of-life for these patients. The present study aimed at investigating one of these morbidities: axillary web syndrome, which occurs after axillary surgical management. From December 2011 to September 2012, according to the inclusion and exclusion criteria, 97 patients, who had been surgically treated for breast cancer, were enrolled, interviewed, and submitted to a specific physical exam. An investigation of the axillary cords, characteristic of this syndrome, was performed in all patients. The axillary web syndrome was diagnosed in 28.86% of the women. Higher risk of triggering the syndrome has been associated with younger age (21.7%), longer time between first treatment and data collection (29.3%), greater number of resected lymph nodes (149.7%) and surgical management medical teams (113.2%). One can conclude that axillary web syndrome was associated with younger age, greater time elapsed since surgery, surgical management of medical staff and number of resected lymph nodes. Further studies are needed to review prior-to-surgery and post-operative follow-up, to properly assess the effects of surgery in the axilla on homeostatic balance, not only in the ipsilateral upper limb, but also assess their compensatory consequences throughout the body.

  3. Applications of positron depth profiling

    Energy Technology Data Exchange (ETDEWEB)

    Hakvoort, R A

    1993-12-23

    In this thesis some contributions of the positron-depth profiling technique to materials science have been described. Following studies are carried out: Positron-annihilation measurements on neon-implanted steel; Void creation in silicon by helium implantation; Density of vacancy-type defects present in amorphous silicon prepared by ion implantation; Measurements of other types of amorphous silicon; Epitaxial cobalt disilicide prepared by cobalt outdiffusion. Positron-annihilation experiments on low-pressure CVD silicon-nitride films. (orig./MM).

  4. Applications of positron depth profiling

    International Nuclear Information System (INIS)

    Hakvoort, R.A.

    1993-01-01

    In this thesis some contributions of the positron-depth profiling technique to materials science have been described. Following studies are carried out: Positron-annihilation measurements on neon-implanted steel; Void creation in silicon by helium implantation; Density of vacancy-type defects present in amorphous silicon prepared by ion implantation; Measurements of other types of amorphous silicon; Epitaxial cobalt disilicide prepared by cobalt outdiffusion. Positron-annihilation experiments on low-pressure CVD silicon-nitride films. (orig./MM)

  5. Sclerotic fibroma (storiform collagenoma)-like stroma in a fibroadenoma of axillary accessory breast tissue.

    Science.gov (United States)

    Val-Bernal, José Fernando; González-Vela, María Carmen; De Grado, Mauricio; Garijo, María Francisca

    2012-08-01

    Accessory breast tissue is a subcutaneous remnant persisting after normal embryological development of the breast. It occurs most frequently in the axilla. Fibroadenomas in axillary breast tissue are rare. We report the case of a 29-year-old female patient who presented a fibroadenoma arising in the accessory breast tissue of the right axillary fossa. The neoplasm showed foci of sclerotic fibroma-like stroma. The patient had no signs of Cowden's syndrome. To the best of our knowledge, a lesion of this kind has not been previously reported. This stromal change suggests an uncommon involutional phase of the fibroadenoma with production of sclerotic and hypocellular collagen. The lesion should be differentiated from extraneural perineuroma, from the changes in fibroadenomas in Cowden's syndrome, from sclerosing lobular hyperplasia (fibroadenomatoid mastopathy) and from pseudoangiomatous stromal hyperplasia. Copyright © 2012 John Wiley & Sons A/S.

  6. Positron annihilation measurements in high-energy alpha-irradiated n-type gallium arsenide

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Sandip; Mandal, Arunava; SenGupta, Asmita [Visva-Bharati, Department of Physics, Santiniketan, West Bengal (India); Roychowdhury, Anirban [UGC-DAE Consortium for Scientific Research, Kolkata Centre, Kolkata, West Bengal (India)

    2015-07-15

    Positron annihilation lifetime spectroscopy and Doppler broadening annihilation line-shape measurements have been carried out in 40-MeV alpha-irradiated n-type GaAs. After irradiation, the sample has been subjected to an isochronal annealing over temperature region of 25-800 C with an annealing time of 30 min at each set temperature. After each annealing, the positron measurements are taken at room temperature. Formation of radiation-induced defects and their recovery with annealing temperature are investigated. The lifetime spectra of the irradiated sample have been fitted with two lifetimes. The average positron lifetime τ{sub avg} = 244 ps at room temperature after irradiation indicates the presence of defects, and the value of τ{sub 2} (262 ps) at room temperature suggests that the probable defects are mono-vacancies. Two distinct annealing stages in τ{sub avg} at 400-600 C and at 650-800 C are observed. The variations in line-shape parameter (S) and defect-specific parameter (R) during annealing in the temperature region 25-800 C resemble the behaviour of τ{sub avg} indicating the migration of vacancies, formation of vacancy clusters and the disappearance of defects between 400 and 800 C. (orig.)

  7. Brief reports: a clinical evaluation of block characteristics using one milliliter 2% lidocaine in ultrasound-guided axillary brachial plexus block.

    LENUS (Irish Health Repository)

    O'Donnell, Brian

    2010-09-01

    We report onset and duration of ultrasound-guided axillary brachial plexus block using 1 mL of 2% lidocaine with 1:200,000 epinephrine per nerve (total local anesthetic volume 4 mL). Block performance time, block onset time, duration of surgery, and block duration were measured. Seventeen consecutive patients were recruited. The mean (SD) block performance and onset times were 271 (67.9) seconds and 9.7 (3.7) minutes, respectively. Block duration was 160.8 (30.7) minutes. All operations were performed using regional anesthesia alone. The duration of anesthesia obtained is sufficient for most ambulatory hand surgery.

  8. International multicenter tool to predict the risk of four or more tumor-positive axillary lymph nodes in breast cancer patients with sentinel node macrometastases

    DEFF Research Database (Denmark)

    Meretoja, Tuomo J; Audisio, R A; Heikkilä, P S

    2013-01-01

    Recently, many centers have omitted routine axillary lymph node dissection (ALND) after metastatic sentinel node biopsy in breast cancer due to a growing body of literature. However, existing guidelines of adjuvant treatment planning are strongly based on axillary nodal stage. In this study, we aim...

  9. High resolution Cerenkov light imaging of induced positron distribution in proton therapy

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi, E-mail: s-yama@met.nagoya-u.ac.jp; Fujii, Kento; Morishita, Yuki; Okumura, Satoshi; Komori, Masataka [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Aichi 461-8673 (Japan); Toshito, Toshiyuki [Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center, Aichi 462-8508 (Japan)

    2014-11-01

    Purpose: In proton therapy, imaging of the positron distribution produced by fragmentation during or soon after proton irradiation is a useful method to monitor the proton range. Although positron emission tomography (PET) is typically used for this imaging, its spatial resolution is limited. Cerenkov light imaging is a new molecular imaging technology that detects the visible photons that are produced from high-speed electrons using a high sensitivity optical camera. Because its inherent spatial resolution is much higher than PET, the authors can measure more precise information of the proton-induced positron distribution with Cerenkov light imaging technology. For this purpose, they conducted Cerenkov light imaging of induced positron distribution in proton therapy. Methods: First, the authors evaluated the spatial resolution of our Cerenkov light imaging system with a {sup 22}Na point source for the actual imaging setup. Then the transparent acrylic phantoms (100 × 100 × 100 mm{sup 3}) were irradiated with two different proton energies using a spot scanning proton therapy system. Cerenkov light imaging of each phantom was conducted using a high sensitivity electron multiplied charge coupled device (EM-CCD) camera. Results: The Cerenkov light’s spatial resolution for the setup was 0.76 ± 0.6 mm FWHM. They obtained high resolution Cerenkov light images of the positron distributions in the phantoms for two different proton energies and made fused images of the reference images and the Cerenkov light images. The depths of the positron distribution in the phantoms from the Cerenkov light images were almost identical to the simulation results. The decay curves derived from the region-of-interests (ROIs) set on the Cerenkov light images revealed that Cerenkov light images can be used for estimating the half-life of the radionuclide components of positrons. Conclusions: High resolution Cerenkov light imaging of proton-induced positron distribution was possible. The

  10. High resolution Cerenkov light imaging of induced positron distribution in proton therapy

    International Nuclear Information System (INIS)

    Yamamoto, Seiichi; Fujii, Kento; Morishita, Yuki; Okumura, Satoshi; Komori, Masataka; Toshito, Toshiyuki

    2014-01-01

    Purpose: In proton therapy, imaging of the positron distribution produced by fragmentation during or soon after proton irradiation is a useful method to monitor the proton range. Although positron emission tomography (PET) is typically used for this imaging, its spatial resolution is limited. Cerenkov light imaging is a new molecular imaging technology that detects the visible photons that are produced from high-speed electrons using a high sensitivity optical camera. Because its inherent spatial resolution is much higher than PET, the authors can measure more precise information of the proton-induced positron distribution with Cerenkov light imaging technology. For this purpose, they conducted Cerenkov light imaging of induced positron distribution in proton therapy. Methods: First, the authors evaluated the spatial resolution of our Cerenkov light imaging system with a 22 Na point source for the actual imaging setup. Then the transparent acrylic phantoms (100 × 100 × 100 mm 3 ) were irradiated with two different proton energies using a spot scanning proton therapy system. Cerenkov light imaging of each phantom was conducted using a high sensitivity electron multiplied charge coupled device (EM-CCD) camera. Results: The Cerenkov light’s spatial resolution for the setup was 0.76 ± 0.6 mm FWHM. They obtained high resolution Cerenkov light images of the positron distributions in the phantoms for two different proton energies and made fused images of the reference images and the Cerenkov light images. The depths of the positron distribution in the phantoms from the Cerenkov light images were almost identical to the simulation results. The decay curves derived from the region-of-interests (ROIs) set on the Cerenkov light images revealed that Cerenkov light images can be used for estimating the half-life of the radionuclide components of positrons. Conclusions: High resolution Cerenkov light imaging of proton-induced positron distribution was possible. The authors

  11. Positron emission tomography

    International Nuclear Information System (INIS)

    Lindback, Stig

    1995-01-01

    Positron Emission Tomography (PET) is an advanced nuclear medicine technique used for research at major centres. Unique diagnostic information is obtained from tomographic measurements of the biochemistry and physiology of tissues and organs. In theory, diseases are related to biochemical changes and these can be observed with PET long before any anatomical changes are detectable. In PET the radioactive component is a positron-emitting isotope or 'tracer'. The positrons annihilate with electrons in the body to produce two gamma rays 180° apart; coincidence detection of these gammas provides a very efficient method of determining the spatial distribution of the radioisotope tracer. Because physiological measurements are usually required in a single imaging session, very short-lived isotopes are used to label the tracer molecules; isotope production and labelling is usually carried out in situ. The most commonly used radionuclides are carbon- 11 (half-life 20 minutes), nitrogen-13 (10 minutes), oxygen-15 (2 minutes), and fluorine-18 (110 minutes). A PET system has three major components: - a particle accelerator with targets for production of the positron-emitting isotopes; - chemistry modules for synthesis and labelling of the desired tracers; - and a PET camera for in-vivo measurements of the distribution of the tracer in the body

  12. Positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lindback, Stig [GEMS PET Systems AB, Uppsala (Sweden)

    1995-07-15

    Positron Emission Tomography (PET) is an advanced nuclear medicine technique used for research at major centres. Unique diagnostic information is obtained from tomographic measurements of the biochemistry and physiology of tissues and organs. In theory, diseases are related to biochemical changes and these can be observed with PET long before any anatomical changes are detectable. In PET the radioactive component is a positron-emitting isotope or 'tracer'. The positrons annihilate with electrons in the body to produce two gamma rays 180° apart; coincidence detection of these gammas provides a very efficient method of determining the spatial distribution of the radioisotope tracer. Because physiological measurements are usually required in a single imaging session, very short-lived isotopes are used to label the tracer molecules; isotope production and labelling is usually carried out in situ. The most commonly used radionuclides are carbon- 11 (half-life 20 minutes), nitrogen-13 (10 minutes), oxygen-15 (2 minutes), and fluorine-18 (110 minutes). A PET system has three major components: - a particle accelerator with targets for production of the positron-emitting isotopes; - chemistry modules for synthesis and labelling of the desired tracers; - and a PET camera for in-vivo measurements of the distribution of the tracer in the body.

  13. Gastric Metastasis of Ectopic Breast Cancer Mimicking Axillary Metastasis of Primary Gastric Cancer

    Directory of Open Access Journals (Sweden)

    Selami Ilgaz Kayılıoğlu

    2014-01-01

    Full Text Available Ectopic breast tissue has the ability to undergo all the pathological changes of the normal breast, including breast cancer. Gastrointestinal metastasis of breast cancer is rarely observed and it is very difficult to differentiate gastric metastases from primary gastric cancer. We present a case of 52-year-old female, who suffered from abdominal pain. Physical examination showed a palpable mass in the left anterior axilla and computerized tomography revealed gastric wall thickening with linitis plastica. When gastroscopic biopsy showed no signs of malignancy, excisional biopsy was performed in the left axilla. Histological examination revealed invasive lobular carcinoma of the breast, consistent with ectopic breast cancer. Further gastroscopic submucosal biopsies and immunohistochemical studies revealed gastric metastases of invasive lobular carcinoma. Axillary ectopic breast tissue carcinomas can mimic axillary lymphadenopathies. Additionally, gastric metastasis of breast cancer is an uncommon but possible condition. To the best of our knowledge, this is the first report of ectopic breast cancer with gastric metastasis.

  14. The cryogenic source of slow monochromatic positrons

    International Nuclear Information System (INIS)

    Meshkov, I.N.; Pavlov, V.N.; Sidorin, A.O.; Yakovenko, S.L.

    2008-01-01

    The cryogenic source of slow monochromatic positrons based on the 22 Na isotope has been designed and constructed at JINR. Positrons emitted from radioactive source 22 Na have a very broad energy spectrum up to 0.5 MeV. To generate monochromatic beam of slow positrons the solid neon is used as a moderator. The solid neon allows forming slow positron beam of the energy of 1.2 eV at the spectrum width of 1 eV. The efficiency of moderation is 1 % of total positron flux

  15. Probing the positron moderation process using high-intensity, highly polarized slow-positron beams

    Science.gov (United States)

    Van House, J.; Zitzewitz, P. W.

    1984-01-01

    A highly polarized (P = 0.48 + or - 0.02) intense (500,000/sec) beam of 'slow' (Delta E = about 2 eV) positrons (e+) is generated, and it is shown that it is possible to achieve polarization as high as P = 0.69 + or - 0.04 with reduced intensity. The measured polarization of the slow e+ emitted by five different positron moderators showed no dependence on the moderator atomic number (Z). It is concluded that only source positrons with final kinetic energy below 17 keV contribute to the slow-e+ beam, in disagreement with recent yield functions derived from low-energy measurements. Measurements of polarization and yield with absorbers of different Z between the source and moderator show the effects of the energy and angular distributions of the source positrons on P. The depolarization of fast e+ transmitted through high-Z absorbers has been measured. Applications of polarized slow-e+ beams are discussed.

  16. Arm morbidity following sentinel lymph node biopsy or axillary lymph node dissection: a study from the Danish Breast Cancer Cooperative Group

    DEFF Research Database (Denmark)

    Husted, Madsen A.; Haugaard, K.; Soerensen, J.

    2008-01-01

    BACKGROUND: Sentinel lymph node biopsy was implemented in the treatment of early breast cancer with the aim of reducing shoulder and arm morbidity. Relatively few prospective studies have been published where the morbidity was assessed by clinical examination. Very few studies have examined...... lymph node biopsy with node negative patients having a lymph node dissection of levels I and II of the axilla, we found significant increase in arm volume among the patients who had an axillary dissection. Only minor, but significant, differences in shoulder mobility were observed comparing the two...... groups of node negative patients. Highly significant difference was found comparing sensibility. Comparing the morbidity in node positive patients who had a one-step axillary dissection with patients having a two-step procedure (sentinel lymph node biopsy followed by delayed axillary dissection) revealed...

  17. Time course of regional myocardial glucose metabolism after transient ischemia assessed by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hoshizaki, Hiroshi (Gunma Univ., Maebashi (Japan). School of Medicine)

    1992-11-01

    The purpose of this study was to examine the significance of glucose metabolism in ischemic canine myocardium after reperfusion. Transient ischemia was induced by 90 or 180 minutes occlusion of the left anterior descending coronary artery. Twelve hours and 4 weeks after reperfusion, myocardial blood flow (MBF) and glucose metabolism were assessed (with H[sub 2][sup 15]O and [sup 18]F-FDG, respectively) by positron emission tomography (PET) under the fasting state, and the metabolic findings were compared with the histologic examination. Glucose metabolism in ischemic regions was inversely related to the amount of tissue necrosis 12 hours and 4 weeks after reperfusion (r=-0.89 and r=-0.82, respectively). The perfusion-metabolism mismatch pattern was seen in the area with less than 10 percent necrosis 12 hours after reperfusion, but this pattern disappeared after 4 weeks. The area with 10 to 50 percent necrosis showed the mismatch pattern until 4 weeks after reperfusion, and in the area with more than 50 percent necrosis, perfusion-metabolism concordantly decreased. Thus, metabolic index assessed early after reperfusion by PET identified myocardial viability, and the perfusion-metabolism mismatch pattern sustained in relation to the degree of ischemic injury. Since some regions estimated to be irreversible by PET were viable by the histologic examination, PET study might underestimate the myocardial viability. (author).

  18. High efficiency positron moderation

    International Nuclear Information System (INIS)

    Taqqu, D.

    1990-01-01

    A new positron moderation scheme is proposed. It makes use of electric and magnetic fields to confine the β + emitted by a radioactive source forcing them to slow down within a thin foil. A specific arrangement is described where an intermediary slowed-down beam of energy below 10 keV is produced. By directing it towards a standard moderator optimal conversion into slow positrons is achieved. This scheme is best applied to short lived β + emitters for which a 25% moderation efficiency can be reached. Within the state of the art technology a slow positron source intensity exceeding 2 x 10 10 e + /sec is achievable. (orig.)

  19. Positron emission tomography

    International Nuclear Information System (INIS)

    Chandrasekhar, Preethi; Himabindu, Pucha

    2000-01-01

    Positron Emission Tomography (PET) is a non-invasive nuclear imaging technique used to study different molecular pathways and anatomical structures. PET has found extensive applications in various fields of medicine viz. cardiology, oncology, psychiatry/psychology, neuro science and pulmonology. This study paper basically deals with the physics, chemistry and biology behind the PET technique. It discusses the methodology for generation of the radiotracers responsible for emission of positrons and the annihilation and detection techniques. (author)

  20. Positron emission tomography

    International Nuclear Information System (INIS)

    Dvorak, O.

    1989-01-01

    The principle is briefly described of positron emission tomography, and its benefits and constraints are listed. It is emphasized that positron emission tomography (PET) provides valuable information on metabolic changes in the organism that are otherwise only very difficult to obtain, such as brain diagnosis including relationships between mental disorders and the physiology and pathophysiology of the brain. A PET machine is to be installed in Czechoslovakia in the near future. (L.O.)

  1. Relevance of slow positron beam research to astrophysical studies of positron interactions and annihilation in the interstellar medium

    International Nuclear Information System (INIS)

    Guessoum, N.; Jean, P.; Gillard, W.

    2006-01-01

    The processes undergone by positrons in the interstellar medium (ISM) from the moments of their birth to their annihilation are examined. Both the physics of the positron interactions with gases and solids (dust grains), and the physical conditions and characteristics of the environments where the processes of energy loss, positronium formation, and annihilation taking place, are reviewed. An explanation is given as to how all the relevant physical information are taken into account in order to calculate annihilation rates and spectra of the 511 keV emission for the various phases of the ISM; special attention is paid to positron interactions with dust and with polycyclic aromatic hydrocarbons. An attempt is made to show to what extent the interactions between positrons and interstellar dust grains are similar to laboratory experiments in which beams of slow positrons impinge upon solids and surfaces. Sample results are shown for the effect of dust grains on positron annihilation spectra in some phases of the ISM which, together with high resolution spectra measured by satellites, can be used to infer useful knowledge about the environment where the annihilation is predominantly taking place and ultimately about the birth place and history of positrons in the Galaxy. The important complementarity between work done by the astrophysical and the solid-state positron communities is strongly emphasized and specific experimental work is suggested which could assist the modeling of the interaction and annihilation of positrons in the ISM

  2. Relevance of slow positron beam research to astrophysical studies of positron interactions and annihilation in the interstellar medium

    Energy Technology Data Exchange (ETDEWEB)

    Guessoum, N. [American University of Sharjah, Physics Department, P.O. Box 26666, Sharjah (United Arab Emirates)]. E-mail: nguessoum@aus.ac.ae; Jean, P. [Centre d' Etude Spatiale des Rayonnements, Toulouse (France); Gillard, W. [Centre d' Etude Spatiale des Rayonnements, Toulouse (France)

    2006-02-28

    The processes undergone by positrons in the interstellar medium (ISM) from the moments of their birth to their annihilation are examined. Both the physics of the positron interactions with gases and solids (dust grains), and the physical conditions and characteristics of the environments where the processes of energy loss, positronium formation, and annihilation taking place, are reviewed. An explanation is given as to how all the relevant physical information are taken into account in order to calculate annihilation rates and spectra of the 511 keV emission for the various phases of the ISM; special attention is paid to positron interactions with dust and with polycyclic aromatic hydrocarbons. An attempt is made to show to what extent the interactions between positrons and interstellar dust grains are similar to laboratory experiments in which beams of slow positrons impinge upon solids and surfaces. Sample results are shown for the effect of dust grains on positron annihilation spectra in some phases of the ISM which, together with high resolution spectra measured by satellites, can be used to infer useful knowledge about the environment where the annihilation is predominantly taking place and ultimately about the birth place and history of positrons in the Galaxy. The important complementarity between work done by the astrophysical and the solid-state positron communities is strongly emphasized and specific experimental work is suggested which could assist the modeling of the interaction and annihilation of positrons in the ISM.

  3. The efficacy of physiotherapy upon shoulder function following axillary dissection in breast cancer, a randomized controlled study

    Directory of Open Access Journals (Sweden)

    Oostendorp Rob AB

    2007-08-01

    Full Text Available Abstract Background Many patients suffer from severe shoulder complaints after breast cancer surgery and axillary lymph node dissection. Physiotherapy has been clinically observed to improve treatment of these patients. However, it is not a standard treatment regime. The purpose of this study is to investigate the efficacy of physiotherapy treatment of shoulder function, pain and quality of life in patients who have undergone breast cancer surgery and axillary lymph node dissection. Methods Thirty patients following breast cancer surgery and axillary lymph node dissection were included in a randomised controlled study. Assessments were made at baseline and after three and six months. The treatment group received standardised physiotherapy treatment of advice and exercises for the arm and shoulder for three months; the control group received a leaflet containing advice and exercises. If necessary soft tissue massage to the surgical scar was applied. Primary outcome variables were amount of pain in the shoulder/arm recorded on the Visual Analogue Scale, and shoulder mobility (flexion, abduction measured using a digital inclinometer under standardized conditions. Secondary outcome measures were shoulder disabilities during daily activities, edema, grip strength of both hands and quality of life. The researcher was blinded to treatment allocation. Results All thirty patients completed the trial. After three and six months the treatment group showed a significant improvement in shoulder mobility and had significantly less pain than the control group. Quality of life improved significantly, however, handgrip strength and arm volume did not alter significantly. Conclusion Physiotherapy reduces pain and improves shoulder function and quality of life following axillary dissection after breast cancer. Trial registration ISRCTN31186536

  4. Three dimensional positron-CT: 3D-PET

    International Nuclear Information System (INIS)

    Ishii, K.

    2000-01-01

    Positron-CT, namely the positron emission tomograph (PET) provides us the metabolism images obtained by the administration of the drug labeled by the positron emission nuclide in the human body. For example, the carbohydrate metabolism image is obtained by the administration of glucose labelled by 18 F-radioisotopes, and it can be applied to early detection of the cancer and research of high-order function of the brain. As well as X-ray CT, the examine receives the exposure in the positron CT. 3D-PET is based on the solid measurement of γ-rays, therefore, the detection sensitivity of 3D-PET becomes very high and it is possible to drastically reduce the dose of the positron emission nuclide. Because the exposure is reduced to the utmost, the positron CT diagnosis would be possible for the child and the exposure of positron CT doctor in charge can be also reduced. This ideal functional diagnostic imaging equipment, namely, 3D-PET is introduced here. (author)

  5. Multidetector-row computed tomography for the preoperative evaluation of axillary nodal status in patients with breast cancer

    International Nuclear Information System (INIS)

    Ogasawara, Yutaka; Doihara, Hiroyoshi; Shiraiwa, Misaki; Ishihara, Setsuko

    2008-01-01

    We evaluated the effectiveness of multidetector-row computed tomography (MD-CT) for detecting axillary lymph nodal status (ALNS) in patients with breast cancer. We reviewed 42 patients with breast cancer. A metastatic lymph node on MD-CT was defined as oval or round, with more than 5 mm on the short axis. We evaluated ALNS preoperatively by both palpation and MD-CT findings and performed sentinel lymph node biopsy (SLNB) and complete axillary lymph node dissection (ALND). For establishing the ALNS, MD-CT showed a sensitivity of 76.9%, a specificity of 96.6%, and an accuracy of 90.5%. On the basis of the MD-CT findings, misdiagnosis was made in 4 of the 42 patients, only one of which was false positive. On the other hand, one patient with a histologically negative sentinel lymph node (SLN) result had metastasis only in a non-SLN. Preoperative MD-CT showed a positive node in this patient. Multidetector-row computed tomography assists in identifying women who require ALND without SLNB, with sufficient positive predictive value. False-negative detection by SLNB could be avoided with careful interpretation of the axillary lymph nodes shown by MD-CT. (author)

  6. Localization studies of metastatic axillary lymph node by radioimmunoimmaging with monoclonal antibody C50 in breast cancer

    International Nuclear Information System (INIS)

    Feng Jue; Gao Yougong

    1993-01-01

    Eleven patients with breast cancer and 2 normal controls (26 axillary lymph-nodes) were studied by the radio immunoimaging with 131 I labelled anti-CEA monoclonal antibody C 50 . Among them, the imaging was positive in 8 patients and negative in 3 patients. 7 of the 8 positive patients were proven by the pathological examination of postoperative lymph nodes. Other one had proved with the presence of CEA-antigen and antigen-antibody immuno complexes in the lymphoid sinus by immuno histochemistry. Cancer cell was not found by pathology in the axillary lymph node of 3 negative imaging patients. 2 normal controls was also negative

  7. Positron lifetime technique with applications in materials science

    International Nuclear Information System (INIS)

    Vries, J. de.

    1987-01-01

    This thesis deals with the positron lifetime technique as a method to measure extremely low concentrations of extremely small cavities in materials. The method is based upon the fact that the positron lieftime decreases as the electron density increases and upon the fact that a positron preferably annihilates in cavity-like defects in lattices. The theory of positron behaviour in materials and technical aspects of measuring positron liefetimes are described in ch.'s 2 and 3 respectively. Three methods for increasing the time resolution are discussed and some positron sources are described (ch.4). Some applications of the positron lifetime technique and experimental results are shown in chapter 5. 125 refs.; 61 figs.; 18 tabs

  8. Results on positron diffusion in Si

    International Nuclear Information System (INIS)

    Nielsen, B.; Lynn, K.G.; Vehanen, A.; Schultz, P.J.

    1984-10-01

    Positron diffusion in Si(100) and Si(111) has been measured using a variable energy positron beam. The diffusion related parameter, E 0 is found to be 4.2 +- 0.2 keV, significantly longer than previously reported values. The positron diffusion coefficient is estimated at D/sub +/ = 2.3 +- 0.4 cm 2 /sec, the uncertainty arising mainly from the characteristics of the assumed positron implantation profile. A drastic reduction in E 0 is found after heating the sample to 1300 0 K, showing that previously reported low values of E 0 are associated with the thermal history of the sample. A high sensitivity to defects introduced by low energy ion bombardment is found, and the defect recovery was followed during heat treatments. Reconstruction of the Si(111) surface into the so-called 7 x 7 structure had no detectable influence on the positron diffusion behavior. No changes in the positron diffusion was observed after covering the surface with atomic hydrogen. However the yield of positronium formation at the surface was enhanced, attributed to an increased density of states at the surface

  9. Positrons from supernova and the origin of the galactic-center positron-annihilation radiation

    International Nuclear Information System (INIS)

    Colgate, S.A.

    1983-01-01

    The emission of positrons from supernova ejecta is dicussed in terms of the galactic-center annihilation radiation. The positrons from the radioactive sequences 56 Ni→ 56 Co→ 56 Fe are the most numerous source from supernova. Only type I supernova will allow a significant fraction to escape the expanding ejecta. For a neutron star model of a type I SN a fraction 4 x 10 -3 of the escaped positron is enough to create the observed several year fluctuation of the annihilation radiation. The likelihood of this model is discussed in terms of other astrophysical evidence as well as the type I SN light curve

  10. Theoretical aspects of positrons in imperfect solids

    International Nuclear Information System (INIS)

    Puska, M.J.

    1987-01-01

    The efficient use of positron annihilation in defect studies requires a deep understanding of the basic processes of positron-imperfect solid interaction. Three stages, i.e. thermalization, trapping by a defect, and the annihilation can be separated during the evolution of the interaction. The last two processes are the most relevant ones for the positron lifetime spectroscopy and they will be discussed in detail in this review. The complete solution of the problem of a localized positron interacting with the electrons around a defect requires the simultaneous self-consistent calculation of the electronic structure and the positron state. This is in principle possible in the two component density functional theory. However, the approximation, in which the electronic structure without the positron influence is used and the electron-positron correlation effects are described by local enhancement factors, has turned out to be feasible in practice and also accurate enough in predicting positron annihilation characteristics. Moreover, a non-self-consistent electron structure is sufficient in many cases. This enables an efficient calculation method in which the positron wave function can be solved in three dimensions for arbitrary defect geometries. Enhancement models for simple metals, transition metals, and semiconductors are represented. Thereafter, applications to vacancies, vacancy clusters, and vacancy-impurity complexes are shown. The positron trapping by defects is mediated by the transfer of the positron binding energy to the solid in the form of electron-hole pairs and phonons. The trapping phenomenon is discussed in the case of metals and semiconductors. Semiconductors are especially challenging because the existence of the energy gap makes the low energy electron-hole excitations impossible and because the defects have different charge states effecting strongly on the trapping rate. (author)

  11. Preoperative axillary lymph node staging by ultrasound-guided cytology using a four-level sonographic score

    International Nuclear Information System (INIS)

    De Coninck, Caroline; Noël, Jean-Christophe; Boutemy, Rachel; Simon, Philippe

    2016-01-01

    The staging of axillary lymph nodes is critical to the management and prognosis of breast cancer, the most frequent cancer in females. Neoadjuvant therapy and lymph node dissection are recommended when malignant cells invade the lymph nodes. Therefore the pre-operative examination of these lymph nodes is crucial to treatment. In this study, we examined the effectiveness of cytology through ultrasound-guided fine needle aspiration (USG-FNA) and ultrasound (US) imaging using an established classification system in correctly identifying lymph node status compared to the final histological results after surgery. Cytology by USG-FNA and US classification were found to be promising methods of axillary lymph node staging. US and CB offer minimally invasive techniques to pre-operatively examine these lymph nodes in patients with primary breast cancer

  12. Design of a transmission electron positron microscope

    International Nuclear Information System (INIS)

    Doyama, Masao; Inoue, M.; Kogure, Y.; Hayashi, Y.; Yoshii, T.; Kurihara, T.; Tsuno, K.

    2003-01-01

    This paper reports the plans and design of positron-electron microscopes being built at KEK (High Energy Accelerator Research Organization), Tsukuba, Japan. A used electron microscope is altered. The kinetic energies of positrons produced by accelerators or by nuclear decays are not a unique value but show a spread over in a wide range. Positron beam is guided to a transmission electron microscope (JEM100SX). Positrons are moderated by a tungsten foil, are accelerated and are focused on a nickel sheet. The monochromatic focused beam is injected into an electron microscope. The focusing and aberration of positrons are the same as electrons in a magnetic system which are used in commercial electron microscopes. Imaging plates are used to record positron images for the transmission electron microscope. (author)

  13. Positron annihilation at defects in sintered high Tc perovskite superconductors

    International Nuclear Information System (INIS)

    Corbel, C.; Bernede, P.; Pascard, H.; Rullier-Albenque, F.; Kormann, R.; Marucco, J.F.

    1988-01-01

    We report positron lifetime measurements in sintered superconducting YBa 2 Cu 3 O 7-x and GdBa 2 Cu 3 O 7-x oxides. It is shown that the thermal behaviour of the positron lifetime spectra strongly depends on the preparation of the ceramics. A lifetime of 190±3 ps is attributed to oxygen deficient regions. Two lifetimes of 251±7 ps and 225±5 ps are attributed to a cation vacancy presenting a temperature dependent atomic arrangement. The lifetime transition (251 → 225 ps) occurs during decreases in temperature across the resistivity superconducting transition. This lifetime change indicates that the volume of the cation vacancy decreases in the superconducting state

  14. Excited, bound and resonant positron-atom systems

    International Nuclear Information System (INIS)

    Bromley, M W J; Mitroy, J

    2010-01-01

    Calculations have demonstrated that eleven neutral atoms can bind positrons, while many more can bind positronium. This is a short review of recent progress made in understanding some of the underlying mechanisms. The emphasis here being on configuration interaction calculations with excited state configurations. These have demonstrated the existence of a 2 P o excited state of e + Ca, which consists predominantly of a positronium cluster orbiting the Ca + ion in the L = 1 partial wave. Preliminary results are presented of excited state positron binding to a model alkali atom, where the excited 1 P o states are stable over a limited region. Implications for the unnatural parity, 2,4 S o , states of PsH, LiPs, NaPs and KPs are also discussed. The e + Mg, e + Cu, e + Zn and e + Cd systems show a lack of a 2 P o excited state, each instead possessing a low-energy p-wave shape resonance of varying strength.

  15. Proactive error analysis of ultrasound-guided axillary brachial plexus block performance.

    LENUS (Irish Health Repository)

    O'Sullivan, Owen

    2012-07-13

    Detailed description of the tasks anesthetists undertake during the performance of a complex procedure, such as ultrasound-guided peripheral nerve blockade, allows elements that are vulnerable to human error to be identified. We have applied 3 task analysis tools to one such procedure, namely, ultrasound-guided axillary brachial plexus blockade, with the intention that the results may form a basis to enhance training and performance of the procedure.

  16. A Unique Branching Pattern of the Axillary Artery: A Case Report

    OpenAIRE

    Bagoji, Ishwar B.; Hadimani, Gavishiddappa A.; Bannur, Balappa M.; Patil, B.G.; Bharatha, Ambadasu

    2013-01-01

    During routine dissection classes for under graduate students, we found a unique and unusual case regarding the anomalous branching in the third part of the axillary artery was terminated into subscapular arterial trunk, superficial brachial artery and deep brachial artery. The subscapular arterial trunk was origin of several important arteries as the circumflex scapular, thoracodorsal, posterior circumflex humeral, thoraco-acromial and lateral thoracic arteries. The deep brachial artery in t...

  17. Persistence of cerebral metabolic abnormalities in chronic schizophrenia as determined by positron emission tomography

    International Nuclear Information System (INIS)

    Wolkin, A.; Jaeger, J.; Brodie, J.D.; Wolf, A.P.; Fowler, J.; Rotrosen, J.; Gomez-Mont, F.; Cancro, R.

    1985-01-01

    Local cerebral metabolic rates were determined by positron emission tomography and the deoxyglucose method in a group of 10 chronic schizophrenic subjects before and after somatic treatment and in eight normal subjects. Before treatment, schizophrenic subjects had markedly lower absolute metabolic activity than did normal controls in both frontal and temporal regions and a trend toward relative hyperactivity in the basal ganglia area. After treatment, their metabolic rates approached those seen in normal subjects in nearly all regions except frontal. Persistence of diminished frontal metabolism was manifested as significant relative hypofrontality. These findings suggest specific loci of aberrant cerebral functioning in chronic schizophrenia and the utility of positron emission tomography in characterizing these abnormalities

  18. Positron-emission tomography imaging of long-term shape recognition challenges

    OpenAIRE

    Rosier, A.; Cornette, L.; Dupont, P.; Bormans, G.; Michiels, J.; Mortelmans, L.; Orban, G. A.

    1997-01-01

    Long-term visual memory performance was impaired by two types of challenges: a diazepam challenge on acquisition and a sensory challenge on recognition. Using positron-emission tomography regional cerebral blood flow imaging, we studied the effect of these challenges on regional brain activation during the delayed recognition of abstract visual shapes as compared with a baseline fixation task. Both challenges induced a significant decrease in differential activation in the left fusiform gyrus...

  19. Electromagnetic solitons in degenerate relativistic electron–positron plasma

    International Nuclear Information System (INIS)

    Berezhiani, V I; Shatashvili, N L; Tsintsadze, N L

    2015-01-01

    The existence of soliton-like electromagnetic (EM) distributions in a fully degenerate electron–positron plasma is studied applying relativistic hydrodynamic and Maxwell equations. For a circularly polarized wave it is found that the soliton solutions exist both in relativistic as well as nonrelativistic degenerate plasmas. Plasma density in the region of soliton pulse localization is reduced considerably. The possibility of plasma cavitation is also shown. (invited comment)

  20. Dynamic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas with superthermal electrons and positrons

    Science.gov (United States)

    Saha, Asit; Pal, Nikhil; Chatterjee, Prasanta

    2014-10-01

    The dynamic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas with superthermal electrons and positrons has been investigated in the framework of perturbed and non-perturbed Kadomtsev-Petviashili (KP) equations. Applying the reductive perturbation technique, we have derived the KP equation in electron-positron-ion magnetoplasma with kappa distributed electrons and positrons. Bifurcations of ion acoustic traveling waves of the KP equation are presented. Using the bifurcation theory of planar dynamical systems, the existence of the solitary wave solutions and the periodic traveling wave solutions has been established. Two exact solutions of these waves have been derived depending on the system parameters. Then, using the Hirota's direct method, we have obtained two-soliton and three-soliton solutions of the KP equation. The effect of the spectral index κ on propagations of the two-soliton and the three-soliton has been shown. Considering an external periodic perturbation, we have presented the quasi periodic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas.

  1. Dynamic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas with superthermal electrons and positrons

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Asit, E-mail: asit-saha123@rediffmail.com, E-mail: prasantachatterjee1@rediffmail.com [Department of Mathematics, Sikkim Manipal Institute of Technology, Majitar, Rangpo, East-Sikkim 737136 (India); Department of Mathematics, Siksha Bhavana, Visva Bharati University, Santiniketan-731235 (India); Pal, Nikhil; Chatterjee, Prasanta, E-mail: asit-saha123@rediffmail.com, E-mail: prasantachatterjee1@rediffmail.com [Department of Mathematics, Siksha Bhavana, Visva Bharati University, Santiniketan-731235 (India)

    2014-10-15

    The dynamic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas with superthermal electrons and positrons has been investigated in the framework of perturbed and non-perturbed Kadomtsev-Petviashili (KP) equations. Applying the reductive perturbation technique, we have derived the KP equation in electron-positron-ion magnetoplasma with kappa distributed electrons and positrons. Bifurcations of ion acoustic traveling waves of the KP equation are presented. Using the bifurcation theory of planar dynamical systems, the existence of the solitary wave solutions and the periodic traveling wave solutions has been established. Two exact solutions of these waves have been derived depending on the system parameters. Then, using the Hirota's direct method, we have obtained two-soliton and three-soliton solutions of the KP equation. The effect of the spectral index κ on propagations of the two-soliton and the three-soliton has been shown. Considering an external periodic perturbation, we have presented the quasi periodic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas.

  2. Interface properties of 4H-SiC MOS structures studied by a slow positron beam

    International Nuclear Information System (INIS)

    Maekawa, M.; Kawasuso, A.; Ichimiya, A.; Yoshikawa, M.

    2004-01-01

    Interfacial defects existing near the SiO 2 /SiC interface are an important issue for fabrication of high performance SiC devices. We investigate a thermally grown SiO 2 /SiC layer of 4H-SiC MOS structure by positron annihilation spectroscopy. The Doppler broadening of annihilation quanta was measured as a function of the incident positron energy and the gate bias. Applying a negative gate bias, significant increases in S-parameters were observed. This indicates the migration of implanted positrons towards the SiO 2 /SiC interface and annihilation at interfacial defects. Ultraviolet (UV) ray irradiation was used to extract the influence of the positron trapping to the interfacial states. S-parameters in the interface region were reduced by UV irradiation. This shows that positron trapping probability decreased because the charge state of interfacial defects changed to positive. From the recovery of S-parameters after 24 hours, the interfacial states discharge slowly and exist in large quantities, because the changes of S-parameter by the UV irradiation are larger than changes induced by bias change. (orig.)

  3. Positron induced scattering cross sections for hydrocarbons relevant to plasma

    Science.gov (United States)

    Singh, Suvam; Antony, Bobby

    2018-05-01

    This article explores positron scattering cross sections by simple hydrocarbons such as ethane, ethene, ethyne, propane, and propyne. Chemical erosion processes occurring on the surface due to plasma-wall interactions are an abundant source of hydrocarbon molecules which contaminate the hydrogenic plasma. These hydrocarbons play an important role in the edge plasma region of Tokamak and ITER. In addition to this, they are also one of the major components in the planetary atmospheres and astrophysical mediums. The present work focuses on calculation of different positron impact interactions with simple hydrocarbons in terms of the total cross section (Qtot), elastic cross section (Qel), direct ionization cross section (Qion), positronium formation cross section (Qps), and total ionization cross section (Qtion). Knowing that the positron-plasma study is one of the trending fields, the calculated data have diverse plasma and astrophysical modeling applications. A comprehensive study of Qtot has been provided where the inelastic cross sections have been reported for the first time. Comparisons are made with those available from the literature, and a good agreement is obtained with the measurements.

  4. Positron probes for mechanical fatigue detection system

    International Nuclear Information System (INIS)

    Holt, W.H.; Mock, W. Jr.

    1976-01-01

    The invention comprises positron-emitting probes for use in testing samples of metals for fatique by positron annihilation techniques comprising a substrate made from the same material as the test sample, positron-emitting material supported by one surface of the substrate, and a cover for the emitting material, the cover is sealed to the substrate and is of such thinness and density as to provide a window through which positron passage is unimpeded

  5. 4.5 Tesla magnetic field reduces range of high-energy positrons -- Potential implications for positron emission tomography

    International Nuclear Information System (INIS)

    Wirrwar, A.; Vosberg, H.; Herzog, H.; Halling, H.; Weber, S.; Mueller-Gaertner, H.W.; Forschungszentrum Juelich GmbH

    1997-01-01

    The authors have theoretically and experimentally investigated the extent to which homogeneous magnetic fields up to 7 Tesla reduce the spatial distance positrons travel before annihilation (positron range). Computer simulations of a noncoincident detector design using a Monte Carlo algorithm calculated the positron range as a function of positron energy and magnetic field strength. The simulation predicted improvements in resolution, defined as full-width at half-maximum (FWHM) of the line-spread function (LSF) for a magnetic field strength up to 7 Tesla: negligible for F-18, from 3.35 mm to 2.73 mm for Ga-68 and from 3.66 mm to 2.68 mm for Rb-82. Also a substantial noise suppression was observed, described by the full-width at tenth-maximum (FWTM) for higher positron energies. The experimental approach confirmed an improvement in resolution for Ga-68 from 3.54 mm at 0 Tesla to 2.99 mm FWHM at 4.5 Tesla and practically no improvement for F-18 (2.97 mm at 0 Tesla and 2.95 mm at 4.5 Tesla). It is concluded that the simulation model is appropriate and that a homogeneous static magnetic field of 4.5 Tesla reduces the range of high-energy positrons to an extent that may improve spatial resolution in positron emission tomography

  6. Model-independent requirements to the source of positrons in the galactic centre

    International Nuclear Information System (INIS)

    Aharonyan, F.A.

    1986-01-01

    The main requirements, following from the observational data in a wide range of electromagnetic waves, to positron source in the galactic centre are formulated. The most probable mechanism providing an efficiency of positron production of 10% is the pair production at photon-photon collisions. This mechanism can be realized a) in a thermal e + e - pair-dominated weak-relativistic plasma and b) at the development of a nonthermal electromagnetic cascade initiated by relativistic particles in the field of X-rays. Gamma-astronomical observations in the region of E γ ≥ 10 11 eV can be crucial in the choice of the model

  7. Role of axillary lymph node ultra-sound and large core biopsy in the preoperative assessment of patients selected for sentinel node biopsy

    International Nuclear Information System (INIS)

    Nori, Jacopo; Boeri, Cecilia; Vanzi, Ermanno; Nori Bufalini, Filippo; Masi, Andrea; Bazzocchi, Massimo; Londero, Viviana; Mangialavori, Giuseppe; Distante, Vito; Simoncini, Roberta

    2005-01-01

    Purpose: To aim of this study was to evaluate the diagnostic accuracy of axillary lymph node sonography, if necessary in collaboration with US-guided large core biopsy, in the preoperative evaluation of breast cancer patients scheduled for quadrantectomy and sentinel lymph node excision. Materials and methods: From July 2001 to December 2002, we evaluated 117 breast cancer patients with ultrasound and, where indicated, FNAB. Breast lesions has diameters between 4 and 26 mm (mean diameter 11 mm). Fifteen (13%) of the 117 patients were excluded from the series as they did not found fulfil the criteria for preliminary sonography of the axilla: in 9 patients fewer than 4 nodes were detected and in 6 patients the breast lesions were intraoperatively found to be benign. Eleven patients (10.7%) with sonographically suspicious axillary nodes were sampled by US-guided core biopsy using a 14 or 16 Gauge Tru-Cut needle. Results: The ultrasound study aims to evaluate the dimensions and morphology of the breast lesion as well as detect and assess at least 4 axillary nodes. These were evaluated for hilar and cortical thickening and radio between the sinus diameter and the total longitudinal diameter. Lymph nodes with hilar diameters equal to or greater than 50% of the longitudinal diameter were considered normal. Of the 102 patients evaluated, 77 (75.7%) had normal axillary nodes according to the US criteria adopted. Negativity was confirmed by histology in 56 cases (72.7%, true negative); 21 (27.3%, false negative) were found to be positive, in contrast with the sonographic appearance. The false negative cases were due to lymph node micrometastasis which probably did not cause morphologic alterations perceptible at ultrasound. The remaining 25 patients (24.5%) had axillary lymph nodes classified as suspicious. In 13 cases of (52%, true positive) there was agreement with histology, whereas in 12 cases (48%, false positive) the US suspicion was not confirmed at surgery. The most

  8. Defect characterization with positron annihilation

    International Nuclear Information System (INIS)

    Granatelli, L.; Lynn, K.G.

    1980-01-01

    Positron annihilation in metal crystals is reviewed. A brief introduction to the positron annihilation technique is presented first. Then the ability of the positron technique to perform microstructural characterization of four types of lattice defects (vacancies, voids, dislocations, grain boundaries) is discussed. It is frequently not possible to obtain samples that contain only one type of defect in nonnegligible concentrations. Such situations exist for some alloys and for fatigued metal samples. Finally, the current limitations and some future prospects of the technique are presented. 79 references, 14 figures, 1 table

  9. Fundamentals of positron emission tomography

    International Nuclear Information System (INIS)

    Ostertag, H.

    1989-01-01

    Positron emission tomography is a modern radionuclide method of measuring physiological quantities or metabolic parameters in vivo. The methods is based on: (1) Radioactive labelling with positron emitters; (2) the coincidence technique for the measurement of the annihilation radiation following positron decay; (3) analysis of the data measured using biological models. The basic aspects and problems of the method are discussed. The main fields of future research are the synthesis of new labelled compounds and the development of mathematical models of the biological processes to be investigated. (orig.) [de

  10. Atomic collisions involving pulsed positrons

    DEFF Research Database (Denmark)

    Merrison, J. P.; Bluhme, H.; Field, D.

    2000-01-01

    Conventional slow positron beams have been widely and profitably used to study atomic collisions and have been instrumental in understanding the dynamics of ionization. The next generation of positron atomic collision studies are possible with the use of charged particle traps. Not only can large...... instantaneous intensities be achieved with in-beam accumulation, but more importantly many orders of magnitude improvement in energy and spatial resolution can be achieved using positron cooling. Atomic collisions can be studied on a new energy scale with unprecedented precion and control. The use...

  11. Characterization of Trichome-Expressed BAHD Acyltransferases in Petunia axillaris Reveals Distinct Acylsugar Assembly Mechanisms within the Solanaceae.

    Science.gov (United States)

    Nadakuduti, Satya Swathi; Uebler, Joseph B; Liu, Xiaoxiao; Jones, A Daniel; Barry, Cornelius S

    2017-09-01

    Acylsugars are synthesized in the glandular trichomes of the Solanaceae family and are implicated in protection against abiotic and biotic stress. Acylsugars are composed of either sucrose or glucose esterified with varying numbers of acyl chains of differing length. In tomato ( Solanum lycopersicum ), acylsugar assembly requires four acylsugar acyltransferases (ASATs) of the BAHD superfamily. Tomato ASATs catalyze the sequential esterification of acyl-coenzyme A thioesters to the R4, R3, R3', and R2 positions of sucrose, yielding a tetra-acylsucrose. Petunia spp. synthesize acylsugars that are structurally distinct from those of tomato. To explore the mechanisms underlying this chemical diversity, a Petunia axillaris transcriptome was mined for trichome preferentially expressed BAHDs. A combination of phylogenetic analyses, gene silencing, and biochemical analyses coupled with structural elucidation of metabolites revealed that acylsugar assembly is not conserved between tomato and petunia. In P. axillaris , tetra-acylsucrose assembly occurs through the action of four ASATs, which catalyze sequential addition of acyl groups to the R2, R4, R3, and R6 positions. Notably, in P. axillaris , PaxASAT1 and PaxASAT4 catalyze the acylation of the R2 and R6 positions of sucrose, respectively, and no clear orthologs exist in tomato. Similarly, petunia acylsugars lack an acyl group at the R3' position, and congruently, an ortholog of SlASAT3, which catalyzes acylation at the R3' position in tomato, is absent in P. axillaris Furthermore, where putative orthologous relationships of ASATs are predicted between tomato and petunia, these are not supported by biochemical assays. Overall, these data demonstrate the considerable evolutionary plasticity of acylsugar biosynthesis. © 2017 American Society of Plant Biologists. All Rights Reserved.

  12. Construction report of the PF slow-positron source. 1

    International Nuclear Information System (INIS)

    Enomoto, Atsushi; Kurihara, Toshikazu; Kobayashi, Hitoshi

    1993-12-01

    The slow positron source utilizing the electron beam of the 2.5 GeV electron beam accelerator which is the synchrotron radiation injector is being constructed. The outline of the project and the present state of construction are reported. As of November, 1993, by injecting the electron beam of about 10 W to the targets for producing positrons, the slow positrons of 4 x 10 4 e + /s has been obtained in the laboratory. Finally, with the electron beam of 30 kW, it is aimed at to obtain the slow positron beam of 2 x 10 9 e + /s. In the slow positron source, the electron beam from the 2.5 GeV linear accelerator is used as the primary beam. This beam is led to the target with electromagnets. Radiation shields were strengthened, and the electrostatic lens system was attached to efficiently extract and send out slow positrons. The conveying system for slow positrons is explained. Primary electron beam, target and moderator for producing slow positrons, the change to continuous current of pulsed slow positron beam and the heightening of luminance of slow positron beam, and the experiment on the utilization of slow positron beam, and the control system for positron conveyance path are reported. (K.I.)

  13. The intense slow positron beam facility at the PULSTAR reactor and applications in nano-materials study

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ming; Moxom, Jeremy; Hawari, Ayman I. [Nuclear Reactor Program, Department of Nuclear Engineering, North Carolina State University, P.O. Box 7909, Raleigh, NC 27695 (United States); Gidley, David W. [Department of Physics, University of Michigan, 450 Church Street, Ann Arbor MI 48109 (United States)

    2013-04-19

    An intense slow positron beam has been established at the PULSTAR nuclear research reactor of North Carolina State University. The slow positrons are generated by pair production in a tungsten moderator from gammarays produced in the reactor core and by neutron capture reactions in cadmium. The moderated positrons are electrostatically extracted and magnetically guided out of the region near the core. Subsequently, the positrons are used in two spectrometers that are capable of performing positron annihilation lifetime spectroscopy (PALS) and positron Doppler broadening spectroscopy (DBS) to probe the defect and free volume properties of materials. One of the spectrometers (e{sup +}-PALS) utilizes an rf buncher to produce a pulsed beam and has a timing resolution of 277 ps. The second spectrometer (Ps-PALS) uses a secondary electron timing technique and is dedicated to positronium lifetime measurements with an approximately 1 ns timing resolution. PALS measurements have been conducted in the e{sup +}-PALS spectrometer on a series of nano-materials including organic photovoltaic thin films, membranes for filtration, and polymeric fibers. These studies have resulted in understanding some critical issues related to the development of the examined nano-materials.

  14. The intense slow positron beam facility at the PULSTAR reactor and applications in nano-materials study

    Science.gov (United States)

    Liu, Ming; Moxom, Jeremy; Hawari, Ayman I.; Gidley, David W.

    2013-04-01

    An intense slow positron beam has been established at the PULSTAR nuclear research reactor of North Carolina State University. The slow positrons are generated by pair production in a tungsten moderator from gammarays produced in the reactor core and by neutron capture reactions in cadmium. The moderated positrons are electrostatically extracted and magnetically guided out of the region near the core. Subsequently, the positrons are used in two spectrometers that are capable of performing positron annihilation lifetime spectroscopy (PALS) and positron Doppler broadening spectroscopy (DBS) to probe the defect and free volume properties of materials. One of the spectrometers (e+-PALS) utilizes an rf buncher to produce a pulsed beam and has a timing resolution of 277 ps. The second spectrometer (Ps-PALS) uses a secondary electron timing technique and is dedicated to positronium lifetime measurements with an approximately 1 ns timing resolution. PALS measurements have been conducted in the e+-PALS spectrometer on a series of nano-materials including organic photovoltaic thin films, membranes for filtration, and polymeric fibers. These studies have resulted in understanding some critical issues related to the development of the examined nano-materials.

  15. Nuclear-charge and positron-energy dependence of the single-quantum annihilation of positrons

    International Nuclear Information System (INIS)

    Palathingal, J.C.; Asoka-Kumar, P.; Lynn, K.G.; Wu, X.Y.

    1995-01-01

    We report an experimental study of the single-quantum annihilation of positrons in a number of elements having atomic numbers between 49 and 90, utilizing a monoenergetic positron beam. Measurements were made of the differential cross sections for the forward direction for the K, L, and M atomic shells in targets of Th, Pb, Au, Hf, Gd, and In, having thicknesses that vary between 2.7 and 4.4 mg/cm 2 . A shielded HPGe detector of high relative photopeak efficiency was used for recording the photon spectrum. Values for the individual atomic shells were obtained in the positron kinetic-energy range 1.02--2.24 MeV. It was observed that the differential cross sections measured for the forward direction varied with energy for each major shell almost alike so that the shell ratios appeared to remain constant while the positron energy varied. The dependence of the cross section on the atomic number Z of the target element was tested for each of the major shells at various energies of measurement. It was seen that the cross sections follow a Z ν relation with ν∼5.1 as the exponent for the K shell. For the higher shells, the exponent is approximately 6.4, which is significantly larger. It was also noted that this pattern is fairly independent of the positron energy. The results on the Z dependence are seen to be clearly at variance with the most updated theoretical predictions

  16. Axillary staging for breast cancer during pregnancy

    DEFF Research Database (Denmark)

    Han, S N; Amant, F; Cardonick, E H

    2018-01-01

    BACKGROUND: Safety of sentinel lymph node (SLN) biopsy for breast cancer during pregnancy is insufficiently explored. We investigated efficacy and local recurrence rate in a large series of pregnant patients. PATIENTS AND METHODS: Women diagnosed with breast cancer who underwent SLN biopsy during...... pregnancy were identified from the International Network on Cancer, Infertility and Pregnancy, the German Breast Group, and the Cancer and Pregnancy Registry. Chart review was performed to record technique and outcome of SLN biopsy, locoregional and distant recurrence, and survival. RESULTS: We identified...... were alive and free of disease. Eleven patients experienced a locoregional relapse, including 1 isolated ipsilateral axillary recurrence (0.7%). Eleven (7.6%) patients developed distant metastases, of whom 9 (6.2%) died of breast cancer. No neonatal adverse events related to SLN procedure during...

  17. Detection of axillary lymph node involvement of breast cancer by Tc-99m MIBI scintimammography

    International Nuclear Information System (INIS)

    Pusuwan, P.; Chakrappe-sirisuk, S.; Amornpichetkul, K.; Padhy, A.K.; Dondi, M.; Watanabe, N.

    2006-01-01

    Breast cancer is the most common malignancy among women, leading to hundreds of thousands of deaths annually around the world. Lymph node status is the most important prognostic indicator in newly diagnosed breast cancer. The presence of axillary lymph node metastases has major prognostic implications in breast cancer patients, and it is an important criterion in determining the need for adjuvant chemotherapy. There is not an accurate anatomical test for detecting axillary lymph node metastasis and clinical examination has inappropriate diagnostic values. Routine lymph node dissection is the only accepted method for therapeutic decisions but it is invasive and produces significant morbidity such as lymphedema and infections. On the other hand, an important proportion of breast cancer patients are nodenegative. Ultrasonography has also been reported to be helpful, especially in conjunction with fine needle aspiration biopsy

  18. Population based study on sentinel node biopsy before or after neoadjuvant chemotherapy in clinically node negative breast cancer patients : Identification rate and influence on axillary treatment

    NARCIS (Netherlands)

    van der Heiden-van der Loo, M.; de Munck, L.; Sonke, G. S.; van Dalen, T.; van Diest, P. J.; van den Bongard, H. J. G. D.; Peeters, P. H. M.; Rutgers, E. J. T.

    The timing of the sentinel lymph node biopsy (SNB) is controversial in clinically node negative patients receiving neoadjuvant chemotherapy (NAC). We studied variation in the timing of axillary staging in breast cancer patients who received NAC and the subsequent axillary treatment in The

  19. Repair of Multiple Subclavian and Axillary Artery Aneurysms in a 58-Year-Old Man with Marfan Syndrome.

    Science.gov (United States)

    Dolapoglu, Ahmet; de la Cruz, Kim I; Preventza, Ourania; Coselli, Joseph S

    2016-10-01

    Dilation of the ascending aorta and aortic dissections are often seen in Marfan syndrome; however, true aneurysms of the subclavian and axillary arteries rarely seem to develop in patients who have this disease. We present the case of a 58-year-old man with Marfan syndrome who had undergone a Bentall procedure and thoracoabdominal aortic repair for an aortic dissection and who later developed multiple aneurysmal dilations of his right subclavian and axillary arteries. The aneurysms were successfully repaired by means of a surgical bypass technique in which a Dacron graft was placed between the carotid and brachial arteries. We also discuss our strategy for determining the optimal surgical approach in these patients.

  20. Bulk Materials Analysis Using High-Energy Positron Beams

    International Nuclear Information System (INIS)

    Glade, S C; Asoka-Kumar, P; Nieh, T G; Sterne, P A; Wirth, B D; Dauskardt, R H; Flores, K M; Suh, D; Odette, G.R.

    2002-01-01

    This article reviews some recent materials analysis results using high-energy positron beams at Lawrence Livermore National Laboratory. We are combining positron lifetime and orbital electron momentum spectroscopic methods to provide electron number densities and electron momentum distributions around positron annihilation sites. Topics covered include: correlation of positron annihilation characteristics with structural and mechanical properties of bulk metallic glasses, compositional studies of embrittling features in nuclear reactor pressure vessel steel, pore characterization in Zeolites, and positron annihilation characteristics in alkali halides

  1. Investigation and realization of a slow-positron beam

    International Nuclear Information System (INIS)

    Ruiz, Nicolas

    2011-01-01

    This research thesis first proposes a presentation of the GBAR project (Gravitational Behaviour of Anti-hydrogen at Rest) within which this research took place, and which aims at performing the first direct test of the Weak Equivalence Principle on anti-matter by studying the free fall of anti-hydrogen atoms in the Earth gravitational field. The author presents different aspects of this project: scientific objective, experiment principle and structure, detailed structure (positron beam, positron trap, positron/positronium conversion, anti-proton beam, trapping, slowing down and neutralisation of anti-hydrogen ions). The author then reports the design of the positron beam: study of source technology, studies related to the fast positron source, design of the low positron line (approach, functions, simulations, technology). The two last chapters report the construction and the characterization of the slow-positron line [fr

  2. Ultrarelativistic electron and positron radiation in planar channeling

    International Nuclear Information System (INIS)

    Kalashnikov, N.P.; Olchack, A.S.

    1980-01-01

    The coherent electromagnetic radiation from channeling electrons and positrons is given by similar expression. However for the channeling positrons the close collisions are suppressed due to the fact that the positron wave function is exponentially small near the atoms of the crystal lattice. It follows that the coherent bremsstrahlung decreases for the channeling positrons. We have investigated the ultrarelativistic channeling electron and positron radiations, connected with the electromagnetic transitions from the continuum spectrum states to the quasi-bound spectrum states and between the different quasi-bound spectrum states. The radiation probabilities are calculated by using the model continuum planar potential. It is shown that the radiation from the channeling electrons is several orders of magnitude larger than the positron radiation, while the electron and positron radiation have similar characteristics such as frequency limitation and angular distribution of the radiation. (orig.)

  3. Evaluation of scintillators and semiconductor detectors to image three-photon positron annihilation for positron emission tomography

    International Nuclear Information System (INIS)

    Abuelhia, E.; Spyrou, N.M.; Kacperski, K.; College University, Middlesex Hospital, London

    2008-01-01

    Positron emission tomography (PET) is rapidly becoming the main nuclear imaging modality of the present century. The future of PET instrumentation relies on semiconductor detectors because of their excellent characteristics. Three-photon positron annihilation has been recently investigated as a novel imaging modality, which demands the crucial high energy resolution of semiconductor detector. In this work the evaluation of the NaI(Tl) scintillator and HPGe and CdZTe semiconductor detectors, to construct a simple three-photon positron annihilation scanner has been explored. The effect of detector and scanner size on spatial resolution (FWHM) is discussed. The characteristics: energy resolution versus count rate and point-spread function of the three-photon positron annihilation image profile from triple coincidence measurements were investigated. (author)

  4. Validation of sentinel lymph node biopsy in breast cancer women N1-N2 with complete axillary response after neoadjuvant chemotherapy. Multicentre study in Tarragona.

    Science.gov (United States)

    Carrera, D; de la Flor, M; Galera, J; Amillano, K; Gomez, M; Izquierdo, V; Aguilar, E; López, S; Martínez, M; Martínez, S; Serra, J M; Pérez, M; Martin, L

    2016-01-01

    The aim of our study was to evaluate sentinel lymph node biopsy as a diagnostic test for assessing the presence of residual metastatic axillary lymph nodes after neoadjuvant chemotherapy, replacing the need for a lymphadenectomy in negative selective lymph node biopsy patients. A multicentre, diagnostic validation study was conducted in the province of Tarragona, on women with T1-T3, N1-N2 breast cancer, who presented with a complete axillary response after neoadjuvant chemotherapy. Study procedures consisted of performing an selective lymph node biopsy followed by lymphadenectomy. A total of 53 women were included in the study. Surgical detection rate was 90.5% (no sentinel node found in 5 patients). Histopathological analysis of the lymphadenectomy showed complete disease regression of axillary nodes in 35.4% (17/48) of the patients, and residual axillary node involvement in 64.6% (31/48) of them. In lymphadenectomy positive patients, 28 had a positive selective lymph node biopsy (true positive), while 3 had a negative selective lymph node biopsy (false negative). Of the 28 true selective lymph node biopsy positives, the sentinel node was the only positive node in 10 cases. All lymphadenectomy negative cases were selective lymph node biopsy negative. These data yield a sensitivity of 93.5%, a false negative rate of 9.7%, and a global test efficiency of 93.7%. Selective lymph node biopsy after chemotherapy in patients with a complete axillary response provides valid and reliable information regarding axillary status after neoadjuvant treatment, and might prevent lymphadenectomy in cases with negative selective lymph node biopsy. Copyright © 2016 Elsevier España, S.L.U. and SEMNIM. All rights reserved.

  5. The rise in the positron fraction. Distance limits on positron point sources from cosmic ray arrival directions and diffuse gamma-rays

    Energy Technology Data Exchange (ETDEWEB)

    Gebauer, Iris; Bentele, Rosemarie [Karlsruhe Institute of Technology, Karlsruhe (Germany)

    2016-07-01

    The rise in the positron fraction as observed by AMS and previously by PAMELA, cannot be explained by the standard paradigm of cosmic ray transport in which positrons are produced by cosmic-ray-gas interactions in the interstellar medium. Possible explanations are pulsars, which produce energetic electron-positron pairs in their rotating magnetic fields, or the annihilation of dark matter. Here we assume that these positrons originate from a single close-by point source, producing equal amounts of electrons and positrons. The propagation and energy losses of these electrons and positrons are calculated numerically using the DRAGON code, the source properties are optimized to best describe the AMS data. Using the FERMI-LAT limits on a possible dipole anisotropy in electron and positron arrival directions, we put a limit on the minimum distance of such a point source. The energy losses that these energetic electrons and positrons suffer on their way through the galaxy create gamma ray photons through bremsstrahlung and Inverse Compton scattering. Using the measurement of diffuse gamma rays from Fermi-LAT we put a limit on the maximum distance of such a point source. We find that a single electron positron point source powerful enough to explain the locally observed positron fraction must reside between 225 pc and 3.7 kpc distance from the sun and compare to known pulsars.

  6. Studies of positron induced luminescence from polymers

    International Nuclear Information System (INIS)

    Xu, J.; Hulett, L.D. Jr.; Lewis, T.A.; Tolk, N.H.

    1994-01-01

    Light emission from polymers (anthracene dissolved in polystryrene) induced by low-energy positrons and electrons has been studied. Results indicate a clear difference between optical emissions under positron and electron bombardment. The positron-induced luminescence spectrum is believed to be generated by both collisional and annihilation processes

  7. The value of level III clearance in patients with axillary and sentinel node positive breast cancer.

    LENUS (Irish Health Repository)

    Dillon, Mary F

    2012-02-01

    BACKGROUND: The value of level III axillary clearance is contentious, with great variance worldwide in the extent and levels of clearance performed. OBJECTIVE: To determine rates of level III positivity in patients undergoing level I-III axillary clearance, and identify which patients are at highest risk of involved level III nodes. METHODS: From a database of 2850 patients derived from symptomatic and population-based screening service, 1179 patients who underwent level I-III clearance between the years 1999-2007 were identified. The pathology, surgical details, and prior sentinel nodes biopsies of patients were recorded. RESULTS: Eleven hundred seventy nine patients had level I-III axillary clearance. Of the patients, 63% (n = 747) were node positive. Of patients with node positive disease, 23% (n = 168) were level II positive and 19% (n = 141) were level III positive. Two hundred fifty patients had positive sentinel node biopsies prior to axillary clearance. Of these, 12% (n = 30) and 9% (n = 22) were level II and level III positive, respectively. On multivariate analysis, factors predictive of level III involvement in patients with node positive disease were tumor size (P < 0.001, OR = 1.36; 95% CI: 1.2-1.5), invasive lobular disease (P < 0.001, OR = 3.6; 95% CI: 1.9-6.95), extranodal extension (P < 0.001, OR = 0.27; 95% CI: 0.18-0.4), and lymphovascular invasion (P = 0.04, OR = 0.58; 95% CI: 0.35-1). Lobular invasive disease (P = 0.049, OR = 4.1; 95% CI: 1-16.8), extranodal spread (P = 0.003, OR = 0.18; 95% CI: 0.06-0.57), and having more than one positive sentinel node (P = 0.009, OR = 4.9; 95% CI: 1.5-16.1) were predictive of level III involvement in patients with sentinel node positive disease. CONCLUSION: Level III clearance has a selective but definite role to play in patients who have node positive breast carcinoma. Pathological characteristics of the primary tumor are of particular use in identifying those who are at various risk of level III nodal

  8. Positron lifetime experiments in indium selenide

    International Nuclear Information System (INIS)

    Cruz, R.M. de la; Pareja, R.

    1988-01-01

    Positron lifetime experiments have been performed on as-grown samples which had been isochronally annealed up to 820 K and plastically deformed and these experiments yield a constant lifetime of 282 ± 2 ps which is attributed to bulk positron states in InSe. Electron-irradiated samples exhibit a two-component spectrum, revealing the presence of positron traps which anneal out at about 330 K. The nature of the native shallow donors in InSe is discussed in the light of the results, which support the idea that native donor centres are probably interstitial In atoms rather than Se vacancies. Positron trapping observed in the electron-irradiated samples is attributed to defects related to In vacancies. (author)

  9. Cosmic Ray Positrons from Pulsars

    Science.gov (United States)

    Harding, Alice K.

    2010-01-01

    Pulsars are potential Galactic sources of positrons through pair cascades in their magnetospheres. There are, however, many uncertainties in establishing their contribution to the local primary positron flux. Among these are the local density of pulsars, the cascade pair multiplicities that determine the injection rate of positrons from the pulsar, the acceleration of the injected particles by the pulsar wind termination shock, their rate of escape from the pulsar wind nebula, and their propagation through the interstellar medium. I will discuss these issues in the context of what we are learning from the new Fermi pulsar detections and discoveries.

  10. Undulator-based production of polarized positrons

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, G. [Tel-Aviv Univ. (Israel); Barley, J. [Cornell Univ., Ithaca, NY (United States); Batygin, Y. [SLAC, Menlo Park, CA (US)] (and others)

    2009-05-15

    Full exploitation of the physics potential of a future International Linear Collider will require the use of polarized electron and positron beams. Experiment E166 at the Stanford Linear Accelerator Center (SLAC) has demonstrated a scheme in which an electron beam passes through a helical undulator to generate photons (whose first-harmonic spectrum extended to 7.9 MeV) with circular polarization, which are then converted in a thin target to generate longitudinally polarized positrons and electrons. The experiment was carried out with a one-meter-long, 400-period, pulsed helical undulator in the Final Focus Test Beam (FFTB) operated at 46.6 GeV. Measurements of the positron polarization have been performed at five positron energies from 4.5 to 7.5 MeV. In addition, the electron polarization has been determined at 6.7MeV, and the effect of operating the undulator with a ferrofluid was also investigated. To compare the measurements with expectations, detailed simulations were made with an upgraded version of GEANT4 that includes the dominant polarization-dependent interactions of electrons, positrons, and photons with matter. The measurements agree with calculations, corresponding to 80% polarization for positrons near 6 MeV and 90% for electrons near 7 MeV. (orig.)

  11. Positron lifetime study of neutron-irradiated molybdenum

    International Nuclear Information System (INIS)

    Hinode, Kenji; Tanigawa, Shoichiro; Kumakura, Hiroaki; Doyama, Masao; Shiraishi, Kensuke.

    1978-01-01

    Annealing behavior of fast-neutron-irradiated molybdenum was studied by means of positron lifetime technique. It was found that Stage III annealing can be mainly identified as the vacancy migration process from the detailed analyses of data. The void growth after successive high temperature annealings was clearly detected through the changes of positron lifetime parameters. An attempt to analyse the size distribution of voids from positron lifetime spectra was presented, and discussions on the evaluation of void concentration from positron data are also given. (author)

  12. Positron annihilation spectroscopy in materials structure studies

    International Nuclear Information System (INIS)

    Grafutin, Viktor I; Prokop'ev, Evgenii P

    2002-01-01

    A relatively new method of materials structure analysis - positron annihilation spectroscopy (PAS) - is reviewed. Measurements of positron lifetimes, the determination of positron 3γ- and 2γ-annihilation probabilities, and an investigation of the effects of different external factors on the fundamental characteristics of annihilation constitute the basis for this promising method. The ways in which the positron annihilation process operates in ionic crystals, semiconductors, metals and some condensed matter systems are analyzed. The scope of PAS is described and its prospects for the study of the electronic and defect structures are discussed. The applications of positron annihilation spectroscopy in radiation physics and chemistry of various substances as well as in physics and chemistry of solutions are exemplified. (instruments and methods of investigation)

  13. Digital positron annihilation spectrometer

    International Nuclear Information System (INIS)

    Cheng Bin; Weng Huimin; Han Rongdian; Ye Bangjiao

    2010-01-01

    With the high speed development of digital signal process, the technique of the digitization and processing of signals was applied in the domain of a broad class of nuclear technique. The development of digital positron lifetime spectrometer (DPLS) is more promising than the conventional positron lifetime spectrometer equipped with nuclear instrument modules. And digital lifetime spectrometer has many advantages, such as low noise, long term stability, flexible online or offline digital processing, simple setup, low expense, easy to setting, and more physical information. Digital constant fraction discrimination is for timing. And a new method of optimizing energy windows setting for digital positron lifetime spectrometer is also developed employing the simulated annealing for the convenient use. The time resolution is 220ps and the count rate is 200cps. (authors)

  14. Positron emission tomography imaging--technical considerations

    International Nuclear Information System (INIS)

    Muehllehner, G.; Karp, J.S.

    1986-01-01

    Positron imaging instrumentation has improved rapidly in the last few years. Scanners currently under development are beginning to approach fundamental limits set by positron range and noncolinearity effects. This report reviews the latest developments in positron emission tomography (PET) instrumentation, emphasizing the development of coding schemes that reduce the complexity and cost of high-resolution scanners. The relative benefits of using time-of-flight (TOF) information is discussed as well. 68 references

  15. Predictors of axillary lymph node metastases in women with early breast cancer in Singapore.

    Science.gov (United States)

    Tan, L G L; Tan, Y Y; Heng, D; Chan, M Y

    2005-12-01

    The presence of axillary lymph node metastases is an important prognostic factor in breast cancer. Sentinel lymph node biopsy (SLNB) is an emerging method for the staging of the axilla. It is hoped that with SLNB, the morbidity from axillary lymph node dissection (ALND) can be avoided without compromising the staging and management of early breast cancer. However, only patients found to be SLNB negative benefit from this procedure, as those with positive SLNB may still require ALND. Our objective is to study the various clinico-pathological factors to find predictive factors for axillary lymph node involvement in early breast cancer. It is hoped that with these factors, we will be better able to identify groups of patients most likely to benefit from SLNB. A retrospective study of 380 early breast cancer cases (stage T1 and T2, N0, N1, M0) in women treated in the Department of General Surgery, Tan Tock Seng Hospital, between January 1999 and August 2002, was conducted. Incidence of nodal metastases was correlated with clinico-pathological factors, and analysed by univariate and multivariate analyses. Approximately 35 percent of the 380 cases of early breast cancer had nodal metastases. Multivariate analyses revealed four independent predictors of node positivity: tumour size (p-value equals 0.0001), presence of lymphovascular invasion (p-value is less than 0.0001), tumours with histology other than invasive ductal or lobular carcinoma (p-value equals 0.04), and presence of progesterone receptors (p-value equals 0.05). We have found independent preoperative predictive factors in our local population for the presence of nodal metastases. This information can aid patient selection for SLNB and improve patient counselling.

  16. Analysis of human cerebral functions using positron emission tomography (PET)

    International Nuclear Information System (INIS)

    Shibasaki, Takashi

    1984-01-01

    Positron emission tomography has two major advantages to analyse human cerebral functions in vivo. First, we can see the distribution of a variety of substance in the living (and doing something) human brain. Positron emitters, 11 C, 13 N, 15 O and 18 F, are made by medical cyclotron and are elements of natural substrates or easily tagged to substrate. Second, the distribution of the tracer is calculated to make a quantitative functional map in a reasonable spatial resolution over the entire brain in the same time. Not only cortical areas but also deeper structures show regional cerebral blood flow (rCBF) or local cerebral metabolic rates (LCMRs). Nowadays, PET is put to practical use for determination of mainly rCBF, LCMR for glucose (LCMRsub(glu)), LCMR for oxygen (LCMRsub(o2)) and regional cerebral blood volume (rCBV). There have been many other pilot studies, such as estimation of distribution of given neurotransmitters or modulators in the brain which also confirms the substances' role in the neuronal function, and observation of protein synthesis relating to memory function. (J.P.N.)

  17. Generation and application of slow positrons based on a electron LINAC

    International Nuclear Information System (INIS)

    Kurihara, Toshikazu

    2002-01-01

    History of slow positron in Institute of Materials Structure Science High Energy Accelerator Research Organization is explained. The principle of generation and application of intense positron beam is mentioned. Two sources of intense positron are radioactive decay of radioactive isotopes emitting positron and electron-positron pair creation. The radioactive decay method uses 58 Co, 64 Cu, 11 C, 13 N, 15 O and 18 F. The electron-positron pair creation method uses nuclear reactor or electron linear accelerator (LINAC). The positron experimental facility in this organization consists of electron LINAC, slow positron beam source, positron transport and experimental station. The outline of this facility is started. The intense slow positron beam is applied to research positronium work function, electron structure of surface. New method such as combination of positron lifetime measurement and slow positron beam or Auger electron spectroscopy by positron annihilation excitation and positron reemission microscope are developed. (S.Y.)

  18. Experimental Study of a Positron\\\\ Source Using Channeling

    CERN Multimedia

    Gavrykov, V; Kulibaba, V; Baier, V; Beloborodov, K; Bojenok, A; Bukin, A; Burdin, S; Dimova, T; Druzhinin, V; Dubrovin, M; Seredniakov, S; Shary, V; Strakhovenko, V; Keppler, P; Major, J; Bogdanov, A V; Potylitsin, A; Vnoukov, I; Artru, X; Lautesse, P; Poizat, J-C; Remillieux, J

    2002-01-01

    Many simulations have predicted that the yield of positrons, resulting from the interaction of fast electrons in a solid target, increases if the target is a crystal oriented with a major axis parallel to the electron beam. Tests made at Orsay and Tokyo confirmed these expectations. The experiment WA 103 concerns the determination of the main characteristics (emittance, energy spread) of a crystal positron source which could replace advantageously the conventional positron converters foreseen in some linear collider projects. The main element of the set-up is a magnetic spectrometer, using a drift chamber, where the positron trajectories are reconstructed (see Figure 1) A first run has been operated in july 2000 and the first results showed, as expected, a significant enhancement in photon and positron generation along the $$ axis of the tungsten crystal. Indications about a significant increase in the number of soft photons and positrons were also gathered : this point is of importance for the positron colle...

  19. Toward a European Network of Positron Laboratories

    Directory of Open Access Journals (Sweden)

    Karwasz Grzegorz P.

    2015-12-01

    Full Text Available Some applications of controlled-energy positron beams in material studies are discussed. In porous organic polysilicates, measurements of 3γ annihilation by Doppler broadening (DB method at the Trento University allowed to trace pore closing and filling by water vapor. In silicon coimplanted by He+ and H+, DB data combined with positron lifetime measurements at the München pulsed positron beam allowed to explain Si blistering. Presently measured samples of W for applications in thermonuclear reactors, irradiated by W+ and electrons, show vast changes of positron lifetimes, indicating complex dynamics of defects.

  20. Recent developments in the theory of positrons at surfaces

    International Nuclear Information System (INIS)

    Walker, A.B.

    1989-01-01

    Positron beams of ever brighter intensity are now establishing themselves as a novel surface probe enabling a wide variety of spectroscopies. The production of high positron intensities and exploitation of the beams depends critically on our understanding of the complex behaviour of positrons at and near surfaces. I will review progress on the theory of positron-surface interactions and of the implantation and diffusion of low energy positrons. Applications of this theory to a variety of experimental techniques such as ACAR (Angular Correlation by Annihilation Radiation) spectra, angle resolved positronium (Ps) spectroscopy, REPELS (Reemitted Positron Energy Loss Spectroscopy), LEPD (Low Energy Positron Diffraction) and measurements of defect profiles will be discussed. 24 refs. (author)