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Sample records for cerebellopontine angle lipoma

  1. Cerebellopontine Angle Lipoma

    PubMed Central

    Schuhmann, Martin U.; Lüdemann, Wolf O.; Schreiber, Hartwig; Samii, Madjid

    1997-01-01

    Intracranial lipomas in an infratentorial and extra-axial location are extremely rare. The presented case of an extensive lipoma of the cerebellopontine angle (CPA) represents 0.05% of all CPA tumors operated on in our department from 1978 to 1996. The lipoma constitutes an important differential diagnosis because the clinical management differs significantly from other CPA lesions. The clinical presentation and management of the presented case are analyzed in comparison to all previously described cases of CPA lipomas. The etiology and the radiological features of CPA lipomas are reviewed and discussed. CPA lipomas are maldevelopmental lesions that may cause slowly progressive symptoms. Neuroradiology enables a reliable preoperative diagnosis. Attempts of complete lipoma resection usually result in severe neurological deficits. Therefore, we recommend a conservative approach in managing these patients. Limited surgery is indicated if the patient has an associated vascular compression syndrome or suffers from disabling vertigo. ImagesFigure 1Figure 2Figure 3Figure 4 PMID:17171031

  2. Intratentorial lipomas with Meckel's cave and cerebellopontine angle extension.

    PubMed

    Ruocco, M J; Robles, H A; Rao, K C; Armonda, R A; Ondra, S L

    1995-08-01

    An unusual case of bilateral intratentorial lipomas with extension into Meckel's caves and the cerebellopontine angle is described. Surgical and histopathologic correlation demonstrate that the lipoma encased the trigeminal nerve in Meckel's caves. The origin of the lipoma from the anteromedial margins of the tentorium is discussed and correlated with a recently proposed theory for the development of intracranial lipomas.

  3. A Case of Bell's Palsy with an Incidental Finding of a Cerebellopontine Angle Lipoma.

    PubMed

    Lagman, Carlito; Choy, Winward; Lee, Seung J; Chung, Lawrance K; Bui, Timothy T; Yang, Isaac; Goldman, Howard W

    2016-08-24

    This case report illustrates the potential fallacy of attributing a patient's symptoms to an incidental finding. Serial imaging of small, asymptomatic cerebellopontine angle (CPA) lipomas is favored. It is imperative to accurately diagnose CPA lipoma on imaging and differentiate it from more common CPA lesions. We herein present a patient with symptoms consistent with Bell's palsy and an incidental finding of a CPA lipoma. Additionally, we performed a review of the literature for case reports of patients presenting with facial symptoms and diagnosed with a CPA lipoma.

  4. A Case of Bell’s Palsy with an Incidental Finding of a Cerebellopontine Angle Lipoma

    PubMed Central

    Choy, Winward; Lee, Seung J; Chung, Lawrance K; Bui, Timothy T; Yang, Isaac; Goldman, Howard W

    2016-01-01

    This case report illustrates the potential fallacy of attributing a patient’s symptoms to an incidental finding. Serial imaging of small, asymptomatic cerebellopontine angle (CPA) lipomas is favored. It is imperative to accurately diagnose CPA lipoma on imaging and differentiate it from more common CPA lesions. We herein present a patient with symptoms consistent with Bell’s palsy and an incidental finding of a CPA lipoma. Additionally, we performed a review of the literature for case reports of patients presenting with facial symptoms and diagnosed with a CPA lipoma. PMID:27733958

  5. Primary Cerebellopontine Angle Melanocytoma: Review

    PubMed Central

    Phang, Isaac; Elashaal, Rahim; Ironside, James; Eljamel, Sam

    2012-01-01

    Introduction Primary cerebellopontine angle melanocytomas (PCPAMs) are very rare. Their natural history and prognosis are not fully understood. We reviewed the literature and add a new case to analyze PCPAM's presentation, radiological features, and outcome of treatment. Methods We performed a literature review using Medline, Embase, PubMed, and Cochrane databases. We searched for melanocytoma, melanoma, and pigmented tumors in the posterior cranial fossa and CPA to identify PCPAM. We have also searched our institution's neuro-oncology database. Results We identified 23 PCPAM from the literature and one case of our own. The mean age at presentation was 44.4 years with slight male preponderance. PCPAM presented with cerebellopontine angle (CPA) syndrome with or without hydrocephalus. Preoperative diagnosis was difficult; they appeared hyperintense on T1 and isointense on T2 magnetic resonance imaging (MRI) and enhanced with gadolinium. However, the final diagnosis was only made by immunohistochemical examination. Total surgical resection of PCPAM was associated with prolonged survival while subtotal excision was associated with frequent recurrence. Conclusion PCPAM are very rare and should be considered in the differential diagnosis of all CPA lesions that appear hyperintense on T1 and isointense on T2 MRI images. Patients with PCPAM should undergo total surgical resection to avoid fatal recurrences. PMID:23946922

  6. Meningiomas of the cerebellopontine angle.

    PubMed

    Matthies, C; Carvalho, G; Tatagiba, M; Lima, M; Samii, M

    1996-01-01

    Meningiomas of the cerebellopontine angle (CPA) represent a clinically and surgically interesting entity. The opportunity of complete surgical excision and the incidence of impairment of nerval structures largely depend on the tumour biology that either leads to displacement of surrounding structures by an expansive type of growth or to an enveloping of nerval and vascular structures by an en plaque type of growth. As the origin and the direction of growth are very variable, the exact tumour extension in relation to the nerval structures and the tumour origin can be identified sometimes only at the time of surgery. Out of a series of 230 meningiomas of the posterior skull base operated between 1978 and 1993, data of 134 meningiomas involving the cerebellopontine angle are presented. There were 20% male and 80% female patients, age at the time of surgery ranging from 18 to 76 years, on the average 51 years. The clinical presentation was characterized by a predominant disturbance of the cranial nerves V (19%), VII (11%), VIII (67%) and the caudal cranial nerves (6%) and signs of ataxia (28%). 80% of the meningiomas were larger than 30 mm in diameter, 53% led to evident brainstem compression or dislocation and 85% extended anteriorly to the internal auditory canal. Using the lateral suboccipital approach in the majority of cases and a combined presigmoidal or combined suboccipital and subtemporal approaches in either sequence in 5%, complete tumour removal (Simpson I and II) was accomplished in 95% and subtotal tumour removal in 5%. Histologically the meningiotheliomatous type was most common (49%) followed by the mixed type (19%), fibroblastic (16%), psammomatous (7%), hemangioblastic (7%) and anaplastic (2%) types. Major post-operative complications were CSF leakage (8%) requiring surgical revision in 2% and hemorrhage (3%) requiring revision in 2%. While the majority of neurological disturbances showed signs of recovery, facial nerve paresis or paralysis was

  7. Facial Nerve Schwannoma of the Cerebellopontine Angle

    PubMed Central

    Lassaletta, Luis; Roda, José María; Frutos, Remedios; Patrón, Mercedes; Gavilán, Javier

    2002-01-01

    Facial nerve schwannomas are rare lesions that may involve any segment of the facial nerve. Because of their rarity and the lack of a consistent clinical and radiological pattern, facial nerve schwannomas located at the cerebellopontine angle (CPA) and internal auditory canal (IAC) represent a diagnostic and therapeutic challenge for clinicians. In this report, a case of a CPA/IAC facial nerve schwannoma is presented. Contemporary diagnosis and management of this rare lesion are analyzed. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5 PMID:17167683

  8. [Differential diagnosis of space demands in the cerebellopontine angle].

    PubMed

    Holst, B; Grunwald, I Q; Brill, G; Reith, W

    2004-11-01

    Most of the space demands in the cerebellopontine angle lie extra-axially. Important structures run within the cisterns of the cerebellopontine angle, such as the trigeminal, facial and vestibulocochlear nerves as well as the anterior inferior and posterior inferior cerebellar arteries and the veins which lead to the petrosal sinus. The most common space demands are caused by acoustic neuromas, meningeomas, vascular ectasia and aneurysms. Less common are epidermoid and other schwannomas as well as metastases, paragangliomas and arachnoidal cysts. Intra-axial tumours in the area of the cerebellopontine angle include the medulloblastoma, astrocytoma and the ependymoma, which occurs predominantly in children, in addition to the uncommon choroid plexus papilloma. Nearby, there are also space demands around the petrous bone, such as cholesterol granuloma, malignant otitis media, paraganglioma and metastases. For differential diagnosis, an understanding of the space requirements of the tumours in the cerebellopontine angle is needed in addition to knowledge of the anatomical structures.

  9. Cerebellopontine angle gangliogliomas: Report of two cases.

    PubMed

    Boissonneau, S; Terrier, L-M; De La Rosa Morilla, S; Troude, L; Lavieille, J P; Roche, P-H

    2016-10-01

    Gangliogliomas are rare tumors of the central nervous system. We report two unusual cases of gangliogliomas located in the cerebellopontine angle (CPA). The first patient was a 57-year-old woman, who presented with dizziness and harbored a non-enhanced heterogeneous mass located in the cisternal space of the CPA. A partial microsurgical removal was performed, and the pathological examination concluded a grade I ganglioglioma according to the WHO Classification. The postoperative course was uneventful without any adjuvant treatment and the 5-year imaging follow-up indicated a stable remnant tumor. The second patient was a 35-year-old male who presented with acute vertigo and imbalance associated with recent prominent headaches; MR imaging showed a large heterogeneous and post-contrast enhanced tumor mass located in the CPA cistern with a mass effect on the brain. An optimal subtotal surgical resection was performed. The pathologists concluded a WHO grade III ganglioglioma. In spite of adjuvant radiotherapy and chemotherapy, the evolution proved unfavorable and patient died from cancer complications within a 2-year period. In both cases, the precise origin of the tumor could not be clearly identified even if the major component was present in the cisternal space. Gangliogliomas growing into the cisternal spaces are exceedingly rare particularly in the CPA. Due to its infiltrating behavior and major difficulties to identify the tumor margins, total resection is not routinely feasible. The histological grading is the most important predictor for oncological prognosis. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  10. The cerebellopontine angle: does the translabyrinthine approach give adequate access?

    PubMed

    Fagan, P A; Sheehy, J P; Chang, P; Doust, B D; Coakley, D; Atlas, M D

    1998-05-01

    A long-standing but unfounded criticism of the translabyrinthine approach is the misperception that this approach does not give adequate access to the cerebellopontine angle. Because of what is perceived as limited visualization and operating space within the cerebellopontine angle, some surgeons still believe that the translabyrinthine approach is inappropriate for large acoustic tumors. In this study, the surgical access to the cerebellopontine angle by virtue of the translabyrinthine approach is measured and analyzed. The parameters are compared with those measured for the retrosigmoid approach. This series objectively confirms that the translabyrinthine approach offers the neurotologic surgeon a shorter operative depth to the tumor, via a similar-sized craniotomy. This permits superior visualization by virtue of a wider angle of surgical access. Such access is achieved with the merit of minimal cerebellar retraction.

  11. Study of malignant peripheral nerve sheath tumor in cerebellopontine angle.

    PubMed

    Hong, WenMing; Cheng, HongWei; Wang, XiaoJie; Hu, XiaoPeng; Feng, ChunGuo

    2014-01-01

    Malignant peripheral nerve sheath tumors (MPNSTs) are very rare soft tissue sarcomas, usually arising from somatic soft tissues or peripheral nerves. Primary MPNST of the cerebellopontine angle is extremely rare, with only a single case reported so far. Here, we report an unusual case of MPNST in cerebellopontine angle in a 25-year-old man presented with dizziness, left facial numbness, and tinnitus. After hospitalization, the tumor was treated with complete surgical excision followed by adjuvant chemotherapy and radiotherapy. Histologically, the tumor showed malignant spindle cells, which were with focal S-100 positivity on immunohistochemistry, and a diagnosis of the MPNST was made. This case is being reported for its rarity and presence in cerebellopontine and illustrated the difficulties in the diagnosis and treatment of MPNST, which to the best of our knowledge, has not been described before in the soft tissue sarcomas.

  12. Frequency of cerebellopontine angle tumours in patients with trigeminal neuralgia. .

    PubMed

    Khan Afridi, Ehtisham Ahmed; Khan, Shahbaz Ali; Qureshi, Waqar-ur-Rehman; Bhatti, Sajid Nazir; Muhammad, Gul; Mahmood, Shakir; Rehman, Abdur

    2014-01-01

    Though the classical type of trigeminal neuralgia is the most common type with the neurovascular conflict causing the symptoms, yet quite some patients have the secondary type of trigeminal neuralgia in which space occupying lesions are responsible for the symptoms. This study was conducted to determine the frequency of cerebellopontine angle tumours in patients presenting with complaints of trigeminal neuralgia. This case series descriptive study was conducted in the department of Neurosurgery, Ayub Medical College, Abbottabad, from January 2009 to January 2012. It included patients who presented with symptoms of trigeminal neuralgia. Patients were subjected to further radiological investigation like Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) to look for secondary causes of trigeminal neuralgia. Among the 134 patients with age ranges 13-64 (51?4.3) years of age, 78(58.2%) were females and 56 (41.7%) were males. Frequency of cerebellopontine angle tumours in patients was 14 (10.4%), among them epidermoid was most common lesion being present in 10 (7.4%) of patients and accounted for 75% of Cerebellopontine Angle tumours in these patients. Meningioma and vestibular schwanoma accounted for 2(1.4%) cases each. In secondary trigeminal neuralgia mean age of onset of symptoms was 39.5±5.2 years as compared to classic trigeminal neuralgia which is 53±2.1 years. Trigeminal Neuralgia can be a typical symptom in cerebellopontine angle tumours like epidermoid, especially in young patients, so all the patients with trigeminal neuralgia should be investigated for lesion in cerebellopontine region.

  13. Teeth in the cerebellopontine angle: an unusual dermoid tumour.

    PubMed

    Amirjamshidi, A; Ghodsi, M; Edraki, K

    1995-01-01

    An hour-glass-shaped multidensity lesion found by CT in a 6-year-old boy who had been admitted to the emergency department after a mild car accident. This lesion turned out to be a congenital dermoid tumour of the right cerebellopontine angle-tentorial notch region containing 12 mature teeth and 14 pseudocarilagenous structures. This is the first case of dermoid tumour containing so many teeth, reported in an asymptomatic person and located off the midline.

  14. Carcinoma Metastatic to Both Cerebellopontine Angles Masquerading as Acoustic Neuromas

    PubMed Central

    Sargent, Eric Winslow; Herschman, Barry Ronald; LaRouere, Michael Joseph

    1995-01-01

    Metastases to the cerebellopontine angles (CPAs) are rare. Typically, the clinical course is one of rapid onset and progression of crarial nerve deficits. The clinical presentation and course of carcinoma metastatic to the CPAs are reviewed. We report a case of bilateral CPA metastases with a radiographic appearance similar to neurofibromatosis type 2 presenting with rapidly progressive bilateral hearing loss followed by unilateral facial nerve palsy. ImagesFigure 1Figure 2Figure 2Figure 3 PMID:17171154

  15. Ho:YAG laser application in cerebellopontine angle tumor operation

    NASA Astrophysics Data System (ADS)

    Pan, Yaohua; Wang, Yu; Li, Xiaoxiong; Xiong, Xiong; Wang, Yong-ling; Li, Shanquan; Luo, Qizhong; Zhu, Jing; Zhang, Weiguo

    2005-07-01

    We reported 25 cases of cerebellopontine angle (CPA) tumor operation with Ho:YAG laser assistance during the operative procedure. We analysed the surgical effects of Ho:YAG laser, compare it with CO2 Nd:YAG argon laser, and illustrated its features and parameters. We think that Ho:YAG laser can be used to ablate and vaporize the tumor efficiently in the operation of the CPA tumors whose vascular supply is abundant and the texture is very tough. It can be used to reduce the bleeding and cooperate to incise tumor in the operation and improve the curable effect of the surgery.

  16. T-cell primary leptomeningeal lymphoma in cerebellopontine angle

    PubMed Central

    Briongos-Figuero, Laisa Socorro; Gómez-Traveso, Tamara; Pérez-Castrillon, José Luis

    2015-01-01

    Primary meningeal lymphomas are very rare and those derived from T cells are even more infrequent (less than 5% of primary central nervous system lymphomas). Cerebellopontine angle involvement in the primary T-cell lymphoma is exceptional. Clinical presentation depends on the type of lesions, and histological diagnosis is needed. We present a rare case of a 50-year-old woman who presented with clinical cerebellar syndrome with posterior opsoclonus-myoclonus syndrome. Necropsy evaluation revealed primary diffuse leptomeningeal non-Hodgkin's T-cell lymphoma. PMID:25750225

  17. Cerebellopontine angle arachnoid cyst associated with mirror movements

    PubMed Central

    Gurkas, Esra; Altan, Buket Yucel; Gücüyener, Kıvılcım; Kolsal, Ebru

    2015-01-01

    Arachnoid cysts are benign developmental collections of cerebrospinal fluid (CSF). They constitute approximately 1% of intracranial masses. The cerebellopontine angle (CPA) arachnoid cysts are rare and often asymptomatic. The onset of symptoms and signs is usually due to the compression of the brain, cranial nerves and obstruction of CSF circulation. The major clinical symptoms for CPA arachnoid cysts were reported as headache, ataxia and 8th cranial nerve palsy. We report a patient with a CPA arachnoid cyst. He presented with cranial nerve palsies and mirror movements found in upper extremities. We postulated that CPA arachnoid cyst compressing the brain stem and the pyramidal decussation may lead to mirror movements. We conclude that mirror movements can be associated with CPA arachnoid cyst. PMID:26962347

  18. Cerebellopontine angle primitive neuroectodermal tumor mimicking trigeminal schwannoma

    PubMed Central

    Khan, Saad Akhtar; Ujjan, Badar Uddin; Salim, Adnan; Shamim, Shahzad

    2016-01-01

    Background: Primitive neuroectodermal tumors (PNETs) comprise a group of aggressive, poorly differentiated embryonal tumors occurring in central nervous system as well as in peripheral locations. Primary cerebellopontine angle (CPA) PNET is an extremely rare entity. It is important to have knowledge of this pathology and to be able to differentiate it from other commonly occurring CPA tumors, such as vestibular and trigeminal schwannomas. This distinction is essential because of the difference in the overall treatment plan and prognosis. Case Description: This report describes a case of a young male presenting with diplopia and numbness of face; magnetic resonance imaging showed a CPA mass. With a provisional diagnosis of trigeminal schwannoma, the patient underwent surgery. Histopathology provided a diagnosis of PNET. Conclusion: We discuss the importance of recognizing this rare condition and how this entity differs from the commonly occurring tumors. PMID:26862446

  19. Cerebellopontine angle arachnoid cyst containing ectopic choroid plexus--case report.

    PubMed

    Singleton, William G B; Lawrence, Tim; Green, Alex L; Jeans, Alex; Kerr, Richard S C

    2010-05-01

    We present a rare and interesting case of a cerebellopontine angle cyst containing ectopic choroid plexus tissue in a 26 year-old female. Surgical resection was performed, and histological examination confirmed the presence of choroid plexus in the cyst wall. This is the first reported case of ectopic choroid plexus at the cerebellopontine angle in an adult. We present the case and review the literature.

  20. Primary glioblastoma of the cerebellopontine angle in adults.

    PubMed

    Wu, Bo; Liu, Weidong; Zhu, Hong; Feng, Hailong; Liu, Jinping

    2011-05-01

    Gliomas are rare entities in the cerebellopontine angle (CPA) in adults. The authors present clinical, neuroradiological, serological, and neuropathological findings in a 60-year-old man with an extraaxial CPA glioblastoma arising from the proximal portion of cranial nerve VIII. The patient presented with progressive left-sided deafness and left-sided facial palsy lasting less than 2 months and progressive dysarthria and dysphagia lasting 2 weeks. Preoperative neuroimaging suggested the diagnosis of CPA meningioma with "dural-tail" sign and involvement of the internal auditory canal. Serological examination showed an increase in the malignant markers of ferritin and neuron-specific enolase, which suggested underlying malignancy. The tumor was subtotally removed, and it was confirmed to be completely separated from the brainstem and cerebellum. Cranial nerves VII and VIII were destroyed and sacrificed. Transient severe bradycardia occurred during surgery due to entrapment of the caudal cranial nerve complex by the tumor in such an infiltrative way. The neuropathological examination revealed a glioblastoma. The patient underwent no further treatment and died of cachexia 2 months postoperatively. To the authors' knowledge, this represents the first case of a primary glioblastoma in the CPA in an adult. A high index of suspicion along with reliance on clinical assessment, radiological findings, and serum detection of specific malignant markers is essential to diagnose such uncommon CPA lesions.

  1. Pediatric cerebellopontine angle and internal auditory canal tumors: clinical article..

    PubMed

    Holman, Michelle A; Schmitt, William R; Carlson, Matthew L; Driscoll, Colin L W; Beatty, Charles W; Link, Michael J

    2013-10-01

    The aim in this study was to describe the clinical presentation, differential diagnosis, and risk for neurofibromatosis Type 2 (NF2) in pediatric patients presenting with cerebellopontine angle (CPA) and internal auditory canal (IAC) tumors. The authors conducted a retrospective study at a tertiary care academic referral center. All patients with an age ≤ 18 years who had presented with an extraaxial CPA or IAC tumor between 1987 and 2012 were included in the study cohort. Data regarding symptoms, diagnosis, tumor characteristics, and NF2 status were collected and analyzed. Sixty patients (55% female, 45% male) harboring 87 tumors were identified. The mean age at diagnosis was 12.8 years (median 14.0 years, range 0.9-18.9 years). Schwannomas were the most commonly identified lesions (57 of 87 tumors, including 52 vestibular, 3 facial, and 2 trigeminal schwannomas), followed by meningiomas (5 of 87) and epidermoid cysts (4 of 87). Six malignant tumors were diagnosed, including small-cell sarcoma, squamous cell carcinoma, malignant meningioma, atypical rhabdoid-teratoid tumor, endolymphatic sac tumor, and malignant ganglioglioma. Headache, followed by hearing loss and imbalance, was the most common presenting symptom, whereas dysphagia, otalgia, and facial pain were uncommon. Neurofibromatosis Type 2 was diagnosed in 20 (61%) of 33 patients with vestibular schwannoma (VS), while the other 13 patients (39%) had sporadic tumors. Nineteen of the 20 patients with NF2 met the diagnostic criteria for that disorder on initial presentation, and 15 of them presented with bilateral VS. At the last follow-up, 19 of the 20 patients subsequently diagnosed with NF2 demonstrated bilateral VSs, whereas 1 patient with a unilateral VS and multiple other NF2-associated tumors has yet to demonstrate a contralateral VS to date. Only 1 patient presenting with an isolated unilateral VS and no family history of NF2 demonstrated a contralateral VS on subsequent radiological screening

  2. Teflon granulomas mimicking cerebellopontine angle tumors following microvascular decompression.

    PubMed

    Deep, Nicholas L; Graffeo, Christopher S; Copeland, William R; Link, Michael J; Atkinson, John L; Neff, Brian A; Raghunathan, Aditya; Carlson, Matthew L

    2017-03-01

    To report two patients with a history of microvascular decompression (MVD) for hemifacial spasm who presented with Teflon granulomas (TG) mimicking cerebellopontine angle (CPA) tumors and to perform a systematic review of the English-language literature. Case series at a single tertiary academic referral center and systematic review. Retrospective chart review with analysis of clinical, radiological, and histopathological findings. Systematic review using PubMed, Embase, MEDLINE, and Web of Science databases. Two patients with large skull base TGs mimicking CPA tumors clinically and radiographically were managed at the authors' institution. The first presented 4 years after MVD with asymmetrical sensorineural hearing loss, multiple progressive cranial neuropathies, and brainstem edema due to a growing TG. Reoperation with resection of the granuloma confirmed a foreign-body reaction consisting of multinucleated giant cells containing intracytoplasmic Teflon particles. The second patient presented 11 years after MVD with asymmetrical sensorineural hearing loss and recurrent hemifacial spasm. No growth was noted over 2 years, and the patient has been managed expectantly. Only one prior case of TG after MVD for hemifacial spasm has been reported in the English literature. TG is a rare complication of MVD for hemifacial spasm. The diagnosis should be suspected in patients presenting with a new-onset enhancing mass of the CPA after MVD, even when performed decades earlier. A thorough clinical and surgical history is critical toward establishing an accurate diagnosis to guide management and prevent unnecessary morbidity. Surgical intervention is not required unless progressive neurologic complications ensue. 4 Laryngoscope, 127:715-719, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  3. Malignant meningioma of the cerebellopontine angle in a 2-year-old girl: a case report and literature review.

    PubMed

    Fan, Ming-Chao; Zhang, Xin; Wang, Qiao-Ling; Cheng, Lei; Dai, Cai-Yun; Yu, Dan; Sun, Peng

    2013-07-01

    Meningioma is a common intracranial tumor in adults. Pediatric cases account for approximately 1.5% of all intracranial meningiomas, and very few cases show malignant histological features. Primary pediatric malignant meningioma in the cerebellopontine angle is extremely uncommon. Herein, we report a 2-year-old girl with malignant meningioma in the cerebellopontine angle. The clinical features, diagnosis, and treatment protocol are discussed.

  4. Malignant meningioma of the cerebellopontine angle in a 2-year-old girl: a case report and literature review

    PubMed Central

    Fan, Ming-Chao; Zhang, Xin; Wang, Qiao-Ling; Cheng, Lei; Dai, Cai-Yun; Yu, Dan; Sun, Peng

    2013-01-01

    Meningioma is a common intracranial tumor in adults. Pediatric cases account for approximately 1.5% of all intracranial meningiomas, and very few cases show malignant histological features. Primary pediatric malignant meningioma in the cerebellopontine angle is extremely uncommon. Herein, we report a 2-year-old girl with malignant meningioma in the cerebellopontine angle. The clinical features, diagnosis, and treatment protocol are discussed. PMID:23470145

  5. Ruptured pediatric cerebellopontine angle epidermoid cyst: a case report detailing radiographic evolution and clinical course.

    PubMed

    Guan, Zhe; Hollon, Todd; Bentley, J Nicole; Garton, Hugh J L

    2015-08-21

    Epidermoid cysts (ECs) are uncommon pediatric tumors that often occur in the cerebellopontine angle. Although cyst rupture is a recognized complication, the radiographic evolution of an EC following rupture and the resultant parenchymal brainstem edema have not been reported. The authors present the case of a 13-year-old female with a newly diagnosed cerebellopontine angle EC who presented with worsening headaches, photophobia, and emesis. Magnetic resonance imaging demonstrated significant pericystic brainstem edema and mass effect with effacement of the fourth ventricle. Refractory symptoms prompted repeat imaging, revealing cyst enlargement and dense rim enhancement. Resection of the EC resolved both her symptoms and the brainstem edema. This case documents the radiographic evolution of EC rupture and subsequent clinical course.

  6. CE-Chirp® ABR in cerebellopontine angle surgery neuromonitoring: technical assessment in four cases.

    PubMed

    Di Scipio, Ettore; Mastronardi, Luciano

    2015-04-01

    Continuous monitoring of wave V of auditory brainstem response (ABR), also called brainstem auditory evoked potential (BAEP), is the most common method used in intraoperative neuromonitoring (IONM) functionality of cochlear nerve during surgery in cerebellopontine angle (CPA). CE-Chirp® ABR represents a recent development of classical ABR. CE-Chirp® is a new acoustic stimulus used in newborn hearing testing, designed to provide enhanced neural synchronicity and faster detection of larger amplitude wave V. In four cases, CE-Chirp® ABR was performed during cerebellopontine angle (CPA) surgery. CE-Chirp® ABR represented a safe and effective method in neuromonitoring functionality of vestibulocochlear nerve. A faster neuromonitoring feedback to surgical equipe was possible with CE-Chirp ABR®.

  7. Unilateral vocal cord palsy and dysphagia: an unusual presentation of cerebellopontine angle meningioma

    PubMed Central

    Senior, Andrew; Douglas, James Andrew; Thompson, Stuart

    2015-01-01

    Cerebellopontine angle (CPA) tumours are the most common neoplasms in the posterior fossa, accounting for 5–10% of intracranial tumours. Most CPA tumours are benign, with most being vestibular schwannomas. Meningiomas arising from the jugular foramen are among the rarest of all with very few being described in the literature. Treatment options vary considerably as experience with these tumours is limited. One option is a skull base approach, but this depends on size, location and ability to preserve lower cranial nerve function. This can be extremely challenging and is accompanied by high mortality risk; therefore, a more conservative option must be considered. This case report highlights the difficulty in management of patients with jugular fossa meningiomas, including appropriate investigations, analysis of surgical versus conservative treatment and associated complications. Furthermore, we elaborate the decision-making process pertaining to the tailoring of the surgical route used for the resection of jugular foramen meningiomas. (Jugular Foramen Meningioma, cerebellopontine angle). PMID:26486157

  8. A case of cerebellopontine angle epidermoid cyst presenting as trigeminal neuropathy.

    PubMed

    Muzammil, Sadat; Leong, King Sun

    2009-05-01

    We present the case of a 35-year-old female who had paraesthesia and numbness on the left side of her face. Initially the ophthalmic division and maxillary divisions on the trigeminal nerve were involved, but later involved the mandibular division as well. On MRI, a cerebellopontine angle (CPA) epidermoid cyst was detected. After 18 months of follow up, her symptoms remain stable and she is being managed conservatively.

  9. Prevalence, characteristics, and management of swallowing disorders following cerebellopontine angle surgery.

    PubMed

    Starmer, Heather M; Best, Simon R; Agrawal, Yuri; Chien, Wade W; Hillel, Alexander T; Francis, Howard W; Tamargo, Rafael J; Akst, Lee M

    2012-03-01

    To describe swallowing disorders encountered after cerebellopontine angle surgery and to explore variables associated with increased incidence of postoperative dysphagia. Case series with chart review. Single academic medical institution. Chart review of 181 consecutive patients undergoing surgical excision of cerebellopontine angle pathology from January 2008 to December 2010 at the Johns Hopkins Hospital. Presence and characteristics of dysphagia were determined by review of speech pathologist reports. Other clinical variables were extracted from the electronic medical record, and statistical analyses were applied to determine factors associated with postoperative dysphagia. Immediate postoperative dysphagia was identified in 57 of 181 patients (31%). Oral, oropharyngeal, and pharyngeal deficits accounted for 51%, 37%, and 12% of dysphagic symptoms, respectively. Facial nerve weakness in the immediate postoperative period was noted in 91% of dysphagic subjects compared with 43% of those without. Mean House-Brackmann score for dysphagic individuals was 4 compared with 2 in the nondysphagic group. Diet alterations were required for 65% of dysphagic individuals, and an additional 9% required tube feeding. Common findings during videofluoroscopic swallowing studies were pharyngeal residue, reduced pharyngeal constriction, and anterior bolus loss. Abnormal penetration-aspiration scores (≥3) were found in 59% of those undergoing videofluoroscopic swallow studies. Oral and pharyngeal swallowing deficits are commonly encountered after cerebellopontine angle surgery. Consultation with the speech-language pathologist appears most critical for any individuals demonstrating postoperative cranial nerve dysfunction, particularly for those with evidence of facial nerve weakness. Early consultation may help to manage short- and long-term functional difficulties.

  10. Body mass index predicts risk for complications from transtemporal cerebellopontine angle surgery.

    PubMed

    Mantravadi, Avinash V; Leonetti, John P; Burgette, Ryan; Pontikis, George; Marzo, Sam J; Anderson, Douglas

    2013-03-01

    To determine the relationship between body mass index (BMI) and risk for specific complications from transtemporal cerebellopontine angle (CPA) surgery for nonmalignant disease. Case series with chart review. Tertiary-care academic hospital. Retrospective review of 134 consecutive patients undergoing transtemporal cerebellopontine angle surgery for nonmalignant disease from 2009 to 2011. Data were collected regarding demographics, body mass index, intraoperative details, hospital stay, and complications including cerebrospinal fluid leak, wound complications, and brachial plexopathy. One hundred thirty-four patients were analyzed with a mean preoperative body mass index of 28.58. Statistical analysis demonstrated a significant difference in body mass index between patients with a postoperative cerebrospinal fluid leak and those without (P = .04), as well as a similar significant difference between those experiencing postoperative brachial plexopathy and those with no such complication (P = .03). Logistical regression analysis confirmed that body mass index is significant in predicting both postoperative cerebrospinal fluid leak (P = .004; odds ratio, 1.10) and brachial plexopathy (P = .04; odds ratio, 1.07). Elevated body mass index was not significant in predicting wound complications or increased hospital stay beyond postoperative day 3. Risk of cerebrospinal fluid leak and brachial plexopathy is increased in patients with elevated body mass index undergoing surgery of the cerebellopontine angle. Consideration should be given to preoperative optimization via dietary and lifestyle modifications as well as intraoperative somatosensory evoked potential monitoring of the brachial plexus to decrease these risks.

  11. [Multimodal intraoperative electrophysiological monitoring during cerebellopontine angle tumor surgery. Benefit or loss?].

    PubMed

    Kwiek, Stanisław; Slusarczyk, Wojciech; Kukier, Wojciech; Luszawski, Jerzy; Bazowski, Piotr; Wolwender, Adam; Duda, Izabela; Grzybowska, Konstancja; Wójcikiewicz, Tomasz

    2003-01-01

    In the Neurosurgery Department, Silesian University School of Medicine, continuous monitoring of selected neurophysiological functions of the central and peripheral nervous system was introduced in 1998 as a routine procedure in cerebellopontine angle surgery and some other operations performed in the petroclival region. Such benefits from this method as increased patient safety, availability of information about dynamic changes in the monitored structures, and the possibility of cranial nerves localization using stimulation in the operating area, are quite obvious. The paper presents results of a detailed statistical analysis of the amount of time required for preparation and for operating in 174 cerebellopontine angle tumor surgeries performed in the years 1986-2002 with (group M) and without (group BM, before the year 1998) intraoperative monitoring. Subgroups distinguished according to the histological type of tumor were evaluated. Out of 95 procedures performed in group M, 57 were operations of acoustic neurinoma cases, 15 meningiomas, 8 cases of epidermal cyst, and 15 other growth processes in the cerebellopontine angle region. Among 79 operations in group BM, there were 57 cases of acoustic neurinoma, 4 cases of meningioma, 8 cases of epidermal cyst, and 10 of other types of neoplastic growth. In group M as compared to group BM the pre-op. preparation time was found to be significantly longer in cases of the VIII-th nerve neurinoma, and of other tumors. No statistically significant differences in the amount of operating time in were found between any of the subgroups. Both radicality of tumor removal and facial nerve status have clearly improved since intraoperative monitoring was introduced.

  12. Cerebral salt wasting syndrome: postoperative complication in tumours of the cerebellopontine angle.

    PubMed

    Ruiz-Juretschke, Fernando; Arístegui, Miguel; García-Leal, Roberto; Fernández-Carballal, Carlos; Lowy, Alejandro; Martin-Oviedo, Carlos; Panadero, Teresa

    2012-02-01

    Cerebral salt wasting (CSW) is a rare complication in posterior fossa tumour surgery. We present two patients with cerebellopontine angle (CPA) tumours who developed cerebral salt wasting postoperatively. Both patients deteriorated in spite of intensive fluid and salt replacement. On CT scan the patients presented mild to moderate ventricular dilation, which was treated with an external ventricular drainage. After the resolution of hydrocephalus, fluid balance rapidly returned to normal in both patients and the clinical status improved. Identification and treatment of secondary obstructive hydrocephalus may contribute to the management of CSW associated to posterior fossa tumour surgery.

  13. Hemifacial spasm caused by a cerebellopontine angle arachnoid cyst. Case report and literature review.

    PubMed

    Ruiz-Juretschke, Fernando; Vargas, Antonio; González-Rodrigalvarez, Rosario; Garcia-Leal, Roberto

    2015-01-01

    Arachnoid cysts involving the cerebellopontine angle are an unusual cause of hemifacial spasm. The case is reported of a 71-year old woman presenting with a right hemifacial spasm and an ipsilateral arachnoid cyst. Preoperative magnetic resonance imaging findings suggested a neurovascular compression caused by displacement of the facial-acoustic complex and the anterior inferior cerebellar artery by the cyst. Cyst excision and microvascular decompression of the facial nerve achieved permanent relief. The existing cases of arachnoid cysts causing hemifacial spasm are reviewed and the importance of a secondary neurovascular conflict identification and decompression in these cases is highlighted.

  14. Coexistence of meningioma and schwannoma in the same cerebellopontine angle in a patients with NF2.

    PubMed

    Matyja, Ewa; Kunert, Przemysław; Grajkowska, Wiesława; Marchel, Andrzej

    2012-01-01

    The coexistence of schwannoma and meningioma in the same cerebellopontine angle (CPA) is uncommon. Especially, the presence of a single mixed tumour composed of demarcated or intermingled components of schwannoma and meningioma tissue is extremely rare. Such a phenomenon is mainly reported in a patient with NF2 or with history of previous irradiation. We present two cases of simultaneous occurrence of schwannoma and meningioma in the same cerebellopontine angle in young adult patients with clinical manifestation of NF2. The first patient was a 18-year-old young man who presented with bilateral CPA tumours, spinal mass lesion and multiple, small, schwannoma-like lesions of the cauda equina. Both CPA tumours was initially diagnosed as schwannomas based on preoperative MR imagings, however right CPA tumour appeared to be composed of a well-circumscribed transitional meningioma located inside schwannoma of Antoni A and B type. The second patient, a young 16-year-old boy, presented bilaterall CPA tumours as well as many meningeal tumours supratentorially and infratentorially. Two adjacent tumours in the left CPA proved to be schwannoma and meningioma. In both cases, the different neoplastic components were confirmed by histopathological and immunohistochemical studies. The possible mechanism underlying the occurrence of such coexisting tumors of different histogenesis remains unclear.

  15. Predictive Value of Postoperative Electrophysiologic Testing of the Facial Nerve After Cerebellopontine Angle Surgery

    PubMed Central

    Selesnick, Samuel H.; Digoy, G. Paul; Ptachewich, Yael; Rubin, Michael; Victor, Jonathan D.

    1998-01-01

    Our objective was to assess the ability of postoperative electroneuronography (ENoG) and electromyography (EMG) to predict clinical facial function 1 year postoperatively in patients with facial paralysis and an intact facial nerve after cerebellopontine angle surgery. The study was a prospective, nonrandomized, uncontrolled clinical trial on an outpatient basis, at a tertiary care hospital. Primary eligibility criteria include: (1) cerebellopontine angle (CPA) surgery with anatomical preservation of facial nerve, (2) complete facial nerve paralysis; and (3) 1 year follow-up. ENoG and EMG were measured at 1 and 3 months postoperatively, House-Brackmann facial nerve grade at 1 year postoperatively. The Kendall coefficient of rank correlation demonstrated that the 1 and 3 month postoperative ENoG data were significant predictors of ultimate facial nerve outcome. Tracking multiple ENoG examinations in a single patient, over time was of little predictive value. EMG was a poor predictor of facial nerve outcome. In general, patients with delayed facial nerve paralysis had better ultimate facial function than patients with immediate paralysis. Postoperative ENoG, but not EMG was a statistically significant predictor of ultimate facial nerve outcome after CPA surgery. Patients with delayed facial paralysis had better outcomes than those with immediate facial paralysis. PMID:17171049

  16. Predictive value of postoperative electrophysiologic testing of the facial nerve after cerebellopontine angle surgery.

    PubMed

    Selesnick, S H; Digoy, G P; Ptachewich, Y; Rubin, M; Victor, J D

    1998-01-01

    Our objective was to assess the ability of postoperative electroneuronography (ENoG) and electromyography (EMG) to predict clinical facial function 1 year postoperatively in patients with facial paralysis and an intact facial nerve after cerebellopontine angle surgery. The study was a prospective, nonrandomized, uncontrolled clinical trial on an outpatient basis, at a tertiary care hospital. Primary eligibility criteria include: (1) cerebellopontine angle (CPA) surgery with anatomical preservation of facial nerve, (2) complete facial nerve paralysis; and (3) 1 year follow-up. ENoG and EMG were measured at 1 and 3 months postoperatively, House-Brackmann facial nerve grade at 1 year postoperatively. The Kendall coefficient of rank correlation demonstrated that the 1 and 3 month postoperative ENoG data were significant predictors of ultimate facial nerve outcome. Tracking multiple ENoG examinations in a single patient, over time was of little predictive value. EMG was a poor predictor of facial nerve outcome. In general, patients with delayed facial nerve paralysis had better ultimate facial function than patients with immediate paralysis. Postoperative ENoG, but not EMG was a statistically significant predictor of ultimate facial nerve outcome after CPA surgery. Patients with delayed facial paralysis had better outcomes than those with immediate facial paralysis.

  17. Angiosarcoma arising in schwannoma of cerebellopontine angle and later associating with meningioma in a patient with neurofibromatosis type 2.

    PubMed

    Sakai, Yasuhiro; Hirose, Takanori; Tomono, Ayako; Kawakami, Fumi; Nakai, Tokiko; Ohbayashi, Chiho; Mizowaki, Takashi; Tanaka, Kazuhiro; Kohmura, Eiji; Itoh, Tomoo

    2014-10-01

    Here, we describe an extremely rare case of angiosarcoma arising in schwannoma of the cerebellopontine angle and later associating with meningioma in a patient with neurofibromatosis type 2. A 33-year-old disabled Japanese man with right drop foot after surgery for an unspecified tumor demonstrated multiple tumors, suspected to be schwannoma, in the bilateral cerebellopontine angles, the cervical and lumbar spinal cord, and on the right nuchal skin. Also present were several tumors in the medulla and thoracic spinal cord suspected to be ependymoma or astrocytoma. The patient was diagnosed with neurofibromatosis type 2 according to the diagnostic criteria by the U.S. National Institutes of Health. The bilateral tumors in the cerebellopontine angle were resected to reduce symptoms and brain stem compression. Histopathological analysis revealed angiosarcoma arising in schwannoma of the bilateral tumors, and angiosarcoma was proportionally larger in the right tumor than in the left. At age 36, the patient underwent a second resection of the regrown tumor in the left cerebellopontine angle, and histopathology demonstrated mixed angiosarcoma and meningioma. That angiosarcoma arises in schwannoma is a pathogenesis within the realm of conjecture, especially that the phenomenon of mixed meningioma and angiosarcoma has not been reported to date.

  18. Pediatric primary pilocytic astrocytoma of the cerebellopontine angle: a case report.

    PubMed

    Mirone, G; Schiabello, L; Chibbaro, S; Bouazza, S; George, B

    2009-02-01

    We describe a rare case of pediatric pilocytic astrocytoma presented as a right cerebellopontine angle (CPA) mass, completely separated from the brain stem and arising from the proximal VIII nerve portion. A 12-year-old boy, with no evidence of neurofibromatosis type 2, presented with progressive hearing loss at the right ear and headache. An initial enhanced magnetic resonance examination suggested the diagnosis of schwannoma. The tumor was resected by a suboccipital retrosigmoid approach. Our case seems to be the first report of a primary pediatric CPA pylocitic astrocytoma arising from the VIII nerve complex and presenting internal auditory canal enlargement. It represents the third reported case of a primary CPA pilocytic astrocytoma (the second pediatric case with the first arising from V nerve) and the eighth report of primary CPA glioma, overall. We discuss the clinical, neuroradiological, and intraoperative findings, and we review the different hypothesis about the origin of these rare tumors.

  19. Cerebellopontine angle and internal auditory canal: neurovascular anatomy on gas CT cisternograms

    SciTech Connect

    Bird, C.R.; Hasso, A.N.; Drayer, B.P.; Hinshaw, D.B. Jr.; Thompson, J.R.

    1985-03-01

    The authors reviewed 103 normal gas CT cisternograms to delineate the appearance of normal neurovascular structures in the cerebellopontine angle (CPA) and internal auditory canal (IAC). Cranial nerves VII and VIII were identified in the CPA in 97% of cases, either separately (53%) or as a bundle (44%). Intracanalicular branches of the VIIIth cranial nerve were identified in 20% of cases, and cranial nerve V was visualized in the CPA in 14%. The characteristic vascular loop, usually the anterior inferior cerebellar artery, was visible in 35% of cases, and, in 22% of visualized cases, was in an intracanalicular location. In 10% of cases, greater than 66% of the IAC was occupied by the neurovascular bundle. Familiarity with the normal anatomy and variations seen on gas CT cisternograms is necessary to prevent false-positive interpretations.

  20. Typical and atypical neurovascular relations of the trigeminal nerve in the cerebellopontine angle: an anatomical study.

    PubMed

    Rusu, M C; Ivaşcu, R V; Cergan, R; Păduraru, D; Podoleanu, L

    2009-08-01

    The aim of the present study was to anatomically evaluate in adults the neurovascular trigeminal relations in the cerebellopontine angle (CPA), from a morphological and topographical perspective and thus to improve, detail and debate the pre-existing information, with educational and surgical implications. For the present anatomical study we performed bilateral dissections on 20 human adult skull bases, in formalin-fixed cadavers, at the level of the cerebellopontine angle, using the anatomical superior approach; we also studied 20 additional drawn specimens-cerebellum and brainstems, from autopsied cadavers, in order to better document the vasculature at the trigeminal root entry zone (REZ). The most constant but not exclusive neurovascular relations of the trigeminal nerves were those with the superior cerebellar artery (SCA) and the superior petrosal vein (the petrosal vein of Dandy). The regular possibility for the SCA to appear divided into a medial and a lateral branch and these to represent individual trigeminal relations at the level of the pontine cistern or REZ must not be neglected. The petrosal vein tributaries can also represent superior, inferior, or interradicular trigeminal relations. Arterioles emerging from the SCA or the anterior inferior cerebellar artery (AICA) represented trigeminal relations either at the REZ or were coursing between the trigeminal roots. A dissected specimen presented a radicular trigeminal artery emerging from the basilar artery and entering the trigeminal cavum inferior to the nerve. Another specimen presented two bony lamellae superior to the trigeminal nerve at the entrance in the trigeminal cavum-these lamellae were embedded within the lateral border of tentorium cerebelli and the posterior petroclinoid ligament. So we bring here an evidence-based support extremely useful not only for specialists dealing with this area but also for educational purposes. It appears important not only to consider the typical anatomy at

  1. Is there a correlation between vascular loops in the cerebellopontine angle and unexplained unilateral hearing loss?

    PubMed

    Gorrie, Adam; Warren, Frank M; de la Garza, Amy N; Shelton, Clough; Wiggins, Richard H

    2010-01-01

    This study was a retrospective analysis of patients who had received magnetic resonance imaging scans of the internal auditory canal (IAC) to evaluate unexplained asymmetric hearing loss. The study aimed to correlate structural features of vascular loops formed by the anterior inferior cerebellar artery (AICA) within the cerebellopontine angle and IAC with asymmetric hearing loss. High-resolution thin-section T2 fast spin echo magnetic resonance imaging scans of 58 patients with asymmetric sensorineural hearing loss were obtained; the structure of the AICA was graded on both sides using 2 scoring systems. The grading senior head and neck radiologist was blinded to the clinical history. The first scoring system used was the Chavda classification, which is based on the anatomic location of the AICA loop. This system identified 92 loops within the cerebellopontine angle; 22 loops extending less than halfway into the IAC and 2 loops extending more than halfway into the IAC. A second classification system was used simultaneously to describe the extent of contact between the AICA loop and the vestibulocochlear nerve. The second system identified 24 loops that were not in contact with the nerve, 60 in which the loop was running adjacent to the nerve but not displacing it; 12 loops were identified that were displacing the vestibulocochlear nerve, and 24 loops were identified running between the facial and the vestibulocochlear nerve. Four loops were classified as both displacing the vestibulocochlear nerve and running between the facial and vestibulocochlear nerves. Tinnitus was present in addition to hearing loss. In 48 of the 58 patients, the statistical analysis was repeated for these patients. No statistically significant association was found between loops classified by the Chavda system and hearing loss. No statistically significant association was present between loops that made no contact with the nerve, ran adjacent to the nerve, or displaced the nerve. A

  2. Clear-Cell Meningioma: CT and MR Imaging Findings in Two Cases Involving the Spinal Canal and Cerebellopontine Angle

    PubMed Central

    Yu, Ki Bong; Kim, Hyung Jin; Suh, Chang Hae; Park, Hyung Chun; Kim, Eun Young; Han, Hye Seung

    2002-01-01

    Clear-cell meningioma is a rare subtype of meningioma which occurs at a younger age and has a higher recurrence rate than other subtypes. We report two cases of clear-cell meningioma, one in the thoracolumbar spinal canal and the other in the cerebellopontine angle. Though the CT and MR imaging findings were not different from those of ordinary meningioma, after surgical removal the condition recurred repeatedly in the patient with spinal canal involvement. PMID:12087202

  3. Vasospasm of labyrinthine artery in cerebellopontine angle surgery: evidence brought by distortion-product otoacoustic emissions.

    PubMed

    Mom, Thierry; Montalban, Audrey; Khalil, Toufic; Gabrillargues, Jean; Chazal, Jean; Gilain, Laurent; Avan, Paul

    2014-10-01

    In cerebellopontine angle (CPA) surgery, postoperative deafness can be due to alteration of cochlear blood flow that is supplied by the labyrinthine artery (LA). In particular, vasospasm is likely to occur and, if so, can be reversed. This work attempted to track down vascular events occurring during CPA surgery. Twenty consecutive patients with vestibular schwannoma were tested with useful preoperative hearing and presence of otoacoustic emissions (OAEs). Distortion-product otoacoustic emissions (DPOAEs), well-known to react within seconds to cochlear ischemia, were used intraoperatively to indirectly monitor cochlear blood flow. Continuous intraoperative monitoring of DPOAEs revealed three different time patterns associated with distinct auditory outcomes. Pattern P1-acute (n = 4) happened when the LA was severed: DPOAEs immediately and irreversibly foundered and led to postoperative deafness. Pattern P2-protracted (n = 7) revealed a progressive deterioration of DPOAEs from the beginning of tumor debulking, likely due to a steady decrease of cochlear blood flow, with postoperative deafness. Pattern P3-unstable (n = 5) corresponded to large DPOAE oscillations between their normal level and noise floor. It was due to acute LA vasospasm that could be reversed in three cases by topical nimodipin. Last, four patients had uneventful cochlear monitoring. In conclusion, cochlear ischemia can occur in vestibular schwannoma surgery, giving three different patterns among which vasospasm can be reversed if detected early.

  4. [Epidemiologic studies of cerebellopontine angle tumors surgically treated in Maracaibo, Venezuela, in 1985-1999].

    PubMed

    Arismendi, G; Bohórquez, M; Romero de Amaro, Z; Cardozo, D; Luzardo, G; Molina, O; Cardozo, J

    2002-02-01

    To analyze the epidemiological, clinical and neuropathological data of cases of cerebellopontine angle (CPA) tumors. The clinical records, neuroimaging and neuropathological studies of 50 patients with diagnosis of CPA tumor operated in different hospitals of Maracaibo, Venezuela, during the lapse January 1st, 1985-December 31, 1999 were reviewed. The variables age, gender, side of the lesion and neuropathological diagnosis were analyzed. A 2:1 female to male ratio was observed. Median age was 48 +/- 12.7 years. Acoustic neuromas (AN) represented 48% of the cases, whereas nonacoustic neuroma tumors (NANT) made up for the rest (52%). Meningiomas were the second more commonly diagnosed lesions, they constituted 32% of the cases. Meningiomas and AN were more frequent in women, their ratios being 7:1 and 1.6:1, respectively. In 60% of the cases the signs and symptoms became eloquent in patients of the fourth and fifth decades of life. The difference between our results and the ones previously reported in the medical literature are due in part to the predominance of female patients in our series. Endocrinologic, genetic and biochemical factors could also be responsible; nevertheless, this does not constitute the objective of the present study.

  5. Adult cerebellopontine angle medulloblastoma originating in the pons mimicking focal brainstem tumor.

    PubMed

    Yoshimura, Junichi; Nishiyama, Kenichi; Fukuda, Masafumi; Watanabe, Masaki; Igarashi, Hironaka; Fujii, Yukihiko

    2009-10-01

    We herein report a rare case of cerebellopontine angle (CPA) medulloblastoma originating in the brainstem that demonstrated a very unusual clinical presentation and radiological appearances. A 25-year-old female was admitted to our hospital with a right hearing disturbance and a right facial palsy. A small non-enhanced lesion having minimal mass effect in the right CPA was identified by using a 1.5-tesla-MR system, whose size remained almost unchanged a year. The 3-tesla MR images revealed that the precise region was in the right side of the tegmentum of the lower pons to the inferior cerebellar peduncle and the flocculus. MR spectroscopic images using a 3-tesla system revealed a high ratio of choline-to-N-acetylaspartate in the region of interest in comparison to the contra-lateral side. Craniotomy and biopsy were performed. The histopathological diagnosis was medulloblastoma. The patient received craniospinal irradiation and chemotherapy, and achieved complete remission by the time of the follow-up MR images. She is now doing well with a full recovery of the right facial palsy. MR spectroscopic imaging is considered to be quite useful for the management of this rare type of brainstem tumor.

  6. Advances in surgical techniques for resection of childhood cerebellopontine angle ependymomas are key to survival.

    PubMed

    Sanford, Robert A; Merchant, Thomas E; Zwienenberg-Lee, Marike; Kun, Larry E; Boop, Frederick A

    2009-10-01

    Childhood cerebellopontine angle (CPA) ependymoma is an uncommon anatomical variant of posterior fossa ependymoma. In infants and young children, the tumor often goes undetected until it causes hydrocephalus. As CPA ependymomas grow, they distort the anatomy and encase cranial nerves and vessels, thereby making resection a formidable surgical challenge. The purpose of this paper is to describe the surgical technique used to achieve gross total resection (GTR) of CPA ependymomas and demonstrate improved survival in these patients. Surgical techniques used for GTR in 45 patients with CPA ependymoma treated from 1997 to 2008 are described. Results of those procedures are compared with data from 11 patients who previously underwent surgical resection (1985-1995). We achieved GTR in 43 (95.6%) patients and near-total resection in two (4.4%); the probability of progression-free survival was 53.8%, and that of overall survival was 64%. Our novel surgical techniques greatly improve central nervous system function and survival among pediatric patients with CPA ependymoma.

  7. Coexistence of extra-axial cavernous malformation and cerebellar developmental venous anomaly in the cerebellopontine angle.

    PubMed

    Wu, Bo; Liu, Weidong; Zhao, Yuan

    2012-01-01

    The coexistence of cavernous malformations (CMs) and developmental venous anomalies (DVAs) in the cerebellopontine angle (CPA) is exceedingly rare. To the authors' knowledge, only one case of CPA CM with concurrence of a neighboring DVA has been reported to date. The authors presented such vascular malformations in a 36-year-old man with progressive CPA syndrome during the course of six weeks. Preoperative neuroimaging suggested the diagnosis of an extra-axial hemorrhagic lesion in the CPA cistern with a cerebellar DVA in the close vicinity. The lesion was totally removed with the DVA untouched and was confirmed to be extra-axial in intimate contact with only the VII-VIII complex and the draining veins of DVA. Pathology revealed a CM. The patient underwent partial improvement in neurological function postoperatively. The radiographic follow-up at one year revealed no recurrence. CMs should be considered in the differential diagnosis of any extra-axial hemorrhagic mass, especially with a DVA in the proximity. The coexistence of CM and DVA in CPA, although maybe just a coincidence, suggests the possibility of a new subtype of extra-axial CPA CM secondary to a preexisting DVA. A long-term follow-up is justified in discovering the potential mechanism and biology of such uncommon vascular malformations. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. A 30 year old man with an acute presentation of a cerebellopontine angle lesion.

    PubMed

    McLaughlin, Nancy; Berthelet, France; Bojanowski, Michel W

    2013-03-01

    Schwannomas are slow-growing tumors with symptoms manifesting progressively. We report the case of a patient who manifested a sudden loss of consciousness as clinical presentation of an intracranial schwannoma with no acute hemorrhage or hydrocephalus. A 30-year-old male presented comatose and posturing. Cerebral CT revealed an extra-axial lesion with a heterogeneous enhancement and a cystic component located on the right cerebellopontine angle (CPA), displacing the brain stem. No acute hemorrhage or hydrocephalus was documented. Through a retrosigmoid suboccipital craniotomy, an extended subtotal tumor resection was performed. The patient experienced no functional hearing impairment and resumed his daily-life activities 3 months after surgery. Histopathological examination was compatible with a benign schwannoma. An exuberant lymphoplasmacytic infiltrate was found in many areas, signing the presence of an unusual inflammatory reaction with adjacent important intratumoral edema. We propose that the exuberant inflammatory infiltrate and the associated intratumoral edema acted as determining elements in the increase of mass effect and sudden clinical deterioration.

  9. Dural Arteriovenous Fistula Following Translabyrinthine Resection of Cerebellopontine Angle Tumors: Report of Two Cases

    PubMed Central

    Li, Peter M.M.C.; Fischbein, Nancy J.; Do, Huy M.; Blevins, Nikolas H.

    2011-01-01

    We describe two cases of dural arteriovenous fistula (DAVF) developing in a delayed fashion after translabyrinthine resection of cerebellopontine angle tumors. Two patients in an academic tertiary referral center, a 46-year-old woman and a 67-year-old man, underwent translabyrinthine resection of a 2-cm left vestibular schwannoma and a 4-cm left petrous meningioma, respectively. Both patients subsequently developed DAVF, and in each case the diagnosis was delayed despite serial imaging follow-up. In one patient, cerebrospinal fluid diversion before DAVF was identified as the cause of her intracranial hypertension; the other patient was essentially asymptomatic but with a high risk of hemorrhage due to progression of cortical venous drainage. Endovascular treatment was effective but required multiple sessions due to residual or recurrent fistulas. Dural arteriovenous fistula is a rare complication of translabyrinthine skull base surgery. Diagnosis requires a high index of clinical suspicion and an understanding of subtle imaging findings that may be present on follow-up studies performed for tumor surveillance. Failure to recognize this complication may lead to misguided interventions for treatment of hydrocephalus and other complications, as well as ongoing risks related to venous hypertension and intracranial hemorrhage. As this condition is generally curable with neurointerventional and/or surgical methods, timely diagnosis and treatment are essential. PMID:23984203

  10. Predictive value of facial nerve electrophysiologic stimulation thresholds in cerebellopontine-angle surgery.

    PubMed

    Selesnick, S H; Carew, J F; Victor, J D; Heise, C W; Levine, J

    1996-05-01

    The predictive value of intraoperative stimulation thresholds for facial nerve function, using a constant-current system, was examined in 49 patients undergoing resection of cerebellopontine-angle tumors. Immediately after surgery, 75% of the 0.1-mA threshold group, 42% of the 0.2-mA group, and 18% of the 0.3-mA or greater group had good (grade I or II) facial nerve function. One year after surgery, 90% of the 0.1-mA group, 58% of the 0.2-mA group, and 41% of the 0.3-mA or greater group had grade I or II function. A statistically significant breakpoint of 0.2 mA was found to predict good postoperative facial function. Delayed facial paralysis occurred in 22% of patients, but the prognosis for these patients was favorable. Both current stimulation threshold and duration are necessary for a meaningful comparison of data between investigators.

  11. Cerebellopontine angle mass mimicking lingual nerve injury after dental implant placement: a case report.

    PubMed

    Momota, Y; Kani, K; Takano, H; Azuma, M

    2015-09-01

    This is a rare case report of a cerebellopontine angle (CPA) mass mimicking lingual nerve injury after a dental implant placement. Lingual nerve injury is a common complication following dental implant placement. CPA masses are likely to cause symptomatic trigeminal neuralgia, and thus can mimic and be easily confused with oral diseases. We experienced a case of CPA mass mimicking lingual nerve injury after dental implant placement. The patient was a 57-year-old Japanese female who complained of glossalgia. She underwent dental implant placement in the mandible before visiting our clinic. Panoramic x-ray radiography revealed no abnormalities; the salivary flow rate by gum test was 7.0 ml/10 min. She was diagnosed with lingual nerve injury and secondary burning mouth syndrome. Vitamin B12 and oral moisturizer did not provide relief; furthermore, numbness in the lower lip emerged. A Semmes Weinstein test demonstrated elevation of her sensitivity threshold. Finally, magnetic resonance imaging revealed a 20-mm diameter mass in the CPA. The patient is now being followed under conservative management. Our experience underscores the importance of including CPA mass in the differential diagnosis of dental diseases. © 2015 Australian Dental Association.

  12. Extra-axial medulloblastoma in the cerebellopontine angle: Report of a rare entity with review of literature

    PubMed Central

    Pant, Ishita; Chaturvedi, Sujata; Gautam, Vinod K. S.; Pandey, Pranjal; Kumari, Rima

    2016-01-01

    With only 33 cases reported so far, a purely extra-axial position of medulloblastoma at cerebellopontine (CP) angle is quite exceptional. We report a case of extra-axial medulloblastoma in a 15-year-old male child located in the CP angle that was surgically treated with a provisional diagnosis of schwannoma. Histopathological diagnosis of medulloblastoma was made with the routine hematoxylin and eosin stain and immunohistochemical markers. This case report highlights the fact that although extremely rare, the possibility of an extra-axial mass being a medulloblastoma does exist. PMID:28217158

  13. Bilaterally Abnormal Head Impulse Tests Indicate a Large Cerebellopontine Angle Tumor

    PubMed Central

    Kim, Hyo-Jung; Park, Seong-Ho; Koo, Ja Won; Kim, Chae-Yong; Kim, Young-Hoon; Han, Jung Ho

    2016-01-01

    Background and Purpose Tumors involving the cerebellopontine angle (CPA) pose a diagnostic challenge due to their diverse manifestations. Head impulse tests (HITs) have been used to evaluate vestibular function, but few studies have explored the head impulse gain of the vestibulo-ocular reflex (VOR) in patients with a vestibular schwannoma. This study tested whether the head impulse gain of the VOR is an indicator of the size of a unilateral CPA tumor. Methods Twenty-eight patients (21 women; age=64±12 years, mean±SD) with a unilateral CPA tumor underwent a recording of the HITs using a magnetic search coil technique. Patients were classified into non-compressing (T1-T3) and compressing (T4) groups according to the Hannover classification. Results Most (23/28, 82%) of the patients showed abnormal HITs for the semicircular canals on the lesion side. The bilateral abnormality in HITs was more common in the compressing group than the non-compressing group (80% vs. 8%, Pearson's chi-square test: p<0.001). The tumor size was inversely correlated with the head impulse gain of the VOR in either direction. Conclusions Bilaterally abnormal HITs indicate that a patient has a large unilateral CPA tumor. The abnormal HITs in the contralesional direction may be explained either by adaptation or by compression and resultant dysfunction of the cerebellar and brainstem structures. The serial evaluation of HITs may provide information on tumor growth, and thereby reduce the number of costly brain scans required when following up patients with CPA tumors. PMID:26754780

  14. Remission of neurovascular conflicts in the cerebellopontine angle in interventional neuroradiology.

    PubMed

    Li, Chuanhui; Li, Youxiang; Jiang, Chuhan; Wu, Zhongxue; Wang, Yang; Yang, Xinjian

    2016-01-01

    To investigate the efficacy of endovascular treatment (EVT) for neurovascular conflicts (NVCs) in the cerebellopontine angle (CPA) caused by intracranial aneurysms (IAs) and intracranial arteriovenous malformations (AVMs), including trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia. From January 2010 to January 2014, 14 consecutive patients presenting with three NVCs caused by IAs or intracranial AVMs were admitted to our department. The clinical outcomes of these NVCs after EVT were retrospectively analyzed. For four patients with IAs, angiographic follow-up confirmed total occlusion of the lesion in all, and the clinical outcomes of NVC were as follows: gradual relief in two (50%), transient partial relief but recurrence in one (25%), and no palliative effect in one (25%). For the 10 patients with intracranial AVMs, one (10%) experienced transient relief of NVC after angiogram examination (no EVT was performed). Of the other nine patients who received EVT, angiographic follow-up was obtained in seven (70%), demonstrating total obliteration of the lesion in three (30%), subtotal obliteration in two (20%), and partial obliteration in two (20%). Clinical outcomes included immediate relief of NVCs after single EVT in two cases (20%), gradual relief after single EVT in five (50%, one of them experienced transient aggravation), and complete relief after two sessions of EVT in two (20%). Complications of transient cranial nerve paresis related to EVT occurred in two cases (20%) with intracranial AVMs. In all, complete lasting relief of the NVCs was obtained finally in 11 cases (78.6%). EVT is a feasible and less invasive approach for relief of NVCs in the CPA caused by IA or intracranial AVM and could be considered as a therapeutic option in these situations. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  15. The relative contribution of magnetic resonance imaging to the assessment and differential diagnosis of cerebellopontine angle mass lesions.

    PubMed

    Worthington, B S; Mawhinney, R R; Holland, I M; Lowe, J; Punt, J; Bydder, G; Young, I R

    1986-01-01

    Forty-nine patients with a space occupying lesion in the cerebellopontine angle cistern were examined by computed tomography (CT), magnetic imaging (MRI) and, where appropriate, conventional neuroradiologic techniques. The presence of an intracanalicular extension and a high signal on T2 weighted sequences were typical of acoustic neuroma and allowed separation from meningioma. Contrast enhancement with gadolinium DTPA was particularly valuable in recurrent acoustic neuroma. Typically epidermoids had long T1 and T2 values. Sequences which highlight flow allow vascular lesions to be identified without the use of contrast media. In separating the several pathologies MRI was superior to CT and also gave information on tissue composition in acoustic neuroma.

  16. The combined microscopic-endoscopic technique for radical resection of cerebellopontine angle tumors.

    PubMed

    Abolfotoh, Mohammad; Bi, Wenya Linda; Hong, Chang-Ki; Almefty, Kaith K; Boskovitz, Abraham; Dunn, Ian F; Al-Mefty, Ossama

    2015-11-01

    The combined microscopic and endoscopic technique has shown significant advantages in the management of various lesions through different approaches. Endoscopic-assisted techniques have frequently been applied to cerebellopontine angle (CPA) surgery in the context of minimally invasive craniotomies. In this paper the authors report on the use of the endoscope in the CPA as a tool to increase the extent of resection, minimize complications, and preserve the function of the delicate CPA structures. They also describe a technique of the simultaneous use of the microscope and endoscope in the CPA and dissection of CPA tumors under tandem endoscopic and microscopic vision to overcome the shortcomings of introducing the endoscope alone in the CPA. The reliability of using the microscope alone in dissecting CPA tumors is evaluated, as is the effectiveness of the combined technique in increasing the resectability of various types of CPA tumors. The authors conducted a retrospective analysis of 50 patients who underwent combined microscopic-endoscopic resection of CPA tumors by the senior author over a period of 3 years (February 2011 to February 2014) at Brigham and Women's Hospital, Harvard Medical School. The reliability of the extent of microscopic removal was evaluated with endoscopic exploration. Additional resection was performed with both microscopic and the combined microscopic-endoscopic technique. Endoscopically verified total resection was validated by intraoperative or postoperative MRI. The function of the cranial nerves was evaluated to assess the impact of the combined technique on their function. A tumor remnant was endoscopically identified in 69% of the 26 patients who were believed to have microscopic total resection. The utilization of the endoscopic visualization and dissection increased endoscopically verified total removal to 38 patients, and 82% of these patients had no sign of residual tumor on postoperative imaging. The technique was most

  17. Extra-axial medulloblastoma in cerebello-pontine angle: A report of a rare case with literature review

    PubMed Central

    Bahrami, Eshagh; Bakhti, Sahar; Fereshtehnejad, Seyed-Mohammad; Parvaresh, Mansour; Khani, Mohammad Reza

    2014-01-01

    Medulloblastoma is quite uncommon in the adult population and even rarer in extra-axial site in cerebello-pontine (CP) angle. In this report, a 23-year-old male patient with a two month history of deafness, nausea, vomiting and ataxia is presented. Clinical and radiological findings demonstrated a heterogeneously enhanced extra-axial lesion in the right CP angle. Total excision was performed and the histopathological features of medulloblastoma were confirmed. After surgery, the patient had no neurological deficit and the audiometric findings were improved. In addition, he underwent adjuant radiotherapy and no sign of metastatic mass was observed in follow-up spinal cord MRI. Although extremely rare, medulloblastoma must be considered in the differential diagnosis of extra-axial CP angle lesions. PMID:25405123

  18. Symptomatic ependymal cysts of the perimesencephalic and cerebello-pontine angle cisterns.

    PubMed

    Sharma, R R; Pawar, S J; Kharangate, P P; Delmendo, A

    2000-11-01

    Primary intracranial ependymal cysts are extremely rare. These are congenital, benign ependyma lined, commonly intraparenchymal and uncommonly extraparenchymal cysts in leptomeningeal location of variable size seen in the adult life. The authors report two cases of symptomatic ependymal cysts: one in the perimesencephalic cistern in a 10-month-old infant presenting with delayed mile stones and another in the cerebello-pontine cistern in a morbidly obese 35-year-old woman with known benign intracranial hypertension now presenting with hemifacial spasm. Neurosurgical intervention was curative in both cases. Interesting clinical, radiological and histological features are presented and discussed.

  19. Ectopic choroid plexus within a juvenile arachnoid cyst of the cerebellopontine angle: cause of cyst formation or reason of cyst growth.

    PubMed

    Schuhmann, M U; Tatagiba, M; Hader, C; Brandis, A; Samii, M

    2000-02-01

    The unusual and rare case of a 6-year-old boy is reported who presented with an arachnoid cyst located in the cerebellopontine angle incorporating an ectopic piece of choroid plexus tissue. A microneurosurgical cyst wall resection was performed and the plexus tissue identified and removed. The rare occurrence of ectopic choroid plexus tissue within cysts of the CNS is discussed.

  20. [Exposing the rabbit cerebellopontine angle through post-sigmoid sinus approach and recording the direct compound action potential of the auditory nerve].

    PubMed

    Zhu, Ming; Wu, Hao; Li, Zhaoji; Chen, Xiangping; Cao, Rongping; Shen, Min; Zhu, Chunsheng; Zhou, Jingfeng

    2005-04-01

    To study the way of exposing the rabbit cerebellopontine angle through post-sigmoid sinus approach and recording the direct compound action potential of the auditory nerve, and to investigate the stability of DCAP N1 wave latency. Fifteen New Zealand rabbits which had normal Preyer's auricle reflex were selected. Each one was studied in the left ear. After anaesthetized,the cerebellopontine angle of rabbits were exposed through post-sigmoid sinus approach under aseptic status,then the needle-shaped pole were inserted into the facial-acoustic nerve complex. The DCAP was recorded at the immediateness, 2 h and 5 h after the insertino sequentially. At last, DCAP N1 wave latencies of 15 rabbits were statisticed and analyzed using paired-samples t-test. To the 15 sides, the distinct curves with well differentiated waves were induced in the all three times. No significant difference in any N1 wave latency had been found among the 3 times. The rabbit cerebellopontine angle could be exposed and the direct compound action potential of the auditory nerve could be recorded successfully by the way studied in this experiment. In normal state, the individual value of DCAP N1 wave latency is stable. During the process of surgery in which the cerebellopontine angle has been exposed, the DCAP N1 wave latency is a practical index for monitoring of hearing impairment.

  1. Preoperative evaluation of neurovascular relationships for microvascular decompression in the cerebellopontine angle in a virtual reality environment.

    PubMed

    Du, Zhuo-Ying; Gao, Xiang; Zhang, Xiao-Luo; Wang, Zhi-Qiu; Tang, Wei-Jun

    2010-09-01

    In this paper the authors' goal was to evaluate the feasibility and efficacy of a virtual reality (VR) system in preoperative planning for microvascular decompression (MVD) procedures treating idiopathic trigeminal neuralgia and hemifacial spasm. The system's role in surgical simulation and training was also assessed. Between May 2008 and April 2009, the authors used the Dextroscope system to visualize the neurovascular complex and simulate MVD in the cerebellopontine angle in a VR environment in 16 patients (6 patients had trigeminal neuralgia and 10 had hemifacial spasm). Reconstructions were carried out 2-3 days before MVD. Images were printed in a red-blue stereoscopic format for teaching and discussion and were brought into the operating room to be compared with real-time intraoperative findings. The VR environment was a powerful aid for spatial understanding of the neurovascular relationship in MVD for operating surgeons and trainees. Through an initial series of comparison/confirmation experiences, the senior neurosurgeon became accustomed to the system. He could predict intraoperative problems and simulate surgical maneuvering, which increased his confidence in performing the procedure. The Dextroscope system is an easy and rapid method to create a stereoscopic neurovascular model for MVD that is highly concordant with intraoperative findings. It effectively shortens the learning curve and adds to the surgeon's confidence.

  2. A connection between neurovascular conflicts within the cerebellopontine angle and vestibular neuritis, a case controlled cohort study.

    PubMed

    Loader, B; Linauer, I; Korkesch, S; Krammer-Effenberger, I; Zielinski, V; Schibany, N; Kaider, A; Vyskocil, E; Tscholakoff, D; Franz, P

    2016-10-01

    This retrospective, observer blinded case-control study aims to compare the prevalence of neurovascular conflicts (NVCs) of the vestibulocochlear nerve and the anterior inferior cerebellar artery (AICA) in patients presenting with clinical signs of acute vestibular neuritis with and without subsequent objective vestibular function loss (VFL). 58 acute cases of clinically suspected acute vestibular neuritis were investigated with same day cranial MRI at a tertiary referral centre and compared to 61 asymptomatic controls. The prevalence of NVCs in cases with objective VFL were also compared to cases without VFL. Radiologists described the NVC as "no contact" (Grade 0), "contact < 2 mm" (Grade 1), "contact > 2 mm" (Grade 2) and "vascular loop presence" (Grade 3) without knowledge of neurotological data. Neurotological data was collected without knowledge of MRI findings. Vestibular function was tested by bithermic caloric irrigation. 26 cases (45%) showed caloric VFL (Group A), whereas 32 (55%) exhibited no VFL (Group B). Group A included 13 cases with NVCs (50%), Group B included 26 NVC cases (82%) (p = 0.012) and the control group included 16 individuals (26%) (p < 0.001 for comparison of all 3 groups). Group B had a significantly higher NVC-Grading than Group A (p = 0.009). There was no statistically significant association between NVCs and either SNHL or tinnitus (p > 0.05). Our results suggest that patients presenting with clinical signs of acute vestibular neuritis who show symmetrical caloric vestibular function test results have a significantly higher NVC prevalence in the cerebellopontine angle.

  3. Sensorineural hearing loss among cerebellopontine-angle tumor patients examined with pure tone audiometry and brainstem-evoked response audiometry

    NASA Astrophysics Data System (ADS)

    Rinindra, A. M.; Zizlavsky, S.; Bashiruddin, J.; Aman, R. A.; Wulani, V.; Bardosono, S.

    2017-08-01

    Tumor in the cerebellopontine angle (CPA) accurs for approximately 5-10% of all intracranial tumors, where unilateral hearing loss and tinnitus are the most frequent symptoms. This study aimed to collect data on sensorineural hearing loss in CPA tumor patients in Dr. Cipto Mangunkusumo Hospital (CMH) using pure tone audiometry and brainstem-evoked response audiometry (BERA). It also aimed to obtaine data on CPA-tumor imaging through magnetic resonance imaging (MRI). This was a descriptive, analytic, and cross-sectional study. The subjects of this study were gathered using a total sampling method from secondary data between July 2012 and November 2016. From 104 patients, 30 matched the inclusion criteria. The CPA-tumor patients in the ENT CMH outpatient clinic were mostly female, middle-aged patients (41-60 years) whose clinical presentation was mostly tinnitus and severe, asymmetric sensorineural hearing loss in 10 subjects. From 30 subjects, 29 showed ipsilaterally impaired BERA results, and 17 subjects showed contralaterally impaired BERA results. There were 24 subjects who with large-sized tumors and 19 subjects who had intracanal tumors that had spread until they were extracanal in 19 subjects.

  4. [Current imaging of vasculo-neural conflicts in the cerebellopontine angle].

    PubMed

    Raybaud, C; Girard, N; Poncet, M; Chays, A; Caces, F; Magnan, J

    1995-01-01

    To demonstrate the high sensitivity of high definition MRI and particularly "Constructive Interference in Steay State" (Ciss) imaging sequence, in depicting neurovascular conflicts in the CP angle cistern, cisternographic imaging and high definition T1 weighed (Turbo flash), contrast enhanced imaging were used to investigate hemifacial spasm (72 patients) and tinnitus with abnormal BER (5 patients). The study was complemented with Angio MR in 25 patients. The results were compared with findings in a control group of 200 patients, and with the surgical observations in 57 operated cases. In hemifacial spasm, the morphology of the neurovascular conflict was determined, as well as the site of compression (lateral medullary fossa 38 cases; nerve 9; both 15 cases), and the vessel involved (VA 25 cases; PICA 16 cases; AICA 10 cases; VA and PICA 8 cases; VA and AICA 3 cases; lateral medullary vein 1 case). In tinnitus (5 cases), the AICA was involved in every case in the IAM. Among 57 operated cases, only one false negative was observed. In the asymptomatic control group, a nerovascular conflict was observed in 3, 5% of the cases only. CISS imaging is the single most efficient technique, but the combined used of the 3 types of imaging brings the highest diagnostic efficiency, for identifying a neurovascular conflict in the CPA cistern.

  5. [Fractionated radiation therapy long-term effectiveness in the treatment of cerebello-pontine angle schwannomas: 12 years of experience in 30 cases].

    PubMed

    Darrouzet, V; Maire, J P; Guérin, J; Duclos, J Y; Caudry, M; Bébéar, J P

    2000-11-01

    The purpose of this research was to evaluate long-term results of fractionated radiation therapy (RT) in the treatment of cerebello-pontine angle schwannomas. from January 1986 to October 1995, 29 patients with stage III and IV scwhannomas were treated with external fractionated RT. One patient was irradiated on both sides and indication for RT was as follows: a) poor general condition or old age contraindicating surgery, 16 cases; b) hearing preservation in bilateral tumors after contralateral tumor removal, 6 cases; c) partial resection or high risk of recurrence after subsequent surgery for relapse, 5 cases; d) non surgical relapse, 3 cases. Most patients were irradiated with 6 to 10 MV photons. A three- to four-field technique with coplanar static beams and conformal blocks was used. Doses were calculated on a 95 % isodose and were given 5 days a week for a mean total dose of 51 Gy (1.8 Gy/fraction). Median follow-up from RT was 66 months (7 to 120); seven patients died, two with progressive disease, five from non tumoral cause. Two patients underwent total removal after RT (1 stable and 1 growing tumor). On the whole, tumor shrinkage was observed in 13 patients (43.3 %), stable disease in 14 (46.6 %), and tumor progression in three. Hearing was preserved in 4 out of 6 hearing patients (1 class A hearing, 2 class B and 1 class C). No patient experienced CN5 or CN7 neuropathy. long-term efficacy or fractionated RT is well documented in this series. Acute and delayed tolerance was excellent. Hearing can be preserved for a long time.

  6. Cardiac lipoma

    PubMed Central

    Ismail, Imtiaz; Al-Khafaji, Khalid; Mutyala, Monica; Aggarwal, Saurabh; Cotter, William; Hakim, Hosam; Khosla, Sandeep; Arora, Rohit

    2015-01-01

    Lipomas of the heart are encapsulated tumors that are composed primarily of mature fat cells. Cardiac lipomas can originate either from subendocardium (approximately 50%), subpericardium (25%), or from the myocardium (25%) and may be located more frequently in left ventricle or right atrium. We report a 74-year-old female who presented with dyspnea on exertion and was found to have 5×5 cm mass occupying most of the right atrium on a transesophageal echocardiogram. PMID:26486106

  7. Bilateral cerebellopontine arachnoid cyst: A rare entity.

    PubMed

    Sharma, Anand; Sharma, Achal; Mittal, Radhey S; Gandhi, Ashok

    2015-01-01

    Bilateral cerebellopontine angle (CPA) arachnoid cysts (ACs) are very rare: only one case is reported in literature. Pathogenesis of those cysts is unknown; they are thought to be congenital. The presenting symptoms of CPA AC are frequently nonspecific or otological. The management of ACs of the CPA is controversial. We are reporting two cases of bilateral CPA AC with their pathophysiology and review of literature.

  8. High-resolution MR cisternography of the cerebellopontine angle, obtained with a three-dimensional fast asymmetric spin-echo sequence in a 0.35-T open MR imaging unit.

    PubMed

    Naganawa, S; Ito, T; Iwayama, E; Fukatsu, H; Ishigaki, T

    1999-01-01

    High-resolution MR cisternography performed with 3D fast asymmetric spin-echo imaging (3D fast spin-echo with an ultra-long echo train length and asymmetric Fourier imaging) was optimized in a 0.35-T open MR imaging unit. The 0.35- and 1.5-T images of the two volunteers and three patients with acoustic schwannomas were then compared. The optimal parameters for images obtained by 3D fast asymmetric spin-echo imaging at 0.35 T were as follows: field of view, 15 cm; matrix, 256 x 256 x 40; section thickness, 1 mm; echo train length, 76; and imaging time, 10 minutes 44 seconds. Scans obtained from both normal volunteers showed the facial, cochlear, and superior and inferior vestibular nerves separately in the internal auditory canal on both 0.35- and 1.5-T images. All three acoustic schwannomas were depicted on both 0.35- and 1.5-T images. Screening for disease at the cerebellopontine angle and in the internal auditory canal, without the administration of contrast material on a low-field open MR imaging unit and within a clinically acceptable imaging time, may be possible. Further controlled prospective studies are required, however, before implementation on a wide basis. If proved effective, this may be of particular value for reducing healthcare costs and for imaging claustrophobic and pediatric patients in an open system.

  9. Intraoral Lipoma: A Case Report

    PubMed Central

    Kumar, L. K. Surej; Kurien, Nikhil Mathew; Raghavan, Varun B.; Menon, P. Varun; Khalam, Sherin A.

    2014-01-01

    Lipomas are rare in oral and maxillofacial regions although they are the most common tumours of mesenchymal origin in human body. The etiology remains unclear. Various different theories explain the pathogenesis of this adipose tissue tumour and also different histological variants of oral lipoma have been given in literature. A case of intraoral lipoma occurring in mental region in a 77-year-old male is reported along with review of the literature. Wide surgical excision was performed and two-year followup showed excellent healing without any recurrence. Lipomas are benign soft tissue neoplasm of mature adipose tissue seen as a common entity in the head and neck region. Intraoral lipomas are a rare entity which may be noticed only during routine dental examinations. Most of them rarely cause pain, resulting in delay to seek treatment. It is mandatory for a clinician to diagnose intraoral lipomas using latest diagnostic methods and conservatively treat them without causing much discomfort. PMID:24592278

  10. Lipedema with multiple lipomas.

    PubMed

    Pascucci, Anabella; Lynch, Peter J

    2010-09-15

    Lipedema is an underdiagnosed syndrome of unclear etiology, characterized by symmetric painful enlargement of the buttocks and lower extremities, which spares the feet. This enlargement is caused by the deposition of adipose tissue. It was first described by Allen and Hines in 1940, who observed that it had a female predilection; patients commonly had an associated family history. We describe a patient with classic lipedema and multiple lipomas of her arms and trunk.

  11. Laryngeal lipoma: a rare cause of dysphonia.

    PubMed

    Nada, Garrouche; Omezzine, Jerbi Saida; Maher, Dhifallah; Nouha, Ben Hamida; Hssine, Hamza

    2017-01-01

    Lipomas are the most common mesenchymal tumors. Laryngeal lipomas represent 1% of all lipomas but unlike other locations may cause life-threatening symptoms by obstruction of the respiratory tract. In this study, the case of a 32-year old woman with laryngeal lipoma is discussed. The lesion was detected on the left aryepiglottic fold, presented as a stalked and dynamic mass of 2 centimeters diameter. The imaging aspects of laryngeal lipoma cases, clinical evaluation, and approaches to treatment will be discussed.

  12. Lipomas of the gastrointestinal system.

    PubMed

    Dolai, Matilda; Andrejić, Bojana; Ivanov, Dejan

    2012-01-01

    Lipomas are rare benign tumors in the gastrointestinal system. Within the gastrointestinal system, 65% of the lipomas are located in the colon (sigmoid part of the colon or rectum) and rarely in the stomach and esophagus. The paper presents two gastrointestinal lipomas. First is the case of lipoma of the sigmoid colon and the other one is gastric lipoma. In both cases the material was sent for histopathological analysis due to suspicion of malignancy of the lesions. In both cases, the histopathologic analysis showed tumor made of mature adipocytes, localized in the submucosa both of the stomach and intestine. Hypercellularity and/or atypia of the cell was found in neither case. Lipomas are shown because of its atypical localization and clinically suspicious malignancy in the stomach and sigmoid colon. These cases show that the applied methods of preoperative diagnosis of tumors in the gastrointestinal system are not sufficient to determine the origin and biological behavior of tumors. Histopathological diagnosis provides a correct insight into the nature of tumors and determine the course of treatment. This paper presents a rare localization of lipomas in the gastrointestinal system. The preoperative diagnosis of lesions in the gastrointestinal system may not be sufficient to determine the origin and biological behavior of the lesions, hence the histopathological diagnosis gives an accurate insight into the nature of the change, preventing the possibility of further aggressive therapy.

  13. Esophageal Lipoma: A Rare Tumor

    PubMed Central

    Feldman, Jeremy; Tejerina, Manfred; Hallowell, Michael

    2012-01-01

    Esophageal lipomas are rare tumors, making up 0.4% of all digestive tract benign neoplasms. Most of these lesions are clinically silent as a result of their small size, however, the majority of lesions over 4 cm have been reported to cause dysphagia, regurgitation and/or epigastralgia. We report a case of a 53 year-old African American female who presented with dysphagia. Computed tomography of the chest and esophagram confirmed esophageal lipoma as the cause of the patient’s symptoms. Accurately diagnosing an esophageal lipoma is crucial in order to rule out potential malignant lesions, relieve patient symptoms and plan the appropriate treatment. PMID:23365708

  14. Lipoma involving the skull. Case report.

    PubMed

    Tomabechi, M; Sako, K; Daita, G; Yonemasu, Y

    1992-02-01

    The case of an intraosseous lipoma involving the left frontal bone is reported. Lipomas of the bone are rare; only three cases of lipomas involving the skull have previously been reported. The differential diagnosis includes a healing bone infarction or fracture, meningioma, hemangioma, and fibrous dysplasia. Diagnosis prior to surgery is difficult.

  15. Meralgia paresthetica secondary to lipoma.

    PubMed

    Rau, Cheng-Shyuan; Hsieh, Ching-Hua; Liu, Yueh-Wei; Wang, Lin-Yi; Cheng, Ming-Hsiung

    2010-01-01

    Meralgia paresthetica (MP) consists of pain or dysthesia in the lateral thigh caused by entrapment of the lateral femoral cutaneous nerve (LFCN) underneath the inguinal ligament. The causes include iliac crest bone graft harvesting, seat belt injury associated with motor vehicle accident, diabetes mellitus, and trauma. The authors present the case of a 50-year-old woman who had a 1-year history of right-sided MP. The patient's history and the results of physical and radiological examinations were otherwise unremarkable except for the finding of a lipoma over the surface of the right sartorius muscle. Electrophysiological studies were interpreted as demonstrating peripheral neuropathy only. Conservative treatment, including heat or ice packing and local anesthetic and steroid injections, failed to control the patient's symptoms. Although sectioning or neurolysis of the LFCN appears to offer good-to-excellent results, the patient underwent excision of the lipoma. The symptoms resolved completely. To the best of the authors' knowledge this is the first case of MP associated with compression caused by a lipoma. The authors conclude that lipoma compression can cause MP, and in such cases, total excision of the lipoma may resolve the condition.

  16. Laryngeal lipoma: a rare cause of dysphonia

    PubMed Central

    Nada, Garrouche; Omezzine, Jerbi Saida; Maher, Dhifallah; Nouha, Ben Hamida; Hssine, Hamza

    2017-01-01

    Lipomas are the most common mesenchymal tumors. Laryngeal lipomas represent 1% of all lipomas but unlike other locations may cause life-threatening symptoms by obstruction of the respiratory tract. In this study, the case of a 32-year old woman with laryngeal lipoma is discussed. The lesion was detected on the left aryepiglottic fold, presented as a stalked and dynamic mass of 2 centimeters diameter. The imaging aspects of laryngeal lipoma cases, clinical evaluation, and approaches to treatment will be discussed. PMID:28450988

  17. Translocation (Y;12) in lipoma.

    PubMed

    Liang, Cher-Wei; Mariño-Enríquez, Adrian; Johannessen, Catherine; Hornick, Jason L; Dal Cin, Paola

    2011-01-01

    Lipomas are the most common benign mesenchymal neoplasm in adults, and have been extensively characterized at the cytogenetic level. Chromosomal aberrations have been observed in the majority of lipomas, two-thirds of which involve chromosomal region 12q14.3. To date, structural rearrangements have been reported affecting every chromosome except chromosome Y. Here we report a case of a lipoma that shows a novel apparently balanced translocation involving chromosomes Y and 12. Fluorescence in situ hybridization using a break-apart HMGA2 in-house probe set detected a single signal on the normal chromosome 12 but not on either the derivative chromosome Y or 12, indicating a cryptic loss of 12q14.3, where HMGA2 is mapped. Immunohistochemical studies, however, revealed overexpression of HMGA2 with nuclear expression in the majority of tumor cells, whereas MDM2 and CDK4 were negative. The overexpression of HMGA2 may be caused by a cryptic chromosomal aberration affecting either the cytogenetically unaltered HMGA2 allele or HMGA2 regulators elsewhere. The current case broadens our knowledge about the translocation partners of HMGA2 in lipomas and highlights the biological complexity in regulating HMGA2 expression.

  18. [Hydromyelia associated with spinal lipoma].

    PubMed

    Wada, K; Morimoto, K; Takemoto, O

    1998-11-01

    We studied morphological changes of hydromyelia complicated with spinal lipoma of infants who were untethered. Since the MRI was introduced, early detection of spinal lipoma with lumbosacral skin abnormalities has become possible. We have experienced 44 surgical cases of spinal lipoma. Out of 36 such cases, 25 (69.4%) had hydromyelia, and hydromyelia of 9 patients was found to be of the terminal ventricle type. As many as 36% of spinal lipoma patients with hydromyelia concurrently had terminal-type hydromyelia, which was considered to fall under a specific category of congenital hydromyelia. At the stage of embryogenesis of the spinal cord, the caudal cell mass undergoes vacuolization, canalization and retrogressive differentiation, and during this process, the terminal ventricle with ependymallined cells becomes morbid. Though the morphological changes of hydromyelia after surgery as untethering were varied, hydromyelia of 9 patients became smaller after untethering, and hydromyelia of 8 expanded but attenuated afterwards, totaling 17 (68.0%). However, 5 had an expanding tendency and 3 did not show any morphological changes during the follow-up period (20.6-26.9 months) by MRI.

  19. Oral cavity lipoma: a case report

    PubMed Central

    Park, Byeong-Gi; Choi, Dong-Ju; Park, Jun-Woo

    2015-01-01

    Intraoral lipomas are a rare clinical entity, comprising only 0.1% to 5% of all benign tumors in the intraoral cavity. A 56-year-old woman suffering from diabetes presented with this relatively rare intraoral lipoma and was treated by surgical excision under general anesthesia. Because the mass was located adjacent to the mental foramen, a precise dissection was necessary to ensure minimal nerve damage. No abnormalities or recurrence was noted at 1-year follow-up and the patient did not complain of numbness. We studied the occurrence of oral lipoma in this diabetic patient and reviewed the relationship between oral lipoma and diabetes in the literature. PMID:26339582

  20. Intraoral Excision of a Huge Cheek Lipoma.

    PubMed

    Coelho, Rodrigo Carvalho Pinto; Oliveira, Eduardo Morato; Silva, Guilherme Costa Carvalho; Aguiar, Evandro Guimarães; Moreira, Allyson Nogueira; Souza, Leandro Napier

    2017-09-29

    Lipomas are benign tumors of mature adipocytes unusual in the oral and maxillofacial region. The average size of cheek lipomas in the literature ranges from 1.5 to 2.5 cm, with the maximum size of 5 cm. Their etiology remains unclear. Lipomas present, clinically, as well circumscribed, slow growing, painless masses, usually treated by complete excision. The aim of this paper is to present a 78-year-old Caucasian male patient with a huge cheek lipoma compromising facial esthetics and treated through an intraoral excision. Postoperative period was uneventful with no signs of recurrence. Concluding, the intraoral approach is a relatively simple technique that should be taken into account when considering the surgical removal of cheek lipomas.

  1. Huge Tongue Lipoma: A Case Report

    PubMed Central

    Damghani, Mohammad Ali; Safari, Mohammad

    2015-01-01

    Introduction: Lipomas are among the most common tumors of the human body. However, they are uncommon in the oral cavity and are observed as slow growing, painless, and asymptomatic yellowish submucosal masses. Surgical excision is the treatment of choice and recurrence is not expected.  Case Report: The case of a 30-year-old woman with a huge lipoma on the tip of her tongue since 3 years, is presented. She had difficulty with speech and mastication because the tongue tumor was filling the oral cavity. Clinical examination revealed a yellowish lesion, measuring 8 cm in maximum diameter, protruding from the lingual surface. The tumor was surgically excised with restoration of normal tongue function and histopathological examination of the tumor confirmed that it was a lipoma. Conclusion: Tongue lipoma is rarely seen and can be a cause of macroglossia. Surgical excision for lipoma is indicated for symptomatic relief and exclusion of associated malignancy. PMID:25938089

  2. An unusual case of lipoma arborescens

    PubMed Central

    Chaturvedi, A; Peach, C

    2016-01-01

    Introduction Lipoma arborescens is a rare condition of the synovial lining. It is particularly uncommon in the bicipitoradial bursae of the elbow. Case Report A 68-year-old woman presented with a 5-month history of anterior elbow pain and swelling causing discomfort. Radiography demonstrated reactive changes of radial tuberosity and magnetic resonance imaging confirmed lipoma arborescens of the bicipitoradial bursa with distal biceps tendinopathy. A bicipital bursa bursectomy and lipoma excision was performed. Gross pathology and histology was consistent with lipoma arborescens. Three months postoperatively, our patient had full range of motion and good strength. Conclusions To our knowledge, this is the first published case report of lipoma arborescens affecting the elbow. Recognising the differential diagnoses of anterior elbow pain and the characteristic imaging is essential for accurate diagnosis. PMID:27241604

  3. [Intermuscular and intramuscular lipomas of the neck].

    PubMed

    Giacomelli, L; Miglietta, A M; Pulcini, A; Granai, A; Fabrizio, G; Manno, A; Messinetti, S

    1992-01-01

    Two cases of deep lipomas of the neck developed between the skeletal muscles were presented: one intermuscular and the other intramuscular. Taking into consideration the rarity of the case, the authors examined the clinical surgical aspect, paying special attention to the relationship between sonographic and computerized tomographic characteristics and the histological aspects in order to define whether the lipomatous tumors were benign or malignant. They also studied the localization of cervical lipomas, of lipoblastomas of hibernomas and of liposarcomas and defined an anatomo-clinical classification of both superficial and deep cervical lipomas.

  4. [Giant compressive mediastinal lipoma: a case report].

    PubMed

    Ndiaye, As; Diarra, O; Diop, A N; Ciss, A G; Dieng, P A; Dangou, J M; Ndiaye, M

    2006-01-01

    Mediastinal lipoma is a rare mesenchymatous fatty tumor in child. Usually asymptomatic, it can cause asphyxiation. The authors report the case of an 18 month-baby-girl referred to us by the pediatric department for asphyxiation. The chest X ray was evocative of a mediastinal tumor. A sudden cardiorespiratory failure leads us to perform thoracotomy. A fatty tumor was found compressing the heart and the left lung. It was easily extirpated. The postoperative recovery was uneventful. Light microscopy showed a lipoma. This compressive form shows the severity of the mediastinal lipoma when it reaches a large size. The literature on this rare pathology is reviewed.

  5. Giant oral lipoma: a rare entity*

    PubMed Central

    Ponce, José Burgos; Ferreira, Gustavo Zanna; Santos, Paulo Sérgio da Silva; Lara, Vanessa Soares

    2016-01-01

    Lipomas are very common benign slow-growing soft tissue neoplasms composed of mature adipose tissue mostly diagnosed in the fifth decade of life. These tumors rarely present in the oral cavity, representing less than approximately 5% of all benign mouth tumors. They are usually less than 2cm in size and etiology remains unclear. We report a young male patient presenting with a giant lipoma in the buccal mucosa. Histopathology revealed a large area of mature fat cells consistent with conventional lipoma and an area of the mucosal lining of the lesion suggestive of morsicatio buccarum. In the present article, we emphasize the clinicopathological features and differential diagnosis of the disease.

  6. Left supraclavicular spindle cell lipoma.

    PubMed

    Olaleye, Oladejo; Fu, Bertram; Moorthy, Ram; Lawson, Charles; Black, Myles; Mitchell, David

    2010-01-01

    Background. Spindle cell lipoma (SCL) is a benign lipomatous tumour, typically occurring in the posterior neck, shoulder or upper back of elderly males. They compose of fat, CD34 positive spindle cells, and ropey collagen on a myxoid matrix. This case highlights a rare presentation of SCL and the need for pre-operative diagnosis. Case Report. A 63-year-old gentleman presented with a pre-existing left supraclavicular mass that had recently increased in size. FNA and CT Scans were performed and results discussed in the mutidisciplinary team meeting. Excisional biopsy was recommended. Radiology. CT neck showed a left supraclavicular mass of fatty density with fine internal septations. A low-grade liposarcoma could not be excluded. Histopathology. FNA was indeterminate. Histology of specimen showed bland spindle cells with no evidence of malignancy. Immuno-histochemistry showed SCL with CD34 positivity and negative staining on CDK4 and p16. Management. Excision biopsy of the mass was performed which was technically difficult as the mass invaginated around the brachial plexus. The patient recovered well post-operatively with no neurological deficits. Conclusion. Spindle cell lipoma is a rare benign tumour and a pre-operative diagnosis based on the clinical context, imaging and immuno-histochemistry is crucial to management.

  7. Endoscopic excision of cheek lipomas.

    PubMed

    Pyon, Jai-Kyong; Park, Bum-Jin; Mun, Goo-Hyun; Cha, Myung-Kyu; Lim, So-Young; Bang, Sa-Ik; Oh, Kap-Sung

    2008-10-01

    Although the removal of forehead and brow benign tumors using an endoscopic technique has proven to be valuable, the efficacy of an endoscopic excision for cheek masses is unclear. A retrospective review was performed on 8 patients with a lipoma (7) and a foreign body granuloma (1) located at the cheek region. There were 7 men and 1 woman with a mean age of 34.8 years (range, 22-54 years). All the excisional procedures were performed with an endoscope through 2 small incisions, one on the hair-bearing sideburns and the other behind the earlobe. The masses varied from 0.7 x 0.7 cm to 4.0 x 3.0 cm in size. There were no intraoperative or postoperative complications, and no recurrence was detected after a 5- to 61-month follow-up. An endoscopically assisted excision of cheek lipomas is an effective procedure and might be a good alternative to the more conventional procedures.

  8. Dermal plexiform spindle cell lipoma.

    PubMed

    Val-Bernal, José Fernando; Hermana, Sandra

    2016-01-01

    Spindle cell lipoma located in the dermis is uncommon. The plexiform variant of this tumor is rare. In fact, only six cases of this variant have been described previously. We report herein a case of dermal plexiform spindle cell lipoma with prominent myxoid matrix. A 47-year-old male patient presented with a solitary, 2.2 cm-cutaneous mass in the right buttock region that had slowly increased in size for over one year. The dermal lesion was characterized by a mixture of mature adipocytes, spindle shaped cells and inconspicuous ropey collagen bundles in a mucinous background. This lesion showed a fascicular and plexiform pattern with adipocytes irregularly arranged, predominant in the depth of the lesion. Immunohistochemically, the spindle cells were positive for CD34, factor XIIIa, and vimentin, and negative for retinoblastoma protein, claudin-1, GLUT-1, epithelial membrane antigen, neurofilament protein, and Sox-10. S100 protein stained a thinned cytoplasmic rim of mature adipocytes and labeled about 25% of spindle cells in the most superficial areas. A review of the seven cases published, including the present report, revealed that there were five females and two males. Most cases located in the thigh-groin-buttock area. The age of the patients ranged from 32 to 58 years with a mean of 45.7 years. Clinical diagnosis suggested a lipomatous or neural tumor in six cases. The main differential diagnosis includes dermal intraneural plexiform neurofibroma and purely intradermal monophasic plexiform spindle cell nevus.

  9. Concomitant cervical and lumbar intradural intramedullary lipoma.

    PubMed

    Muthusubramanian, Vikram; Pande, Anil; Vasudevan, Madhabushi Chakravarthy; Ramamurthi, Ravi

    2008-03-01

    Lipomas of the spinal cord are often a component of spinal dysraphic states. Nondysraphic intramedullary spinal cord lipomas are rare, and concomitant isolated cervical and lumbar intradural intramedullary lipomata are very rare. One patient with concomitant isolated nondysraphic cervical and lumbar spinal cord lipomata has been reported and management options discussed. A young girl presented with insidious-onset diffuse neck pain and early myelopathic signs. Conventional radiographs were normal. Magnetic resonance imaging of the whole neuraxis revealed concomitant cervical and lumbar intradural intramedullary lipoma. Subtotal resection of the lesion was performed at both levels, after which the patient improved symptomatically and was ambulant independently. Concomitant intradural lipomas at 2 different locations unassociated with a dysraphic state is very rare. Magnetic resonance imaging with fat suppression study is the investigation of choice. Adequate decompression with subtotal removal is the treatment of choice.

  10. Lipomas of the Cord and Round Ligament

    PubMed Central

    Lilly, Michael C.; Arregui, Maurice E.

    2002-01-01

    Objective To determine the incidence, significance, and anatomy of spermatic cord and round ligament lipomas. Methods This was a retrospective review of 280 hernia repairs on 217 patients performed by a single surgeon (M.E.A.) from January 1996 to January 2000. The incidence of cord lipoma and relationship to inguinal hernia were evaluated. Further, when identified at the time of laparoscopic preperitoneal hernia repair, the anatomy of the lipomas was studied both at the time of surgery and again on review of videotapes. Results One hundred ninety-nine laparoscopic and 81 open inguinal hernia repairs were performed on 192 male patients and 25 female patients. Sixty-three lipomas of the cord were identified for an incidence of 22.5%. Overall, 18 cord lipomas were found in groins without hernias, and these were identified before surgery in 10 (2 by physical examination, 7 by groin ultrasound, and 1 by magnetic resonance imaging). The remaining nine were misidentified as a hernia before surgery. Fourteen of these patients presented with groin pain and four were asymptomatic. Forty-five lipomas were associated with hernias and were characterized as a hernia by examination in 43 instances. There were 32 (51%) cord lipomas associated with indirect hernias, 11 (17%) with direct hernias, and 1 each with pantaloon and femoral hernias. Nine lipomas were found in women, seven presenting with groin pain and six found without an associated peritoneal defect. Two patients presented with symptomatic cord lipomas after laparoscopic hernia repair. A lipoma of the cord is herniated fat that appears to originate from the retroperitoneal fat outside and posterior to the internal spermatic fascia and protrudes through the internal ring lateral to the cord. They are generally not visible by transperitoneal inspection unless manually reduced. Conclusions Lipomas of the cord and round ligament occur with a significant incidence. They can cause hernia-type symptoms in the absence of a true

  11. Solitary lipoma in the retromandibular region

    PubMed Central

    Shetty, Nandesh; Shabari, U B; Jaydeep, N A; Patnaik, Pritish

    2015-01-01

    Lipomas are the most common subcutaneous soft-tissue tumors. These are benign tumors originating from the adipocytes. They may be located in any part of the body and can be confused clinically with other soft tissue masses. They infrequently occur in the head and neck region. We present a case of solitary lipoma arising in the neck region that was reported to our division of oral and maxillofacial surgery. PMID:25767361

  12. Lipoma arborescens of the biceps tendon sheath.

    PubMed

    White, Eric A; Omid, Reza; Matcuk, George R; Domzalski, Jerome T; Fedenko, Alexander N; Gottsegen, Christopher J; Forrester, Deborah M; Patel, Dakshesh B

    2013-10-01

    Lipoma arborescens, described as lipomatous infiltration and distention of synovial villi resulting in a frond-like appearance, most frequently affects the suprapatellar recess of the knee. While there have been reports of this entity involving the upper extremity joints, bursa, and tendon sheaths, we present the first reported case of lipoma arborescens isolated to the biceps tendon sheath. We describe imaging and histologic findings with clinical correlation.

  13. Lipoma

    MedlinePlus

    ... N.Y.: The McGraw-Hill Companies; 2012. http://accessmedicine.mhmedical.com/book.aspx?bookid=392. Accessed Nov. ... N.Y.: The McGraw-Hill Companies; 2013. http://accessmedicine.mhmedical.com/book.aspx?bookId=682. Accessed Nov. ...

  14. Clinical evaluation of submucosal colonic lipomas: Decision making

    PubMed Central

    Tascilar, Oge; Cakmak, Güldeniz Karadeniz; Gün, Banu Dogan; Uçan, Bülent Hamdi; Balbaloglu, Hakan; Cesur, Ali; Emre, Ali Ugur; Comert, Mustafa; Erdem, Lütfü Oktay; Aydemir, Selim

    2006-01-01

    Even lipomas are the most common mesenchymal benign tumors of the gastrointestinal tract, symptomatic colonic presentation is rare. Herein, we evaluated four patients suffering from various size of colonic lipomas and approached by different therapeutic modalities. PMID:16937511

  15. A Rare Cause of Obstructive Sleep Apnea Syndrome: Retropharyngeal Lipoma

    PubMed Central

    Dilek, Okan; Yilmaz, Cengiz; Gulek, Bozkurt; Akin, Mehmet Ali

    2017-01-01

    Lipoma is the most common benign mesenchymal neoplasm. About 16% of lipomas arise in the head and neck region, especially in the posterior neck. Large lipomas that originate from the retropharyngeal space may cause dyspnea, dysphagia, and snoring and occasionally may lead to obstructive sleep apnea syndrome (OSAS). Herein, we report a 45-year-old male patient with OSAS caused by a giant retropharyngeal lipoma with emphasis on CT findings. PMID:28912996

  16. Computed tomography as a definitive method for diagnosing gastrointestinal lipomas

    SciTech Connect

    Heiken. J.P.; Forde, K.A; Gold, R.P.

    1982-02-01

    Four cases of gastrointestinal lipoma that were demonstrated by computed tomography (CT) are presented. Until now, definitive diagnosis of gastrointestinal lipomas has required fiberoptic endoscopy, biopsy, or surgical excision. The results of this study indicate that CT may become a definitive diagnostic examination for lipomas of the gastrointestinal tract.

  17. Pedunculated colonic lipoma prolapsing through the anus.

    PubMed

    Ghanem, Omar M; Slater, Julia; Singh, Puneet; Heitmiller, Richard F; DiRocco, Joseph D

    2015-05-16

    Colorectal lipomas are the second most common benign tumors of the colon. These masses are typically incidental findings with over 94% being asymptomatic. Symptoms-classically abdominal pain, bleeding per rectum and alterations in bowel habits-may arise when lipomas become larger than 2 cm in size. Colonic lipomas are most often noted incidentally by colonoscopy. They may also be identified by abdominal imaging such as computed tomography or magnetic resonance imaging. We report a case of a sixty-one years old male who presented to our emergency room with a 6.7 cm × 6.3 cm soft tissue mucosal mass protruding transanally. The patient was stable with a benign abdominal examination. The mass was initially thought to be a rectal prolapse; however, a limited digital rectal exam was able to identify this as distinct from the anal canal. Since the mass was irreducible, it was elected to be resected under anesthesia. At surgery, manipulation of the mass identified that the lesion was pedunculated with a long and thickened stalk. A laparoscopic linear cutting stapler was used to resect the mass at its stalk. Pathology showed a polypoid submucosal lipoma of the colon with overlying ulceration and necrosis. We report this case to highlight this rare but possible presentation of colonic lipomas; an incarcerated, trans-anal mass with features suggesting rectal prolapse. Trans-anal resection is simple and effective treatment.

  18. Pedunculated colonic lipoma prolapsing through the anus

    PubMed Central

    Ghanem, Omar M; Slater, Julia; Singh, Puneet; Heitmiller, Richard F; DiRocco, Joseph D

    2015-01-01

    Colorectal lipomas are the second most common benign tumors of the colon. These masses are typically incidental findings with over 94% being asymptomatic. Symptoms-classically abdominal pain, bleeding per rectum and alterations in bowel habits-may arise when lipomas become larger than 2 cm in size. Colonic lipomas are most often noted incidentally by colonoscopy. They may also be identified by abdominal imaging such as computed tomography or magnetic resonance imaging. We report a case of a sixty-one years old male who presented to our emergency room with a 6.7 cm × 6.3 cm soft tissue mucosal mass protruding transanally. The patient was stable with a benign abdominal examination. The mass was initially thought to be a rectal prolapse; however, a limited digital rectal exam was able to identify this as distinct from the anal canal. Since the mass was irreducible, it was elected to be resected under anesthesia. At surgery, manipulation of the mass identified that the lesion was pedunculated with a long and thickened stalk. A laparoscopic linear cutting stapler was used to resect the mass at its stalk. Pathology showed a polypoid submucosal lipoma of the colon with overlying ulceration and necrosis. We report this case to highlight this rare but possible presentation of colonic lipomas; an incarcerated, trans-anal mass with features suggesting rectal prolapse. Trans-anal resection is simple and effective treatment. PMID:25984520

  19. Peripheral nerve lipoma: Case report of an intraneural lipoma of the median nerve and literature review

    PubMed Central

    Teles, Alisson Roberto; Finger, Guilherme; Schuster, Marcelo N.; Gobbato, Pedro Luis

    2016-01-01

    Adipose lesions rarely affect the peripheral nerves. This can occur in two different ways: Direct compression by an extraneural lipoma, or by a lipoma originated from the adipose cells located inside the nerve. Since its first description, many terms have been used in the literature to mention intraneural lipomatous lesions. In this article, the authors report a case of a 62-year-old female who presented with an intraneural median nerve lipoma and review the literature concerning the classification of adipose lesions of the nerve, radiological diagnosis and treatment. PMID:27695575

  20. [An unusual case of massive funicular lipoma].

    PubMed

    Masciovecchio, Stefano; Saldutto, Pietro; Del Rosso, Alessandro; Galatioto, Giuseppe Paradiso; Vicentini, Carlo

    2014-01-01

    Intrascrotal lipomas are benign diseases that originate from adipose tissue inside the scrotal sac or constituting the scrotal wall itself. Paratesticular spermatic cord lipomas are a rare type of intrascrotal lipomas. A 78 years old patient in good health comes to our attention for massive tense-elastic swelling of left hemiscrotum appeared about 3 years ago and slowly increasing. Ultrasound evaluation of the intrascrotal mass showed inhomogeneous images mainly hyperechoic, not infiltrating the ipsilateral testis and scrotal wall. The ultrasonography found a lipomatous lesion with benign characteristics and a surgical excision has been performed. The lipomatous mass removed presented a size equal to 25 cm x 14 cm x 11 cm and a weight of about 490 gr. The microscopic examination of the tissue showed only the presence of mature adipocytes in the absence of cellular atypia, of other cellular types and of vascular abnormalities.

  1. Lipoma of the Palate: An Uncommon Finding

    PubMed Central

    Volpato, Luiz Evaristo Ricci; Vasconcelos, Artur Cunha; Lambert, Nayane Assis; de Souza Castro, Paulo Henrique; Aburad, Arlindo; Borges, Alvaro Henrique

    2016-01-01

    Background: Lipoma is a benign neoplasm originated from adipose cells circumscribed by connective tissue. This neoplasm represents about 1% to 4.4% of all oral benign tumors and it is rarely located in the palate area. Objective: This case reports the occurrence of an oral lipoma in the hard palate of a 57-year-old woman and discusses its etiology and treatment. Case Report: The treatment consisted in the total resection of the lesion and laser therapy. The patient is being followed up for forty three months with no signs of recurrence. Conclusion: Lipoma in hard palate is a rare entity that may be associated with endocrine factors and local inflammation. PMID:28077968

  2. Treatment of lipoma by injection lipolysis.

    PubMed

    Nanda, Soni

    2011-05-01

    Injection lipolysis or lipodissolve is the practice of injecting phosphatidyl choline/ sodium deoxycholate (PDC/DC) compounds in the subcutaneous fat. Though this practice is being used extensively for nonsurgical contouring of body and dissolving localized collections of excess fat, it's use as a treatment modality for lipomas needs further evaluation. We present a case where this technique was used for treating a lipoma, with no recurrence after 9 months of follow up. Injection lipolysis as a treatment modality for lipomas needs to be evaluated for safety and efficacy in trials on larger population. This could prove to be a very valuable adjunct to the current practice of excision, if done by a trained person in a properly selected patient. Also the side effects and the controversies regarding this procedure have been discussed in detail in the present paper.

  3. Symptomatic subserosal gastric lipoma successfully treated with enucleation.

    PubMed

    Krasniqi, Avdyl-Selmon; Hoxha, Faton-Tatil; Bicaj, Besnik-Xhafer; Hashani, Shemsedin-Isuf; Hasimja, Shpresa-Mehmet; Kelmendi, Sadik-Mal; Gashi-Luci, Lumturije-Hasan

    2008-10-14

    Gastric lipomas are rare tumors, accounting for 2%-3% of all benign gastric tumors. They are of submucosal or extremely rare subserosal origin. Although most gastric lipomas are usually detected incidentally, they can cause abdominal pain, dyspeptic disorders, obstruction, invagination, and hemorrhages. Subserosal gastric lipomas are rarely symptomatic. There is no report on treatment of subserosal gastric lipomas in the English literature. We present a case of a 50-year-old male with symptomatic subserosal gastric lipoma which was successfully managed with removal, enucleation of lipoma, explorative gastrotomy and edge resection for histology check of gastric wall. The incidence of gastric lipoma, advanced diagnostic possibilities and their role in treatment modalities are discussed.

  4. Intraosseous lipoma of the iliac: case report☆

    PubMed Central

    de Moraes, Frederico Barra; Paranahyba, Rodrigo Marques; do Amaral, Rogério Andrade; Bonfim, Vinícius Mendes; Jordão, Nathalya Ducarmo; Souza, Raimundo Djalma

    2016-01-01

    Lipomas are benign tumors that attack fat cells and most often affecting soft tissues in adulthood. On rare occasions, they may affect bones, preferentially the metaphyses of the long bone. They are generally asymptomatic and radiography shows radiolucent lesions with a thin sclerotic rim or radiodense lesions with a thick sclerotic rim. Malignant transformation of these tumors is rare, as is their recurrence, and there is no need for surgery in most cases. In this report, we present a rare case of intraosseous lipoma in the iliac bone. PMID:26962507

  5. Lipoma of the larynx: a case report

    PubMed Central

    De Vincentiis, M; Greco, A; Mascelli, A; Soldo, P; Zambetti, G

    2010-01-01

    Summary Lipoma is a benign tumour of mesenchymal origin with a very rare occurrence in the upper aero-digestive tract. To date, approximately 100 cases have been described in the literature. This lesion has a slow growth and, therefore, can present with various symptoms due to the mass effect with obstruction and compression on neighbouring structures, including dysphagia for liquid and solid food, dyspnoea and hoarseness. For a precise pre-operative diagnosis, indirect or direct laryngoscopy (flexible fibre-optic laryngoscopy) can be employed or, if necessary, also imaging techniques such as computed tomography scan and magnetic resonance imaging scan. These offer more useful information for better treatment planning. Surgery is the treatment of choice and includes endoscopic techniques and an external surgical approach (cervicotomy). It is very important to completely remove these benign neoplasms in order to avoid local recurrence. The present report refering to a case of laryngeal lipoma removed through an external surgical approach, aims to demonstrate that the choice of an external surgical approach is required for complete surgical removal of a large lipoma in order to prevent any possible recurrence. Furthermore, it is useful to keep in mind the possibility of recurrence of lipomas after long free intervals; therefore, it is mandatory to observe these patients at long-term follow-up. PMID:20559475

  6. A rare presentation of lipoma on mandibular mucogingival junction

    PubMed Central

    Sharma, Gaurav; Jain, Kanu; Nagpal, Archna; Baiju, Chandrababu Sudha

    2016-01-01

    Lipoma is the most common tumor of mesenchymal tissues of body, but its occurrence in oral cavity is infrequent. Buccal mucosa is the most common intraoral site of lipoma followed by tongue, floor of the mouth, and buccal vestibule. The involvement of mucogingival junction is rare. We present a unique case report of oral lipoma occurring on mandibular mucogingival junction with review of literature which has emphasis on differential diagnosis. PMID:27143835

  7. Intrasynovial lipoma causing trigger wrist and carpal tunnel syndrome.

    PubMed

    Imai, Shinji; Kodama, Narihito; Matsusue, Yoshitaka

    2008-01-01

    Triggering of the flexor tendon at the wrist is rare. We report a case of intrasynovial lipoma that caused a trigger wrist. As far as we know it is unique in that the intrasynovial lipoma simultaneously caused carpal tunnel syndrome. The massive tenosynovitis and adhesion of flexors tendons after the locking of the intrasynovial lipoma may have resulted from inflammation caused by attrition within the carpal tunnel.

  8. Co-existence of intramuscular spindle cell lipoma with an intramuscular ordinary lipoma:report of a case.

    PubMed

    Laliotis, Aggelos; De Bree, Eelco; Vasilaki, Stavrianthi; Papadakis, Michael; Melissas, John

    2013-10-01

    Spindle cell lipoma is a relatively rare adipocytic neoplasm, which usually occurs in the posterior neck, shoulder or upper back of male patients aged 45-65 years. We report here an unusual coexistence of ordinary and spindle cell lipoma. The patient presented with a painless mass in the area of the right scapula. Imaging was suggestive of a lipomatous mass, possibly liposarcoma. Histological examination revealed the concurrent existence of an intramuscular spindle cell lipoma and an ordinary lipoma. In the literature there are only fourteen cases of intramuscular spindle cell lipoma and only in four cases there was a coexisting mature lipoma. As exclusion of malignancy remains clinicians main concern,diagnosis and treatment of deep seated lipomatous tumors remains challenging.

  9. Spindle cell lipoma in a 14-month-old girl.

    PubMed

    Diau, G Y; Chu, C C; Chou, G S; Tsao, T Y

    1995-11-01

    This case report concerns a girl with spindle cell lipoma of the neck. Spindle cell lipoma is a variant of lipomas and was first described by Enzinger and Harvey in 1975. It occurs chiefly in males between 40 and 70 years of age. It is a benign lesion that can be cured by excision, and local recurrence is rare. Spindle cell lipoma is composed of adipocytes and non-fat-storing immature mesenchymal cells. The condition is uncommon in adults and had not been reported to occur in children.

  10. Gastric lipoma: an unusual cause of dyspeptic symptoms.

    PubMed

    Nasa, Mukesh; Choksey, Ajay; Phadke, Aniruddha; Sawant, Prabha

    2016-06-22

    Gastric lipomas are rare tumours accounting for 2-3% of all benign gastric tumours. These are usually submucosal in origin but in rare cases may be subserosal in origin. Although a majority of gastric lipomas are asymptomatic and usually detected incidentally, occasionally these can cause abdominal pain, dyspeptic disorders, obstruction, invagination and haemorrhages. In the literature, only 200 cases of gastric lipomas have been reported so far. We report a case of a 56-year-old female with a submucosal symptomatic gastric lipoma presenting with disabling dyspeptic symptoms. 2016 BMJ Publishing Group Ltd.

  11. Duodenal Lipoma as a Rare Cause of Upper Gastrointestinal Bleeding.

    PubMed

    Ouwerkerk, Helga M; Raber; Freling, G; Klaase, J M

    2010-12-01

    A 52-year-old female was referred because of melaena. After initital work-up, including gastroduodenoscopy, endosonography and CT scan, a duodenotomy was performed. Definite diagnosis was a duodenal lipoma based on histological findings. Lipomas of the gastrointestinal tract are rare. Only 4% occur in the duodenum. The peak incidence is around the 5th and 7th decade of life, with a slight female preponderance. Gastrointestinal lipomas are usually asymptomatic, but can present with mild to severe gastrointestinal bleeding, intussusceptions, abdominal pain, constipation and diarrhea. Clinical, endoscopical, surgical, and radiological features are described in this case of duodenal lipoma.

  12. Duodenal Lipoma as a Rare Cause of Upper Gastrointestinal Bleeding

    PubMed Central

    Ouwerkerk, Helga M.; Raber; Freling, G.; Klaase, J.M.

    2010-01-01

    A 52-year-old female was referred because of melaena. After initital work-up, including gastroduodenoscopy, endosonography and CT scan, a duodenotomy was performed. Definite diagnosis was a duodenal lipoma based on histological findings. Lipomas of the gastrointestinal tract are rare. Only 4% occur in the duodenum. The peak incidence is around the 5th and 7th decade of life, with a slight female preponderance. Gastrointestinal lipomas are usually asymptomatic, but can present with mild to severe gastrointestinal bleeding, intussusceptions, abdominal pain, constipation and diarrhea. Clinical, endoscopical, surgical, and radiological features are described in this case of duodenal lipoma. PMID:27942311

  13. Classic tongue lipoma: a common tumour at a rare site

    PubMed Central

    Magadum, Dilip; Sanadi, Appasab; Agrawal, Jiwanasha Manish; Agrawal, Manish Suresh

    2013-01-01

    Lipoma is the commonest benign tumour occurring at any anatomical site where fat is present, but occurrence in the oral cavity is rare. Tongue which is totally devoid of fat cells is a rare site for lipoma. This is one such rare case of the universal tumour, presenting at the lateral margin of the tongue, for which complete tumour excision was done. Macroscopically the mass had a hard consistency and measured 3.0×2.0 cm. From microscopic examination, diagnosis of lipoma was made. Recurrence of tongue lipoma is rare. PMID:23370950

  14. Delayed intramedullary abscess in operated case of spinal lipoma

    PubMed Central

    Bhaisora, Kamlesh Singh; Godbole, Chaitanya; Das, Kuntal Kanti; Mehrotra, Anant; Jayesh, Shardhara; Sahu, Rabi Narayan; Behari, Sanjay; Srivastava, Arun Kumar; Jaiswal, Awadhesh Kumar

    2016-01-01

    Intramedullary abscess is a rare condition with high rate of mortality and morbidity. We are presenting a case of delayed intramedullary abscess in an operated case of spinal lipoma, after 2 years of primary surgery. To best of our knowledge this only second case of intramedullary abscess in a case of spinal lipoma without dermal sinus. PMID:27857795

  15. Giant Esophageal Lipoma as an Uncommon Cause of Diverticula

    PubMed Central

    Yekeler, Erdal; Yazicioglu, Alkin; Subasi, Mahmut; Boztepe, Hacer

    2016-01-01

    Esophageal lipoma is an uncommon benign tumor of the esophagus and accounts for only 0.4% of all benign neoplasms of the gastrointestinal system. The majority of these are located in the cervical part; only very few are located in the lower third of the esophagus. We discuss the case of a 37-year-old female who presented with dysphagia and an esophageal lipoma located in the lower third of the esophagus. The patient underwent right mini-thoracotomy and enucleation of lipoma. Histopathologic examination revealed adipose tissue with a collection of matured adipose tissue. We present the case because of the atypical localization of an esophageal lipoma and development of a diverticulum, which was caused by the lipoma and required an additional surgical procedure. PMID:27721731

  16. Fat Free Pleomorphic Lipoma of Oral Cavity: A Rare Entity.

    PubMed

    Ranganathan, Kannan; Mathew, Seema Alice; Sreena, Nellimad Sreedharan; Lavanya, Nagarajan

    2017-03-01

    Pleomorphic lipoma is a rare, benign, soft tissue neoplasm that characteristically occurs as a subcutaneous mass in the posterior neck or upper back and rarely in the tonsillar fossa and oral cavity. Histologically, pleomorphic lipoma contains varying amounts of mature fat, areas of spindle and pleomorphic cells, floret giant cells and thick rope - like collagen in a myxoid stroma. Pleomorphic lipoma with scanty fatty elements is called the fat free variant of pleomorphic lipoma. The combination of meagre amount of fat and presence of pleomorphic elements gives a pseudosarcomatous picture under the microscope leading to misdiagnosis and over treatment. Here, we report a case of fat free pleomorphic lipoma, first of its kind in the oral cavity and discuss the diagnostic features and differential diagnosis.

  17. Interhemispheric Lipoma, Callosal Anomaly, and Malformations of Cortical Development: A Case Series.

    PubMed

    Niwa, Tetsu; de Vries, Linda S; Manten, Gwendolyn T R; Lequin, Maarten; Cuppen, Inge; Shibasaki, Jun; Aida, Noriko

    2016-04-01

    Intracranial lipomas are rare congenital malformations. The most common type of intracranial lipoma is the interhemispheric lipoma, which is frequently associated with callosal anomalies such as hypogenesis or agenesis of the corpus callosum. In contrast, interhemispheric lipomas are less often accompanied with malformations of cortical development (MCD). We report magnetic resonance imaging findings of three infants with an interhemispheric lipoma, associated with a callosal anomaly, and MCD: two infants with nodular interhemispheric lipoma, agenesis of the corpus callosum, and polymicrogyria, and one infant with interhemispheric curvilinear lipoma, hypoplasia of the corpus callosum, and heterotopias. An association was suggested regarding the occurrence of these malformations.

  18. Clinical and radiological aspects of cerebellopontine neurinoma presenting with recurrent spontaneous bleedings.

    PubMed

    Maimone, Giuseppe; Giuseppe, Maimone; Ganau, Mario; Mario, Ganau; Nicassio, Nicola; Nicola, Nicassio; Cambria, Mauro; Mauro, Cambria

    2013-01-01

    Neurinomas are benign, usually encapsulated, tumors growing in peripheral nerve sheath with a high incidence in the cerebellopontine angle. We report a case of vestibular neurinoma (VN) with a "biphasic" pattern of intratumoral hemorrhage presenting with cephalalgia along with progressive ipsilateral mild impairment of both VII and VIII cranial nerves. A thorough preoperative magnetic resonance imaging study better characterized the patchy pattern of the round shaped lesion, resulting in three different intensity signals, due to the peculiar characteristics of the tumoral mass and the recurrent bleedings, respectively. Postoperatively, histological examination confirmed the diagnosis of neurinoma. Hemorrhagic VN are rare tumors; from the first case described in 1974 only 43 more have been reported in the literature so far. Noteworthy, "biphasic" bleedings are even rarer. From an accurate review of the literature we collected and thus emphasized the radiological and clinical features of this rare entity. Eventually, we suggest that the early surgical removal of clots and tumor is essential to provide the best chance of neurological improvement.

  19. Atypical spindle cell lipoma: a clinicopathologic, immunohistochemical, and molecular study emphasizing its relationship to classical spindle cell lipoma.

    PubMed

    Creytens, David; van Gorp, Joost; Savola, Suvi; Ferdinande, Liesbeth; Mentzel, Thomas; Libbrecht, Louis

    2014-07-01

    We studied a series of spindle cell lipomas arising in atypical sites and showing unusual morphologic features (which we called atypical spindle cell lipoma) to assess if these lesions have the same chromosomal alterations as classical spindle cell lipoma but different from those found in atypical lipomatous tumor/well-differentiated liposarcoma. We investigated alterations of different genes in the 13q14 region and the amplification status of the MDM2 and CDK4 genes at 12q14-15 by multiplex ligation-dependent probe amplification (MLPA) and fluorescence in situ hybridization (FISH) analysis. In the atypical spindle cell lipomas, MLPA revealed deletions in the two nearest flanking genes of RB1 (ITM2B and RCBTB2) and in multiple important exons of RB1. In contrast, in classical spindle cell lipomas, a less complex loss of RB1 exons was found but no deletion of ITM2B and RCBTB2. Moreover, MLPA identified a deletion of the DLEU1 gene, a finding which has not been reported earlier. We propose an immunohistochemical panel for lipomatous tumors which comprises of MDM2, CDK4, p16, Rb, which we have found useful in discriminating between atypical or classical spindle cell lipomas and other adipocytic neoplasms, especially atypical lipomatous tumor/well-differentiated liposarcoma. Our findings strengthen the link between atypical spindle cell lipoma and classical spindle cell lipoma, and differentiate them from atypical lipomatous tumor/well-differentiated liposarcoma.

  20. An intraosseous lipoma of the calcaneus: a case report.

    PubMed

    Pappas, Alexander J; Haffner, Kyle E; Mendicino, Samuel S

    2014-01-01

    Intraosseous lipomas are one of the rarest bone tumors found in the body. The incidence has been reported to be <0.1% of all primary bone tumors. The differential diagnoses of an intraosseous lipoma in the calcaneus include plantar fasciitis, retrocalcaneal bursitis, gout, stress fracture, unicameral bone cyst, aneurysmal bone cyst, osteoblastoma, enchondroma, chondromyxoid fibroma, nonossifying fibroma, giant cell tumor, chondroblastoma, fibrous dysplasia, and chondrosarcoma. It has been reported that 60% to 70% of patients with an intraosseous lipoma present with symptoms. This article describes a case of a pathologic fracture secondary to a large intraosseous lipoma, the surgical treatments, and the subsequent resolution of symptoms. The purpose of our report was 3-fold: (1) to increase awareness of intraosseous lipomas and their potential to cause pathologic fractures in the calcaneus; (2) to suggest a possible treatment protocol for intraosseous lipomas in the calcaneus; and (3) to describe a rare case of an intraosseous lipoma of the calcaneus not located exclusively in the neutral triangle.

  1. [Giant mesenteric lipoma in children: A case-report].

    PubMed

    Hida, M; Azahouani, A; Elazzouzi, D

    2017-03-27

    Mesenteric lipoma is an extremely rare disease in children. Fewer than 50 cases have been reported in the literature. Diagnosis is based on clinical examination, ultrasound, and computed tomography (CT). However, only the histological study of the specimen during laparotomy or laparoscopy can confirm the diagnosis. Thus, surgery, be it by laparotomy or laparoscopic, is both a means of exploration and treatment in mesenteric lipoma. We report on a case of giant lipoma of the mesentery in a 7-year-old girl presenting paroxysmal abdominal pain with a subocclusive syndrome lasting 1 week.

  2. Como Lo Hago Yo: Lipomas Medulares

    PubMed Central

    Portillo, Santiago

    2014-01-01

    Basados en la experiencia de 82 casos; en 5% se observaron anomalías pélvicas asociadas. En los menores de 3 años el motivo de consulta (85%) fue la tumoración. En los mayores de 3 años (42%) tenía problemas neurológicos. Solo el 24% preocupados por la tumoración. El objetivo de la cirugía es desanclar la médula y no remover la totalidad del lipoma. El lipoma de filum es el que es mas simple para operar. Aún cuando la escuela francesa propone operar solamente cuando hay síntomas favorezco cirugía preventiva. Favorezco una segunda cirugía si hay signos de anclaje postoperatorio, aún cuando observamos empeoramiento postoperatorio motor en 2.5% de los operados y urológico a largo plazo en 6% de los operados. PMID:24791218

  3. Infiltrating intramuscular spindle cell lipoma of the face.

    PubMed

    Mandal, Rajni V; Duncan, Lyn M; Austen, William G; Nielsen, G Petur

    2009-10-01

    Spindle cell lipoma is a benign lipomatous tumor, which usually arises on the back of the neck, shoulder or upper back of males in the third to seventh decade of life. We report herein an unusual infiltrating intramuscular spindle cell lipoma arising in the nose of a 53-year-old man. The patient presented with a 0.5-cm 'cyst' of the nose, just above the right alar crease, which was removed. Four years later, the lesion recurred and was re-excised. Histologically, a proliferation of mature adipocytes, ropey collagen fibers and spindle cells within a myxoid stroma was present in the subcutaneous tissue and infiltrated between skeletal muscle fibers. Nine cases of intramuscular spindle cell lipoma with histological examination have previously been reported and have involved the oral cavity and muscles of the extremities. To our knowledge, this is the first report of an infiltrating intramuscular spindle cell lipoma arising on the face.

  4. Ohtahara syndrome associated with hemimegalencephaly and intracranial lipoma

    PubMed Central

    Gowda, Vykuntaraju K.; Bhat, Ashwini; Bhat, Maya; Ramaswamy, Premalatha

    2015-01-01

    Hemimegalencephaly is a disorder of cortical malformation and is associated with various disorders including various neurocutaneous syndromes and many seizure types. We present a case of hemimegalencephaly associated with Ohtahara syndrome and intracranial and facial lipoma. PMID:26167232

  5. Ohtahara syndrome associated with hemimegalencephaly and intracranial lipoma.

    PubMed

    Gowda, Vykuntaraju K; Bhat, Ashwini; Bhat, Maya; Ramaswamy, Premalatha

    2015-01-01

    Hemimegalencephaly is a disorder of cortical malformation and is associated with various disorders including various neurocutaneous syndromes and many seizure types. We present a case of hemimegalencephaly associated with Ohtahara syndrome and intracranial and facial lipoma.

  6. Heel lipoma mimicking plantar fasciitis in a ballroom dancer.

    PubMed

    Taweel, Nicholas R; Raikin, Steven M

    2015-01-01

    The present case illustrates a lipoma as an unusual cause of heel pain. A 64-year-old female ballroom dancer presented with 8 months of pain that was unresponsive to previous treatment of plantar fasciitis. Magnetic resonance imaging revealed a heel lipoma. Her pain was fully resolved after surgical excision. Soft tissue tumors should be included in the differential diagnosis of heel pain, especially when symptoms and treatment response do not follow the typical course of plantar fasciitis.

  7. Renal cell carcinoma metastasis to the cerebellopontine cistern: intraoperative Onyx embolization via direct needle puncture

    PubMed Central

    Johnson, Jeremiah; Morcos, Jacques; Elhammady, Mohamed; Pao, Christine L; Aziz-Sultan, Mohammad Ali

    2013-01-01

    We report a rare case of a renal cell carcinoma (RCC) metastasis occupying the cerebellopontine and cerebellomedullary cisterns, and describe an alternative strategy for embolizing hypervascular intracranial tumors. A middle aged patient with a distant history of RCC presented with headaches, nausea, and vomiting, and was found to have an enhancing mass in the left cerebellopontine and cerebellopontine cisterns. The initial surgical resection was aborted due to excessive bleeding. After an unsuccessful attempt at intra-arterial embolization, the patient returned to the operating room and the tumor was devascularized by direct needle puncture Onyx embolization under biplane fluoroscopy. The devascularized tumor was then successfully dissected from the brainstem and adherent lower cranial nerves. In properly selected cases, open surgical direct needle puncture embolization of intracranial vascular tumors under biplane fluoroscopy is a viable alternative devascularization method. PMID:24347447

  8. Cytogenetic Analysis of a Pseudoangiomatous Pleomorphic/Spindle Cell Lipoma.

    PubMed

    Panagopoulos, Ioannis; Gorunova, Ludmila; Lobmaier, Ingvild; Andersen, Hege Kilen; Bjerkehagen, Bodil; Heim, Sverre

    2017-05-01

    Pseudoangiomatous pleomorphic/spindle cell lipoma is a rare subtype of pleomorphic/spindle cell lipoma. Only approximately 20 such tumors have been described. Genetic information on pseudoangiomatous pleomorphic/spindle cell lipoma is restricted to a single case in which deletion of the forkhead box O1 (FOXO1) gene was found, using fluorescence in situ hybridization (FISH). G-banding and FISH analyses were performed on a pseudoangiomatous pleomorphic/spindle cell lipoma. G-banding of tumor cells showed complex karyotypic changes including loss of chromosome 13. FISH analysis revealed that the deleted region contained the RB1 gene (13q14.2) and the part of chromosome arm 13q (q14.2-q14.3) in which spans the TRIM13 gene, the two non-coding RNA genes, DLEU1 and DLEU2, and the genetic markers RH44686 and D13S25. Several acquired genomic aberrations were found in the tumor. Among them was loss of chromosome 13 material. Results confirm the (cyto)genetic similarity between pseudoangiomatous pleomorphic/spindle cell lipoma and spindle cell lipomas. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  9. [Episacral lipoma: a treatable cause of low back pain].

    PubMed

    Erdem, Hatice Rana; Nacır, Barış; Özeri, Zuhal; Karagöz, Aynur

    2013-01-01

    Episacral lipoma is a small, tender subcutaneous nodule primarily occurring over the posterior iliac crest. Episacral lipoma is a significant and treatable cause of acute and chronic low back pain. Episacral lipoma occurs as a result of tears in the thoracodorsal fascia and subsequent herniation of a portion of the underlying dorsal fat pad through the tear. This clinical entity is common, and recognition is simple. The presence of a painful nodule with disappearance of pain after injection with anaesthetic, is diagnostic. Medication and physical therapy may not be effective. Local injection of the nodule with a solution of anaesthetic and steroid is effective in treating the episacral lipoma. Here we describe 2 patients with painful nodules over the posterior iliac crest. One patient complained of severe lower back pain radiating to the left lower extremity and this patient subsequently underwent disc operation. The other patient had been treated for greater trochanteric pain syndrome. In both patients, symptoms appeared to be relieved by local injection of anaesthetic and steroid. Episacral lipoma should be considered during diagnostic workup and in differential diagnosis of acute and chronic low back pain.

  10. Surgical Removal of lipoma from an area with tattooed skin

    PubMed Central

    Inchingolo, Francesco; Tatullo, Marco; Abenavoli, Fabio M.; Marrelli, Massimo; Inchingolo, Alessio D.; Corelli, Roberto; Servili, Andrea; Inchingolo, Angelo M.; Dipalma, Gianna

    2010-01-01

    The presence of tattoos on the skin of people of all ages is on the rise. On occasion, the tattoo is in close proximity to an area which has to undergo a surgical operation, therefore why not using the tattoo itself to cover the cicatrix? The case we treated was that of a 39 year old female who, for a couple of years, had a large lipoma on her right shoulder which she never treated because it was beneath a large tattoo. During the surgical treatment of the lipoma, we followed the exact lines of the tattoo itself thus obtaining precise access for lipoma removal which minimized visible post operative cicatrix while maintaining the original tattoo design. No similar case was found in literature. PMID:21103075

  11. [Deep muscular lipoma of the shoulder. Apropos of 4 cases].

    PubMed

    Le Huec, J C; Leger, O; Schaeverbeke, T; Moinard, M; Rupp, L; Le Rebeller, A

    1996-01-01

    The authors report 4 cases of inter and intra-muscular lipoma of the shoulder and make a review of the diagnosis of this localization. All 4 cases had shoulder pain and some limitation of shoulder motion, one had hypoesthesia on the lateral side of the arm. 3 had magnetic resonance imaging (MRI) and two ultrasonography examination, three of them had a surgical resection and for one surgery was considered too aggressive and had a MRI control one year later. There was no problem for the surgical procedure and the histology confirmed the diagnosis. The last patient had a rehabilitation program and the MRI control showed lesion stability. Lipoma are rare, X-rays, ultra-sonography and CT scans are not sufficient, MRI is the best exploration to differentiate lipoma and lipo-sarcoma, but the main problem is for low grade sarcoma. Histology is the only way to make the diagnosis with the whole tumor.

  12. Successful bronchoscopic cryorecanalization in a case of endobronchial lipoma.

    PubMed

    Lamprecht, B; Hutarew, G; Porsch, P; Wegleitner, B; Studnicka, M

    2011-01-01

    Endobronchial lipomas are rare benign tumors; less than 150 cases have been reported so far. Bronchial occlusion usually leads to a misdiagnosis of asthma/COPD or malignancy. We report the case of a 67-year-old man with a history of heavy smoking (100 pack years), dyspnea on exertion, cough, and malaise who was treated for pneumonia for three weeks. Due to nonresolving atelectasis of the superior segment of the right lower lobe, a malignant endobronchial tumor was suspected. Rigid bronchoscopy with cryorecanalization led to both the definite histopathological diagnosis of endobronchial lipoma and the reopening of an endoluminal airway obstruction during one procedure.

  13. Transanal resection of a colonic lipoma, mimicking rectal prolapse.

    PubMed

    Tzilinis, Argyrios; Fessenden, John M; Ressler, Kristie M; Clarke, Leon E

    2003-01-01

    Colonic lipomas are benign tumors usually asymptomatic. Occasionally, they may cause symptoms such as bleeding, intussusception, obstruction, or rectal prolapse. We present a 44-year-old African-American female that presented with an 8 cm colonic lipoma protruding through the anal verge. We also reviewed all the reported cases in the English literature. The patient was treated successfully with transanal resection, which has rarely been done before for this large a tumor. Transanal resection of large benign tumors of the rectosigmoid is possible.

  14. Poland syndrome associated with ipsilateral lipoma and dextrocardia.

    PubMed

    Li, Wenya; Zhang, Lin; Zhang, Qigang; Du, Jiang; Zhang, Shuguang; Liu, Xiangli

    2011-12-01

    A 22-year-old man was admitted with a rapidly enlarging soft mass on the left chest wall, which was diagnosed as lipoma by postoperative pathology. A chest roentgenogram revealed a defect of the fourth rib, scoliosis, dextrocardia, and diaphragmatic hernia. A computed tomographic scan showed maldevelopment of the pectoralis major and minor muscles. This is the first reported case of Poland syndrome with ipsilateral lipoma of the chest wall. Dextrocardia associated with Poland syndrome may be considered dextroposition, rather than a dextroinversion, and it may arise as a result of Poland syndrome. Copyright © 2011 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  15. Management of seventh and eighth nerve involvement by cerebellopontine angle tumors.

    PubMed

    Samii, M; Turel, K E; Penkert, G

    1985-01-01

    Microsurgical techniques have made a significant contribution in the advancement of surgery. Since then, the field of neurosurgery has made great and rapid strides. Neurosurgeons now venture through the deep and delicate regions of the brain where they dared not venture only a few years ago. In particular, the morbidity and mortality of surgery in the CPA has seen a progressive decrease. This presentation deals with 200 consecutive tumors in the CPA operated on using microsurgical techniques during the last 6 years. One hundred sixty-seven (83.5%) of them were acoustic neuromas (which included 12 patients with bilateral tumors). Of the remaining 33, there were 21 meningiomas, 10 epidermoids, and 2 angioblastomas. Preoperative investigation has been aimed at arriving at a diagnosis which is as exact as possible in order to plan the operative strategy. All patients, ranging in age from 16 to 84, have been operated upon in the lounging position (with the necessary precautions) through a unilateral suboccipital craniectomy. The basic surgical technique, irrespective of the tumor, is to decompress it from within in order to relieve its tension and pressure on surrounding nerves, vessels, and the brain stem. The structures which are only compressed are spontaneously relieved of compression. This helps define their full anatomic course. Having been identified, they are protected from damage. The most adherent points between tumor and nerves are recognized and handled last under direct vision when there is sufficient space to allow manipulation of the tumor. In the rare event of the facial nerve being interrupted, nerve graft procedures are attempted during the same operation. Our experience with the technique of intracranial-intratemporal facial nerve grafting has yielded excellent results. The cochlear nerve lacks a Schwann cell cover in the CPA and is more prone to being affected, either by tumor processes or surgical manipulation. Of our 167 acoustic nerve tumors, 60% were larger than 3 cm in diameter. The two important factors with regard to predicting the preservation of the seventh and eighth cranial nerves are tumor size (less than 3 cm) and preoperative hearing loss (less than 40 dB). The preservation of facial nerve function after tumor removal was achieved in 87.8% of patients. The facial nerve was preserved in all patients with other tumors. With regard to hearing ability the overall result of preservation of function was achieved in 27.6%. However, when a low hearing loss (less than 40 dB) and small tumor size (less than 3 cm) are taken into account, the preservation was as high as 58%.(ABSTRACT TRUNCATED AT 400 WORDS)

  16. Differential Diagnosis of Parotid Lipoma in a Breast Ca Patient

    PubMed Central

    2017-01-01

    Lipomas are common benign tumors usually detected on the torso, neck, upper thighs, and upper arms. However, they are rarely found in the parotid gland region. Because of their rarity at this site, they are not often considered in the differential diagnosis of parotid tumors. This report describes a rare case of a lipoma in the superficial lobe of parotid gland. A 71-year-old female patient admitted to our department complaining about swelling and pain in the posterior area of the left mandibular region since one month. Her medical history included mastectomy after breast CA fifteen years ago. Clinical examination revealed a smooth-surfaced, soft, and painful mass, with well-defined margins in the left mandibular region. Differential diagnosis of metastasis, inflammatory neck swellings, and benign salivary gland tumors were considered for the patient. Advanced imaging methods such as ultrasonography and contrast tomography revealed that the lesion was a lipoma of parotid gland. A surgical intervention under general anesthesia was planned for the removal of the mass; however patient refused the surgical treatment. Patient was placed on six-month periodic recall. This article reviews the radiographic appearance and differential diagnoses of lipoma in this rare location. PMID:28255469

  17. Gene expression and single nucleotide polymorphism array analyses of spindle cell lipomas and conventional lipomas with 13q14 deletion.

    PubMed

    Bartuma, Hammurabi; Nord, Karolin H; Macchia, Gemma; Isaksson, Margareth; Nilsson, Jenny; Domanski, Henryk A; Mandahl, Nils; Mertens, Fredrik

    2011-08-01

    Spindle cell lipomas (SCL) are circumscribed, usually s.c. tumors that typically occur on the posterior neck, shoulder, and back of middle aged men. Cytogenetically, almost all SCL are characterized by deletions of chromosome arm 13q, often in combination with loss of 16q. Deletions of 13q are seen also in approximately 15% of conventional lipomas. Through single nucleotide polymorphism (SNP) array analyses, we identified two minimal deleted regions (MDR) in 13q14 in SCL. In MDR1, four genes were located, including the tumor suppressor gene RB1. MDR1 in SCL overlapped with the MDR detected in conventional lipomas with 13q14 deletion. In MDR2 in SCL there were 34 genes and the two microRNA (miRNA) genes miR-15a and miR-16-1. Global gene expression analysis was used to study the impact of the deletions on genes mapping to the two SCL-associated MDR. Five genes (C13orf1, DHRS12, ATP7B, ALG11, and VPS36) in SCL and one gene (C13orf1) in conventional lipomas with 13q-deletions were found to be significantly underexpressed compared with control tissues. Quantitative real-time PCR showed that miR-16-1 was expressed at lower levels in SCL than in the control samples. No mutations were found at sequencing of RB1, miR-15a, and miR-16-1. Our findings further delineate the target region for the 13q deletion in SCL and conventional lipomas and show that the deletions are associated with down-regulated expression of several genes, notably C13orf1, which was the only gene to be significantly down-regulated in both tumor types. Copyright © 2011 Wiley-Liss, Inc.

  18. Lipoma of corpus callosum associated with dysraphic lesions and trisomy 13

    SciTech Connect

    Wainwright, H.; Bowen, R.; Radcliffe, M.

    1995-05-22

    We report on a further case of corpus callosal lipoma and frontal cranial defects. Most cases in the literature of corpus callosal lipoma in association with {open_quotes}dysraphic{close_quotes} lesions have been frontal in location. Malformation of the corpus callosum is said to be associated with 50% of these lipomas. Trisomy 13 was confirmed by the 13q14 cosmid probe on paraffin-embedded liver tissue. 19 refs., 5 figs.

  19. Intraosseous Lipoma of the Mandibula: A Case Report and Review of the Literature

    PubMed Central

    Waśkowska, Jadwiga; Wójcik, Sylwia; Koszowski, Rafał; Drozdzowska, Bogna

    2017-01-01

    Abstract Lipoma is a benign tumour originating from mature adipose tissue. It can occur in any place in the body where adipose tissue is located. Intraosseous lipoma is a very rare bone tumour. The authors present an infrequent case involving intraosseous lipoma of the mandible in a 32-year old man and provide a review of case studies documented earlier in the literature. PMID:28401200

  20. Lipoma of the cheek presenting with recurrent sialadenitis of the right parotid gland: a case report.

    PubMed

    Tom, Osundwa; Tom, Ochola

    2016-11-03

    Lipomas are benign neoplasms arising from adipose tissue. Oral lipomas have been reported in the buccal mucosa, tongue, floor of the mouth and lips; however, the case of a lipoma occurring as an antecedent lesion to recurrent sialadenitis is hitherto unreported in the English literature. We report the case of an intraoral lipoma occurring with signs and symptoms of recurrent sialadenitis in a 15-year-old Kenyan girl of Kikuyu descent. The lipoma was antecedent leading to partial obstruction and stasis related to the right Stensen's duct culminating in recurrent sialadenitis of the ipsilateral parotid gland. Due to the slow growth, softness, diffuse nature and lack of pain, lipomas may exist below the diagnostic radar, hence, the need to have a high index of suspicion and utilize diagnostic aids as necessary. In this case magnetic resonance imaging was key in establishing the existence of the lipoma. The lipoma was excised with resolution of the recurrent sialadenitis. The purpose of this report is to present the diagnostic challenge emanating from the pressure effects of an intraoral soft tissue lipoma masquerading as recurrent sialadenitis with a view to improving on patient care through sensitization.

  1. An unusual case of an intramuscular lipoma of the biceps brachii.

    PubMed

    Lahrach, Kamal; el Kadi, Khalid Ibn; Mezzani, Amine; Marzouki, Amine; Boutayeb, Fawzi

    2013-01-01

    Lipomas are common benign neoplasms consisting of mature fatty tissue. They are usually of roundish or ovoid shape and are situated in a single anatomical region. They most frequently occur on the back and in the extremities. Most lipomas are subcutaneous and require no imaging evaluation. When deep, large and unusual in location, MRI can identify and localise these tumours and is the best exploration to differentiate lipoma and lipo-sarcoma. We describe a case of a patient with an intramuscular lipoma of the biceps brachii.

  2. Xanthelasma and lipoma in Leonardo da Vinci's Mona Lisa.

    PubMed

    Dequeker, Jan; Muls, Erik; Leenders, Kathleen

    2004-08-01

    The painting Mona Lisa in the Louvre, Paris, by Leonardo da Vinci (1503-1506), shows skin alterations at the inner end of the left upper eyelid similar to xanthelasma, and a swelling of the dorsum of the right hand suggestive of a subcutaneous lipoma. These findings in a 25-30 year old woman, who died at the age of 37, may be indicative of essential hyperlipidemia, a strong risk factor for ischemic heart disease in middle age. As far as is known, this portrait of Mona Lisa painted in 1506 is the first evidence that xanthelasma and lipoma were prevalent in the sixteenth century, long before the first description by Addison and Gall in 1851.

  3. Lipoma in the subscapularis muscle causing scapular malposition

    PubMed Central

    Kawano, Yusuke; Nakamichi, Noriaki

    2015-01-01

    A 70-year-old woman had pain and fatigability of her left shoulder with asymmetric scapular position. The medial border of the scapula was more prominent in the left side compared to the right scapula, and scapular motion was different between sides. Magnetic resonance imaging showed a mass on the ventral surface of the scapula. Tumour resection was performed through the medial approach, and the tissue samples were found to be a lipoma with a pathological examination. Post-operatively, her pain immediately disappeared. Two years after surgery, no recurrence of the tumour had been found. Soft tissue tumours have never been reported as a cause of scapular malposition or winging. We reported a case with scapular malposition and dyskinesis caused by lipoma in the subscapularis muscle. Surgical resection successfully relieved her symptoms and improved the scapular motion. Soft tissue tumour occurring in the subscapularis muscle could possibly cause abnormal scapular position and motion. PMID:27582987

  4. A rare case of obstructive right atrial lipoma

    PubMed Central

    Andreas, M; Wiedemann, D; Rath, C; Kocher, A

    2014-01-01

    Benign cardiac tumours are rare and cardiac lipomas account only for a small fraction among those. Most of these tumours differ in terms of clinical manifestation, diagnosis, morphology and size, and are therefore not diagnosed easily unless they become symptomatic. We report the case of a 71-year-old Caucasian woman with recurrent episodes of shortness of breath presenting with an acute exacerbation of dyspnoea and hypertensive crisis. Diagnosis of a right atrial lipoma with a coexisting patent foramen ovale was established on echocardiography and computed tomography, and the patient was evaluated for elective surgery. Comprising the entire free wall of the right atrium, the tumour was removed during open heart surgery on cardiopulmonary bypass. The right atrium and the orifices of both the superior and inferior vena cava were reconstructed with bovine pericardium. No evidence of tumour relapse was observed during successive follow-up visits. PMID:25245725

  5. Intravestibular space occupying lesions of lipoma and schwannoma.

    PubMed

    Choi, Jeong-Seok; Kim, Young Hyo; Han, Chang Dok; Kim, Kyu-Sung

    2012-08-01

    Intravestibular lipoma (IVL) and intravestibular schwannoma (IVS) are rare tumors occupying the intravestibular space. Patients with IVL or IVS complain of hearing impairment, tinnitus or recurrent rotatory vertigo. Therefore, the clinical practitioner could misdiagnose them as sudden sensorineural hearing loss or Meniere's disease. Since delayed diagnosis and treatment could lead to more severe and refractory symptoms, clinicians should have a high index of suspicion for early diagnosis. Recent advancements in imaging diagnostic tools such as computed tomography and magnetic resonance imaging have facilitated the correct diagnosis of these intravestibular tumors without surgical removal. Presently, we report two different kinds of intravestibular tumors of lipoma and schwannoma which manifest different clinical course and treatment strategies.

  6. Frontal Lobe Lipoma Associated with Cortical Dysplasia and Abnormal Vasculature

    PubMed Central

    Baskan, Ozdil; Geyik, Serdar

    2014-01-01

    Summary Intracranial lipomas (ICLs) are rare lesions, the vast majority encountered as incidental findings on imaging studies. ICLs are generally pericallosal midline lesions and thought to be asymptomatic and can be accompanied by additional intracranial congenital malformations. We describe a 17-year old male with an unusual case of ICL on the frontal lobe associated with cortical dysplasia and abnormal vasculature mimicking arteriovenous malformation on magnetic resonance images. PMID:25489889

  7. Results of irradiation of infiltrative lipoma in 13 dogs.

    PubMed

    McEntee, M C; Page, R L; Mauldin, G N; Thrall, D E

    2000-01-01

    Thirteen dogs with infiltrative lipomas were treated with cobalt 60 radiation. Four of the thirteen dogs also received either whole body (n = 2) or combination local/whole body (n = 2) hyperthermia in conjunction with radiation therapy. Cytoreductive surgery was performed prior to radiation in 10 dogs, although only 3 dogs had microscopic disease at the time of radiation therapy. Dogs received a total dose of 45.6 Gy-63 Gy in 2.5-4 Gy/fraction on either a Monday/Wednesday/Friday schedule or on a daily Monday through Friday schedule. Twelve of the 13 dogs had computed tomography (CT) images acquired prior to irradiation. Survival time was determined from the time of completion of radiation therapy. Survival ranged from 6 months to 94 months, with a median (95% confidence interval) of 40 (18.5-77) months and a mean of 46.4 months. Only one dog was euthanized due to persistent signs related to the infiltrative lipoma at 6 months after the end of radiation therapy. There was no apparent difference in response based on whether or not the dogs received hyperthermia in conjunction with irradiation, although the numbers were too small to make any significant conclusions. It appears that dogs with infiltrative lipomas can benefit from external beam irradiation alone or in combination with surgery to effect long-term local tumor control.

  8. Giant gastric lipoma mimicking well-differentiated liposarcoma

    PubMed Central

    Brahim, Ehsen Ben; Salah, Mériam belhaj; Haouas, Nooman; Bouhafa, Ahmed; Chedly-Debbiche, Achraf

    2012-01-01

    Gastric lipoma is a rare tumor, accounting for only 5% of gastrointestinal tract lipomas and less than 1% of all gastric tumors. Histological diagnosis is usually easy. However, the tumor may sometimes undergo significant inflammatory changes leading to a difficult differential diagnosis with well-differentiated liposarcoma. Authors report the case of a 51-year-old man, presenting with epigastralgia of recent onset. Physical exam was unremarkable. Endoscopy revealed a large, ulcerated, submucosal, and antral tumor. CT scan showed an antral mass with fat attenuation. The patient underwent a total gastrectomy. Macroscopic examination identified in the antral wall a 9-cm, well-circumscribed, nodular lesion, with a greasy cut surface. On histological examination, the tumor was composed of a mature adipocytes proliferation, showing significant variation in cell size, associated to some lipoblasts. Nuclei were sometimes large, irregular, neither with hyperchromasia nor mitosis. Diagnosis of a well-differentiated liposarcoma was suspected and molecular cytogenetic analyses showed neither MDM2 nor CDK4 gene amplification on fluorescent in situ hybridization. The diagnosis of lipoma was made. Twelve months after surgery, the patient is doing well. In conclusion, Differentiating benign from malignant fatty tumors is sometimes difficult in morphologic features. In these cases, cytogenetic procedures are the only means for an accurate diagnosis. PMID:24834200

  9. [Spinal cord compression due to a epidural lipoma].

    PubMed

    Urculo, E; Samprón, N; Alfaro, R; Arrazola, M; Linazasoro, G

    2008-04-01

    The spinal extradural space is normally occupied by adipose tissue and a venous plexus, so it should be not surprising that lipomas arise and reach sufficient size to compress symptomatically the spinal cord. Nevertheless, the spinal epidural lipomas are rare and benign tumours may present as a progressive spinal cord compression syndrome. Magnetic resonance imaging is useful in demonstrating the full extent and characteristics of these lesions, the severity of cord compression and the location in the canal. Usually, the lesion is amenable to total surgical extirpation and the functional prognosis is good. Histopathologically the tumour consists of a mature adipose cells matrix intermixed with vascular endothelial channels, that is the reason why it is also named angiolipomas. A 47 year-old woman complained of dorsal and bilateral submamarian pain lasting two years and progressive loss of sensibility and weakness in her legs. Following magnetic resonance studies a posterior spinal cord compression by an extradural tumour at T3-T7 levels was observed. She was operated on and we found an extradural yellow tumour easily to dissect and it was completely removed. One year later she is asymptomatic. Spinal epidural lipoma is a benign tumour which initially presents itself with local or radicular pain accompanied by progressive spinal cord compression syndrome. The choice treatment is laminectomy and total excision. Probably, this is one of the easiest tumours to remove of the spinal canal and a source of satisfaction because a complete recovery can usually be achieved.

  10. Intraneural lipoma of the ulnar nerve at the elbow: A case report and literature review

    PubMed Central

    Balakrishnan, Anila; Chang, Yeon Jen; Elliott, David A; Balakrishnan, Chenicheri

    2012-01-01

    Intraneural lipomas of the ulnar nerve or its branches are rare benign tumours. Although most intraneural lipomas present as asymptomatic tumours, some may present as compression neuropathies due to their location. In the majority of cases these tumours can be enucleated without damage to the nerve fibres. PMID:23997597

  11. S-100 protein expressing spindle cells in spindle cell lipoma: a diagnostic pitfall.

    PubMed

    Mentzel, T; Rütten, A; Hantschke, M; Hornick, J L; Brenn, T

    2016-10-01

    Spindle cell lipoma represents a distinct clinicopathological entity and is related to cellular angiofibroma and mammary-type myofibroblastoma. Spindle cell lipomas are composed of mature lipogenic cells and a variable number of CD34-positive spindle cells that show loss of retinoblastoma protein expression. Spindle cell lipomas occasionally express S-100 protein. We studied one case of purely dermal spindle cell lipoma and four cases of classical subcutaneous spindle cell lipoma arising in one female and four male patients (age ranged from 55 to 69 years). The neoplasms arose on the nose, the chin, the neck, the forehead and retroauricular, and all lesions had been marginally or incompletely excised. The studied cases showed classical histological and immunohistochemical features of spindle cell lipoma and, in addition, strong expression of S-100 protein by spindle-shaped tumour cells. S-100-expression in spindle cell lipoma may cause problems in the differential diagnosis with neural and melanocytic neoplasms and emphasizes the plasticity of the spindle cells in spindle cell lipoma.

  12. Inverted Meckel diverticulum as a lead point of small bowel intussusception: misinterpreting case as a lipoma.

    PubMed

    Kim, Kyung Ho; Kang, Kyung A; Lim, Jae Hoon; Lee, Kyung Goo; Kwon, Tae Jung

    2016-01-01

    Inverted Meckel diverticulum is an uncommon cause of intussusception in adults. It may be confused for an intraluminal lipoma. We present a case of small bowel intussusception due to inverted Meckel diverticulum with characteristic computed tomography finding potentially distinguishable from lipoma. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Giant submucosal lipoma cause colo-colonic intussusception. A case report and review of literature.

    PubMed

    Grasso, Emanuele; Guastella, Tommaso

    2012-01-01

    Lipoma of the large intestine is rare, with a reported incidence ranging between 0.2% and 4.4%. We present a case of a giant colonic lipoma causing descending-colonic intussusception. A 54-year-old woman visited our emergency room with sudden onset of intermittent abdominal cramps. She was nauseous and had rectal blood loss for three days. Physical examination showed a tender palpable mass in the left lower abdominal quadrant. Rectal examination showed little blood on the glove. A CT scan demonstrated a clear intussusception of the descending-colonic (Fig. 1). Since the clinical presentation was that of an imminent ileus a laparotomy was performed. The intussusception was found in the descending coloni (Fig. 2), en-bloc resection with left hemicolectomy and was performed with end-to-end anastomosis. Lipomas of the gastrointestinal tract are rare conditions first described by Baurer in 1757. Lipomas in the intestinal tract are still relatively rare, however, being present in only 0.2% of a large autopsy series of 60 000 cases reported in 1955. In 90% of cases, lipoma of the colon are localized at submucous level. Submucosal lipomas are usually asymptomatic but may cause bleeding, obstruction, intussusception, or abdominal pain. Accurate preoperative diagnosis is difficult and lipoma is often mistaken for adenomatous polyp or carcinoma. Differential diagnosis includes malignancy, diverticulosis, adenomatous polyps and previous anastomosis. CT is the examination of choice. Surgical approach remains the treatment of choice for large colon lipoma.

  14. Endoscopic resection of subcutaneous lipoma and tumor-like lesion of the foot.

    PubMed

    Lui, Tun Hing

    2016-03-01

    Open resection is the standard surgical treatment for subcutaneous lipoma. However, it may result in cosmetically non-desirable scars in case of large lesion. Endoscopic resection of subcutaneous lipoma and tumor-like lesions may result in better cosmetic result and patient satisfaction. The basis of the endoscopic technique is described.

  15. A Rare Cause of Childhood Ileus: Giant Mesenteric Lipoma and a Review of the Literature

    PubMed Central

    Turk, Erdal; Edirne, Yesim; Karaca, Fahri; Memetoglu, Mehmet Erdal; Unal, Emel; Ermumcu, Ozgur

    2013-01-01

    Mesenteric lipomas are benign tumors of mature fat cells. They are usually asymptomatic and create a clinical picture that depends on the localization and size of the lipoma. Although rare, unusually large mesenteric giant lipomas can cause partial or complete bowel obstruction. Lipomas resulting in partial bowel obstruction can present with symptoms such as intermittent abdominal pain and abdominal distention. With complete obstruction, a child can present with an acute abdomen. Treatment is the excision of the mass along with the affected portion of bowel. In this case study, a 2-year-old female presented with a bowel obstruction due to the presence of a giant mesenteric lipoma. Clinical features of 16 cases published in the English literature to date are presented. PMID:25610284

  16. Large benign submucosal lipoma presented with descending colonic intussusception in an adult

    PubMed Central

    Allos, Ziad; Zhubandykova, Dina

    2013-01-01

    Patient: Female, 34 Final Diagnosis: Lipoma of the large intestine Symptoms: Abdominal pain • bloating • blood in stool • constipation • lose of appetite • nausea Medication: — Clinical Procedure: — Specialty: Surgery Objective: Rare disease Background: Lipoma of the large intestine is rare, account for only 5% of all gastrointestinal tumors. Lipomas are usually asymptomatic but rarely may cause bleeding, obstruction and intussusception. We present a case of a giant colonic lipoma causing descending-colonic intussusception. Case Report: 34 yo F presented with the intermittent left lower quadrant abdominal pain for 3 weeks. The pain initially was associated with bloating and constipation and for the last several days frank blood in stool, nausea and decreased appetite. CT scan of the abdomen revealed descending colonic obstruction by a 5.3 cm colonic lipomatous mass with resultant intussusception. Patient initially underwent colonoscopy that revealed polypoid lesion at 3–40 similar to lipoma with intussusception that was reduced. Patient subsequently underwent laparoscopic segmental left colectomy for the descending colonic intussusception due to large colonic lipomatous mass. Pathology confirmed the histology of lipoma. Conclusions: Adult bowel intussusception is a rare but challenging condition to diagnose in a timely manner. Preoperative diagnosis is usually missed or delayed because of nonspecific and often subacute symptoms. Lipoma is a rare cause of the intussusception. A high index of suspicion and appropriate investigations (abdominal ultrasound, CT scan and colonoscopy) can result in prompt diagnosis. Lipoma of the large intestine is very rare. Submucosal lipomas are usually asymptomatic but may cause bleeding, obstruction, intussusception, or abdominal pain. Accurate preoperative diagnosis is difficult and lipoma is often mistaken for adenomatous polyp or carcinoma. Treatment usually requires formal resection of the involved bowel segment

  17. Breast lipoma with central fat necrosis: case report

    PubMed Central

    Bouroumane, Mohamed Reda; Khalil, Reda; Khalil, Hind; Jalal, Hicham

    2016-01-01

    Fat necrosis of the breast is a benign non-suppurative inflammatory process of adipose tissue that most commonly occurs as the result of minor breast trauma. We present a case of a 40-years-old female with fat necrosis in a breast lipoma. She presented with an overlapping mass on the lateral quadrants. Mammography showed Well delineated radiolucent mass with peripheral “egg-shell” calcifications, that appeared an hypoechoic mass with posterior shadowing on ultrasonography. A history of accidental trauma raises the suspicion of fat necrosis. Pathology is necessary when radiological findings simulate malignancy.

  18. Intraoral lipomas: Review of literature and report of two clinical cases

    PubMed Central

    Egido-Moreno, Sonia; Lozano-Porras, Ana-Belén; Mishra, Siddharth; Allegue-Allegue, Marcos; Marí-Roig, Antonio

    2016-01-01

    Background Lipomas are benign mesenchymal tumors composed of mature adipocytes. They are classified according to their histological pattern and their etiology remains unclear. Objectives: To present two cases and review the literature. Material and Methods A search was conducted in the Medline / PubMed and Scielo data bases of the last 10 years (2004-2014) with the keywords “ intraoral lipoma OR oral cavity lipoma”. Results 46 articles with 95 cases (56 women and 39 men) were reviewed. The average age was found to be 52.28 years (52.28 ± 18.55); and most of them occurred between the 4th and 6th decade of life. Lipomas occur mostly in the buccal mucosa (n = 36, 37.9%), followed by the tongue (n = 23, 24.2%) and other locations (n = 36, 37.9%). The most common histologic pattern was simple lipomas (n = 40, 42%), followed by fibrolipomas (n = 18, 18.9%) and other types (n = 37, 39.1%). The average tumor size was 19.77 ± 16.26mm. Conclusions Lipomas are a relatively rare finding in the oral cavity. Surgical excision is the treatment of choice and recurrence is not expected. Key words:Benign oral tumor, oral lipoma, lipoma, oral cavity. PMID:27957277

  19. Total Resection of Complex Spinal Cord Lipomas: How, Why, and When to Operate?

    PubMed Central

    PANG, Dachling

    2015-01-01

    This article shows the long-term advantage of total resection of complex spinal cord lipomas over partial resection and over non-surgical treatment for children with asymptomatic lipomas. The classification, embryogenesis, and technique of total resection of complex lipomas are described. The 20-year outcome of 315 patients who had total resection is measured by overall progression-free survival (PFS, Kaplan-Meier), and by subgroup Cox multivariate hazard analysis for the influence of four variables: lipoma type, symptoms, prior surgery, and post-operative cord-sac ratio. These results are compared to 116 patients who underwent partial resection, and to two published series of asymptomatic lipomas followed without surgery. The PFS after total resection for all lipomas is 88.1% over 20 years vs. 34.6% for partial resection at 10.5 years (p < 0.0001). The PFS for total resection of asymptomatic virgin lipomas rose to 98.8% vs. 60% and 67% for non-surgical treatment. Partial resection also compares poorly to non-surgical treatment for asymptomatic lipomas. Multivariate analyses show that a low cord-sac ratio is the only independent variable that predicts good outcome. Pre-operative profiling shows the ideal patient for total resection is a young child with a virgin asymptomatic lipoma, who, with a PFS of 99.2%, is essentially cured. The technique of total resection can be learned by any neurosurgeon. Its long-term protection against symptomatic recurrence is better than partial resection and conservative management. The surgery should be done at diagnosis, except for asymptomatic small infants in whom surgery should be postponed till 6 months to minimize morbidity. PMID:26345666

  20. The Case of Huge Pure Lipoma of the Spermatic Cord Misdiagnosed as Inguinal Hernia.

    PubMed

    Jo, Dong In; Choi, Sang Kyu; Kim, Soon Heum; Kim, Cheol Keun; Chung, Hong; Kim, Hong Sup

    2017-07-01

    Clinically, pure spermatic-cord lipoma has not been recognized as a disease entity but regarded as an incidental finding at the time of hernia repair, because it presents groin symptoms and clinical findings indistinguishable from those of inguinal hernia. We report the successful treatment of case of huge pure spermatic-cord lipoma originally misdiagnosed as inguinal hernia. The patients had tumor excision without orchiectomy. Symptoms improved without any complication. In patients with inguinal hernia symptoms, pure spermatic-cord lipoma should be recognized as a significant clinical entity, and differential diagnosis should be achieved using ultrasonography and computed tomography to avoid unnecessary hernia repair.

  1. Posterior interosseous nerve palsy caused by parosteal lipoma of proximal radius.

    PubMed

    Nishida, J; Shimamura, T; Ehara, S; Shiraishi, H; Sato, T; Abe, M

    1998-07-01

    Lipomas are common benign soft tissue tumors which tend to be indolent, and symptoms caused by nerve compression are unusual. However, a parosteal lipoma, occurring adjacent to the proximal radius may easily cause paralysis of the posterior interosseous nerve because of a specific anatomical relationship of these structures in that area. Two cases of parosteal lipoma of the proximal radius causing paralysis of the posterior interosseous nerve are reported. CT and MR imaging demonstrate the characteristic fatty mass around the radius and are specific in making the diagnosis. Surgical excision should be promptly performed to ensure optimal recovery from the nerve paralysis.

  2. Giant lipoma of the hand causing median nerve compression.

    PubMed

    Clesham, Kevin; Galbraith, John Gerard; Ramasamy, Ashok; Karkuri, Ahmed

    2017-06-28

    Lipomas are benign neoplasms derived from adipose tissue composed of mature adipocytes. They account for almost 50% of all soft-tissue neoplasms and occur in up to 2% of the population. They usually present asymptomatically as solitary discrete mobile lumps found most commonly on the neck, upper back, proximal limbs and chest. In less than 1% of cases, they can be found in the distal extremities.We discuss the case of a 65-year-old man who presented with a 2-year history of a slowly enlarging left palm swelling, with recent-onset numbness and loss of power in the distribution of the median nerve. MRI studies showed that the 5×4×2.7 cm lipoma had a component extending into the distal aspect of the carpal tunnel, compressing the median nerve. It was successfully excised, and at follow-up the patient reported complete resolution of his symptoms. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  3. Intraosseous lipoma of the calcaneus mimicking plantar fascitis.

    PubMed

    Karthik, K; Aarthi, S

    2011-06-01

    Benign lytic lesions of the calcaneus are rare and are usually asymptomatic. We report this case of a 55-year-old man with bilateral non-traumatic plantar heel pain, which was treated conservatively as plantar fasciitis. At three months follow-up, the patient had complete relief of symptoms in the left heel with partial relief of symptoms on the right side. However under the insistence of the patient an X-ray was taken, which revealed an expansile lytic lesion of the right calcaneus and a normal left heel. CT-scan revealed an expansile lytic lesion on the right calcaneus and an early lytic lesion in the left calcaneus. Following surgical intervention, the diagnosis was confirmed as intra-osseous lipoma and the patient was completely symptom free at two-year follow-up. Patients presenting with non-traumatic heel pain should be explained about the possible causes of heel pain, and should be offered X-ray at the first visit. In patients with X-ray showing unilateral lipoma of the calcaneus, CT scan should be offered to rule out involvement of the opposite side.

  4. Successful Endoscopic Submucosal Dissection of a Large Terminal Ileal Lipoma

    PubMed Central

    Noda, Hisatsugu; Ogasawara, Naotaka; Tamura, Yasuhiro; Kondo, Yoshihiro; Izawa, Shinya; Ebi, Masahide; Funaki, Yasushi; Sasaki, Makoto; Kasugai, Kunio

    2016-01-01

    A 78-year-old woman who had recurrent right lower abdominal pain for about 1 year underwent computed tomography (CT) because of a follow-up observation 1 year after right breast cancer surgery. CT revealed a tumor in the colon. The patient was referred to our hospital for detailed examinations. An abdominal CT showed a low-density tumor of approximately 30 mm in the ascending colon, and the CT density inside the tumor was same as that of fatty tissues. A subsequent colonoscopy showed a submucosal tumor (SMT) in the proximal ascending colon developing from the terminal ileum. A colonoscopic ultrasonography revealed that the SMT was a high-echoic mass mainly localized in the submucosal layer. Based on the findings from CT, colonoscopy, and colonoscopic ultrasonography, the SMT was diagnosed as a pedunculated lipoma originating from the terminal ileum and treated with endoscopic submucosal dissection (ESD) because of recurrent abdominal pain. The 40-mm tumor was resected en bloc without complications. ESD may be more appropriate than polypectomy and surgery for removal of small intestinal tumors, because ESD allows direct visualization of the cutting line and exactly dissects the submucosal layers without damaging the muscular layers. ESD is a potentially useful treatment to remove intestinal lipomas. PMID:27843426

  5. Polyarticular lipoma arborescens--a clinical and aesthetical case.

    PubMed

    Silva, Lígia; Terroso, Georgina; Sampaio, Luzia; Monteiro, Eurico; Pimenta, Sofia; Pinto, Fernanda; Pinto, José A; Ventura, Francisco S

    2013-06-01

    Lipoma arborescens is a benign tumor, but it may be a reactive process to other disorders, and its clinical, analytical, radiological and ultrasound presentation may be redundant to any synovial tumor. Despite the characteristic feature on magnetic resonance imaging (MRI), the correct differential diagnosis in atypical presentation, and the need for timely removal of the lesion to prevent joint damage, forces, ultimately, to invasive procedures. The clinical case reported here, fourth described in English language publications on the polyarticular form, also presented other specificities related to one of the swellings, in the knee. Because of its atypical location in the popliteal fossa, recurrent episodes of joint effusion, personal history of knee trauma, pulmonary tuberculosis, and family history of rheumatoid arthritis required particular attention. This process was hampered by the refusal of knee (and ankle) surgery by the patient. He accepted surgical removal of the swellings of the wrists, for aesthetical reasons, with pathologic confirmation of the diagnosis, and clinical success in that location. MRI of the knee showed the typical image of lipoma arborescens, but also other changes that compromise the prognosis.

  6. Computed tomography of the cerebellopontine cistern in normal and acoustic tumor patients.

    PubMed

    Fagerlund, M

    1987-01-01

    Air computed tomography of the cerebellopontine cistern was performed in 15 consecutive patients. The series comprised 7 patients with a normal cistern and 8 patients with tumor, including one with bilateral tumors. Two tumors were of small size (less than 10 mm i diameter), 3 were medium sized (10-20 mm in diameter), and 4 were large (greater than 20 mm in diameter). In the normal group, the jugular foramen nerve bundle (the 9th, 10th and 11th nerves), the trigeminal nerve, or the brain stem margin were clearly defined by air. In the tumor group, the possible extension of the tumor to these structures could be defined. Differentiation between a compression or attachment of the trigeminal nerve to the tumor was not always possible. The importance of using reconstruction views is stressed.

  7. Surgical treatment of spinal lipoma without spina bifida at lumbar region-three case reports-.

    PubMed

    Sugawara, Atsushi; Kim, Kyongsong; Isobe, Masanori; Matsumoto, Ryoji; Isu, Toyohiko

    2009-12-01

    Three men aged 40 to 60 years presented with rare lumbar spinal intradural lipomas without spina bifida manifesting as worsening numbness, pain of the lower extremities, and bladder dysfunction. All 3 patients underwent decompressive laminectomy. The lipoma and cauda equina nerves were dissected from the dura mater under the operating microscope, untethering the spinal cord and returning the cauda equina nerves to the original position. Duralplasty was performed using an expanded polytetrafluoroethylene sheet. Postoperatively, all patients experienced improvement of their neurological deficits. In the surgical treatment of spinal lipomas, the primary purpose is untethering and decompression, which can be achieved by untethering the spinal cord, returning the cauda equina nerves to the normal position, laminectomy, and duralplasty, without removal of the lipoma.

  8. [Acute abdomen caused by colo-colic invagination: a case of invagination of a colonic lipoma].

    PubMed

    Rassu, P C; Bronzino, P; Cassinelli, G; La Spisa, C; Cuneo, A; Partipilo, F; Rusca, I; Boccardo, F; Zoppi, S; Casaccia, M

    2003-03-01

    The Authors report a case of intestinal occlusion due to a colo-colonic intussusception arising from a lipoma of trasverse colon and, by a review of the cases in the Literature, they discuss diagnostic and therapeutic procedures in emergency.

  9. Adult sigmoidorectal intussusception related to colonic lipoma: A rare case report with an atypical presentation

    PubMed Central

    Mohamed, Mohamed; Elghawy, Karim; Scholten, Donald; Wilson, Kenneth; McCann, Michael

    2015-01-01

    Introduction Adult intussusception is rare. Lipoma is the second most common benign tumor of the colon and most common to cause colonic intussusception in adults, but rare. Presentation of case A 35-years-old male presented with a history of intermittent abdominal pain and bright red rectal bleeding, with symptoms waxing and waning for one month. On physical examination, the abdomen was distended with tenderness over the periumbilical, suprapubic, and left lower quadrant regions with guarding. CT demonstrated colo-colonic intussusception of the sigmoid colon with a 2.3 cm × 2.6 cm intra-mural lipoma of the rectosigmoid region. The patient underwent an exploratory laparotomy with partial reduction of the intussusception, sigmoid colon resection and end colostomy. Histopathology confirmed a 2.5 cm sub-mucosal lipoma without evidence of malignancy. Discussion Sixty–sixty five percent of cases with intussusception of the large bowel in adults are related to a malignant etiology and most cases of sigmoidorectal intussusception reported in the literature are secondary to underlying malignancy. Colo-colic intussusception is the most common type of intussusception in adults. The incidence of lipomas of the large intestine is reported to range from 0.035% to 4.4%. Ninety percent of colonic lipomas are submuscosal and are mostly located in the right hemicolon. Only 25% of patients with colonic lipoma develop symptoms. Colonic lipomas of the rectosigmoid region represent a very rare occurrence and subsequent etiology for sigmoidorectal intussusceptions in adults. Conclusion Colonic lipoma should be considered in the differential diagnosis of adults with intussusception, with reduction and resection leading to excellent results. PMID:25839433

  10. Multiple cardiac lipomas and pericardial lipomatosis: multidedector-row computer tomography findings.

    PubMed

    Sanal, Hatice Tuba; Kocaoğlu, Murat; Yildirim, Düzgün; Ors, Fatih

    2007-10-01

    Being rare tumors of the heart, cardiac lipomas are usually discovered incidentally during non-cardiac-related examinations of the chest. Although they are reported to be typically solitary, multiplicity has been described in tuberosclerosis patients. Here we reported the multidedector-row computer tomography (MDCT) findings of a nontuberosclerosis case with multiple cardiac lipomas along with pericardial lipomatosis, who presented with symptoms of left heart failure after a hysterectomy surgery but otherwise healthy before that operation.

  11. Condylar intramedullary intraosseous lipoma: Contribution of a new case and review of the literature

    PubMed Central

    Dean, Alicia; Garcia, Blas; Alamillos, Francisco; Roldan, Elisa; Blanco, Antonio

    2017-01-01

    Background Lipoma is the most common benign tumour of the human body, being intraosseous involvement very rare. Just 1 to 4% of all cases of lipoma are located in the oral cavity, only 0.1% being intraosseous. The jaw is its most uncommon bone location. Etiology of intraosseous lipoma (IOL) is unknown, although several theories have been proposed. Usually asymptomatic, the symptoms, when present, will depend on its location and size. Its origin may be intraosseous or juxtacortical. A biopsy is essential for diagnosis, and definitive treatment involves resection or curettage of the lesion. The aim of this paper is to present a new case of intramedullary intraosseous lipoma of the mandible with involvement of the left mandibular ramus and condylar neck. Material and Methods A case of intramedullary intraosseous lipoma (IOL) on the left mandibular ramus and condyle is presented. No history of trauma in temporomandibular joint existed. The radiology showed a radiolucent multi-lobulated lesion with values of attenuation in the range of fat. Curettage is performed and the histopathology showed a conglomerate of adipocytes without trabeculae, calcifications or atypia. Results According to the bibliography 24 cases of mandibular IOL have been described. This is the second reported case of condylar involvement and the first with cortical expansion. Conclusions Lipoma intraosseous is a very rare benign bone neoplasm. Histology is required for the differential diagnosis from other radiolucent lesions. The IOL treatment is the curettage with a good prognosis, although malignant transformation to liposarcoma has been reported in other locations. It is a disease with a difficult differential diagnosis, therefore the publication of new cases is important. Key words:Intraosseous lipoma, lipoma, jaw tumour, condylar tumour. PMID:28298998

  12. LIPOMA ARBORESCENS: RARE CASE OF ROTATOR CUFF TEAR ASSOCIATED WITH THE PRESENCE OF LIPOMA ARBORESCENS IN THE SUBACROMIAL-SUBDELTOID AND GLENOHUMERAL BURSA

    PubMed Central

    Benegas, Eduardo; Neto, Arnaldo Amado Ferreiro; Teodoro, Daniel Sabatini; da Silva, Marcos Vinícius Muriano; de Oliveira, Augusto Medaglia; Filippi, Renée Zon; de Santis Prada, Flávia

    2015-01-01

    Lipoma arborescens is a rare intra-articular disease that is usually monoarticular and is characterized by extensive proliferation of the synovial villi and hyperplasia of the subsynovial fat. The synovial tissue is progressively replaced by mature fat cells in the synovial membrane. The present study reports a case of a rare condition of lipoma arborescens that was simultaneously intra-articular (glenohumeral joint) and in the subacromial-subdeltoid bursa, in association with a torn supraspinatus tendon. The clinical, histological and radiographic presentations and treatment are discussed here. The description of this case includes radiographic and magnetic resonance evaluations and pathological examination. Although lipoma arborescens is a rare condition, it should be taken into consideration in cases presenting synovial hyperproliferation and synovial fat replacement. PMID:27047861

  13. Can Experienced Observers Differentiate between Lipoma and Well-Differentiated Liposarcoma Using Only MRI?

    PubMed

    O'Donnell, Patrick W; Griffin, Anthony M; Eward, William C; Sternheim, Amir; White, Lawrence M; Wunder, Jay S; Ferguson, Peter C

    2013-01-01

    Well-differentiated liposarcoma represents a radiographic diagnostic dilemma. To determine the accuracy, interrater reliability, and relationship of stranding, nodularity, and size in the MRI differentiation of lipoma and well-differentiated liposarcoma, MRI scans of 60 patients with large (>5 cm), deep, pathologically proven lipomas or well-differentiated liposarcomas were examined by 10 observers with subspecialty training blinded to diagnosis. Observers indicated whether the amount of stranding, nodularity, and size of each tumor suggested a benign or malignant diagnosis and rendered a diagnosis of lipoma or well-differentiated liposarcoma. The accuracy, reliability, and relationship of stranding, nodularity, and size to diagnosis were calculated for all samples. 69% of reader MRI diagnoses agreed with final pathology diagnosis (95% CI 65-73%). Readers tended to err choosing a diagnosis of liposarcoma, correctly identifying lipomas in 63% of cases (95% CI 58-69%) and liposarcomas in 75% of cases (95% CI 69-80%). Assessment of the relationship of stranding, nodularity, and size to correct diagnosis showed that the presence of each was associated with a decreased likelihood of a lipoma pathological diagnosis (P < 0.01). While the radiographic diagnosis of lipoma or well-differentiated liposarcoma cannot be made with 100% certainty, experienced observers have a 69% chance of rendering a correct diagnosis.

  14. Can Experienced Observers Differentiate between Lipoma and Well-Differentiated Liposarcoma Using Only MRI?

    PubMed Central

    O'Donnell, Patrick W.; Griffin, Anthony M.; Eward, William C.; Sternheim, Amir; White, Lawrence M.; Wunder, Jay S.; Ferguson, Peter C.

    2013-01-01

    Well-differentiated liposarcoma represents a radiographic diagnostic dilemma. To determine the accuracy, interrater reliability, and relationship of stranding, nodularity, and size in the MRI differentiation of lipoma and well-differentiated liposarcoma, MRI scans of 60 patients with large (>5 cm), deep, pathologically proven lipomas or well-differentiated liposarcomas were examined by 10 observers with subspecialty training blinded to diagnosis. Observers indicated whether the amount of stranding, nodularity, and size of each tumor suggested a benign or malignant diagnosis and rendered a diagnosis of lipoma or well-differentiated liposarcoma. The accuracy, reliability, and relationship of stranding, nodularity, and size to diagnosis were calculated for all samples. 69% of reader MRI diagnoses agreed with final pathology diagnosis (95% CI 65–73%). Readers tended to err choosing a diagnosis of liposarcoma, correctly identifying lipomas in 63% of cases (95% CI 58–69%) and liposarcomas in 75% of cases (95% CI 69–80%). Assessment of the relationship of stranding, nodularity, and size to correct diagnosis showed that the presence of each was associated with a decreased likelihood of a lipoma pathological diagnosis (P < 0.01). While the radiographic diagnosis of lipoma or well-differentiated liposarcoma cannot be made with 100% certainty, experienced observers have a 69% chance of rendering a correct diagnosis. PMID:24385845

  15. A case of lipoma of lateral anterior neck treated with surgical enucleation.

    PubMed

    Grecchi, Francesco; Zollino, Ilaria; Candotto, Valentina; Gallo, Francesco; Rubino, Giuseppe; Bianchi, Raffaella; Carinci, Francesco

    2012-12-01

    Lipoma arise in almost 50% of all soft tumours. The neck lipomas are rare tumours that may present as painless masses with slow growth, in the lateral portions of the neck. Some lipomas, such as the one studied in our case, grow deep in the subcutaneous tissue, in close contact with muscles. Here, we report a case of lipoma extending from pre-tragal region up to the ascending branch of the mandible in a 62 year old man, treated with enucleation. The inferior margin of lipoma involved the pharyngeal and the superior margin was achieved by the top of the skull base. The mass of lipoma caused breathing difficulties in the patient, preventing regular sleep. No complication was recorded in the post-operative period and no further surgery was performed. The complete resolution after one year's follow-up, together with the rarity of the anatomical site, makes this case worthy of description. A correct diagnosis facilitated removal of this lesion with a surgical method.

  16. A case of lipoma of lateral anterior neck treated with surgical enucleation

    PubMed Central

    Grecchi, Francesco; Zollino, Ilaria; Candotto, Valentina; Gallo, Francesco; Rubino, Giuseppe; Bianchi, Raffaella; Carinci, Francesco

    2012-01-01

    Lipoma arise in almost 50% of all soft tumours. The neck lipomas are rare tumours that may present as painless masses with slow growth, in the lateral portions of the neck. Some lipomas, such as the one studied in our case, grow deep in the subcutaneous tissue, in close contact with muscles. Here, we report a case of lipoma extending from pre-tragal region up to the ascending branch of the mandible in a 62 year old man, treated with enucleation. The inferior margin of lipoma involved the pharyngeal and the superior margin was achieved by the top of the skull base. The mass of lipoma caused breathing difficulties in the patient, preventing regular sleep. No complication was recorded in the post-operative period and no further surgery was performed. The complete resolution after one year's follow-up, together with the rarity of the anatomical site, makes this case worthy of description. A correct diagnosis facilitated removal of this lesion with a surgical method. PMID:23814589

  17. Subdeltoid lipoma causing shoulder impingement syndrome – a case report

    PubMed Central

    Lenza, Mario; Lenza, Miguel Vicente; Carrerra, Eduardo da Frota; Ferretti, Mario

    2014-01-01

    The impingement syndrome is defined by the compression of the rotator cuff tendons against the coracoacromial arch. Several factors contribute to this condition and they are classified as structural or functional factors. The former are changes in the coracoacromial arch, proximal humerus, bursa and rotator cuff, and the latter are related to the mechanism of the upper limb by means of synchronized activity and balanced between the rotator cuff and scapular girdle muscles. The authors report here a case of parosteal lipoma of the proximal humerus, located between the muscles deltoid, teres minor and infraspinatus causing clinical signs of impingement. It is a rare occurrence, characterized as a structural cause for the onset of this symptom. PMID:25167335

  18. Targeted disruption of the mouse Lipoma Preferred Partner gene

    SciTech Connect

    Vervenne, Hilke B.V.K.; Crombez, Koen R.M.O.; Delvaux, Els L.; Janssens, Veerle; Ven, Wim J.M. van de Petit, Marleen M.R.

    2009-02-06

    LPP (Lipoma Preferred Partner) is a zyxin-related cell adhesion protein that is involved in the regulation of cell migration. We generated mice with a targeted disruption of the Lpp gene and analysed the importance of Lpp for embryonic development and adult functions. Aberrant Mendelian inheritance in heterozygous crosses suggested partial embryonic lethality of Lpp{sup -/-} females. Fertility of Lpp{sup -/-} males was proven to be normal, however, females from Lpp{sup -/-} x Lpp{sup -/-} crosses produced a strongly reduced number of offspring, probably due to a combination of female embryonic lethality and aberrant pregnancies. Apart from these developmental and reproductive abnormalities, Lpp{sup -/-} mice that were born reached adulthood without displaying any additional macroscopic defects. On the other hand, Lpp{sup -/-} mouse embryonic fibroblasts exhibited reduced migration capacity, reduced viability, and reduced expression of some Lpp interaction partners. Finally, we discovered a short nuclear form of Lpp, expressed mainly in testis via an alternative promoter.

  19. Giant gastric lipoma mimicking well-differentiated liposarcoma

    PubMed Central

    Hamdane, Mohamed Moncef; Brahim, Ehsen Ben; Salah, Mériam belhaj; Haouas, Nooman; Bouhafa, Ahmed; Chedly-Debbiche, Achraf

    2012-01-01

    Authors report the case of a 51-year-old man, presenting with epigastralgia of recent onset. Physical exam was unremarkable. Endoscopy revealed a large, ulcerated, submucosal, antral tumor. CT scan reveals an antral mass with fat attenuation. The patient underwent a total gastrectomy. Macroscopic examination identified in the antral wall a 9-cm, well-circumscribed, nodular lesion, with a yellow, greasy cut surface. On histological examination, the tumor was composed of a mature adipocytes proliferation, showing significant variation in cell size, associated to some lipoblasts. Nuclei were sometimes large, slightly irregular, but without hyperchromasia nor mitosis. Diagnosis of a well-differentiated liposarcoma was suspected and molecular cytogenetic analyses showed no MDM2 nor CDK4 gene amplification on fluorescent in situ hybridization. The diagnosis of lipoma was made. Twelve months following surgery, the patient is doing well. PMID:23308321

  20. [Management of cerebellopontine angle meningiomas and the posterior part of the temporal bone. Report on 44 cases].

    PubMed

    Le Garlantezec, C; Vidal, V Franco; Guerin, J; Bébéar, J P; Liguoro, D; Darrouzet, V

    2005-01-01

    To review and study the management of CPA meningiomas through the experience of an otoneurosurgical team. Fourty-two patients (44 meningiomas) were considered. Seventy-seven per cent of tumors (34 cases) were operated on; 6 tumors (14.6%) were exclusively irradiated using fractionated radiation therapy (FRT) and four only surveyed (9,8%). transpetrosal approaches were exclusively used. These were translabyrinthine (TLA) in 47%, widened retrolabyrinthine (WRLA) in 41% of cases, transcochlear approach (TCA) in three cases and a middle fossa in one. A transtentorial approach was combined in 35% of cases (8 TLA, 4 WRLA). Surgical removal was incomplete in 11,8% of cases; in 3 cases growing tumor was treated by FRT included one case of anaplasic tumor Postoperative complications were: 1 meningitis, 1 wound abscess, 2 hydrocephalus (6%) and 4 CSF fistulas (12%). No complications have been observed during the last 7 years (21 cases). House and Brackmann Grade 1 or 2 facial function was obtained in 59% of cases (but 10 patients had a preoperative facial nerve paresis). A normal or subnormal AAO-HNS Class A-B Hearing could be preserved in 57% of WRLA. Radiation therapy allowed tumor shrinkage in all cases. In 3 cases this regression was of more than 50%. Surgery is the gold standard in treating CPA meningiomas. Transpetrosal approaches and particularly WRLA pure or combined to a transtentorial approach are for us the best way to remove these tumors in preserving hearing and facial nerve function. When hearing is poor or when tumor extension to the clivus or the premeatal area is consistent a TLA is either planned preoperatively or obtained from a WRLA.

  1. Real-time ultrasound Doppler enhances precision in image-guided approaches to the cerebello-pontine angle.

    PubMed

    Baghdasaryan, Davit; Albrecht, Marcel; Shahnazaryan, Mihr; Rosahl, Steffen

    2017-08-10

    To evaluate efficacy and reliability of intraoperative Doppler sonography in localizing the transverse and sigmoid sinuses during lateral suboccipital craniotomy. A 16-Mhz intraoperative micro-Doppler ultrasound (16Mhz, Multi-Dop pro®, Compumedics, Germany) was applied to detect the medial border of the sigmoid sinus and the inferior border of the transverse sinus in 25 patients. Micro-Doppler measurements were compared to MR- and CT-based image-guidance (Kolibri®, Brainlab, Germany). Visual detectability of the sinuses under the operating microscope was also documented. Inadvertent incision of the transverse or sigmoid sinuses did not occur in any case when the two localizing methods have been used in combination. The mean mismatch of image-guided system and micro-Doppler was 2.64mm (range 0-6mm, SD 1.55 mm). Under the microscope the transverse sinus was invisible in seven cases, the sigmoid sinus was visually undetectable in one case. The micro-Doppler indicated blood flow outside the visible borders of the sinuses in five cases. A combination of image-guidance and micro-Doppler enhances the accuracy in localizing the margins of the transverse and sigmoid sinuses in the retrosigmoid approach, thus preventing inadvertent injury. The method could potentially be applied during other craniotomies involving the exposure of a venous sinus. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. A rare case of parotid gland lipoma arising from the deep lobe of the parotid gland

    PubMed Central

    Paparo, Francesco; Massarelli, Mauro; Giuliani, Giorgio

    2016-01-01

    Lipomas are the most commonly encountered benign mesenchymal tumors, but their occurrence in the head and neck is rare, even more at the level of the parotid region where they can be found nearby the parotid capsule, inside the capsule, or within the gland. In addition, lipomas involving the deep parotid lobe are extremely unusual. That is why lipomas are not often considered for differential diagnosis of parotid lumps. Concerning diagnostic tools, magnetic resonance imaging (MRI) is nowadays considered as the main imaging examination for parotid lipomas due to a characteristic signal intensity on T1- and T2-weighted images. Furthermore, even if the cost of MRI is nearly three times that of computed tomography, MRI is accurate, safe, and has few biological costs for the patient. In this reported case, MRI provided all information for either diagnosis or preoperative planning being the best diagnostic tool regarding tumor margin characteristics and surrounding tissues’ involvement. Concerning treatment, surgical excision of parotid masses is always mandatory for definitive diagnosis, but it is challenging because of the facial nerve. For this reason, a well-established surgical technique is mandatory for success. The authors present a rare case of parotid gland lipoma arising from the deep lobe and discuss diagnostic tools and surgical technique. PMID:28299278

  3. Novel method of minimally invasive removal of large lipoma after laser lipolysis with 980 nm diode laser.

    PubMed

    Stebbins, William G; Hanke, C William; Petersen, Jeffrey

    2011-01-01

    Lipomas are the most common benign tumor of the soft tissue, often presenting as soft, mobile subcutaneous masses. These lesions are often removed for cosmetic reasons, although they may be removed secondary to considerable discomfort or paresthesias. The large majority of lipomas appear as small, solitary lesions that are best removed by surgical excision. However, surgical removal of large (>10 cm) or multiple lesions may result in significant scarring. Tumescent local anesthesia and liposuction of larger lesions has been successful in a number of cases although this technique can be hindered by overly fibrous lesions. Laser lipolysis, performed alone or before liposuction, can further facilitate removal of these lesions. This technique is a minimally invasive and effective method of lipoma removal, resulting in an excellent cosmetic outcome. This report describes step-by-step removal of a large lipoma located on the back, as well as a review of currently employed techniques for minimally invasive treatment of lipomas. © 2011 Wiley Periodicals, Inc.

  4. [Diaphragmatic lipoma needed to distinguish from Bochdalek hernia; report of a case].

    PubMed

    Naomi, Akira; Oyamatsu, Yoshinori; Narita, Kunio; Nakayama, Masato; Maeda, Shouki

    2014-09-01

    A 69-year-old woman had been followed up for an abnormal shadow on the left diaphragm at a nearby hospital, which showed gradual increase in size and she was referred to our hospital for treatment. Chest computed tomography(CT) showed a dome-shaped and homogeneous mass with smooth surface on the left diaphragm. CT showed 50×60 mm hypodense mass and partly interrupted diaphragm. Magnetic resonance imaging( MRI) revealed fat signal intensity on both T1 and T2 weighted image and fat suppressed T1 image. Bochdalek hernia or diaphragm lipoma was suggested and surgery was done. Yellowish round tumor on the diaphragm was resected. The omentum was easily separated from the tumor. Histopathological finding revealed the lipoma cell invading into striated muscle of diaphragm, and the tumor was diagnosed as a mature lipoma originated from diaphragm.

  5. Chronic lingual ulceration caused by lipoma of the oral cavity. Case report.

    PubMed

    Del Castillo Pardo de Vera, Jose Luis; Cebrián Carretero, Jose Luis; Gómez García, Elena

    2004-01-01

    Although lipomas are among the most frequent tumors in the human body, their presentation in the oral cavity is not common. Oral cavity lipomas usually show a slow painless and assymptomatic growing. When these tumors reach big sizes, they can cause compressive symptons and deformities. In this paper we present the case of a patient in whom oral lipoma was the final finding in the differential diagnosis of a chronic mucosal ulcer. CT scan and MRI images and microscopical examination after fine-needle aspiration were the clue for the final diagnosis. The surgical excision of the tumor was the basis for the healing of the ulcer. We also review the most relevant and recent literature about clinic, diagnosis and treatment for these tumors.

  6. Bilateral hamartomatous medullary lipoma within the nasal turbinate bones in a cynomolgus monkey (Macaca fascicularis)

    PubMed Central

    KATSUTA, Osamu; SHIBATA, Toru; KURIKI-YAMAMOTO, Yumi; MOCHIZUKI, Takaharu; YOSHIMI, Miwa; NOTO, Takahisa; MANO, Hidetoshi

    2016-01-01

    A 15-year-old male cynomolgus monkey (Macaca fascicularis) showed large bilateral masses in the maxillary sinus. In histopathological examination, both masses revealed benign medullary lipomas within the turbinate bones. The tumors were composed of well-developed lipocytes, trabecular bones and a few blood vessels. Although we initially diagnosed the tumor as bilateral lipomas in the nasal turbinates, it was not differentiated from lipomatous hamartoma. Findings, such as unique symmetrical proliferation, lack of border from the normal marrow and the intact surrounding tissue, indicated a lipomatous hamartoma/hamartomatous lipoma, thought to be a suitable diagnosis of the lesion. Of most interest was that such a proliferating lesion occurred in the nasal turbinate. PMID:27499062

  7. Liposuction--removal of giant lipomas for weight loss in a dog with severe hip osteoarthritis.

    PubMed

    Böttcher, P; Klüter, S; Krastel, D; Grevel, V

    2007-01-01

    An extremely obese, mixed breed dog, with severe bilateral hip osteoarthritis was presented with progressive hindlimb lameness. In addition, three giant lipomas were diagnosed, one causing mechanical irritation within the left axillary region. Previous treatments of dietary weight loss and non-steroidal anti-inflammatory drugs had failed. Minimally invasive liposuction of the lipomas was performed, resulting in weight loss of 3 kg, representing 10 per cent of the dog's bodyweight. Conservative treatment was continued, and the dog improved rapidly postoperatively. Liposuction of lipomas may be considered as an alternative to traditional surgical resection in cases where seroma formation and delayed wound healing may be expected. Acute weight loss through liposuction may improve lameness associated with osteoarthritis and motivate the owner compliance for further weight loss.

  8. Colonic intussusception in descending colon: An unusual presentation of colon lipoma

    PubMed Central

    Bagherzadeh Saba, Reza; Sadeghi, Amir; Rad, Neda; Safari, Mohammad Taghi; Barzegar, Farnoush

    2016-01-01

    Lipomas of the colon are relatively rare benign soft tissue tumors derived from mature adipocytes of mesenchymatic origin. During colonoscopy, surgery or autopsy they are generally discovered incidentally. Most cases are asymptomatic, with a small tumor size, and do not need any special treatment. However, in the cases with larger in size of tumor some symptoms such as anemia, abdominal pain, constipation, diarrhea, bleeding, or intussusception may be presented. We reported a 47-year-old woman with colonic intussusception in the descending colon caused by colonic lipoma and diagnosed after surgical exploration for obstructive colonic mass. PMID:28224035

  9. Spindle Cell Lipomas in Women: A Report of 53 Cases.

    PubMed

    Ko, Jennifer S; Daniels, Brianne; Emanuel, Patrick O; Elson, Paul; Khachaturov, Vadim; McKenney, Jesse K; Goldblum, John R; Billings, Steven D

    2017-09-01

    Spindle cell lipomas (SCL) are typically tumors of the upper back/neck (shawl region) of men (80% to 90%). In general, there is a frequent tendency to restrict the diagnosis to this specific clinical scenario and a hesitancy to diagnose SCL in women. We hypothesized that SCL in women have a more varied presentation. A total of 395 SCL were diagnosed at our institution over the last 11 years. The diagnosis of SCL in women was confirmed by re-review. Immunohistochemical stains for CD34, desmin, estrogen receptor, and p16 were performed. In a subset, fluorescence in situ hybridization to detect Retinoblastoma1 (RB1) gene deletion was performed. Of 395 SCLs, 331 (86%) occurred in men; 53 (14%) occurred in women (11 cases excluded). Of the 64 SCL in women, 58 had available material. In total, 53 of 58 were confirmed as SCL. Women were younger at diagnosis (median, 51 y; range, 5 to 76 y) compared with men (64 y; range, 23 to 98 y), P<0.0001, t test. SCL in women typically occurred outside the shawl distribution (36/53, 68%) compared with men (95/331, 29%) (P<0.001), including extremities (16/53, 30% vs. 32/331, 10%) and face (11/53, 21% vs. 47/331, 14%). Dermal SCL in women were also relatively common (16/53, 30%). The cases demonstrated varying proportions of bland spindled cells, ropey collagen, myxoid matrix, and adipocytes. By immunohistochemistry, 46/46 were CD34, 48 of 48 were desmin negative, 33 of 42 were estrogen receptor negative, and 29 of 42 had loss of p16 expression. In total, 12 of 14 showed RB1 loss by fluorescence in situ hybridization. SCL in women frequently occurs in unconventional locations and in at a slightly younger patient age.

  10. Ileo-colic intussusception by ileo-cecal valve lipoma - an infrequent ultrasonographic occurrence. A case report.

    PubMed

    Stancu, Bogdan; Chira, Alexandra; Chira, Romeo Ioan; Grigorescu, Ioana; Gherman, Claudia Diana; Dumitraşcu, Dan Lucian

    2016-09-01

    We present a rare cause of intestinal obstruction in an adult, due to ileo-colic intussusception by a lipoma of the ileo-cecal valve and its ultrasonographic presentation. The case presented in emergency for spontaneously appearing and disappearing palpable elastic mass in the right iliac fossa. The ultrasonographic examination raised the suspicion of an ileo-colic intussusception due to a polypoid tumor. The contrast-enhanced computed tomography confirmed the finding and suggested that the polypoid tumor was more likely a lipoma. Right hemicolectomy and cholecystectomy were performed and the pathological examination confirmed the lipoma. The evolution of the patient was favourable and uneventful.

  11. Lipoma with dumb-bell extradural extension through the intervertebral foramen into the spinal canal. Case report.

    PubMed

    Park, Jin Soo; Shirachi, Isao; Sato, Kimiaki; Ando, Noriyuki; Nagata, Kensei

    2005-01-01

    The authors present the case of a 60-year-old woman with a neck lipoma that developed dumb-bell extradural extension, causing radiculopathy. To the best of the authors' knowledge, this is the first report of a lipoma originating in the neck with dumb-bell extradural extension through the intervertebral foramen and into the spinal canal. The lipoma was first excised from the foramen via a posterior approach to allow decompression of the nerve roots. The remaining lipomatous tissue was then resected via an anterior approach to avoid the region around the vertebral artery.

  12. Intramuscular Lipoma-Induced Occipital Neuralgia on the Lesser Occipital Nerve.

    PubMed

    Han, Hyun Ho; Kim, Hak Soo; Rhie, Jong Won; Moon, Suk Ho

    2016-06-01

    Occipital neuralgia (ON) is commonly characterized by a neuralgiform headache accompanied by a paroxysmal burning sensation in the dermatome area of the greater, lesser, or third occipital nerve. The authors report a rare case of ON caused by an intramuscular lipoma originating from the lesser occipital nerve.A 52-year-old man presented with sharp pain in the left postauricular area with a 3 × 2-cm palpable mass. Computed tomography revealed a mass suspiciously resembling an intramuscular lipoma within splenius muscle. In the operation field, a protruding mass causing stretching of the lesser occipital nerve was found. After complete resection, the neuralgiform headache symptom had resolved and the intramuscular lipoma was confirmed through histopathology.Previous studies on the causes of ON have reported that variation in normal anatomic structures results in nerve compression. Occipital neuralgia, however, caused by intramuscular lipomas in splenius muscles have not been previously reported, and the dramatic resolution following surgery makes it an interesting case worth reporting.

  13. Pedunculated lipoma causing colo-colonic intussusception: a rare case report.

    PubMed

    Mouaqit, Ouadii; Hasnai, Hafid; Chbani, Leila; Oussaden, Abdelmalek; Maazaz, Khalid; Amarti, Afaf; Taleb, Khalid Ait

    2013-10-30

    Intussusception is a relatively common cause of intestinal obstruction in children but a rare clinical entity in adults, representing fewer than 1% of intestinal obstructions in this patient population. Colonic lipomas are uncommon nonepithelial neoplasms that are typically sessile, asymptomatic and incidentally found during endoscopy, surgery, or autopsy. A 55-year old man visited our emergency department with severe abdominal pain, multiple episodes of vomiting, abdominal distension. Abdominal ultrasound sonography and computed tomography showed a sausage-shaped mass presenting as a target sign, suggestive of intussusception. Surgery revealed a hard elongated mass in the right colon wihch telescoped in the transverse colon and caused colo-colonic intussusception. Rhigt hémicolectomy was performed and pathology documented a mature submucosal lipoma of the colon. We describe the difficulties in diagnosis and management of this rare cause of bowel obstruction and review the literature on adult intussusceptions. A large submucosal lipoma is a very rare cause of colon intussusception that presents as intestinal obstruction in patients without malignancy. CT and magnetic resonance imaging remain the methods of choice for studying abdominal lipomas, particularly those rising into the layers of the colonic wall. Surgical resection remains the treatment of choice and produces an excellent prognosis.

  14. Bilateral macrodystrophia lipomatosa of the upper extremities with syndactyly and multiple lipomas.

    PubMed

    van der Meer, Saskia; Nicolai, Jean-Philippe A; Schut, Simone M; Meek, Marcel F

    2011-12-01

    Macrodystrophia lipomatosa is a rare disease that causes congenital local gigantism of part of an extremity, which is characterised by an increase in all mesenchymal elements, particularly fibroadipose tissue. This is the first report to our knowledge of a case of histologically confirmed bilateral macrodystrophia lipomatosa of the upper extremities with syndactyly and multiple lipomas.

  15. Laparoscopic examination and resection for giant lipoma of the omentum: a case report and review of related literature.

    PubMed

    Shiroshita, Hidefumi; Komori, Yoko; Tajima, Masaaki; Bandoh, Toshio; Arita, Tsuyoshi; Shiraishi, Norio; Kitano, Seigo

    2009-10-01

    We report herein the case of a giant lipoma of the greater omentum that was treated by laparoscopic surgery. A 71-year-old male patient was admitted with a diagnosis of sigmoid colon cancer. During preoperative examination, a gallbladder stone and an intra-abdominal giant lipoma were accidentally diagnosed. Laparoscopic examination revealed a smooth-surfaced, giant yellow tumor at the lower border of the greater omentum that was unattached to the surrounding organs. After laparoscopic resection of the tumor and cholecystectomy, a 10-cm midline incision was made in the lower abdomen to remove the tumor and the gallbladder. We then performed a sigmoidectomy for sigmoid colon cancer through the same laparotomy. The resected tumor measured 29 x 19 x 3 cm and weighed 1250 g, and a histopathologic examination revealed a benign lipoma. Laparoscopic examination and resection of a giant lipoma of the omentum are particularly useful.

  16. Molecular characterization of the t(4;12)(q27~28;q14~15) chromosomal rearrangement in lipoma.

    PubMed

    Agostini, Antonio; Gorunova, Ludmila; Bjerkehagen, Bodil; Lobmaier, Ingvild; Heim, Sverre; Panagopoulos, Ioannis

    2016-09-01

    Lipomas are common benign soft tissue tumors whose genetic and cytogenetic features are well characterized. The karyotype is usually near- or pseudodiploid with characteristic structural chromosomal aberrations. The most common rearrangements target the high mobility group AT-hook 2 (HMGA2) gene in 12q14.3, with breakpoints occurring within or outside of the gene locus leading to deregulation of HMGA2. The most common fusion partner for HMGA2 in lipoma is lipoma-preferred partner (3q27), but also other genes frequently recombine with HMGA2. Furthermore, truncated HMGA2 transcripts are recurrently observed in lipomas. The present study describes 5 lipomas carrying the translocation t(4;12)(q27~28;q14~15) as the sole chromosomal anomaly, as well as 1 lipoma in which the three-way translocation t(1;4;12)(q21;q27~28;q14~15) was identified. Molecular analyses performed on 4 of these cases detected 4 truncated forms of HMGA2. In 3 tumors, the HMGA2 truncated transcripts included sequences originating from the chromosomal sub-band 4q28.1. Notably, in 2 of these cases, the fourth exon of HMGA2 was fused to transposable elements located in 4q28.1.

  17. Molecular characterization of the t(4;12)(q27~28;q14~15) chromosomal rearrangement in lipoma

    PubMed Central

    Agostini, Antonio; Gorunova, Ludmila; Bjerkehagen, Bodil; Lobmaier, Ingvild; Heim, Sverre; Panagopoulos, Ioannis

    2016-01-01

    Lipomas are common benign soft tissue tumors whose genetic and cytogenetic features are well characterized. The karyotype is usually near- or pseudodiploid with characteristic structural chromosomal aberrations. The most common rearrangements target the high mobility group AT-hook 2 (HMGA2) gene in 12q14.3, with breakpoints occurring within or outside of the gene locus leading to deregulation of HMGA2. The most common fusion partner for HMGA2 in lipoma is lipoma-preferred partner (3q27), but also other genes frequently recombine with HMGA2. Furthermore, truncated HMGA2 transcripts are recurrently observed in lipomas. The present study describes 5 lipomas carrying the translocation t(4;12)(q27~28;q14~15) as the sole chromosomal anomaly, as well as 1 lipoma in which the three-way translocation t(1;4;12)(q21;q27~28;q14~15) was identified. Molecular analyses performed on 4 of these cases detected 4 truncated forms of HMGA2. In 3 tumors, the HMGA2 truncated transcripts included sequences originating from the chromosomal sub-band 4q28.1. Notably, in 2 of these cases, the fourth exon of HMGA2 was fused to transposable elements located in 4q28.1. PMID:27588119

  18. Lipoma Arborescens of the Knee: Report of Three Cases and Review of the Literature

    PubMed Central

    Kapoutsis, Dimitrios; Tzavellas, Anastasios-Nektarios; Kalaitzoglou, Ioannis; Tsikes, Apostolos; Gkouvas, George

    2017-01-01

    Lipoma arborescens is a chronic, slow-growing, intra-articular lesion of benign nature, which is characterized by villous proliferation of the synovium, with replacement of the subsynovial connective tissue by mature fat cells. It usually involves the suprapatellar pouch of the knee joint. It is not a neoplasm but is rather considered a nonspecific reactive response to chronic synovial irritation, due to either mechanical or inflammatory insults. We report three cases of lipoma arborescens affecting the knee, the first in a young male without previous history of arthritis or trauma, the second in a 58-year-old male associated with osteoarthritis, and the final in a 44-year-old male diagnosed with psoriatic arthritis, which cover the entire pathologic spectrum of this unusual entity. We highlight the clinical findings and imaging features, by emphasizing especially the role of MRI, in the differential diagnosis of other, more complex intra-articular masses. PMID:28243256

  19. Unusual Association of Congenital Kyphosis and Conus Lipoma Presenting as a Double Spinal Cord Tether

    PubMed Central

    Aguiar, Carlos A; Mendoza-Lattes, Sergio; Cobb, Peter; Menezes, Arnold; Weinstein, Stuart L

    2007-01-01

    The case of a four-year-old child is described who presented to our institution with cervicothoracic deformity and a two-year history of progressive paraparesis. His past medical history was significant for meningocele which was closed at age two months. Imaging studies revealed severe congenital kyphosis with a hypoplastic t3 vertebra, as well as a tethered filum terminale with a conus lipoma. the spinal cord was found to be severely compressed at the apex of the kyphotic deformity. Discussion is focused on the diagnosis of tethered cord syndrome, and treatment options. In particular, this case required careful thought on the order of events, which followed initial tethered cord release and removal of the conus lipoma, and subsequent kyphectomy and fusion of the upper thoracic spine. A favorable clinical outcome was obtained with complete reversal of the paraparesis. PMID:17907436

  20. A symptomatic Sylvian fissure lipoma in a post-traumatic patient

    PubMed Central

    Bokhari, Rakan Farouk; Bangash, Mohammad Hasan; Ahamed, Naushad Ali Basheer; Addas, Jameel

    2014-01-01

    Lipomatous extra-axial lesions in the Sylvian fissure are a rare entity. Their identification, however, is usually simple if a systematic radiological approach is adopted. The best line of management for these lesions is still a matter of controversy and fraught with complications. We present a case of a Sylvian fissure lipoma referred to our neurosurgery services with symptomatic seizures and in a post-traumatic patient. The radiological differentiating features of intracranial lipomas and intracranial dermoids have been discussed. The unusual location of the lesion, in combination with the history of seizures and the nature of presentation (trauma being a red-herring) make this case an interesting find. The lesion was managed conservatively with good outcomes at follow up, on anti-epileptic medications. PMID:24967029

  1. Invasive Ductal Breast Carcinoma Underneath a Lipoma in a Male Patient

    PubMed Central

    Landero, James; Glick, Bradley P.

    2012-01-01

    Male breast cancer is a rare malignancy and accounts for less than one percent of all cancers in men. The authors describe the case of a 76-year-old Caucasian man with invasive ductal breast carcinoma who presented with a common lipoma. This paper reviews the current literature on epidemiology, risk factors, etiology, different types of breast cancer, clinical presentation, imaging, diagnostic workup, and treatment. PMID:23125888

  2. Gastric lipoma and pyloric obstruction in a 51-year-old woman.

    PubMed

    Furtado, W S; Mello, D A C P G; Santos, V M; Bringel, T L; Oliveira Junior, W P; Moura, H J L

    2013-01-01

    Gastric lipoma is considered a rare condition that may constitute a challenging diagnosis. A 51-year-old woman presented dysphagia and abdominal pain, and an upper digestive endoscopic study disclosed a gastric tumor located in the submucosa of the pyloric antrum. Conclusive diagnosis was established after repeated endoscopic biopsies, and the patient was subjected to an atypical gastrectomy, which evolved into a pyloric stenosis. This complication was appropriately corrected and the patient remains symptomless, under outpatient surveillance.

  3. Rare cases of benign tumors of the head and neck: lipoma of larynx and sternocleidomastoid muscle.

    PubMed

    Demir, Deniz; Eraslan, Özden; Güven, Mehmet; Kösem, Mustafa

    2016-01-01

    In this article, we report two rare cases of lipoma in the head and neck region. Thirty-four-year-old case 1 presented with hoarseness and sensation of foreign body in throat. While 54-year-old case 2 presented with complaint of a mass in left side of neck. The imaging methods showed the masses in false vocal fold and the sternocleidomastoid muscle. Diagnosis and treatment of the masses were discussed in light of the literature.

  4. Lipoma Arborescens: Review of an Uncommon Cause for Swelling of the Knee

    PubMed Central

    De Vleeschhouwer, M.; Van Den Steen, E.; Vanderstraeten, G.; Huysse, W.; De Neve, J.; Vanden Bossche, L.

    2016-01-01

    Lipoma arborescens is a rare cause of chronic monoarticular arthritis, with only a few cases reported in the literature. It is most commonly seen in the knee, but cases in other joints such as the wrist, shoulder, and elbow have also been described. It is a benign condition, in which the subsynovial tissue is replaced diffusely by mature fat cells. We describe a case involving the knee and discuss the symptoms, diagnosis, and treatment. PMID:27293937

  5. Clinics in diagnostic imaging (172). Colocolic intussusception with a lipoma as the lead point.

    PubMed

    Low, Hsien Min; Chinchure, Dinesh

    2016-12-01

    A 50-year-old Chinese man presented with abdominal pain associated with bloody mucoid stools, loss of appetite and weight loss. Contrast-enhanced computed tomography of the abdomen and pelvis revealed a colocolic intussusception secondary to a lipoma. The patient subsequently underwent a left hemicolectomy. Clinical and imaging findings of intussusception in adults are discussed in this article. Copyright: © Singapore Medical Association.

  6. Assessment of yttrium-90 citrate radiosynovectomy treatment with bone scintigraphy in lipoma arborescens.

    PubMed

    Vatankulu, Betul; Nemetyazar, Jamal; Demir, Yusuf; Samancı, Cesur; Sager, Sait

    2016-01-01

    A 37-year-old male patient presented with right knee pain and swelling. The patient had a 6-year history of rheumatoid arthritis. Physical examination was notable for swelling and tenderness of the right knee. The diagnosis of lipoma arborescens (LA) was confirmed from the magnetic resonance imaging of the right knee. Herein, we report the use of bone scintigraphy in a case of LA treated with yttrium-90 radiosynovectomy.

  7. New understanding of dorsal dysraphism with lipoma (lipomyeloschisis): radiologic evaluation and surgical correction

    SciTech Connect

    Naidich, T.P.; McLone, D.G.; Mutluer, S.

    1983-06-01

    The spinal anomaly designated dorsal dysraphism with lipoma (lipomyeloschisis) consists of skin-covered, focal spina bifida; focal partial clefting of the dorsal half of the spinal cord; continuity of the dorsal cleft with the central canal of the cord above (and occasionally below) the cleft; deficiency of the dura underlying the spina bifida; deep extension of subcutaneous lipoma through the spina bifida and the dural deficiency to insert directly into the cleft on the dorsal half of the cord; variable cephalic extension of lipoma into the contiguous central canal of the cord; and variable ballooning of the subarachnoid space to form an associated meningocele. The variable individual expressions of the anomaly are best understood by reference to their archetypal concept. Careful analysis of radiographic and surgical findings in human lipomyeloschisis and correlation with an animal model of lipomyeloschisis indicate that plain spine radiographs and high-resolution metrizamide computed tomographic myelography successfully delineate the precise anatomic derangements associated with lipomyeloschisis and provide the proper basis for planning surgical therapy of this condition.

  8. Intestinal Obstruction Caused by Ileocolic and Colocolic Intussusception in an Adult Patient with Cecal Lipoma.

    PubMed

    Casiraghi, Tiziana; Masetto, Alessandro; Beltramo, Massimo; Girlando, Mauro; Di Bella, Camillo

    2016-01-01

    Introduction. Intussusception is a rare clinical entity in adults (<1% of intestinal obstructions). Colonic intussusception is even rarer, particularly when caused by lipomas. Case Presentation. A 47-year-old woman presented to our emergency department complaining of abdominal pain with vomiting and diarrhoea. X-ray and CT showed bowel obstruction due to ileocolonic and colocolonic intussusception; a giant colonic lipoma (9 × 4 × 4 cm) was recognizable immediately distally to the splenic flexure of the colon. The patient underwent emergency laparotomy and right hemicolectomy. Assessment of the resected specimen confirmed the diagnosis of giant colonic polypoid lesion near to the ileocecal valve, causing a 12 cm long intussusception with moderate ischemic damage. Conclusion. Colonic obstruction due to intussusception caused by lipomas is a very rare condition that needs urgent treatment. CT is the radiologic modality of choice for diagnosis (sensitivity 80%, specificity near 100%); since the majority of colonic intussusceptions are caused by primary adenocarcinoma, if the etiology is uncertain, the lesion must be interpreted as malignant and extensive resection is recommended. At present, surgery is the treatment of choice and determines an excellent outcome.

  9. Intestinal Obstruction Caused by Ileocolic and Colocolic Intussusception in an Adult Patient with Cecal Lipoma

    PubMed Central

    Masetto, Alessandro; Beltramo, Massimo; Girlando, Mauro; Di Bella, Camillo

    2016-01-01

    Introduction. Intussusception is a rare clinical entity in adults (<1% of intestinal obstructions). Colonic intussusception is even rarer, particularly when caused by lipomas. Case Presentation. A 47-year-old woman presented to our emergency department complaining of abdominal pain with vomiting and diarrhoea. X-ray and CT showed bowel obstruction due to ileocolonic and colocolonic intussusception; a giant colonic lipoma (9 × 4 × 4 cm) was recognizable immediately distally to the splenic flexure of the colon. The patient underwent emergency laparotomy and right hemicolectomy. Assessment of the resected specimen confirmed the diagnosis of giant colonic polypoid lesion near to the ileocecal valve, causing a 12 cm long intussusception with moderate ischemic damage. Conclusion. Colonic obstruction due to intussusception caused by lipomas is a very rare condition that needs urgent treatment. CT is the radiologic modality of choice for diagnosis (sensitivity 80%, specificity near 100%); since the majority of colonic intussusceptions are caused by primary adenocarcinoma, if the etiology is uncertain, the lesion must be interpreted as malignant and extensive resection is recommended. At present, surgery is the treatment of choice and determines an excellent outcome. PMID:28044120

  10. Resolution of intussusception after spontaneous expulsion of an ileal lipoma per rectum: a case report and literature review

    PubMed Central

    2014-01-01

    We herein report a case of spontaneous rectal expulsion of an ileal lipoma in a 65-year-old female patient who presented with recurrent attacks of subacute intestinal obstruction. During each episode, the patient developed severe abdominal pain and expelled a fleshy mass from her rectum. The fleshy mass was histopathologically diagnosed as a lipoma comprising fat cells, fibers, and blood vessels. Upon expulsion, the pain disappeared and the intussusception was immediately resolved. Colonoscopic examination revealed a 2.5-cm diameter ulcerated lesion near the ileocecal valve, which was confirmed to be inflammation by pathological examination. A subsequent barium series revealed a normal colonic tract, and the patient remained completely symptom-free for 4 months after the incident. According to the relevant literature and our clinical experience, the treatment method for a lipoma depends on the patient’s clinical manifestations and the size of the tumor. However, the various diagnostic and therapeutic modalities currently available continue to be debated; whether an asymptomatic lipoma requires treatment is controversial. When histopathological examination results allow for the exclusion of malignant lesions such as sarcoma, a lipoma can be resected surgically. PMID:24884620

  11. A giant adrenal lipoma presenting in a woman with chronic mild postprandial abdominal pain: a case report.

    PubMed

    Kapetanakis, Stylianos; Drygiannakis, Ioannis; Tzortzinis, Anastasios; Papanas, Nikolaos; Fiska, Aliki

    2011-04-05

    Adrenal lipomas are rare, small, benign, non-functioning tumors, which must be histopathologically differentiated from other tumors such as myelolipomas or liposarcomas. They are usually identified incidentally during autopsy, imaging, or laparotomy. Occasionally, they may present acutely due to complications such as abdominal pain from retroperitoneal bleeding, or systemic symptoms of infection. We report a giant adrenal lipoma (to the best of our knowledge, the second largest in the literature) clinically presenting with chronic mild postprandial pain. A 54-year-old Caucasian woman presented several times over a period of 10 years to various emergency departments complaining of long-term mild postprandial abdominal pain. Although clinical examinations were unrevealing, an abdominal computed tomography scan performed at her most recent presentation led to the identification of a large lipoma of the left adrenal gland, which occupied most of the retroperitoneal space. Myelolipoma was ruled out due to the absence of megakaryocytes, immature leukocytes, or erythrocytes. Liposarcoma was ruled out due to the absence of lipoblasts. The size of the lipoma (16 × 14 × 7 cm) is, to the best of our knowledge, the second largest reported to date. After surgical resection, our patient was relieved of her symptoms and remains healthy six years postoperatively. Physicians should be aware that differential diagnosis of mild chronic abdominal pain in patients presenting in emergency rooms may include large adrenal lipomas. When initial diagnostic investigation is not revealing, out-patient specialist evaluation should be planned to enable appropriate further investigations.

  12. Surgical procedure "simplified retrosigmoid approach" for C-P angle lesions.

    PubMed

    Yamashima, Tetsumori; Lee, Joung H; Tobias, Samuel; Kim, Chang-Hyun; Chang, Jong Hee; Kwon, Jeong-Taik

    2004-02-01

    Previously, we reported surgical results of the simplified retrosigmoid approach for vestibular nerve sectioning in the cases with intractable vertigo. Here, we introduce in details surgical procedures of the simplified retrosigmoid (also called "subasterional" here for simplification) approach developed by one of the authors (J.H.L.). This approach is to operate cerebello-pontine (C-P) angle lesions through a small upper lateral window below the transverse-sigmoid junction. The retroauricular 4-5 cm skin incision, triangular craniectomy 2 cm in width, dural opening and closure, special considerations, and reconstruction of the skull defect were outlined. The bony landmarks for triangle craniectomy below asterion were described in detail. The C-P angle was appropriately approached for microvascular decompression, removal of C-P angle tumors, and vestibular nerve resection. This subasterional approach was characterized by short operation time of 1-3 h and less postoperative discomforts compared to the conventional retrosigmoid approach.

  13. The General Surgeon’s Quandary: Atypical Lipomatous Tumor vs Lipoma, Who Needs a Surgical Oncologist?

    PubMed Central

    Fisher, Sarah B; Baxter, Katherine J; Staley, Charles A; Monson, David K; Murray, Douglas R; Oskouei, Shervin V; Weiss, Sharon W; Kooby, David A; Maithel, Shishir K; Delman, Keith A

    2013-01-01

    Background Differentiating large lipomas from atypical lipomatous tumors (ALT) is challenging and preoperative management guidelines are not well-defined. The diagnostic ambiguity leads many surgeons to refer all patients with large lipomatous masses to an oncologic specialist, perhaps unneccessarily. Study Design In this retrospective cohort study of patients with nonretroperitoneal lipomatous tumors, preoperative characteristics discernible without invasive diagnostic procedures were evaluated for diagnostic predictive value. Results 319 patients (256 with lipomas, 63 with ALTs) treated between 1994 and 2012 were identified. Patients with ALTs were older (60.5 vs. 53.5 years, p<0.0001), had larger tumors (16.0 vs 8.3 cm, p<0.0001), had tumors more often located on an extremity (88.9% vs. 60.5% torso, p<0.0001), and more frequently had a history of prior operations at the same site, exclusive of excision leading to diagnosis and referral (20.6% vs. 5.9%, p=0.001). Local recurrence was observed in 2 patients with lipomas (0.8%) vs. 14 with ALTs (22.6%, p<0.0001). No patients with ALTs developed distant metastases or disease-specific mortality with a median follow-up of 27.4 months (range 0–164.6 months). On multivariate analysis age ≥55 years, tumor size ≥10 cm, extremity location, and history of prior operations were predictors for diagnosis of ALT (p<0.05). Conclusions Characteristics of lipomatous masses that are associated with a diagnosis of ALT include patient age ≥55 years, tumor size ≥10 cm, previous resection, and extremity location (vs torso). These easily identifiable traits may guide surgical management or referral to a specialist. PMID:24074812

  14. Endobronchial lipomatous tumors: clinicopathologic analysis of 12 cases with molecular cytogenetic evidence supporting classification as "lipoma".

    PubMed

    Boland, Jennifer M; Fritchie, Karen J; Erickson-Johnson, Michele R; Oliveira, Andre M; Colby, Thomas V; Folpe, Andrew L

    2013-11-01

    Lipomatous lesions rarely involve the bronchial tree, and detailed morphologic and molecular cytogenetic analysis of these tumors is lacking. The clinicopathologic features of 12 endobronchial lipomatous neoplasms were studied, with ancillary fluorescence in situ hybridization performed in subsets of cases for CPM, which is amplified in atypical lipomatous tumors/well-differentiated liposarcomas (ALT/WDL), and HMGA1 and HMGA2, which are often rearranged in lipomas. The cases occurred predominately in older men (91%) (age range 44 to 80 y, mean 65 y). Most patients (80%) had a former or current history of heavy smoking (20 to 100 pack-years). Three patients had concurrent pulmonary squamous cell carcinoma, and 1 had a history of multiple lung cancers. Most lesions were small (<2.5 cm) and discovered incidentally. A subset of tumors showed atypical morphologic features that would be suggestive of ALT/WDL in soft tissue sites, including regions of fibrosis and scattered hyperchromatic stromal cells. However, all cases with atypia were CPM negative and behaved in a clinically benign manner. Seven cases were tested for HMGA1 and HMGA2 rearrangement; 4 showed HMGA2 rearrangement, and 1 showed HMGA1 rearrangement, consistent with lipomas. Two cases were negative for HMGA1/2 rearrangements. We conclude that endobronchial lipomatous neoplasms represent lipomas, even in the presence of morphologic features suggestive of ALT/WDL. Ancillary fluorescence in situ hybridization testing may be very valuable in the analysis of these rare tumors, as true ALT/WDL seem to be very rare or nonexistent at this anatomic site.

  15. Dysphagia Caused by Spindle Cell Lipoma of Hypopharynx: Presentation of Clinical Case and Literature Review

    PubMed Central

    Peña-Valenzuela, Alberto; García León, Nathalia

    2012-01-01

    Spindle cell lipoma of the hypopharynx is an extremely rare entity. Here, we present the first case of this lesion originated in the cricopharyngeal region, with symptoms of chronic progressive dysphagia, which can be confused with other pathologies; endoscopic and magnetic resonance imaging (MRI) evaluation are the methods of choice for its diagnostic approach. The best therapeutic approach is endoscopic resection with rapid recovery and few complications. Long-term followup is recommended, either endoscopic or imaging, given that it can be confused with an undiagnosed liposarcoma; additionally, its long-term behavior is unknown. PMID:23326743

  16. [Lipoma as the cause of intussusception of the rectum in a 46-year-old woman].

    PubMed

    Sørensen, Jeanette; Nygaard, Helene

    2013-03-04

    We present a case with a 46-year-old woman who had experienced six days of abdominal pain and some days of anal bleeding. She had no prior medical history. At the clinical examination it was found that she had a soft abdomen, but there was tenderness in the lower part. A computed tomography showed an intussusception of the sigmoideum into the rectum. An oncological resection was performed, since it could not at the time of the operation be determined if it was a malignant proces. The histology showed a benign submucosal lipoma.

  17. Jejunojejunal intussusception secondary to submucosal lipoma resulting in a 5-year history of intermittent abdominal pain.

    PubMed

    Seow-En, Isaac; Foo, Fung Joon; Tang, Choong Leong

    2014-10-29

    Jejunal lipomata are an unusual cause of adult intussusception. We report a case of a 44-year-old Chinese woman who presented with a 3-day history of abdominal pain and nausea; she had a 5-year history of similar episodic symptoms after meals. Contrast-enhanced CT revealed a fat-density lead point in the jejunum resulting in intussusception. Single port laparoscopic surgery was performed with reduction of the intussusception, bowel resection and primary anastamosis. Histology confirmed a benign submucosal lipoma. We discuss the recent published literature on this rare entity and show CT images and intraoperative pictures. 2014 BMJ Publishing Group Ltd.

  18. Arthroscopic Marginal Resection of a Lipoma of the Supraspinatus Muscle in the Subacromial Space

    PubMed Central

    Pagán Conesa, Alejandro; Aznar, Carlos Verdú; Herrera, Manuel Ruiz; Lopez-Prats, Fernando Anacleto

    2015-01-01

    Subacromial impingement syndrome is a common cause of shoulder pain in young adults and seniors at present. The etiology of this syndrome is associated with several shoulder disorders, most related to aging, overhead activities, and overuse. The subacromial space is well circumscribed and limited in size, and soft-tissue growing lesions, such as tumors, can endanger the normal function of the shoulder girdle. We present a case of shoulder impingement syndrome caused by an intramuscular lipoma of the supraspinatus muscle in the subacromial space in a 50-year-old male bank manager. Radiographs, magnetic resonance imaging, and a computed tomography scan showed a well-circumscribed soft-tissue tumor at the supraspinatus-musculotendinous junction. It was arthroscopically inspected and dissected and complete marginal excision was performed through a conventional augmented anterolateral portal, avoiding the need to open the trapezius fascia or perform an acromial osteotomy. Microscopic study showed a benign lipoma, and the shoulder function of the patient was fully recovered after a rehabilitation period of 4 months. This less invasive technique shows similar results to conventional open surgery. PMID:26759779

  19. A case of gastric lipoma resected by endoscopic submucosa dissection with difficulty in preoperative diagnosis.

    PubMed

    Ichinose, Mizue; Hikichi, Takuto; Kanno, Yukiko; Gunji, Naohiko; Fujita, Masashi; Kuroda, Masahito; Terashima, Kumiko; Sato, Yoshinori; Kawana, Satoshi; Hashimoto, Yuko; Ohira, Hiromasa; Miyata, Masayuki

    2017-09-14

    A 66-year-old man was referred to our hospital with an increasing subepithelial lesion in the gastric antrum. Using esophagogastroduodenoscopy, a tumor with a steep, 20-mm-high rise protruding in the lumen was observed. The mucosal surface of the tumor was reddish, with ulcers forming at the base. Moreover, the tumor was mobile and soft. A biopsy specimen was taken from the ulcer, but tumor tissue was not collected from the submucosa. Endoscopic ultrasonography (EUS) showed a high echoic mass in the submucosa. However, because the mucosal surface of the ulceration was red, the mesenchymal tumor with internal bleeding was inferred to be lipoma. Additionally, because the tumor was small, flexible, and soft, collecting tumor tissue under EUS-guided fine-needle aspiration was inferred as difficult. We were unable to make a final diagnosis because the lesion showed a small tumor with atypical macroscopic morphology. Therefore, endoscopic submucosa dissection (ESD) was chosen for the diagnostic treatment. Sodium hyaluronate sufficient for separation from the muscular layer was injected into the submucosa. Then submucosal dissection was performed just above the muscle layer. Results demonstrate the possibility of removing the tumor reliably without perforation. Pathological evaluation of the ESD specimen indicated a diagnosis of gastric lipoma.

  20. Painful total hip replacement due to sciatic nerve entrapment in scar tissue and lipoma.

    PubMed

    Wettstein, Michael; Garofalo, Raffaele; Mouhsine, Elyazid

    2010-11-01

    Painful total hip replacement remains a challenging problem because of the large amount of possible diagnoses. We report about a 64-year-old female patient who was misdiagnosed during 4 years as psychiatric. She suffered of excruciating left retrotrochanteric pain after the implantation of a cementless total hip replacement and revision because of recurrent hip dislocations. Walking was limited to short distances using two crutches. The work-up at this time included the usual diagnoses and remained unsuccessful. No loosening, infection or malposition of the prosthesis could be found, and she had no neurologic deficits in her operated leg. An MRI was obtained to visualize the retrotrochanteric soft tissues and showed a tight scar surrounding the sciatic nerve, which was also compressed by an adjacent lipoma. Therefore, she was reoperated on to remove the lipoma and the scar tissue around the sciatic nerve. To decrease the risk of recurrent scarring around the sciatic nerve, an adhesion barrier was applied before closure. One year after the operation, the patient has no neurologic deficit, no more pain and is able to walk unlimited distances without crutches. Scar tissue around the sciatic nerve is frequently observed during revision surgery. However, we feel that sciatic nerve entrapment by scar tissue should be a part of the differential diagnosis of painful THR. MRI may be a useful tool to achieve this diagnosis.

  1. Adult ileoileal intussusception induced by an ileal lipoma diagnosed preoperatively: report of a case and review of the literature.

    PubMed

    Namikawa, Tsutomu; Hokimoto, Norihiro; Okabayashi, Takehiro; Kumon, Masamitsu; Kobayashi, Michiya; Hanazaki, Kazuhiro

    2012-07-01

    We herein report a case of adult ileoileal intussusception induced by an ileal lipoma. A 68-year-old woman with a history of small intestinal tumors was admitted to our hospital with severe, colicky lower abdominal pain, similar to episodes experienced in the past. A barium meal enema at the initial admission demonstrated a small intestinal tumor in the ileum 30 cm proximal to the ileocecal valve. Abdominal ultrasound sonography and computed tomography showed a sausage-shaped mass presenting as a target sign in the right lower abdomen, suggestive of intussusception. There was also a round mass of fat attenuation representing a lipoma, which was considered the lead point of the intussusception. The patient underwent emergency surgery and partial resection of the ileum, including the ileal tumor, following reduction of the intussusception. The resected specimen contained a round tumor measuring 1.5 × 1.5 × 1.4 cm, which was diagnosed histopathologically as an intestinal lipoma. The patient made a satisfactory recovery and was discharged on postoperative day 10. The clinical characteristics of previously reported lipomas with intussusception are also discussed, including the relationships between the tumor size and symptoms or location.

  2. Intraneural lipoma of the radial nerve presenting as Wartenberg syndrome: A case report and review of literature

    PubMed Central

    Balakrishnan, Chenicheri; Bachusz, Rebecca C; Balakrishnan, Anila; Elliot, David; Careaga, Daniel

    2009-01-01

    The superficial branch of the radial nerve is highly vulnerable to trauma, irritation and compression due to its anatomical location. Intraneural lipomas and fibrolipomas arising from the supporting tissues of this peripheral nerve can cause compression of the adjacent nerve leading to symptoms of neuritis of the radial nerve or Wartenberg syndrome. PMID:21119833

  3. The modified lateral supraorbital approach for tumors of the petroclival junction extending into the anterior cerebellopontine area.

    PubMed

    Lim, Jaejoon; Cho, Kyunggi

    2016-05-01

    Various surgical approaches for the removal of meningioma and trigeminal schwannoma in the petroclival junction (PCJ) and anterior cerebellopontine area (CPA) have been described previously. In this study, we compared the surgical outcomes of the combined petrosal approach and a modified lateral supraorbital (MLSO) approach and evaluated the reliability and safety of the MLSO approach. Fifty patients underwent surgical treatment using the combined petrosal or MLSO approach between 1996 and 2011. We retrospectively analyzed the clinical data and compared the two approaches. Among 50 patients, 27 patients underwent operation through the combined petrosal approach and 23 underwent operation through the MLSO approach. The operation time of the MLSO approach was significantly shorter than that of the combined petrosal approach (p = 0.03). There was no significant difference in the gross total resection rate between the two approaches (p = 0.67). After the operation, the improvement in Karnofsky performance score and Mean Glasgow outcomes scales were better in the MLSO approach, but without statistical significance (p = 0.723, p = 0.20 respectively). Complications occurred more often with the combined petrosal approach than with MLSO. Facial nerve palsy was the most common complication, followed by hearing difficulty. The frequency of these two complications was higher in the combined petrosal approach. Various tumors occurring in the PCJ and anterior CPA remain a challenging problem for neurosurgeons. The new modified approach of MLSO yielded good surgical results for these tumors compared to the combined petrosal approach. Therefore, the MLSO approach might be a good option for removal of tumors in the PCJ including anterior CPA.

  4. Craniofacial Features Resembling Frontonasal Dysplasia with a Tubulonodular Interhemispheric Lipoma in the Adult 3H1 tuft Mouse

    PubMed Central

    Fong, Keith S. K.; Cooper, Tiffiny Baring; Drumhiller, Wallace C.; Somponpun, Jack; Yang, Shiming; Ernst, Thomas; Chang, Linda; Lozanoff, Scott

    2012-01-01

    Intracranial lipomas are rare, but 45% of them occur along the midline cisterns between the hemispheres and are often associated with corpus callosum hypoplasia and craniofacial defects. They are difficult to detect, as they are generally asymptomatic and visible by MRI or by postmortem examination. The exact cause of these interhemispheric lipomas is not known, but they arise from a developmental defect resulting in the maldifferentiation of mesenchymal cells into mesodermal derivatives that are not normally present. We have identified a new mouse mutant called tuft, exhibiting a forebrain, intracranial lipoma with midline craniofacial defects resembling frontonasal dysplasia (FND) that arose spontaneously in our wild-type 3H1 colony. The tuft trait appears to be transmitted in recessive fashion, but approximately 80% less frequent than the expected Mendelian 25%, due to either incomplete penetrance or prenatal lethality. MRI and histological analysis revealed that the intracranial lipoma occurred between the hemispheres and often protruded through the sagittal suture. We also observed a lesion at the lamina terminalis that may indicate improper closure of the anterior neuropore. We have mapped the tuft trait to within an 18 cM region on mouse chromosome 10 by microsatellite linkage analysis and identified several candidate genes involved with craniofacial development and cellular differentiation of adipose tissue. tuft is the only known mouse model for midline craniofacial defects with an intracranial lipoma. Identifying the gene(s) and mutation(s) causing this early developmental defect will help us understand the pathogenesis of FND and related craniofacial disorders. PMID:22246904

  5. Cerebellopontine angle tumors in young children, displaying cranial nerve deficits, and restricted diffusion on diffusion-weighted imaging: a new clinical triad for atypical teratoid/rhabdoid tumors.

    PubMed

    Katz, Joel S; Peruzzi, Pier Paolo; Pierson, Christopher R; Finlay, Jonathan L; Leonard, Jeffrey R

    2017-05-01

    Atypical teratoid/rhabdoid tumors (AT/RT) of the central nervous system (CNS) are rare, highly malignant neoplasms that carry a poor prognosis. Even with prompt diagnosis, gross total resection and early initiation of intensive adjuvant therapy, the majority of patients will succumb within 9-12 months of diagnosis. The CPA location in children harbors lesions along a wide spectrum varying from benign to highly malignant. Imaging features of lesions within the CPA that aid the diagnostic process will help to initiate early treatment in higher-grade lesions. We report three cases, in very young children, all with cranial nerve deficits, who displayed CPA lesions with restricted diffusion on diffusion-weighted imaging (DWI) with pathology confirming AT/RT. We propose that in young children with a CPA tumor diffusion-weighted imaging should be routinely evaluated to aid in prompt management. In addition, the diagnosis of AT/RT should be highly suggestive in infants presenting with cranial nerve findings as well as DWI restricted diffusion within the CPA.

  6. Superior and anterior inferior cerebellar arteries and their relationship with cerebello-pontine angle cranial nerves revisited in the light of cranial cephalometric indexes: a cadaveric study.

    PubMed

    Habibi, Zohreh; Meybodi, Ali Tayebi; Maleki, Farid; Tabatabai, Seyed

    2011-01-01

    The aim was to clarify the anatomical features of the superior and anterior inferior cerebellar arteries in relation to the trigeminal nerve and acoustic-facial complex and to the bony structures of the skull in a sample of male Iranian cadavers. Bilateral dissections, calvariectomy, and brain evacuation were performed on 31 adult human fresh brains and skull bases to assess the neurovascular associations, and skull base morphometry. Equations were defined to estimate posterior fossa volume and the relationships between bony and neurovascular elements. Eight SCAs were duplicated from origin. There were 9 cases of SCA-trigeminal contacts, which were at the root entry zone in 7. Mean distance from the origin of AICA to the vertebrobasilar junction was 11.80 mm, while 79% of AICAs originated from the lower half of the BA. This was significantly associated with "posterior fossa funneling" and "basilar narrowing" indexes. In most cases AICA crossed the acoustic-facial complex and coursed between neural bundles (48.3%). The AICA reached or entered the internal acoustic canal in 22.6% of cases and was medial to porous in 77.4%. We documented anatomical variations of the superior and anterior inferior cerebellar arteries along with some cephalometric equations with relevant neurovascular anatomy in Iranian cadavers.

  7. Cytohistological Features of Spindle Cell Lipoma- A Case Report with Differential Diagnosis

    PubMed Central

    Khatib, Yasmeen; Shah, Vinaya B; Khare, Manisha S

    2017-01-01

    Spindle Cell Lipoma (SCL) is an uncommon benign tumour of adipose tissue that is usually superficially located in the neck, back and shoulder region. Although it has characteristic histological features it can pose a diagnostic dilemma on cytology. It presents with a mixture of spindle cells, adipocytes, collagen fibres and a myxoid matrix in varying proportions sometimes with mild pleomorphism. Hence, it can be mistaken for other spindle cell, adipose and myxoid tumours which can be benign or malignant. We present a case of SCL of the back in a 47-year-old male, who presented with a slow growing lesion. Fine Needle Aspiration Cytology (FNAC) showed the characteristic cytological features described above and a diagnosis could be given after clinical correlation. We report this case as the cytology of this uncommon tumour has been described in relatively few cases and a correct pre-operative diagnosis will aid in proper management of this tumour. PMID:28384874

  8. Posterior interosseous nerve discontinuity due to compression by lipoma: report of 2 cases.

    PubMed

    Maldonado, Andrés A; Howe, Benjamin M; Spinner, Robert J

    2017-05-01

    Paralysis of the posterior interosseous nerve (PIN) secondary to compression is a rare clinical condition. Entrapment neuropathy may occur at fibrous bands at the proximal, middle, or distal edge of the supinator. Tumors are a relatively rare but well-known potential cause. The authors present 2 cases of PIN lesions in which compression by a benign lipoma at the level of the elbow resulted in near transection (discontinuity) of the nerve. They hypothesize a mechanism-a "sandwich effect"-by which compression was produced from below by the mass and from above by a fibrous band in the supinator muscle (i.e., the leading edge of the proximal supinator muscle [arcade of Fröhse] in one patient and the distal edge of the supinator muscle in the other). A Grade V Sunderland nerve lesion resulted from the advanced, chronic compression. The authors are unaware of a similar case with such an advanced pathoanatomical finding.

  9. A rare case of dumb-bell lipoma of the sole.

    PubMed

    Satish, Chetan

    2011-12-01

    A rare case of dumb-bell shaped lipoma of sole of foot in a middle aged lady which had crippled her life for almost a decade in-spite of multiple surgeries. She was initially misdiagnosed to have a corn on her sole and had undergone 3 surgeries spanning about 5 years. Due to the big size of the soft tissue swelling an MRI was done which showed a dumb-bell shaped swelling of foot. A major portion of swelling was lying deep to the plantar fascia after breaching the fascia. She underwent an excision of the swelling and is free of any recurrence after 2 years. She is now able to walk with a normal gait.

  10. Angle detector

    NASA Technical Reports Server (NTRS)

    Parra, G. T. (Inventor)

    1978-01-01

    An angle detector for determining a transducer's angular disposition to a capacitive pickup element is described. The transducer comprises a pendulum mounted inductive element moving past the capacitive pickup element. The capacitive pickup element divides the inductive element into two parts L sub 1 and L sub 2 which form the arms of one side of an a-c bridge. Two networks R sub 1 and R sub 2 having a plurality of binary weighted resistors and an equal number of digitally controlled switches for removing resistors from the networks form the arms of the other side of the a-c bridge. A binary counter, controlled by a phase detector, balances the bridge by adjusting the resistance of R sub 1 and R sub 2. The binary output of the counter is representative of the angle.

  11. Rare association in a female DSD case of phallus, accessory phallic urethra, perineal lipoma and anterior ectopic anus.

    PubMed

    Mahalik, Santosh Kumar; Mahajan, Jai Kumar; Sodhi, Kushaljit Singh; Garge, Saurabh; Vaiphei, Kim; Rao, Kattragadda L

    2013-02-01

    Disorders of sex differentiation (DSD) are a heterogeneous and broad spectrum group of diseases with a varied appearance. Presence of an accessory phallus with a phallic urethra in association with a normal vagina in a female is an extremely uncommon anomaly. We present a rare case of a genotypically female child with a normal urethra and vagina in association with a phallus, accessory phallic urethra, perineal lipoma and anterior ectopic anus.

  12. Adult intussusceptions caused by a lipoma in the jejunum: report of a case and review of the literature.

    PubMed

    Mouaqit, Ouadii; Hasnai, Hafid; Chbani, Leila; Benjelloun, Bachir; El Bouhaddouti, Hicham; Ibn El Majdoub, Karim; Toughrai, Imane; Laalim, Said Ait; Oussaden, Abdelmalek; Maazaz, Khalid; Amarti, Afaf; Taleb, Khalid Ait

    2012-08-22

    Intussusceptions in adults is rare. Gastrointestinal lipomas are rare benign tumors and intussusceptions due to a gastrointestinal lipoma constitutes an infrequent clinical entity. Lipoma may develop as a benign tumor in all organs and rarely in large or small intestine. The present report describes a case of jejunojejunal intussusceptions in an adult with a history of colicky upper abdominal pain. Ileo-ileal invagination was diagnosed by computed tomography scan. Exploratory laparotomy revealed jejunojejunal intussusceptions secondary to a lipoma which was successfully treated with segmental intestinal resection. A review of the literature is also performed regarding this rare association revealing the diagnostic and therapeutic debates that exist. ABSTRACT (FRENCH): L'invagination chez les adultes est rare. Les lipomes gastro-intestinaux sont de rares tumeurs bénignes et l'invagination intestinale due à un lipome gastro-intestinal constitue une entité clinique trés rare. Le lipome peut se développer comme une tumeur bénigne dans tous les organes et rarement dans l'intestin grêle ou le colon. Le présent rapport décrit un cas d'invagination jéjunojéjunale chez un adulte avec une histoire de douleurs abdominales. Iléo-iléale invagination a été diagnostiquée par tomodensitométrie. Une laparotomie exploratrice a révélé l'existence d'une invagination jéjunojéjunale secondaire à un lipome qui a été traitée avec succès par une résection intestinale segmentaire. Une revue de la littérature est également effectuée au sujet de cette association rare révélant les débats diagnostiques et thérapeutiques qui existent.

  13. Laparoscopic management of an octogenarian adult intussusception caused by an ileal lipoma suspected preoperatively: a case report.

    PubMed

    Shimazaki, Jiro; Nakachi, Takeshi; Tabuchi, Takanobu; Suzuki, Shuji; Ubukata, Hideyuki; Tabuchi, Takafumi

    2015-02-22

    Adult intussusception is rare and usually caused by a tumor acting as the lead point. Therefore, laparotomy should be considered for the treatment. Laparoscopic procedures for use in cases of adult intussusception have been recently reported; however, there is no consensus regarding the safety and efficacy. Here, we describe a successful case of laparoscopic management of an octogenarian adult intussusception caused by an ileal lipoma, which was preoperatively suspected. An 87-year-old male presented with progressive abdominal distention and vomiting. Contrast radiography of the small intestine showed an ileal tumor, and magnetic resonance imaging indicated a target-like mass, consistent with an ileal intussusception. The patient was suspected with an intussusception due to an ileal lipoma, and laparoscopic surgery was performed. An approximately 10-cm-long ileal intussusception with a preceding tumor was present, and partial resection of the ileum, including the tumor, was performed. Macroscopic examination of the excised specimen showed a pedunculated tumor measuring 4.0 × 3.5 × 1.9 cm with an uneven surface, yielding a histological diagnosis of lipoma. The patient had an uneventful recovery and was discharged on postoperative day 8. This successful case showed that laparoscopic surgery can be a useful, safe, and efficacious procedure for adult intussusception, even in octogenarians.

  14. [Bilateral cerebellopontine arachnoid cyst].

    PubMed

    Gelabert-Gonzalez, M; Aran-Echabe, E; Pita-Buezas, L

    2016-06-16

    Introduccion. Los quistes aracnoideos bilaterales del angulo pontocerebeloso son excepcionales, y unicamente existen tres casos publicados en la bibliografia. Caso clinico. Niña de 14 años, previamente sana, que acude a consultas por presentar cefalea bifrontal de seis semanas de evolucion. La exploracion clinica era normal y la resonancia magnetica craneal mostraba dos lesiones extraaxiales localizadas en ambos angulos pontocerebelosos, siendo ligeramente mayor la izquierda. Las lesiones se comportaban como homogeneamente intensas en T1 e hiperintensas en T2, no captaban contraste y no existia restriccion en las secuencias de difusion. No se indico tratamiento quirurgico. Conclusiones. Los quistes aracnoideos bilaterales situados en el angulo pontocerebeloso son excepcionales. La principal indicacion para el tratamiento quirurgico es la presencia de sintomas o signos neurologicos coincidentes con la localizacion de los quistes.

  15. Management of intraneural fibro-lipoma of the median nerve and the role of Pressure-Specified Sensory Device (PSSD) for the patient's motor and sensorial evaluations.

    PubMed

    Sever, Celalettin; Sahın, Cihan; Bayram, Yalcın; Kapı, Emin; Kulahcı, Yalcın; Berber, Ufuk; Incedayı, Mehmet; Uygur, Fatih

    2013-01-01

    The intraneural fibro-lipoma is a benign, uncommon tumor which is characterised with infiltration of the epineurium and perineurium by fibrofatty tissue. The preoperative diagnosis is difficult. However, the Pressure-Specified Sensory Device (PSSD) may support identifying the earliest stages of intraneural fibro-lipoma when traditional electrodiagnostic testing will not be able to detect a change in peripheral nerve function. Five patients (3 male, 2 female, age 23-53; mean 41 years) with intraneural fibro-lipoma were operated on. Grip strength, pinch strength and sensorial functions were assessed in all patients before surgery and at the end of the follow-up period by PSSD. The patients were followed-up for 7 to 24 months (mean; 12 month). All patient's condition improved dramatically following the operation and all patients had total relief of pain and paresthesia. The decompression of intraneural fibro-lipoma of the nerve with limited excision and epineurotomy without sacrificing the main nerve and its branches is the ideal surgical procedure. We recommend the use of PSSD in the investigation of patients with peripheral nerve compression, and chronic unusual volar forearm and wrist swelling. PSSD is an important tool for pre-operative evaluation and diagnosis of intraneural fibro-lipoma.

  16. Grynfeltt Hernia: A Deceptive Lumbar Mass with a Lipoma-Like Presentation

    PubMed Central

    Zadeh, Jonathan R.; Buicko, Jessica L.; Patel, Chetan; Kozol, Robert; Lopez-Viego, Miguel A.

    2015-01-01

    The Grynfeltt-Lesshaft hernia is a rare posterior abdominal wall defect that allows for the herniation of retro- and intraperitoneal structures through the upper lumbar triangle. While this hernia may initially present as a small asymptomatic bulge, the defect typically enlarges over time and can become symptomatic with potentially serious complications. In order to avoid that outcome, it is advisable to electively repair Grynfeltt hernias in patients without significant contraindications to surgery. Due to the limited number of lumbar hernioplasties performed, there has not been a large study that definitively identifies the best repair technique. It is generally accepted that abdominal hernias such as these should be repaired by tension-free methods. Both laparoscopic and open techniques are described in modern literature with unique advantages and complications for each. We present the case of an unexpected Grynfeltt hernia diagnosed following an attempted lipoma resection. We chose to perform an open repair involving a combination of fascial approximation and dual-layer polypropylene mesh placement. The patient's recovery was uneventful and there has been no evidence of recurrence at over six months. Our goal herein is to increase awareness of upper lumbar hernias and to discuss approaches to their surgical management. PMID:26697256

  17. Prolapsed giant sigmoid lipoma: a rare cause of adult ischaemic intussusception.

    PubMed

    Elliott, Mark; Martin, Jennifer; Mullan, Fred

    2014-05-22

    Intussusception is a rare cause of obstruction in adults and has a variable, non-specific presentation. Adult intussusception is usually associated with an underlying organic pathology, such as a benign or malignant tumour which acts as the lead point. Prolapse of the lead-point mass through the anal canal is an extremely rare presentation with very few reported cases in the literature. We describe a case of a 67-year-old man who presented with rectal prolapse of a large soft tissue mass. CT of the abdomen and barium enema revealed partial intussusception of an upper sigmoid lipomatous polyp. Examination under anaesthesia was performed and the prolapse reduced. A laparoscopic sigmoid colectomy was planned. The patient subsequently re-presented clinically unwell with a recurrent necrotic prolapsing mass. Laparotomy and sigmoid colectomy was performed and the patient recovered fully. The resected mass was a 7×4.5×4.0 cm necrotic sigmoid lipoma. 2014 BMJ Publishing Group Ltd.

  18. [Wide resection of chest wall for intramuscular lipoma in serratus anterior muscle reconstructed by autologous tissue;report of a case].

    PubMed

    Mizuno, Kiyomichi; Urabe, Norikazu; Nakatsuka, Kazuhiko; Ishikawa, Kayoko; Eguchi, Masanobu

    2015-02-01

    A 60-years-old man with a right lateral chest wall mass visited our hospital. There was a mass of 50×45 mm on the 5th rib. The mild atypical cells were detected by the percutaneous needle biopsy, and the tumor was resected with the chest wall of which detect was reconstructed with fascia lata and latissimus dorsi muscle cutaneous flap. Pathological diagnosis was lipoma in the serratus anterior muscle. The postoperative course was uneventful without paradoxical respiration and surgical site infection. Since intramuscular lipoma is very rare and is reported to have a risk of recurrence, careful observation is necessary.

  19. Ileocolocolic intussusception secondary to a submucosal lipoma: an unusual cause of intermittent abdominal pain in a 62-year-old woman.

    PubMed

    Kuzmich, Siarhei; Connelly, James P; Howlett, David C; Kuzmich, Tatsiana; Basit, Rizwan; Doctor, Cyrus

    2010-01-01

    We present a case of subacute nonobstructing ileocolocolic intussusception secondary to a submucosal lipoma and a mobile cecum diagnosed sonographically in a 62-year-old woman. The patient was seen following a 2-month history of nonspecific intermittent pain in the right and middle abdomen and weight loss. Sonography revealed ongoing intussusception involving distal ascending and transverse colon. Analysis of the distal intussusception end demonstrated a 3.0 x 2.5 cm echogenic polypoid lesion consistent with a lipoma serving as a lead point. The sonographic diagnosis was confirmed at surgery. (c) 2009 Wiley Periodicals, Inc. J Clin Ultrasound, 2010.

  20. Surgical treatment for lumbar hyperlordosis after resection of a spinal lipoma associated with spina bifida: A case report.

    PubMed

    Sato, Tatsuya; Yonezawa, Ikuho; Onda, Shingo; Yoshikawa, Kei; Takano, Hiromitsu; Shimamura, Yukitoshi; Okuda, Takatoshi; Kaneko, Kazuo

    2017-09-01

    A hyperlordosis deformity of the lumbar spine is relatively rare, and surgical treatment has not been comprehensively addressed. In this case report, we describe the clinical presentation, surgical treatment, and medium-term follow-up of a patient presenting with a progressive lumbar hyperlordosis deformity after resection of a spinal lipoma associated with spina bifida. The patient was a 20-year-old woman presenting with a progressive hyperlordosis deformity of the lumbar spine associated with significant back pain (visual analog pain score of 89/100 mm), but with no neurological symptoms. The lumbar lordosis (LL), measured on standing lateral view radiographs, was 114°, with a sagittal vertical axis (SVA) of -100 mm. The patient had undergone excision of a lipoma, associated with spina bifida of the lumbar spine, at 7 months of age.She was first evaluated at our hospital at 18 years of age for progressive spinal deformity and lumbago. An in situ fusion, from T5 to S1, using pedicle screws with bone graft obtained from the iliac crest, was performed. Postoperatively, the LL decreased to 93°, and the SVA decreased to -50 mm. The decision to not correct the hyperlordosis deformity fully was intentional. Seven years and 1 month postsurgery, the patient had no limitations in standing and walking and reported a pain score of 8/100 mm; there was no evidence of a loss of correction. Lumbar hyperlordosis after resection of a spinal lipoma associated with spina bifida is rare. Posterior fixation provided an effective treatment in this case. As the lumbar hyperlordosis deformity is often high, correction can be difficult. In this case, although the correction and fusion were performed in situ, there was no progression of either the deformity or the lumbago. Early detection remains an essential component of effective treatment, allowing correction when the spinal deformity is easily reversible.

  1. The value of intraoperative neurophysiological monitoring for microsurgical removal of conus medullaris lipomas: a 12-year retrospective cohort study

    PubMed Central

    2014-01-01

    Background Lipomas in the lower spinal canal can lead to progressive neurological deficits, so they may have to be surgically removed. Intraoperative neurophysiological monitoring serves to minimize the morbidity of the surgical procedure. However, so far there are no evidence-based recommendations which type of monitoring procedure or combination of procedures to choose. Methods The aim of this study was to evaluate the feasibility and value of various intraoperative monitoring techniques: motor and sensory evoked potentials (MEP, SEP), free-running and triggered electromyography (EMG). Thirty cases of spinal lipomas of the Conus medullaris (dorsal Type A: 20.0%; caudal Type B: 33.3%; transitional Type C: 46.7%) were retrospectively evaluated over a 12-year period. Results The patients were mostly pediatric and suffered from persistent pain (73.3%), pareses (56.7%), sensory deficits (43.4%), and/or urogenital dysfunctions (60.0%). SEPs were successfully evoked in 66.7% of cases, MEPs in 86.7% of cases, and EMGs in 100%. MEP alterations correlated with direct mechanical maneuvers in the operating site. SEP changes correlated mostly with physiological events, such as rinsing/cooling of the operating site. Spike-, burst- or tonic train-activity was found in the free-running EMG that occurred only with certain manipulation patterns. Irreversible MEP changes and signal loss in the triggered EMG correlated with post-operative deficits. Conclusions The results of this study showed, that intraoperative monitoring could be considered a helpful tool during lipoma tumor surgery near the Conus medullaris. Most reliable results were obtained from transcranial MEPs, free-running EMGs, and triggered EMGs. That’s why the authors favor a routine set-up consisting of at least these three techniques, as this enables mapping at the beginning of the operation, continuous functional testing during surgery, and prognosis of the post-operative symptomology. PMID:25473420

  2. [Intracranial lipoma associated with partial paralysis of the homolateral oculomotor nerve diagnosed by means of computerized axial tomography].

    PubMed

    Marini, D; Querin, F

    1983-01-01

    The authors refer a case of lipoma of the middle cranial fossa in a 48-year-old-man, who also showed a incomplete paralysis of third omolateral cranial nerve. By the analysis of clinical symptoms and of the data in the literature, the AA. are of the opinion that the third nerve deficit they observed is due to a primary malformation of the nerve itself. The importance of radiological findings is emphasized: the stratigraphy showed sphenoid bone defects; the CT allowed the right diagnosis displaying an area of low attenuations values.

  3. Multiple symmetric lipomas with high levels of mtDNA with the tRNA(Lys) A-->G(8344) mutation as the only manifestation of disease in a carrier of myoclonus epilepsy and ragged-red fibers (MERRF) syndrome.

    PubMed Central

    Holme, E; Larsson, N G; Oldfors, A; Tulinius, M; Sahlin, P; Stenman, G

    1993-01-01

    We have investigated the morphology, cytogenetics, and the fraction of mtDNA with the tRNA(Lys) A-->G(8344) mutation in three lipomas in a carrier of this mutation. The son of the patient had myoclonus epilepsy and ragged-red fibers syndrome. The fraction of mtDNA with the tRNA(Lys) mutation varied between 62% and 80% in cultured skin fibroblasts, lymphocytes, normal adipose tissue, and muscle. In the three lipomas the mean fraction of mutated mtDNA was 90%, 94%, and 94%. Ultrastructural examination of the lipomas revealed numerous mitochondria with changes such as electron-dense inclusions in some adipocytes. When considered cytogenetically, the lipomas were characterized by a mixture of karyotypically abnormal and normal cells. An identical del(6)(q24) was found in two tumors. The fraction of mutated mtDNA in cultured lipoma cells was the same as in the lipoma in situ, indicating that the cultured cells were representative of the primary tumor. These findings indicate that the lipomas have originated with a grossly normal stem line and subsequently have developed the 6q deletion. We conclude that the lipomas represent clonal growth of adipocytes with a high content of mtDNA with the tRNA(Lys) mutation. The tRNA(Lys) mutation may be either the direct or the indirect cause of pertubation of the maturation process of the adipocytes, leading to an increased risk of lipoma formation. Images Figure 1 Figure 2 Figure 3 PMID:8447321

  4. Ileocolic Intussusception Caused by a Giant Ulcerating Lipoma of Bauhin's Valve: an Unusual Cause of Intestinal Obstruction in the Adult.

    PubMed

    Gys, B; Haenen, F; Gys, T

    2015-04-01

    We report a case of intestinal obstruction in a 73-year-old woman caused by ileocolic intussusception. The underlying cause was a giant submucosal ulcerating lipoma (6 × 3.3 × 3.8 cm) extending from the superior mucosal lip of Bauhin's valve. Abdominal ultrasonography showed a pathognomonic target-like mass appearing as multiple concentric rings. CT scan confirmed the diagnosis. Because of apparent obstruction, a laparotomy with right hemicolectomy and ileocolic anastomosis was performed. Lipomas most frequently occur in the cecum and ascending colon where they represent the most common submucosal mesenchymal tumor. They typically occur in elderly women with an incidence that varies from 0.15 to 0.56 %. Pain, rectal bleeding, and obstruction are typical symptoms. When faced with an intussusception in children, reduction with air per rectum can be performed. In adults, however, malignant cell spreading and seeding is of big concern. Since approximately 20-50 % of all underlying causes are malignant, explorative surgery is favored in adults.

  5. C11orf95-MKL2 is the Resulting Fusion Oncogene of t(11;16)(q13;p13) in Chondroid Lipoma

    PubMed Central

    Huang, Dali; Sumegi, Janos; Cin, Paola Dal; Reith, John D.; Yasuda, Taketoshi; Nelson, Marilu; Muirhead, David; Bridge, Julia A.

    2010-01-01

    Chondroid lipoma, a rare benign adipose tissue tumor, may histologically resemble myxoid liposarcoma or extraskeletal myxoid chondrosarcoma, but is genetically distinct. In the current study, an identical reciprocal translocation, t(11;16)(q13;p13) was identified in three chondroid lipomas, a finding consistent with previous isolated reports. A fluorescence in situ hybridization (FISH)-based positional cloning strategy using a series of bacterial artificial chromosome (BAC) probe combinations designed to narrow the 16p13 breakpoint revealed MKL2 as the candidate gene. Subsequent 5′ RACE studies demonstrated C11orf95 as the MKL2 fusion gene partner. MKL/myocardin-like 2 (MKL2) encodes myocardin-related transcription factor B (MRTF-B) in a megakaryoblastic leukemia gene family, and C11orf95 (chromosome 11 open reading frame 95) is a hypothetical protein. Sequencing analysis of RT-PCR generated transcripts from all three chondroid lipomas defined the fusion as occurring between exons 5 and 9 of C11orf95 and MKL2, respectively. Dual-color breakpoint spanning probe sets custom-designed for recognition of the translocation event in interphase cells confirmed the anticipated rearrangements of the C11orf95 and MKL2 loci in all cases. The FISH and RT-PCR assays developed in this study can serve as diagnostic adjuncts for identification of this novel C11orf95-MKL2 fusion oncogene in chondroid lipoma. PMID:20607705

  6. Three dosimetry models of lipoma arborescens treated by {sup 90}Y synovectomy

    SciTech Connect

    O’Doherty, Jim; Clauss, Ralf; Scuffham, James; Khan, Aman; Petitguillaume, Alice; Desbrée, Aurélie

    2014-05-15

    Purpose: Lipoma arborescens (LA) is a benign intra-articular lipomatous proliferation of the synovial membrane. This extremely rare condition has previously been treated by intra-articular{sup 90}Y radiosynoviorthesis but dosimetry literature on this form of radionuclide therapy is nonexistent. The authors detail methodology for successful treatment of LA and provide for the first time estimates of radiation dosimetry. The authors also analyze the biodistribution of the radiopharmaceutical over the course of the patient's treatment through sequential imaging. Methods: A patient with bilateral LA underwent intracavity injection of{sup 90}Y citrate colloid to the right and left knee joint spaces (181 and 198 MBq, respectively). SPECT/CT datasets were acquired over 9 days to quantify the biodistribution and kinetics of the radiopharmaceutical. Radiation dosimetry was performed using the MIRD schema (through OLINDA software), a custom voxel-based method, and a direct Monte Carlo calculation (OEDIPE). Results: Follow-up MRI showed marked reduction in LA size in both knees. Mean absorbed doses to the LA were 21.2 ± 0.8 and 42.9 ± 2.3 Gy using OLINDA, 8.1 ± 0.3 and 16.7 ± 0.5 Gy using voxel based methodology, and 8.2 ± 0.3 and 15.7 ± 0.5 Gy for OEDIPE in the right and left LA, respectively. Distribution of the radiopharmaceutical within the joint space alters over the imaging period, with less than 1% of the remaining activity having moved posteriorly in the knee cavity. No uptake was detected outside of the joint space after assessment with whole-body scintigraphy. Conclusions: An activity of approximately 185 MBq successfully relieved clinical symptoms of LA. There was good correlation between direct Monte Carlo and voxel based techniques, but OLINDA was shown to overestimate the absorbed dose to the tumor. Accurate dosimetry may help select an activity more tailored to the specific size and location of the LA.

  7. A new angle on the Euler angles

    NASA Technical Reports Server (NTRS)

    Markley, F. Landis; Shuster, Malcolm D.

    1995-01-01

    We present a generalization of the Euler angles to axes beyond the twelve conventional sets. The generalized Euler axes must satisfy the constraint that the first and the third are orthogonal to the second; but the angle between the first and third is arbitrary, rather than being restricted to the values 0 and pi/2, as in the conventional sets. This is the broadest generalization of the Euler angles that provides a representation of an arbitrary rotation matrix. The kinematics of the generalized Euler angles and their relation to the attitude matrix are presented. As a side benefit, the equations for the generalized Euler angles are universal in that they incorporate the equations for the twelve conventional sets of Euler angles in a natural way.

  8. Tethered spinal cord and an intradural lipoma associated with a meningocele in a Manx-type cat.

    PubMed

    Plummer, S B; Bunch, S E; Khoo, L H; Spaulding, K A; Kornegay, J N

    1993-10-15

    An 8-month-old neutered male Manx-type cat was evaluated because of clear fluid that had been draining from a skin mass dorsocaudal to the sacrum for 1 week. Neurologically, the cat had poor postural reactions and poor withdrawal reflexes in the hind limbs. Ultrasonography of the dorsal sacral area revealed a 3-cm-long hypoechoic tract extending from the skin mass cranioventrally to the area of the sacrum. The tract appeared to contain a circular mass. Results of myelography and computed tomography helped to confirm the diagnosis of a meningocutaneous tract containing a mass. Surgical exploration was performed and the tract was excised. Histologic changes were similar to those in human beings with tethered spinal cord syndrome and an intradural lumbosacral lipoma. Surgery was indicated in this cat to prevent progression of neurologic signs associated with tethered cord syndrome and to prevent problems associated with loss of CSF through a fistulated meningocele.

  9. Spontaneous recurrent hemarthrosis of the knee joint in elderly patients with osteoarthritis: an infrequent presentation of synovial lipoma arborescens.

    PubMed

    Ji, Jong-Hun; Lee, Yeon-Soo; Shafi, Mohamed

    2010-10-01

    Synovial lipoma arborescens (SLA) is a rare, benign, fat-containing synovial proliferative lesion that is typically known to affect the knee joint in adults, although it has also been described in other joints. SLA usually presents as a painless swelling and recurrent joint effusion, and the laboratory test results, including aspirated synovial fluid, are usually normal. We present here two cases of SLA of the knee, which presented as spontaneous recurrent hemarthroses in elderly patients with osteoarthritis (OA) with bloody aspirated synovial fluid. Magnetic resonance imaging (MRI) and arthroscopic synovectomy suggested the diagnosis of SLA; the histopathologic examination confirmed the diagnosis. One year later, both patients remain symptom-free and report no new episodes of hemarthrosis. We postulate that SLA should be included in the differential diagnosis of patients with recurrent joint effusions with hemarthrosis in elderly patients with OA. The clinical presentation, MRI findings, and treatment of SLA are described, and the entity is briefly reviewed.

  10. Expression of HMGI-C and HMGI(Y) in ordinary lipoma and atypical lipomatous tumors: immunohistochemical reactivity correlates with karyotypic alterations.

    PubMed Central

    Tallini, G.; Dal Cin, P.; Rhoden, K. J.; Chiapetta, G.; Manfioletti, G.; Giancotti, V.; Fusco, A.; Van den Berghe, H.; Sciot, R.

    1997-01-01

    The high mobility group proteins (HMGs) are a class of low molecular weight, nonhistone, nuclear proteins that bind DNA and function as transcription cofactors. This class includes the HMGI family members HMGI-C and HMGI(Y). Both are not significantly expressed in differentiated adult tissues, including fat, but their expression is induced in proliferating and transformed cells. Their involvement in the development of lipomatous tumors has been recently demonstrated for HMGI-C, which is encoded by a gene located at 12q15, the chromosomal segment often rearranged in ordinary lipomas. The same chromosomal segment is consistently amplified in the ring and giant marker chromosomes of atypical lipomatous tumors (ALTs), a term used to designate tumors previously labeled as well differentiated liposarcomas or atypical lipomas. The involvement of HMGI(Y) is strongly suspected as the gene coding for HMGI(Y) is located at 6p21, a chromosomal segment rearranged in a subset of ordinary lipomas. HMGI-C or HMGI(Y) protein expression was analyzed immunohistochemically in a group of 39 well differentiated adipose neoplasms (19 lipomas and 20 ALTs) of known karyotype using polyclonal antibodies raised against a recombinant protein (HMGI-C) and against a synthetic peptide (HMGI(Y)). The results of this study demonstrate that HMGI proteins are commonly expressed in well differentiated adipose neoplasms. Seventeen of twenty ALTS (85.0%), all of which had ring or giant marker chromosomes with amplification of 12q13-15, strongly expressed HMGI-C. HMGI-C expression was detected in 7 of 11 ordinary lipomas (63.6%) with alterations at 12q14-15 and in one case with an abnormal karyotype that included double minute chromosomes. HMGI-C immunoreactivity correlates with 12q13-15 chromosomal alterations (P = 0.001). HMGI(Y) reactivity was demonstrated in only two ordinary lipomas: one with 6p21 rearrangement and one with normal karyotype. No significant HMGI(Y) expression was found in the ALT

  11. Infantile fibrosarcoma successfully treated with chemotherapy, with occurrence of calcifying aponeurotic fibroma and pleomorphic/spindled celled lipoma at the site 12 years later.

    PubMed

    DeComas, Amalia M; Heinrich, Stephen D; Craver, Randall

    2009-06-01

    The treatment of infantile fibrosarcoma has traditionally been wide resection. Chemotherapy has been investigated as an adjuvant and primary treatment in cases in which surgery would cause unacceptable morbidity. Recurrences normally occur within a year of completion of the chemotherapy and display the same histology. We present a child with an infantile fibrosarcoma of the elbow, successfully treated with chemotherapy alone, who developed a calcifying aponeurotic fibroma and a spindle cell/pleomorphic lipoma at the tumor site 12 years later.

  12. An unusual and spectacular case of spindle cell lipoma of the posterior neck invading the spinal cervical canal and posterior cranial fossa.

    PubMed

    Petit, Damien; Menei, Philippe; Fournier, Henri-Dominique

    2011-11-01

    The authors describe the first case of spindle cell lipoma of the posterior neck invading the upper cervical spinal canal and the posterior cranial fossa. Spindle cell lipoma is an extremely rare variant of benign lipoma. It usually occurs as a solitary subcutaneous well-circumscribed lesion in the posterior neck or shoulders of adult men. Local aggressiveness is unusual. This 61-year-old man presented with an increased left cerebellar syndrome and headaches. He also had a posterior neck tumefaction, which had been known about for a long time. Computed tomography and MR imaging studies revealed a voluminous mass extending to the upper cervical canal and posterior cranial fossa and eroding the neighboring bones. The lesion was well delimited, and contrast enhancement was intense and heterogeneous. The tumor, which had initially developed under the muscles of the posterior neck, was totally resected. Histological assessment revealed numerous fat cells with spindle cells secreting collagen. The large size of the tumor and the submuscular location, bone erosion, and compression of the CNS were unusual in this rare subtype of benign adipose tumor. Its presentation could simulate a sarcoma.

  13. Auditory Hallucinosis as a Presenting Feature of Interpeduncular Lipoma with Proximal P1 Segment Fenestration: Report of a Rare Case and Review of Literature on Peduncular Hallucinosis

    PubMed Central

    Kulhari, Ashish; Manjila, Sunil; Singh, Gagandeep; Kumar, Kunal; Tarr, Robert W; Bambakidis, Nicholas

    2016-01-01

    The authors present a unique case of intracranial lipoma in the interpeduncular cistern associated with proximal P1 segment fenestration. This patient is a 20-year-old male with extensive psychiatric history and complaints of recent auditory hallucinations. Cranial magnetic resonance imaging (MRI) (T1, T2, and FLAIR) showed a hyperintense lesion in the left aspect of interpeduncular cistern with a prominent flow void within the hyperintense lesion suggestive of a combined vascular–lipomatous lesion. Computed tomography (CT) angiography showed a high-riding large tortuous P1 segment on the left side with proximal fenestration, the ectatic posteromedial limb harboring a fusiform dilated segment. Since there are anecdotal cases of cerebral aneurysms associated with intracranial lipomas, a conventional angiography was done, which confirmed a proximal left P1 fenestration and a fusiform-dilated segment, and no aneurysm. There are few cases of hallucinations associated with a vascular midbrain pathology reported in literature, but hallucinations associated with a combination of lipoma and arterial ectasia have never been reported. This article not only demonstrates the MRI and angiographic appearance of this rare lipomatous lesion but also highlights this unique association and significance of auditory hallucinations as a clinical presentation, akin to peduncular hallucinosis. PMID:27403217

  14. Mutations in the lipoma HMGIC fusion partner-like 5 (LHFPL5) gene cause autosomal recessive nonsyndromic hearing loss.

    PubMed

    Kalay, Ersan; Li, Yun; Uzumcu, Abdullah; Uyguner, Oya; Collin, Rob W; Caylan, Refik; Ulubil-Emiroglu, Melike; Kersten, Ferry F J; Hafiz, Gunter; van Wijk, Erwin; Kayserili, Hulya; Rohmann, Edyta; Wagenstaller, Janine; Hoefsloot, Lies H; Strom, Tim M; Nürnberg, Gudrun; Baserer, Nermin; den Hollander, Anneke I; Cremers, Frans P M; Cremers, Cor W R J; Becker, Christian; Brunner, Han G; Nürnberg, Peter; Karaguzel, Ahmet; Basaran, Seher; Kubisch, Christian; Kremer, Hannie; Wollnik, Bernd

    2006-07-01

    In two large Turkish consanguineous families, a locus for autosomal recessive nonsyndromic hearing loss (ARNSHL) was mapped to chromosome 6p21.3 by genome-wide linkage analysis in an interval overlapping with the loci DFNB53 (COL11A2), DFNB66, and DFNB67. Fine mapping excluded DFNB53 and subsequently homozygous mutations were identified in the lipoma HMGIC fusion partner-like 5 (LHFPL5) gene, also named tetraspan membrane protein of hair cell stereocilia (TMHS) gene, which was recently shown to be mutated in the "hurry scurry" mouse and in two DFNB67-linked families from Pakistan. In one family, we found a homozygous one-base pair deletion, c.649delG (p.Glu216ArgfsX26) and in the other family we identified a homozygous transition c.494C>T (p.Thr165Met). Further screening of index patients from 96 Turkish ARNSHL families and 90 Dutch ARNSHL patients identified one additional Turkish family carrying the c.649delG mutation. Haplotype analysis revealed that the c.649delG mutation was located on a common haplotype in both families. Mutation screening of the LHFPL5 homologs LHFPL3 and LHFPL4 did not reveal any disease causing mutation. Our findings indicate that LHFPL5 is essential for normal function of the human cochlea.

  15. Compound double ileoileal and ileocecocolic intussusception caused by lipoma of the ileum in an adult patient: A case report

    PubMed Central

    2011-01-01

    Introduction The initial diagnosis of intussusception in adults very often can be missed and cause delayed treatment and possible serious complications. We report the case of an adult patient with complicated double ileoileal and ileocecocolic intussusception. Case presentation A 46-year-old Caucasian man was transferred from the gastroenterology service to the abdominal surgery service with severe abdominal pain, nausea, and vomiting. An abdominal ultrasound, barium enema, and abdominal computed tomography scan revealed an intraluminal obstruction of his ascending colon. Plain abdominal X-rays showed diffuse air-fluid levels in his small intestine. A double ileoileal and ileocecocolic intussusception was found during an emergent laparotomy. A right hemicolectomy, including resection of a long segment of his ileum, was performed. The postoperative period was complicated by acute renal failure, shock liver, and pulmonary thromboembolism. Our patient was discharged from the hospital after 30 days. An anatomical pathology examination revealed a lipoma of his ileum. Conclusions Intussusception in adults requires early surgical resection regardless of the nature of the initial cause. Delayed treatment can cause very serious complications. PMID:21910876

  16. Posterior Interosseous Nerve Syndrome Resulting from Parosteal Lipoma of the Proximal Radius: An Elusive Diagnosis Yet Excellent Outcome

    PubMed Central

    Saaiq, Muhammad; Siddiui, Saad

    2017-01-01

    A 53-year old man presented with seven months history of progressive weakness of extension of the digits and the thumb of the left hand. The wrist extension was normal and sensations were also intact. The patient had also been noticing a progressively enlarging lump on the lower anterolateral aspect of the left antecubital fossa for the last three months. Physical examination andelectro diagnostic studies revealed motor deficit along the posterior interosseous nerve (PIN) distribution with preservation of sensations. Also a soft tissue solitary lump (measuring 6×5 cm in its greatest dimensions) was palpable in the left antecubital fossa. The magnetic resonance imaging (MRI) of the forearm revealed a well-defined, non-enhancing, homogenous, fat intensity lesion in the left antecubital fossa, attached to the proximal radius. The patient underwent surgical excision of the lump with decompression of the PIN in the radial tunnel. Histopathology confirmed the diagnosis of parosteal lipoma. Although the diagnosis was elusive at the very outset, yet prudent clinical judgment, appropriate ancillary investigations and timely surgical intervention resulted in optimal functional recovery of the hand drop. There was complete motor recovery at 4-months follow up with no recurrence of the lipomaafter one year. PMID:28289621

  17. Reading Angles in Maps

    ERIC Educational Resources Information Center

    Izard, Véronique; O'Donnell, Evan; Spelke, Elizabeth S.

    2014-01-01

    Preschool children can navigate by simple geometric maps of the environment, but the nature of the geometric relations they use in map reading remains unclear. Here, children were tested specifically on their sensitivity to angle. Forty-eight children (age 47:15-53:30 months) were presented with fragments of geometric maps, in which angle sections…

  18. Reading Angles in Maps

    ERIC Educational Resources Information Center

    Izard, Véronique; O'Donnell, Evan; Spelke, Elizabeth S.

    2014-01-01

    Preschool children can navigate by simple geometric maps of the environment, but the nature of the geometric relations they use in map reading remains unclear. Here, children were tested specifically on their sensitivity to angle. Forty-eight children (age 47:15-53:30 months) were presented with fragments of geometric maps, in which angle sections…

  19. The recurrent chromosomal translocation t(12;18)(q14~15;q12~21) causes the fusion gene HMGA2-SETBP1 and HMGA2 expression in lipoma and osteochondrolipoma.

    PubMed

    Panagopoulos, Ioannis; Gorunova, Ludmila; Bjerkehagen, Bodil; Lobmaier, Ingvild; Heim, Sverre

    2015-09-01

    Lipomas are the most common soft tissue tumors in adults. They often carry chromosome aberrations involving 12q13~15 leading to rearrangements of the HMGA2 gene in 12q14.3, with breakpoints occurring within or outside of the gene. Here, we present eleven lipomas and one osteochondrolipoma with a novel recurrent chromosome aberration, t(12;18)(q14~15;q12~21). Molecular studies on eight of the tumors showed that full-length HMGA2 transcript was expressed in three and a chimeric HMGA2 transcript in five of them. In three lipomas and in the osteochondrolipoma, exons 1-3 of HMGA2 were fused to a sequence of SETBP1 on 18q12.3 or an intragenic sequence from 18q12.3 circa 10 kbp distal to SETBP1. In another lipoma, exons 1-4 of HMGA2 were fused to an intronic sequence of GRIP1 which maps to chromosome band 12q14.3, distal to HMGA2. The ensuing HMGA2 fusion transcripts code for putative proteins which contain amino acid residues of HMGA2 corresponding to exons 1-3 (or exons 1-4 in one case) followed by amino acid residues corresponding to the fused sequences. Thus, the pattern is similar to the rearrangements of HMGA2 found in other lipomas, i.e., disruption of the HMGA2 locus leaves intact exons 1-3 which encode the AT-hooks domains and separates them from the 3'-terminal part of the gene. The fact that the examined osteochondrolipoma had a t(12;18) and a HMGA2-SETBP1 fusion identical to the findings in the much more common ordinary lipomas, underscores the close developmental relationship between the two tumor types.

  20. The recurrent chromosomal translocation t(12;18) (q14~15;q12~21) causes the fusion gene HMGA2-SETBP1 and HMGA2 expression in lipoma and osteochondrolipoma

    PubMed Central

    PANAGOPOULOS, IOANNIS; GORUNOVA, LUDMILA; BJERKEHAGEN, BODIL; LOBMAIER, INGVILD; HEIM, SVERRE

    2015-01-01

    Lipomas are the most common soft tissue tumors in adults. They often carry chromosome aberrations involving 12q13~15 leading to rearrangements of the HMGA2 gene in 12q14.3, with breakpoints occurring within or outside of the gene. Here, we present eleven lipomas and one osteochondrolipoma with a novel recurrent chromosome aberration, t(12;18) (q14~15;q12~21). Molecular studies on eight of the tumors showed that full-length HMGA2 transcript was expressed in three and a chimeric HMGA2 transcript in five of them. In three lipomas and in the osteochondrolipoma, exons 1–3 of HMGA2 were fused to a sequence of SETBP1 on 18q12.3 or an intragenic sequence from 18q12.3 circa 10 kbp distal to SETBP1. In another lipoma, exons 1–4 of HMGA2 were fused to an intronic sequence of GRIP1 which maps to chromosome band 12q14.3, distal to HMGA2. The ensuing HMGA2 fusion transcripts code for putative proteins which contain amino acid residues of HMGA2 corresponding to exons 1–3 (or exons 1–4 in one case) followed by amino acid residues corresponding to the fused sequences. Thus, the pattern is similar to the rearrangements of HMGA2 found in other lipomas, i.e., disruption of the HMGA2 locus leaves intact exons 1–3 which encode the AT-hooks domains and separates them from the 3′-terminal part of the gene. The fact that the examined osteochondrolipoma had a t(12;18) and a HMGA2-SETBP1 fusion identical to the findings in the much more common ordinary lipomas, underscores the close developmental relationship between the two tumor types. PMID:26202160

  1. Viewing angle changeable display

    NASA Astrophysics Data System (ADS)

    Leng, Jinbi; Huang, Ziqiang; Yang, Wenjun; Chen, Xiaoxi

    2010-10-01

    Viewing angle changeable display can change the display viewing angle as needed: In the public place the display could have a narrow viewing angle for privacy, while in the private place the displays could have a wide viewing angle for the convenience of the operation and better viewing experience. This article propose a novel adjustable optical transmission device to realize the viewing angle changes for LCD by using the principle of guest- host effect of liquid crystal. The major technology is to insert a special equipment between the backlight and the LCD, through which the backlight will display either parallel or scattered features to get an either narrow or wide viewing angle. The equipment is an adjustable transmission cell (ATC) which is actually a black G-H LC cell. This ATC is the main focus of our invention. The ATC consists of a polarizer sheet and a special guest-host liquid crystal device filled with the two-phase dye (called as GH-LC in this report), to achieve the viewing angle change in the LCD. When an electrical field charges to the ATC, only the so-called near-axis lights can pass through the ATC within a relatively small angle, while the other scattered lights are absorbed sequentially by GH-LC and the polarizer sheet. On the other hand, when there is no electrical charge to the ATC, the cell behaves like a normal polarizer; and the scattered light can pass through the cell and polarizer in a normal way. This paper describes the principle and structure of the device, applies the electric field on the sample to observe the electro-optical properties, combine the theoretical and experimental research, getting the viewing angle effects of the display.

  2. Photoelectric angle converter

    NASA Astrophysics Data System (ADS)

    Podzharenko, Volodymyr A.; Kulakov, Pavlo I.

    2001-06-01

    The photo-electric angle transmitter of rotation is offered, at which the output voltage is linear function of entering magnitude. In a transmitter the linear phototransducer is used on the basis of pair photo diode -- operating amplifier, which output voltage is linear function of the area of an illuminated photosensitive stratum, and modulator of a light stream of the special shape, which ensures a linear dependence of this area from an angle of rotation. The transmitter has good frequent properties and can be used for dynamic measurements of an angular velocity and angle of rotation, in systems of exact drives and systems of autocontrol.

  3. Meteorite incidence angles

    NASA Astrophysics Data System (ADS)

    Hughes, D. W.

    1993-06-01

    Think about an asteroid smashing into the surface of the Moon and excavating a crater; or hitting Earth and scattering meteorite fragments over a strewn field. Imagine a fragment of cometary dust burning out in the Earth's atmosphere and producing a meteor. These bodies have paths that are inclined at some angle to the vertical. But what is the predominant value of this angle of incidence, i? How does the number of incident bodies vary as a function of angle i? And how do both these affect the prevalence of non- circular lunar craters and the ellipticity of meteorite strewn fields?

  4. Angles, Time, and Proportion

    ERIC Educational Resources Information Center

    Pagni, David L.

    2005-01-01

    This article describes an investigation making connections between the time on an analog clock and the angle between the minute hand and the hour hand. It was posed by a middle school mathematics teacher. (Contains 8 tables and 6 figures.)

  5. Rb1 and Pten Co-Deletion in Osteoblast Precursor Cells Causes Rapid Lipoma Formation in Mice

    PubMed Central

    Filtz, Emma A.; Emery, Ann; Lu, Huarui; Forster, Colleen L.; Karasch, Chris; Hallstrom, Timothy C.

    2015-01-01

    The Rb and Pten tumor suppressor genes are important regulators of bone development and both are frequently mutated in the bone cancer osteosarcoma (OS). To determine if Rb1 and Pten synergize as tumor suppressor genes for osteosarcoma, we co-deleted them in osteoprogenitor cells. Surprisingly, we observed rapid development of adipogenic but not osteosarcoma tumors in the ΔRb1/Pten mice. ΔPten solo deleted mice also developed lipoma tumors but at a much reduced frequency and later onset than those co-deleted for Rb1. Pten deletion also led to a marked increase in adipocytes in the bone marrow. To better understand the function of Pten in bone development in vivo, we conditionally deleted Pten in OSX+ osteoprogenitor cells using OSX-Cre mice. μCT analysis revealed a significant thickening of the calvaria and an increase in trabeculae volume and number in the femur, consistent with increased bone formation in these mice. To determine if Pten and Rb1 deletion actively promotes adipogenic differentiation, we isolated calvarial cells from Ptenfl/fl and Ptenfl/fl; Rb1fl/fl mice, infected them with CRE or GFP expressing adenovirus, treated with differentiation media. We observed slightly increased adipogenic, and osteogenic differentiation in the ΔPten cells. Both phenotypes were greatly increased upon Rb1/Pten co-deletion. This was accompanied by an increase in expression of genes required for adipogenesis. These data indicate that Pten deletion in osteoblast precursors is sufficient to promote frequent adipogenic, but only rare osteogenic tumors. Rb1 hetero- or homo-zygous co-deletion greatly increases the incidence and the rapidity of onset of adipogenic tumors, again, with only rare osteosarcoma tumors. PMID:26317218

  6. 'Magic Angle Precession'

    SciTech Connect

    Binder, Bernd

    2008-01-21

    An advanced and exact geometric description of nonlinear precession dynamics modeling very accurately natural and artificial couplings showing Lorentz symmetry is derived. In the linear description it is usually ignored that the geometric phase of relativistic motion couples back to the orbital motion providing for a non-linear recursive precession dynamics. The high coupling strength in the nonlinear case is found to be a gravitomagnetic charge proportional to the precession angle and angular velocity generated by geometric phases, which are induced by high-speed relativistic rotations and are relevant to propulsion technologies but also to basic interactions. In the quantum range some magic precession angles indicating strong coupling in a phase-locked chaotic system are identified, emerging from a discrete time dynamical system known as the cosine map showing bifurcations at special precession angles relevant to heavy nuclei stability. The 'Magic Angle Precession' (MAP) dynamics can be simulated and visualized by cones rolling in or on each other, where the apex and precession angles are indexed by spin, charge or precession quantum numbers, and corresponding magic angles. The most extreme relativistic warping and twisting effect is given by the Dirac spinor half spin constellation with 'Hyperdiamond' MAP, which resembles quark confinement.

  7. Morphometric analysis of posterior fossa in Indian CP angle acoustic schwannoma patients

    PubMed Central

    Patibandla, Mohana Rao; Panigrahi, Manas K.; Gurram, Paniraj L.; Thotakura, Amit Kumar; Kulkarni, Dilip

    2016-01-01

    Aim: To study the morphometry of posterior fossa in Indian CP angle schwannoma patients in order to know its influence on the extent of excision of the CP angle acoustic schwannomas. Materials and Methods: One hundred cases of cerebellopontine angle schwannomas treated surgically by the senior author and 20 controls between January 2006 and June 2011 were consecutively investigated with computed tomography (CT) using the high-resolution CT bone windows before surgery. Evaluation of anatomic parameters of the petrous bone and posterior fossa cavity were done in all patients and controls. Data were entered in Excel software and were analyzed using NCSS software. All possible regression analysis was done to select the important variables to be included in the model to predict the excision of tumor with these variables. A prediction model was developed defining the binary outcome as total excision or subtotal excision as dependent variable and the morphometric data and grading of tumor as independent variables. Results: Interpetrous distance (IP) is the distance between the two petrous apices. Sigmoid distance (IS) distance is the distance between the two sigmoid points. Sigmoid point is the point at which the scalloped impression of the sigmoid sinus straightens to join the occipital bone posteriorly. SAG is the distance between the mid IP point and the mid-point on the inner wall of the occipital bone. The PM angle was 47.8±4.14 degrees (38-58), the PA angle was 42.68±4.47 degrees (34-53), the IP distance was 2.07±0.13 cm (1.5-2.8), the sagittal diameter of posterior fossa was 6.22±0.73 cm (5.1-9.8) and the intersigmoid distance was 9.45±0.73 cm (7.4-11). There was no significant gender difference in the posterior fossa morphometry between patients and controls. Inter-sigmoid distance and the petrous-apex angle were more in the Indians when compared to the European population mentioned in the Mathies and Samii study. Conclusions: The posterior fossa

  8. Morphometric analysis of posterior fossa in Indian CP angle acoustic schwannoma patients.

    PubMed

    Patibandla, Mohana Rao; Panigrahi, Manas K; Gurram, Paniraj L; Thotakura, Amit Kumar; Kulkarni, Dilip

    2016-01-01

    To study the morphometry of posterior fossa in Indian CP angle schwannoma patients in order to know its influence on the extent of excision of the CP angle acoustic schwannomas. One hundred cases of cerebellopontine angle schwannomas treated surgically by the senior author and 20 controls between January 2006 and June 2011 were consecutively investigated with computed tomography (CT) using the high-resolution CT bone windows before surgery. Evaluation of anatomic parameters of the petrous bone and posterior fossa cavity were done in all patients and controls. Data were entered in Excel software and were analyzed using NCSS software. All possible regression analysis was done to select the important variables to be included in the model to predict the excision of tumor with these variables. A prediction model was developed defining the binary outcome as total excision or subtotal excision as dependent variable and the morphometric data and grading of tumor as independent variables. Interpetrous distance (IP) is the distance between the two petrous apices. Sigmoid distance (IS) distance is the distance between the two sigmoid points. Sigmoid point is the point at which the scalloped impression of the sigmoid sinus straightens to join the occipital bone posteriorly. SAG is the distance between the mid IP point and the mid-point on the inner wall of the occipital bone. The PM angle was 47.8±4.14 degrees (38-58), the PA angle was 42.68±4.47 degrees (34-53), the IP distance was 2.07±0.13 cm (1.5-2.8), the sagittal diameter of posterior fossa was 6.22±0.73 cm (5.1-9.8) and the intersigmoid distance was 9.45±0.73 cm (7.4-11). There was no significant gender difference in the posterior fossa morphometry between patients and controls. Inter-sigmoid distance and the petrous-apex angle were more in the Indians when compared to the European population mentioned in the Mathies and Samii study. The posterior fossa morphological parameters of the Indian and European population

  9. An Iterative Angle Trisection

    ERIC Educational Resources Information Center

    Muench, Donald L.

    2007-01-01

    The problem of angle trisection continues to fascinate people even though it has long been known that it can't be done with straightedge and compass alone. However, for practical purposes, a good iterative procedure can get you as close as you want. In this note, we present such a procedure. Using only straightedge and compass, our procedure…

  10. Casting and Angling.

    ERIC Educational Resources Information Center

    Little, Mildred J.; Bunting, Camille

    The self-contained packet contains background information, lesson plans, 15 transparency and student handout masters, drills and games, 2 objective examinations, and references for teaching a 15-day unit on casting and angling to junior high and senior high school students, either as part of a regular physical education program or as a club…

  11. Casting and Angling.

    ERIC Educational Resources Information Center

    Smith, Julian W.

    As part of a series of books and pamphlets on outdoor education, this manual consists of easy-to-follow instructions for fishing activities dealing with casting and angling. The manual may be used as a part of the regular physical education program in schools and colleges or as a club activity for the accomplished weekend fisherman or the…

  12. The Rainbow Angle.

    ERIC Educational Resources Information Center

    Sims, B.

    1978-01-01

    Two articles in the "Scientific American" form the background of this note. The rainbow angle for the primary bow of a monochromatic Cartesian rainbow is calculated. Special projects for senior high school students could be patterned after this quantitative study. (MP)

  13. Casting and Angling.

    ERIC Educational Resources Information Center

    Little, Mildred J.; Bunting, Camille

    The self-contained packet contains background information, lesson plans, 15 transparency and student handout masters, drills and games, 2 objective examinations, and references for teaching a 15-day unit on casting and angling to junior high and senior high school students, either as part of a regular physical education program or as a club…

  14. Spinal column shortening for tethered cord syndrome associated with myelomeningocele, lumbosacral lipoma, and lipomyelomeningocele in children and young adults.

    PubMed

    Aldave, Guillermo; Hansen, Daniel; Hwang, Steven W; Moreno, Amee; Briceño, Valentina; Jea, Andrew

    2017-06-01

    OBJECTIVE Tethered cord syndrome is the clinical manifestation of an abnormal stretch on the spinal cord, presumably causing mechanical injury, a compromised blood supply, and altered spinal cord metabolism. Tethered cord release is the standard treatment for tethered cord syndrome. However, direct untethering of the spinal cord carries potential risks, such as new neurological deficits from spinal cord injury, a CSF leak from opening the dura, and retethering of the spinal cord from normal scar formation after surgery. To avoid these risks, the authors applied spinal column shortening to children and transitional adults with primary and secondary tethered cord syndrome and report treatment outcomes. The authors' aim with this study was to determine the safety and efficacy of spinal column shortening for tethered cord syndrome by analyzing their experience with this surgical technique. METHODS The authors retrospectively reviewed the demographic and procedural data of children and young adults who had undergone spinal column shortening for primary or secondary tethered cord syndrome. RESULTS Seven patients with tethered cord syndrome caused by myelomeningocele, lipomyelomeningocele, and transitional spinal lipoma were treated with spinal column shortening. One patient with less than 24 months of follow-up was excluded from further analysis. There were 3 males and 4 females; the average age at the time was surgery was 16 years (range 8-30 years). Clinical presentations for our patients included pain (in 5 patients), weakness (in 4 patients), and bowel/bladder dysfunction (in 4 patients). Spinal column osteotomy was most commonly performed at the L-1 level, with fusion between T-12 and L-2 using a pedicle screw-rod construct. Pedicle subtraction osteotomy was performed in 6 patients, and vertebral column resection was performed in 1 patient. The average follow-up period was 31 months (range 26-37 months). Computed tomography-based radiographic outcomes showed solid

  15. A Different Angle on Perspective

    ERIC Educational Resources Information Center

    Frantz, Marc

    2012-01-01

    When a plane figure is photographed from different viewpoints, lengths and angles appear distorted. Hence it is often assumed that lengths, angles, protractors, and compasses have no place in projective geometry. Here we describe a sense in which certain angles are preserved by projective transformations. These angles can be constructed with…

  16. A Different Angle on Perspective

    ERIC Educational Resources Information Center

    Frantz, Marc

    2012-01-01

    When a plane figure is photographed from different viewpoints, lengths and angles appear distorted. Hence it is often assumed that lengths, angles, protractors, and compasses have no place in projective geometry. Here we describe a sense in which certain angles are preserved by projective transformations. These angles can be constructed with…

  17. Angles in the Sky?

    NASA Astrophysics Data System (ADS)

    Behr, Bradford

    2005-09-01

    Tycho Brahe lived and worked in the late 1500s before the telescope was invented. He made highly accurate observations of the positions of planets, stars, and comets using large angle-measuring devices of his own design. You can use his techniques to observe the sky as well. For example, the degree, a common unit of measurement in astronomy, can be measured by holding your fist at arm's length up to the sky. Open your fist and observe the distance across the sky covered by the width of your pinky fingernail. That is, roughly, a degree! After some practice, and knowing that one degree equals four minutes, you can measure elapsed time by measuring the angle of the distance that the Moon appears to have moved and multiplying that number by four. You can also figure distances and sizes of things. These are not precise measurements, but rough estimates that can give you a "close-enough" answer.

  18. Laser angle sensor

    NASA Technical Reports Server (NTRS)

    Pond, C. R.; Texeira, P. D.

    1985-01-01

    A laser angle measurement system was designed and fabricated for NASA Langley Research Center. The instrument is a fringe counting interferometer that monitors the pitch attitude of a model in a wind tunnel. A laser source and detector are mounted above the model. Interference fringes are generated by a small passive element on the model. The fringe count is accumulated and displayed by a processor in the wind tunnel control room. This report includes optical and electrical schematics, system maintenance and operation procedures.

  19. Contact angle hysteresis explained.

    PubMed

    Gao, Lichao; McCarthy, Thomas J

    2006-07-04

    A view of contact angle hysteresis from the perspectives of the three-phase contact line and of the kinetics of contact line motion is given. Arguments are made that advancing and receding are discrete events that have different activation energies. That hysteresis can be quantified as an activation energy by the changes in interfacial area is argued. That this is an appropriate way of viewing hysteresis is demonstrated with examples.

  20. Small Angle Neutron Scattering

    SciTech Connect

    Urban, Volker S

    2012-01-01

    Small Angle Neutron Scattering (SANS) probes structural details at the nanometer scale in a non-destructive way. This article gives an introduction to scientists who have no prior small-angle scattering knowledge, but who seek a technique that allows elucidating structural information in challenging situations that thwart approaches by other methods. SANS is applicable to a wide variety of materials including metals and alloys, ceramics, concrete, glasses, polymers, composites and biological materials. Isotope and magnetic interactions provide unique methods for labeling and contrast variation to highlight specific structural features of interest. In situ studies of a material s responses to temperature, pressure, shear, magnetic and electric fields, etc., are feasible as a result of the high penetrating power of neutrons. SANS provides statistical information on significant structural features averaged over the probed sample volume, and one can use SANS to quantify with high precision the structural details that are observed, for example, in electron microscopy. Neutron scattering is non-destructive; there is no need to cut specimens into thin sections, and neutrons penetrate deeply, providing information on the bulk material, free from surface effects. The basic principles of a SANS experiment are fairly simple, but the measurement, analysis and interpretation of small angle scattering data involves theoretical concepts that are unique to the technique and that are not widely known. This article includes a concise description of the basics, as well as practical know-how that is essential for a successful SANS experiment.

  1. Wide Angle Movie

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This brief movie illustrates the passage of the Moon through the Saturn-bound Cassini spacecraft's wide-angle camera field of view as the spacecraft passed by the Moon on the way to its closest approach with Earth on August 17, 1999. From beginning to end of the sequence, 25 wide-angle images (with a spatial image scale of about 14 miles per pixel (about 23 kilometers)were taken over the course of 7 and 1/2 minutes through a series of narrow and broadband spectral filters and polarizers, ranging from the violet to the near-infrared regions of the spectrum, to calibrate the spectral response of the wide-angle camera. The exposure times range from 5 milliseconds to 1.5 seconds. Two of the exposures were smeared and have been discarded and replaced with nearby images to make a smooth movie sequence. All images were scaled so that the brightness of Crisium basin, the dark circular region in the upper right, is approximately the same in every image. The imaging data were processed and released by the Cassini Imaging Central Laboratory for Operations (CICLOPS)at the University of Arizona's Lunar and Planetary Laboratory, Tucson, AZ.

    Photo Credit: NASA/JPL/Cassini Imaging Team/University of Arizona

    Cassini, launched in 1997, is a joint mission of NASA, the European Space Agency and Italian Space Agency. The mission is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  2. Laser angle measurement system

    NASA Technical Reports Server (NTRS)

    Pond, C. R.; Texeira, P. D.; Wilbert, R. E.

    1980-01-01

    The design and fabrication of a laser angle measurement system is described. The instrument is a fringe counting interferometer that monitors the pitch attitude of a model in a wind tunnel. A laser source and detector are mounted above the mode. Interference fringes are generated by a small passive element on the model. The fringe count is accumulated and displayed by a processor in the wind tunnel control room. Optical and electrical schematics, system maintenance and operation procedures are included, and the results of a demonstration test are given.

  3. Measures on mixing angles

    SciTech Connect

    Gibbons, Gary W.; Gielen, Steffen; Pope, C. N.; Turok, Neil

    2009-01-01

    We address the problem of the apparently very small magnitude of CP violation in the standard model, measured by the Jarlskog invariant J. In order to make statements about probabilities for certain values of J, we seek to find a natural measure on the space of Kobayashi-Maskawa matrices, the double quotient U(1){sup 2}/SU(3)/U(1){sup 2}. We review several possible, geometrically motivated choices of the measure, and compute expectation values for powers of J for these measures. We find that different choices of the measure generically make the observed magnitude of CP violation appear finely tuned. Since the quark masses and the mixing angles are determined by the same set of Yukawa couplings, we then do a second calculation in which we take the known quark mass hierarchy into account. We construct the simplest measure on the space of 3x3 Hermitian matrices which reproduces this known hierarchy. Calculating expectation values for powers of J in this second approach, we find that values of J close to the observed value are now rather likely, and there does not seem to be any fine-tuning. Our results suggest that the choice of Kobayashi-Maskawa angles is closely linked to the observed mass hierarchy. We close by discussing the corresponding case of neutrinos.

  4. Variable angle correlation spectroscopy

    SciTech Connect

    Lee, Young Kyo

    1994-05-01

    In this dissertation, a novel nuclear magnetic resonance (NMR) technique, variable angle correlation spectroscopy (VACSY) is described and demonstrated with 13C nuclei in rapidly rotating samples. These experiments focus on one of the basic problems in solid state NMR: how to extract the wealth of information contained in the anisotropic component of the NMR signal while still maintaining spectral resolution. Analysis of the anisotropic spectral patterns from poly-crystalline systems reveal information concerning molecular structure and dynamics, yet in all but the simplest of systems, the overlap of spectral patterns from chemically distinct sites renders the spectral analysis difficult if not impossible. One solution to this problem is to perform multi-dimensional experiments where the high-resolution, isotropic spectrum in one dimension is correlated with the anisotropic spectral patterns in the other dimensions. The VACSY technique incorporates the angle between the spinner axis and the static magnetic field as an experimental parameter that may be incremented during the course of the experiment to help correlate the isotropic and anisotropic components of the spectrum. The two-dimensional version of the VACSY experiments is used to extract the chemical shift anisotropy tensor values from multi-site organic molecules, study molecular dynamics in the intermediate time regime, and to examine the ordering properties of partially oriented samples. The VACSY technique is then extended to three-dimensional experiments to study slow molecular reorientations in a multi-site polymer system.

  5. A model for column angle evolution during oblique angle deposition

    NASA Astrophysics Data System (ADS)

    Tanto, B.; Ten Eyck, G.; Lu, T.-M.

    2010-07-01

    We present a semiempirical model based on the shadowing effect to describe quantitatively the aggregation of columnar structure during physical vapor condensation onto a surface with an array of line seeds and a flat surface. Specifically, we predict the relationship between the column angle and the incident flux angle and how this relationship changes with processing conditions and materials. The model uses one input parameter, the fan angle generated at normal incident flux. The model describes well our experimental data on the Ge column angle evolution as a function of a wide range of incident flux angles.

  6. Enhanced backscattering at grazing angles.

    PubMed

    Gu, Zu-Han; Fuks, I M; Ciftan, Mikael

    2002-12-02

    Backscattering signals at small grazing angles are important for space vehicle atmospheric reentrance and subsurface radar sensing applications. They are also useful in Fourier-transform infrared grazing-angle microscopy. Recently we performed an experimental study of far-field scattering at small grazing angles, in particular, of enhanced backscattering at grazing angles. For a randomly weak rough dielectric film upon a reflecting metal substrate, a large enhanced backscattering peak was measured. Experimental results are compared with small perturbation theoretical predictions.

  7. Heterodyne Interferometer Angle Metrology

    NASA Technical Reports Server (NTRS)

    Hahn, Inseob; Weilert, Mark A.; Wang, Xu; Goullioud, Renaud

    2010-01-01

    A compact, high-resolution angle measurement instrument has been developed that is based on a heterodyne interferometer. The common-path heterodyne interferometer metrology is used to measure displacements of a reflective target surface. In the interferometer setup, an optical mask is used to sample the measurement laser beam reflecting back from a target surface. Angular rotations, around two orthogonal axes in a plane perpendicular to the measurement- beam propagation direction, are determined simultaneously from the relative displacement measurement of the target surface. The device is used in a tracking telescope system where pitch and yaw measurements of a flat mirror were simultaneously performed with a sensitivity of 0.1 nrad, per second, and a measuring range of 0.15 mrad at a working distance of an order of a meter. The nonlinearity of the device is also measured less than one percent over the measurement range.

  8. Narrow Angle movie

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This brief three-frame movie of the Moon was made from three Cassini narrow-angle images as the spacecraft passed by the Moon on the way to its closest approach with Earth on August 17, 1999. The purpose of this particular set of images was to calibrate the spectral response of the narrow-angle camera and to test its 'on-chip summing mode' data compression technique in flight. From left to right, they show the Moon in the green, blue and ultraviolet regions of the spectrum in 40, 60 and 80 millisecond exposures, respectively. All three images have been scaled so that the brightness of Crisium basin, the dark circular region in the upper right, is the same in each image. The spatial scale in the blue and ultraviolet images is 1.4 miles per pixel (2.3 kilometers). The original scale in the green image (which was captured in the usual manner and then reduced in size by 2x2 pixel summing within the camera system) was 2.8 miles per pixel (4.6 kilometers). It has been enlarged for display to the same scale as the other two. The imaging data were processed and released by the Cassini Imaging Central Laboratory for Operations (CICLOPS) at the University of Arizona's Lunar and Planetary Laboratory, Tucson, AZ.

    Photo Credit: NASA/JPL/Cassini Imaging Team/University of Arizona

    Cassini, launched in 1997, is a joint mission of NASA, the European Space Agency and Italian Space Agency. The mission is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  9. Delayed diagnosed intermuscular lipoma causing a posterior interosseous nerve palsy in a patient with cervical spondylosis: the “priceless” value of the clinical examination in the technological era

    PubMed Central

    COLASANTI, R.; IACOANGELI, M.; DI RIENZO, A.; DOBRAN, M.; DI SOMMA, L.; NOCCHI, N.; SCERRATI, M.

    2016-01-01

    Background Posterior interosseous nerve (PIN) palsy may present with various symptoms, and may resemble cervical spondylosis. Case report We report about a 59-year-old patient with cervical spondylosis which delayed the diagnosis of posterior interosseous nerve (PIN) palsy due to an intermuscular lipoma. Initial right hand paraesthesias and clumsiness, together with MR findings of right C5–C6 and C6–C7 foraminal stenosis, misled the diagnostic investigation. The progressive loss of extension of all right hand fingers brought to detect a painless mass compressing the PIN. Electrophysiological studies confirmed a right radial motor neuropathy at the level of the forearm. Results Surgical tumor removal and nerve decompression resulted in a gradual motor deficits recovery. Conclusions A thorough clinical examination is paramount, and electrophysiology may differentiate between cervical and peripheral nerve lesions. Ultrasonography and MR offer an effective evaluation of lipomas, which represent a rare cause of PIN palsy. Surgical decompression and lipoma removal generally determine excellent prognoses, with very few recurrences. PMID:27142825

  10. Equilibrium contact angle or the most-stable contact angle?

    PubMed

    Montes Ruiz-Cabello, F J; Rodríguez-Valverde, M A; Cabrerizo-Vílchez, M A

    2014-04-01

    It is well-established that the equilibrium contact angle in a thermodynamic framework is an "unattainable" contact angle. Instead, the most-stable contact angle obtained from mechanical stimuli of the system is indeed experimentally accessible. Monitoring the susceptibility of a sessile drop to a mechanical stimulus enables to identify the most stable drop configuration within the practical range of contact angle hysteresis. Two different stimuli may be used with sessile drops: mechanical vibration and tilting. The most stable drop against vibration should reveal the changeless contact angle but against the gravity force, it should reveal the highest resistance to slide down. After the corresponding mechanical stimulus, once the excited drop configuration is examined, the focus will be on the contact angle of the initial drop configuration. This methodology needs to map significantly the static drop configurations with different stable contact angles. The most-stable contact angle, together with the advancing and receding contact angles, completes the description of physically realizable configurations of a solid-liquid system. Since the most-stable contact angle is energetically significant, it may be used in the Wenzel, Cassie or Cassie-Baxter equations accordingly or for the surface energy evaluation.

  11. Generalization of the Euler Angles

    NASA Technical Reports Server (NTRS)

    Bauer, Frank H. (Technical Monitor); Shuster, Malcolm D.; Markley, F. Landis

    2002-01-01

    It is shown that the Euler angles can be generalized to axes other than members of an orthonormal triad. As first shown by Davenport, the three generalized Euler axes, hereafter: Davenport axes, must still satisfy the constraint that the first two and the last two axes be mutually perpendicular if these axes are to define a universal set of attitude parameters. Expressions are given which relate the generalized Euler angles, hereafter: Davenport angles, to the 3-1-3 Euler angles of an associated direction-cosine matrix. The computation of the Davenport angles from the attitude matrix and their kinematic equation are presented. The present work offers a more direct development of the Davenport angles than Davenport's original publication and offers additional results.

  12. Small angle neutron scattering

    NASA Astrophysics Data System (ADS)

    Cousin, Fabrice

    2015-10-01

    Small Angle Neutron Scattering (SANS) is a technique that enables to probe the 3-D structure of materials on a typical size range lying from ˜ 1 nm up to ˜ a few 100 nm, the obtained information being statistically averaged on a sample whose volume is ˜ 1 cm3. This very rich technique enables to make a full structural characterization of a given object of nanometric dimensions (radius of gyration, shape, volume or mass, fractal dimension, specific area…) through the determination of the form factor as well as the determination of the way objects are organized within in a continuous media, and therefore to describe interactions between them, through the determination of the structure factor. The specific properties of neutrons (possibility of tuning the scattering intensity by using the isotopic substitution, sensitivity to magnetism, negligible absorption, low energy of the incident neutrons) make it particularly interesting in the fields of soft matter, biophysics, magnetic materials and metallurgy. In particular, the contrast variation methods allow to extract some informations that cannot be obtained by any other experimental techniques. This course is divided in two parts. The first one is devoted to the description of the principle of SANS: basics (formalism, coherent scattering/incoherent scattering, notion of elementary scatterer), form factor analysis (I(q→0), Guinier regime, intermediate regime, Porod regime, polydisperse system), structure factor analysis (2nd Virial coefficient, integral equations, characterization of aggregates), and contrast variation methods (how to create contrast in an homogeneous system, matching in ternary systems, extrapolation to zero concentration, Zero Averaged Contrast). It is illustrated by some representative examples. The second one describes the experimental aspects of SANS to guide user in its future experiments: description of SANS spectrometer, resolution of the spectrometer, optimization of spectrometer

  13. Angle Performance on Optima XE

    SciTech Connect

    David, Jonathan; Satoh, Shu

    2011-01-07

    Angle control on high energy implanters is important due to shrinking device dimensions, and sensitivity to channeling at high beam energies. On Optima XE, beam-to-wafer angles are controlled in both the horizontal and vertical directions. In the horizontal direction, the beam angle is measured through a series of narrow slits, and any angle adjustment is made by steering the beam with the corrector magnet. In the vertical direction, the beam angle is measured through a high aspect ratio mask, and any angle adjustment is made by slightly tilting the wafer platen during implant.Using a sensitive channeling condition, we were able to quantify the angle repeatability of Optima XE. By quantifying the sheet resistance sensitivity to both horizontal and vertical angle variation, the total angle variation was calculated as 0.04 deg. (1{sigma}). Implants were run over a five week period, with all of the wafers selected from a single boule, in order to control for any crystal cut variation.

  14. The Critical Angle Can Override the Brewster Angle

    ERIC Educational Resources Information Center

    Froehle, Peter H.

    2009-01-01

    As a culminating activity in their study of optics, my students investigate polarized light and the Brewster angle. In this exercise they encounter a situation in which it is impossible to measure the Brewster angle for light reflecting from a particular surface. This paper describes the activity and explains the students' observations.

  15. The Critical Angle Can Override the Brewster Angle

    ERIC Educational Resources Information Center

    Froehle, Peter H.

    2009-01-01

    As a culminating activity in their study of optics, my students investigate polarized light and the Brewster angle. In this exercise they encounter a situation in which it is impossible to measure the Brewster angle for light reflecting from a particular surface. This paper describes the activity and explains the students' observations.

  16. Spinning angle optical calibration apparatus

    DOEpatents

    Beer, Stephen K.; Pratt, II, Harold R.

    1991-01-01

    An optical calibration apparatus is provided for calibrating and reproducing spinning angles in cross-polarization, nuclear magnetic resonance spectroscopy. An illuminated magnifying apparatus enables optical setting an accurate reproducing of spinning "magic angles" in cross-polarization, nuclear magnetic resonance spectroscopy experiments. A reference mark scribed on an edge of a spinning angle test sample holder is illuminated by a light source and viewed through a magnifying scope. When the "magic angle" of a sample material used as a standard is attained by varying the angular position of the sample holder, the coordinate position of the reference mark relative to a graduation or graduations on a reticle in the magnifying scope is noted. Thereafter, the spinning "magic angle" of a test material having similar nuclear properties to the standard is attained by returning the sample holder back to the originally noted coordinate position.

  17. Angle closure in younger patients.

    PubMed Central

    Chang, Brian M; Liebmann, Jeffrey M; Ritch, Robert

    2002-01-01

    PURPOSE: Angle-closure glaucoma is rare in children and young adults. Only scattered cases associated with specific clinical entities have been reported. We evaluated the findings in patients in our database aged 40 or younger with angle closure. METHODS: Our database was searched for patients with angle closure who were 40 years old or younger. Data recorded included age at initial consultation; age at the time of diagnosis; gender; results of slit-lamp examination, gonioscopy, and ultrasound biomicroscopy (from 1993 onward); clinical diagnosis; and therapy. Patients with previous incisional surgery were excluded, as were patients with anterior chamber proliferative mechanisms leading to angle closure. RESULTS: Sixty-seven patients (49 females, 18 males) met entry criteria. Mean age (+/- SD) at the time of consultation was 34.4 +/- 9.4 years (range, 3-68 years). Diagnoses included plateau iris syndrome (35 patients), iridociliary cysts (8 patients), retinopathy of prematurity (7 patients), uveitis (5 patients), isolated nanophthalmos (3 patients), relative pupillary block (2 patients), Weill-Marchesani syndrome (3 patients), and 1 patient each with Marfan syndrome, miotic-induced angle closure, persistent hyperplastic primary vitreous, and idiopathic lens subluxation. CONCLUSION: The etiology of angle closure in young persons is different from that in the older population and is typically associated with structural or developmental ocular anomalies rather than relative pupillary block. Following laser iridotomy, these eyes should be monitored for recurrent angle closure and the need for additional laser or incisional surgical intervention. PMID:12545694

  18. Hysteresis during contact angles measurement.

    PubMed

    Diaz, M Elena; Fuentes, Javier; Cerro, Ramon L; Savage, Michael D

    2010-03-15

    A theory, based on the presence of an adsorbed film in the vicinity of the triple contact line, provides a molecular interpretation of intrinsic hysteresis during the measurement of static contact angles. Static contact angles are measured by placing a sessile drop on top of a flat solid surface. If the solid surface has not been previously in contact with a vapor phase saturated with the molecules of the liquid phase, the solid surface is free of adsorbed liquid molecules. In the absence of an adsorbed film, molecular forces configure an advancing contact angle larger than the static contact angle. After some time, due to an evaporation/adsorption process, the interface of the drop coexists with an adsorbed film of liquid molecules as part of the equilibrium configuration, denoted as the static contact angle. This equilibrium configuration is metastable because the droplet has a larger vapor pressure than the surrounding flat film. As the drop evaporates, the vapor/liquid interface contracts and the apparent contact line moves towards the center of the drop. During this process, the film left behind is thicker than the adsorbed film and molecular attraction results in a receding contact angle, smaller than the equilibrium contact angle. 2009 Elsevier Inc. All rights reserved.

  19. Ring magnet firing angle control

    DOEpatents

    Knott, M.J.; Lewis, L.G.; Rabe, H.H.

    1975-10-21

    A device is provided for controlling the firing angles of thyratrons (rectifiers) in a ring magnet power supply. A phase lock loop develops a smooth ac signal of frequency equal to and in phase with the frequency of the voltage wave developed by the main generator of the power supply. A counter that counts from zero to a particular number each cycle of the main generator voltage wave is synchronized with the smooth AC signal of the phase lock loop. Gates compare the number in the counter with predetermined desired firing angles for each thyratron and with coincidence the proper thyratron is fired at the predetermined firing angle.

  20. Two Comments on Bond Angles

    NASA Astrophysics Data System (ADS)

    Glaister, P.

    1997-09-01

    Tetrahedral Bond Angle from Elementary Trigonometry The alternative approach of using the scalar (or dot) product of vectors enables the determination of the bond angle in a tetrahedral molecule in a simple way. There is, of course, an even more straightforward derivation suitable for students who are unfamiliar with vectors, or products thereof, but who do know some elementary trigonometry. The starting point is the figure showing triangle OAB. The point O is the center of a cube, and A and B are at opposite corners of a face of that cube in which fits a regular tetrahedron. The required bond angle alpha = AÔB; and using Pythagoras' theorem, AB = 2(square root 2) is the diagonal of a face of the cube. Hence from right-angled triangle OEB, tan(alpha/2) = (square root 2) and therefore alpha = 2tan-1(square root 2) is approx. 109° 28' (see Fig. 1).

  1. Relativistic Transformation of Solid Angle.

    ERIC Educational Resources Information Center

    McKinley, John M.

    1980-01-01

    Rederives the relativistic transformations of light intensity from compact sources (stars) to show where and how the transformation of a solid angle contributes. Discusses astrophysical and other applications of the transformations. (Author/CS)

  2. Angles of multivariable root loci

    NASA Technical Reports Server (NTRS)

    Thompson, P. M.; Stein, G.; Laub, A. J.

    1982-01-01

    A generalized eigenvalue problem is demonstrated to be useful for computing the multivariable root locus, particularly when obtaining the arrival angles to finite transmission zeros. The multivariable root loci are found for a linear, time-invariant output feedback problem. The problem is then employed to compute a closed-loop eigenstructure. The method of computing angles on the root locus is demonstrated, and the method is extended to a multivariable optimal root locus.

  3. The Semiotic and Conceptual Genesis of Angle

    ERIC Educational Resources Information Center

    Tanguay, Denis; Venant, Fabienne

    2016-01-01

    In the present study, we try to understand how students at the end of primary school conceive of angle: Is an angle a magnitude for them or a geometric figure, and how do they manage to coordinate the two aspects in their understanding of the concepts of angle and of angle measurement? With the aim of better grasping the way "angle" is…

  4. The Semiotic and Conceptual Genesis of Angle

    ERIC Educational Resources Information Center

    Tanguay, Denis; Venant, Fabienne

    2016-01-01

    In the present study, we try to understand how students at the end of primary school conceive of angle: Is an angle a magnitude for them or a geometric figure, and how do they manage to coordinate the two aspects in their understanding of the concepts of angle and of angle measurement? With the aim of better grasping the way "angle" is…

  5. Modulation of stretch-induced myocyte remodeling and gene expression by nitric oxide: a novel role for lipoma preferred partner in myofibrillogenesis.

    PubMed

    Hooper, Charlotte L; Paudyal, Anju; Dash, Philip R; Boateng, Samuel Y

    2013-05-15

    Prolonged hemodynamic load as a result of hypertension eventually leads to maladaptive cardiac adaptation and heart failure. The signaling pathways that underlie these changes are still poorly understood. The adaptive response to mechanical load is mediated by mechanosensors that convert the mechanical stimuli into a biological response. We examined the effect of cyclic mechanical stretch on myocyte adaptation using neonatal rat ventricular myocytes with 10% (adaptive) or 20% (maladaptive) maximum strain at 1 Hz for 48 h to mimic in vivo mechanical stress. Cells were also treated with and without nitro-L-arginine methyl ester (L-NAME), a general nitric oxide synthase (NOS) inhibitor to suppress NO production. Maladaptive 20% mechanical stretch led to a significant loss of intact sarcomeres that were rescued by L-NAME (P < 0.05; n ≥ 5 cultures). We hypothesized that the mechanism was through NO-induced alteration of myocyte gene expression. L-NAME upregulated the mechanosensing proteins muscle LIM protein (MLP; by 100%; P < 0.05; n = 5 cultures) and lipoma preferred partner (LPP), a novel cardiac protein (by 80%; P < 0.05; n = 4 cultures). L-NAME also significantly altered the subcellular localization of LPP and MLP in a manner that favored growth and adaptation. These findings suggest that NO participates in stretch-mediated adaptation. The use of isoform selective NOS inhibitors indicated a complex interaction between inducible NOS and neuronal NOS isoforms regulate gene expression. LPP knockdown by small intefering RNA led to formation of α-actinin aggregates and Z bodies showing that myofibrillogenesis was impaired. There was an upregulation of E3 ubiquitin ligase (MUL1) by 75% (P < 0.05; n = 5 cultures). This indicates that NO contributes to stretch-mediated adaptation via the upregulation of proteins associated with mechansensing and myofibrillogenesis, thereby presenting potential therapeutic targets during the progression of heart failure.

  6. PP2A binds to the LIM domains of lipoma-preferred partner through its PR130/B″ subunit to regulate cell adhesion and migration

    PubMed Central

    Janssens, Veerle; Zwaenepoel, Karen; Rossé, Carine; Petit, Marleen M. R.; Goris, Jozef; Parker, Peter J.

    2017-01-01

    Here, we identify the LIM protein lipoma-preferred partner (LPP) as a binding partner of a specific protein phosphatase 2A (PP2A) heterotrimer that is characterised by the regulatory PR130/B″α1 subunit (encoded by PPP2R3A). The PR130 subunit interacts with the LIM domains of LPP through a conserved Zn2+-finger-like motif in the differentially spliced N-terminus of PR130. Isolated LPP-associated PP2A complexes are catalytically active. PR130 colocalises with LPP at multiple locations within cells, including focal contacts, but is specifically excluded from mature focal adhesions, where LPP is still present. An LPP–PR130 fusion protein only localises to focal adhesions upon deletion of the domain of PR130 that binds to the PP2A catalytic subunit (PP2A/C), suggesting that PR130–LPP complex formation is dynamic and that permanent recruitment of PP2A activity might be unfavourable for focal adhesion maturation. Accordingly, siRNA-mediated knockdown of PR130 increases adhesion of HT1080 fibrosarcoma cells onto collagen I and decreases their migration in scratch wound and Transwell assays. Complex formation with LPP is mandatory for these PR130-PP2A functions, as neither phenotype can be rescued by re-expression of a PR130 mutant that no longer binds to LPP. Our data highlight the importance of specific, locally recruited PP2A complexes in cell adhesion and migration dynamics. PMID:26945059

  7. Critical rolling angle of microparticles

    NASA Astrophysics Data System (ADS)

    Farzi, Bahman; Vallabh, Chaitanya K. P.; Stephens, James D.; Cetinkaya, Cetin

    2016-03-01

    At the micrometer-scale and below, particle adhesion becomes particularly relevant as van der Waals force often dominates volume and surface proportional forces. The rolling resistance of microparticles and their critical rolling angles prior to the initiation of free-rolling and/or complete detachment are critical in numerous industrial processes and natural phenomenon involving particle adhesion and granular dynamics. The current work describes a non-contact measurement approach for determining the critical rolling angle of a single microparticle under the influence of a contact-point base-excitation generated by a transient displacement field of a prescribed surface acoustic wave pulse and reports the critical rolling angle data for a set of polystyrene latex microparticles.

  8. A new angle on the Angle of Louis.

    PubMed

    Ramana, Ravi K; Sanagala, Thriveni; Lichtenberg, Robert

    2006-01-01

    Previous literature has stated that the center of the right atrium lies approximately 5 cm below the sternal angle regardless of body position. Our objective was to measure the distance from the Angle of Louis to various locations in the right atrium and determine whether these distances vary with patients' body habitus. The authors conducted a cross-sectional study with 52 consecutive patients who underwent computed tomography. The Angle of Louis was measured to various right atrial anatomic locations and was correlated with patients' body habitus characteristics. There was a positive correlation between patients' weight or body mass index and the distance of the Angle of Louis to right atrial locations. Therefore, using the traditional 5 cm in an obese patient can and usually will result in an underestimation of right atrial pressure. The authors suggest that in patients with body mass index > 35 kg/m2 (body surface area > 2.5 m2), a jugular venous column height at the clavicle is likely to indicate significantly elevated jugular venous pressure and should be considered abnormal. Therefore, further clinical assessment and subsequent therapeutic decisions of these morbidly obese patients with abnormal jugular venous pressures should be made accordingly.

  9. Cydonia: Wide Angle Color Image

    NASA Technical Reports Server (NTRS)

    2000-01-01

    [figure removed for brevity, see original site]

    Although the resolution of the MOC wide angle cameras is too low to tell much about the geomorphology of the Cydonia region, the images from the red and blue wide angle cameras provide us with two types of information that is of interest in their own right: color and stereoscopic data. Above are a color view and a stereoscopic anaglyph rendition of Geodesy Campaign images acquired by MGS MOC in May 1999. To view the stereo image, you need red/blue '3-D' glasses.

  10. Tiny incident light angle sensor

    NASA Astrophysics Data System (ADS)

    Mitrenga, D.; Schädel, M.; Winzer, A. T.; Völlmeke, S.; Preuß, K. D.; Freitag, J.; Brodersen, O.

    2017-05-01

    A novel device for detecting the intensity and the angles of incoming light is presented. The silicon chip with 1 mm edge length comprises a segmented photo diode with four active areas within the inclined surfaces of a deep etched cavity. Simple signal difference analysis of these signals allow for accurate azimuth and inclination measurement in the range of 0 to 360° and 0 to 55°, respectively. Using an artificial neural network (ANN) calibration strategy the operation range of inclination can be increased up to 85° with typical angle errors below 2°. In this report we present details on design, fabrication, signal analysis and calibration strategies.

  11. Discovering the Inscribed Angle Theorem

    ERIC Educational Resources Information Center

    Roscoe, Matt B.

    2012-01-01

    Learning to play tennis is difficult. It takes practice, but it also helps to have a coach--someone who gives tips and pointers but allows the freedom to play the game on one's own. Learning to act like a mathematician is a similar process. Students report that the process of proving the inscribed angle theorem is challenging and, at times,…

  12. Discovering the Inscribed Angle Theorem

    ERIC Educational Resources Information Center

    Roscoe, Matt B.

    2012-01-01

    Learning to play tennis is difficult. It takes practice, but it also helps to have a coach--someone who gives tips and pointers but allows the freedom to play the game on one's own. Learning to act like a mathematician is a similar process. Students report that the process of proving the inscribed angle theorem is challenging and, at times,…

  13. Supercritical Angle Fluorescence Correlation Spectroscopy

    PubMed Central

    Ries, Jonas; Ruckstuhl, Thomas; Verdes, Dorinel; Schwille, Petra

    2008-01-01

    We explore the potential of a supercritical angle (SA) objective for fluorescence correlation spectroscopy (FCS). This novel microscope objective combines tight focusing by an aspheric lens with strong axial confinement of supercritical angle fluorescence collection by a parabolic mirror lens, resulting in a small detection volume. The tiny axial extent of the detection volume features an excellent surface sensitivity, as is demonstrated by diffusion measurements in model membranes with an excess of free dye in solution. All SA-FCS measurements are directly compared to standard confocal FCS, demonstrating a clear advantage of SA-FCS, especially for diffusion measurements in membranes. We present an extensive theoretical framework that allows for accurate and quantitative evaluation of the SA-FCS correlation curves. PMID:17827221

  14. Angle interferometer cross axis errors

    NASA Astrophysics Data System (ADS)

    Bryan, J. B.; Carter, D. L.; Thompson, S. L.

    1994-01-01

    Angle interferometers are commonly used to measure surface plate flatness. An error can exist when the centerline of the double comer cube mirror assembly is not square to the surface plate and the guide bar for the mirror sled is curved. Typical errors can be one to two microns per meter. A similar error can exist in the calibration of rotary tables when the centerline of the double comer cube mirror assembly is not square to the axes of rotation of the angle calibrator and the calibrator axis is not parallel to the rotary table axis. Commercial double comer cube assemblies typically have non-parallelism errors of ten milli-radians between their centerlines and their sides and similar values for non-squareness between their centerlines and end surfaces. The authors have developed a simple method for measuring these errors and correcting them.

  15. Angle interferometer cross axis errors

    SciTech Connect

    Bryan, J.B.; Carter, D.L.; Thompson, S.L.

    1994-01-01

    Angle interferometers are commonly used to measure surface plate flatness. An error can exist when the centerline of the double comer cube mirror assembly is not square to the surface plate and the guide bar for the mirror sled is curved. Typical errors can be one to two microns per meter. A similar error can exist in the calibration of rotary tables when the centerline of the double comer cube mirror assembly is not square to the axes of rotation of the angle calibrator and the calibrator axis is not parallel to the rotary table axis. Commercial double comer cube assemblies typically have non-parallelism errors of ten milli-radians between their centerlines and their sides and similar values for non-squareness between their centerlines and end surfaces. The authors have developed a simple method for measuring these errors and correcting them by remachining the reference surfaces.

  16. High Angle of Attack Aerodynamics

    DTIC Science & Technology

    1979-01-01

    describe the behaviour of the air. The Symposium made it clear that the present state of knowledge in the area of high angle-of-attack aerodynamics...TESTING EXPERIENCE by C.W. Smith and C.A.Anderson S FOREBODY-WING VORTEX INTERACTIONS AND THEIR INFLUENCE ON DEPARTURE AND SPIN RESISTANCE by A.MSkow...Figure 6) caused by asymmetric flow conditions. ., s already mentioned, asymmetric flow occurs not only when an air- craft flies at non-zero sideslip

  17. Gaia basic angle monitoring system

    NASA Astrophysics Data System (ADS)

    Gielesen, W.; de Bruijn, D.; van den Dool, T.; Kamphues, F.; Mekking, J.; Calvel, B.; Laborie, A.; Coatantiec, C.; Touzeau, S.; Erdmann, M.; Gare, P.; Monteiro, D.

    2013-09-01

    The Gaia mission1 will create an extraordinarily precise three-dimensional map of more than one billion stars in our Galaxy. The Gaia spacecraft2, built by EADS Astrium, is part of ESA's Cosmic Vision programme and scheduled for launch in 2013. Gaia measures the position, distance and motion of stars with an accuracy of 24 micro-arcsec using two telescopes at a fixed mutual angle of 106.5°, named the `Basic Angle', at an operational temperature of 100 K. This accuracy requires ultra-high stability at cryogenic conditions, which can only be achieved by using Silicon Carbide for both the optical bench and the telescopes. TNO has developed, built and space qualified the Silicon carbide Basic Angle Monitoring (BAM) on-board metrology system3 for this mission, measuring the relative motion of Gaia's telescopes with accuracies in the range of 0.5 micro-arcsec. This is achieved by a system of two laser interferometers able to detect Optical Path Differences (OPD) as small as 1.5 picometer rms. Following a general introduction on Gaia and the use of Silicon Carbide as base material this paper addresses the specific challenges towards the cryogenic application of the Gaia BAM including design, integration and verification/qualification by testing.

  18. OPENING ANGLES OF COLLAPSAR JETS

    SciTech Connect

    Mizuta, Akira; Ioka, Kunihito

    2013-11-10

    We investigate the jet propagation and breakout from the stellar progenitor for gamma-ray burst (GRB) collapsars by performing two-dimensional relativistic hydrodynamic simulations and analytical modeling. We find that the jet opening angle is given by θ{sub j} ∼ 1/5Γ{sub 0} and infer the initial Lorentz factor of the jet at the central engine, Γ{sub 0}, is a few for existing observations of θ{sub j}. The jet keeps the Lorentz factor low inside the star by converging cylindrically via collimation shocks under the cocoon pressure and accelerates at jet breakout before the free expansion to a hollow-cone structure. In this new picture, the GRB duration is determined by the sound crossing time of the cocoon, after which the opening angle widens, reducing the apparent luminosity. Some bursts violating the maximum opening angle θ{sub j,{sub max}} ∼ 1/5 ∼ 12° imply the existence of a baryon-rich sheath or a long-acting jet. We can explain the slopes in both Amati and Yonetoku spectral relations using an off-centered photosphere model, if we make only one assumption that the total jet luminosity is proportional to the initial Lorentz factor of the jet. We also numerically calibrate the pre-breakout model (Bromberg et al.) for later use.

  19. Discrimination of geometric angles by adult humans.

    PubMed

    Reichert, James F; Kelly, Debbie M

    2012-03-01

    Men and women learned to discriminate between two different size angles presented to them as objects within a real-world task. During Experiment 1, participants in group 50 were trained to choose a 50° angle and participants in group 75 were trained to choose a 75° angle. During testing, both groups were provided with a choice between their training angle and one of a set of test angles that was either smaller or larger than the training angle. Results showed a generalized pattern of responding, with group 50 showing increased responding to test angles smaller than 50° and group 75 showing increased responding to test angles larger than 75°. Further analysis of the response patterns revealed that participants in group 50 showed evidence of absolute learning, whereas participants in group 75 showed evidence of relational learning. During Experiment 2, a third group of participants (group 25) trained to choose a smaller angle (25°) was included in addition to group 50 and group 75. Participants were trained with three angles present and tested with just two, one being their training angle and the other being one of a set of novel test angles. Similar to the participants from Experiment 1, group 75 showed evidence of relational learning. Group 50, for which no relational rule could be applied during training, showed an absolute learning pattern with no response shift to test angles smaller or larger than their training angle. Group 25 showed evidence of absolute responding that was more pronounced than that found for the smallest training angle during Experiment 1. These findings suggest differential learning of geometric angles based on amplitude with smaller angles perceived as more distinct and thus more resistant to broader generalization than larger angles. Implications of these results are that certain geometric properties may be subject to different learning processes based on the specific magnitude of that property.

  20. Aircraft flight path angle display system

    NASA Technical Reports Server (NTRS)

    Lambregts, Antonius A. (Inventor)

    1991-01-01

    A display system for use in an aircraft control wheel steering system provides the pilot with a single, quickened flight path angle display to overcome poor handling qualities due to intrinsic flight path angle response lags, while avoiding multiple information display symbology. The control law for the flight path angle control system is designed such that the aircraft's actual flight path angle response lags the pilot's commanded flight path angle by a constant time lag .tau., independent of flight conditions. The synthesized display signal is produced as a predetermined function of the aircraft's actual flight path angle, the time lag .tau. and command inputs from the pilot's column.

  1. Management of Secondary Angle Closure Glaucoma.

    PubMed

    Parivadhini, Annadurai; Lingam, Vijaya

    2014-01-01

    Secondary angle closure glaucomas are a distinct entity from primary angle closure glaucoma (PACG). Unlike PACG, secondary angle closure glaucoma's have an identifable contributory factor/s for angle closure and obstruction of aqueous fow which is usually unrelieved by iridotomy. The treatment of each type of secondary angle closure glaucoma is varied, so identification of the primary cause aids in its effective management. How to cite this article: Annadurai P, Vijaya L. Management of Secondary Angle Closure Glaucoma. J Current Glau Prac 2014;8(1):25-32.

  2. Theta angle in holographic QCD

    NASA Astrophysics Data System (ADS)

    Järvinen, Matti

    2017-03-01

    V-QCD is a class of effective holographic models for QCD which fully includes the backreaction of quarks to gluon dynamics. The physics of the θ-angle and the axial anomaly can be consistently included in these models. We analyze their phase diagrams over ranges of values of the quark mass, Nf/Nc, and θ, computing observables such as the topological susceptibility and the meson masses. At small quark mass, where effective chiral Lagrangians are reliable, they agree with the predictions of V-QCD.

  3. Gaia basic angle monitoring system

    NASA Astrophysics Data System (ADS)

    Gielesen, W.; de Bruijn, D.; van den Dool, T.; Kamphues, F.; Meijer, E.; Calvel, B.; Laborie, A.; Monteiro, D.; Coatantiec, C.; Touzeau, S.; Erdmann, M.; Gare, P.

    2012-09-01

    The Gaia mission will create an extraordinarily precise three-dimensional map of more than one billion stars in our Galaxy. The Gaia spacecraft, built by EADS Astrium, is part of ESA's Cosmic Vision programme and scheduled for launch in 2013. Gaia measures the position, distance and motion of stars with an accuracy of 24 micro-arcsec using two telescopes at a fixed mutual angle of 106.5°, named the ‘Basic Angle’. This accuracy requires ultra-high stability, which can only be achieved by using Silicon Carbide for both the optical bench and the telescopes. TNO has developed, built and space qualified the Silicon carbide Basic Angle Monitoring (BAM) on-board metrology system for this mission. The BAM measures the relative motion of Gaia’s telescopes with accuracies in the range of 0.5 micro-arcsec. This is achieved by a system of two laser interferometers able to measure Optical Path Differences (OPD) as small as 1.5 picometer rms. Following a general introduction to the Gaia mission, the Payload Module (PLM) and the use of Silicon Carbide as base material, this presentation will address an overview of the challenges towards the key requirements, design, integration and testing (including space-level qualification) of the Gaia BAM.

  4. Predictive models of large neutrino mixing angles

    SciTech Connect

    Barr, S.M.

    1997-02-01

    Several experimental results could be interpreted as evidence that certain neutrino mixing angles are large, of order unity. However, in the context of grand unified models the neutrino angles come out characteristically to be small, like the KM angles. It is shown how to construct simple grand-unified models in which neutrino angles are not only large but completely predicted with some precision. Six models are presented for illustration. {copyright} {ital 1997} {ital The American Physical Society}

  5. Bilarge neutrino mixing and the Cabibbo angle

    NASA Astrophysics Data System (ADS)

    Boucenna, S. M.; Morisi, S.; Tórtola, M.; Valle, J. W. F.

    2012-09-01

    Recent measurements of the neutrino mixing angles cast doubt on the validity of the so-far popular tribimaximal mixing Ansatz. We propose a parametrization for the neutrino mixing matrix where the reactor angle seeds the large solar and atmospheric mixing angles, equal to each other in first approximation. We suggest such a bilarge mixing pattern as a model-building standard, realized when the leading order value of θ13 equals the Cabibbo angle λC.

  6. Optoelectronic Shaft-Angle Encoder Tolerates Misalignments

    NASA Technical Reports Server (NTRS)

    Osborne, Eric P.

    1991-01-01

    Optoelectronic shaft-angle encoder measures angle of rotation of shaft with high precision while minimizing effects of eccentricity and other misalignments. Grooves on disk serve as reference marks to locate reading heads and measure increments of rotation of disk. Shaft-angle encoder, resembling optical compact-disk drive, includes two tracking heads illuminating grooves on disk and measures reflections from them.

  7. A new procedure for measuring contact angle

    SciTech Connect

    Concus, P.; Finn, R.

    1994-05-01

    Described here are some recent work regarding the mathematic design of apparatus that exploits microgravity conditions for accurate experimental determination of contact angle. The underlying motivation for the procedures rests on a discontinuous dependence of the capillary free surface interface S on the contact angle {gamma}, in a cylindrical capillary tube whose section (base) {Omega} contains a protruding corner with opening angle 2{alpha}.

  8. Primary open-angle glaucoma.

    PubMed

    Weinreb, Robert N; Khaw, Peng Tee

    2004-05-22

    Primary open-angle glaucoma is a progressive optic neuropathy and, perhaps, the most common form of glaucoma. Because the disease is treatable, and because the visual impairment caused by glaucoma is irreversible, early detection is essential. Early diagnosis depends on examination of the optic disc, retinal nerve fibre layer, and visual field. New imaging and psychophysical tests can improve both detection and monitoring of the progression of the disease. Recently completed long-term clinical trials provide convincing evidence that lowering intraocular pressure prevents progression at both the early and late stages of the disease. The degree of protection is related to the degree to which intraocular pressure is lowered. Improvements in therapy consist of more effective and better-tolerated drugs to lower intraocular pressure, and more effective surgical procedures. New treatments to directly treat and protect the retinal ganglion cells that are damaged in glaucoma are also in development.

  9. Individualized optimal release angles in discus throwing.

    PubMed

    Leigh, Steve; Liu, Hui; Hubbard, Mont; Yu, Bing

    2010-02-10

    The purpose of this study was to determine individualized optimal release angles for elite discus throwers. Three-dimensional coordinate data were obtained for at least 10 competitive trials for each subject. Regression relationships between release speed and release angle, and between aerodynamic distance and release angle were determined for each subject. These relationships were linear with subject-specific characteristics. The subject-specific relationships between release speed and release angle may be due to subjects' technical and physical characteristics. The subject-specific relationships between aerodynamic distance and release angle may be due to interactions between the release angle, the angle of attack, and the aerodynamic distance. Optimal release angles were estimated for each subject using the regression relationships and equations of projectile motion. The estimated optimal release angle was different for different subjects, and ranged from 35 degrees to 44 degrees . The results of this study demonstrate that the optimal release angle for discus throwing is thrower-specific. The release angles used by elite discus throwers in competition are not necessarily optimal for all discus throwers, or even themselves. The results of this study provide significant information for understanding the biomechanics of discus throwing techniques.

  10. Wafer scale oblique angle plasma etching

    DOEpatents

    Burckel, David Bruce; Jarecki, Jr., Robert L.; Finnegan, Patrick Sean

    2017-05-23

    Wafer scale oblique angle etching of a semiconductor substrate is performed in a conventional plasma etch chamber by using a fixture that supports a multiple number of separate Faraday cages. Each cage is formed to include an angled grid surface and is positioned such that it will be positioned over a separate one of the die locations on the wafer surface when the fixture is placed over the wafer. The presence of the Faraday cages influences the local electric field surrounding each wafer die, re-shaping the local field to be disposed in alignment with the angled grid surface. The re-shaped plasma causes the reactive ions to follow a linear trajectory through the plasma sheath and angled grid surface, ultimately impinging the wafer surface at an angle. The selected geometry of the Faraday cage angled grid surface thus determines the angle at with the reactive ions will impinge the wafer.

  11. Angle illusion in a straight road.

    PubMed

    Osa, Atsushi; Nagata, Kazumi; Honda, Yousuke; Ichikawa, Makoto; Matsuda, Ken; Miike, Hidetoshi

    2011-01-01

    We report a new angle illusion observed when viewing a real scene involving a straight road. The scene portrays two white lines which outline a traffic lane on a road and converge to a vanishing point. In experiment 1, observers estimated the angle created by these converging lines in this scene or in its image projected onto a screen. Results showed strong underestimation of the angle, ie over 50% for observations of both the real scene and its projected image. Experiment 2 assessed how depth cues in projected images influence the angle illusion. Results showed that this angle illusion disappeared when scene information surrounding convergent lines was removed. In addition, the illusion was attenuated with projection of an inverted scene image. These findings are interpreted in terms of a misadoption of depth information in the processing of angle perception in a flat image; in turn, this induces a massive angle illusion.

  12. Assessment and predictability of ANB angle.

    PubMed

    Chandra, P K; Godfrey, K

    1990-03-01

    This cephalometric study consisting of thirty three orthodontic patients in the age group of 13 to 15 years was carried out to: 1. Evaluate the relationship between angle ANB and horizontal distance between jaws at the level of point A (r = 0.99); 2. Evaluate the relationship between angle ANB and Wits appraisal (r = 0.95 when mandibular plane angle is within normal limits of 32 +/- 5); 3. Predict angle ANB from Wits appraisal and vice versa (which was 90 percent correct in mesofacial type and obtained by the regression equation: angle ANB = 2.31 + 1.00 x Wits value; and 4. Evaluate the validity of angle ANB compared to other methods (angle ANB 78.5 percent in agreement with the standard followed by Wits 64.28 percent).

  13. Foot Progression Angle Walking Test

    PubMed Central

    Ranawat, Anil S.; Gaudiani, Michael A.; Slullitel, Pablo A.; Satalich, James; Rebolledo, Brian J.

    2017-01-01

    Background: Determining an accurate clinical diagnosis for nonarthritic hip pain may be challenging, as symptoms related to femoroacetabular impingement (FAI) or hip instability can be difficult to elucidate with current testing methods. In addition, commonly utilized physical examination maneuvers are static and do not include a dynamic or weightbearing assessment to reproduce activity-related symptoms. Therefore, implementing a dynamic assessment for FAI and hip instability could help to improve diagnostic accuracy for routine clinical examinations of patients with nonarthritic hip pain. Purpose: To assess the efficacy of a novel diagnostic foot progression angle walking (FPAW) test for identifying hip pathology related to FAI or hip instability. Study Design: Prospective cohort study; Level of evidence, 3. Methods: This prospective study included 199 consecutive patients who were evaluated for unilateral hip pain and who underwent FPAW testing along with standard physical examination testing. Demographic data, including age, sex and hip laterality, were collected from each patient. FPAW testing was performed with directed internal and external foot progression angles from their baseline measurements, with a positive test reproducing pain and/or discomfort. Comparisons were then made with flexion adduction internal rotation (FADIR) and flexion abduction external rotation (FABER) tests as the designated diagnostic standard examinations for FAI and hip instability, respectively. Sensitivity and specificity, along with the McNemar chi-square test for group comparison, were used to generate summary statistics. In addition, areas under the combined receiver operating characteristic curves (AUC) of test performance were calculated for both FPAW and the designated standard examination tests (FADIR, FABER). Radiographic imaging was used subsequently to confirm the diagnosis. Results: The average age of the study cohort was 35.4 ± 11.8 years, with 114 patients being

  14. Dynamic contact angle measurements on superhydrophobic surfaces

    NASA Astrophysics Data System (ADS)

    Kim, Jeong-Hyun; Kavehpour, H. Pirouz; Rothstein, Jonathan P.

    2015-03-01

    In this paper, the dynamic advancing and receding contact angles of a series of aqueous solutions were measured on a number of hydrophobic and superhydrophobic surfaces using a modified Wilhelmy plate technique. Superhydrophobic surfaces are hydrophobic surfaces with micron or nanometer sized surface roughness. These surfaces have very large static advancing contact angles and little static contact angle hysteresis. In this study, the dynamic advancing and dynamic receding contact angles on superhydrophobic surfaces were measured as a function of plate velocity and capillary number. The dynamic contact angles measured on a smooth hydrophobic Teflon surface were found to obey the scaling with capillary number predicted by the Cox-Voinov-Tanner law, θD3 ∝ Ca. The response of the dynamic contact angle on the superhydrophobic surfaces, however, did not follow the same scaling law. The advancing contact angle was found to remain constant at θA = 160∘, independent of capillary number. The dynamic receding contact angle measurements on superhydrophobic surfaces were found to decrease with increasing capillary number; however, the presence of slip on the superhydrophobic surface was found to result in a shift in the onset of dynamic contact angle variation to larger capillary numbers. In addition, a much weaker dependence of the dynamic contact angle on capillary number was observed for some of the superhydrophobic surfaces tested.

  15. Large Angle Satellite Attitude Maneuvers

    NASA Technical Reports Server (NTRS)

    Cochran, J. E.; Junkins, J. L.

    1975-01-01

    Two methods are proposed for performing large angle reorientation maneuvers. The first method is based upon Euler's rotation theorem; an arbitrary reorientation is ideally accomplished by rotating the spacecraft about a line which is fixed in both the body and in space. This scheme has been found to be best suited for the case in which the initial and desired attitude states have small angular velocities. The second scheme is more general in that a general class of transition trajectories is introduced which, in principle, allows transfer between arbitrary orientation and angular velocity states. The method generates transition maneuvers in which the uncontrolled (free) initial and final states are matched in orientation and angular velocity. The forced transition trajectory is obtained by using a weighted average of the unforced forward integration of the initial state and the unforced backward integration of the desired state. The current effort is centered around practical validation of this second class of maneuvers. Of particular concern is enforcement of given control system constraints and methods for suboptimization by proper selection of maneuver initiation and termination times. Analogous reorientation strategies which force smooth transition in angular momentum and/or rotational energy are under consideration.

  16. Cystic acoustic schwannomas.

    PubMed

    Lunardi, P; Missori, P; Mastronardi, L; Fortuna, A

    1991-01-01

    Three cases with large space-occupying cysts in the cerebellopontine angle are reported. CT and MRI findings were not typical for acoustic schwannomas but at operation, besides the large cysts, small acoustic schwannomas could be detected and removed. The clinical and neuroradiological features of this unusual variety and the CT and MRI differential diagnosis of cerebellopontine angle lesions are discussed.

  17. A thermodynamic model of contact angle hysteresis

    NASA Astrophysics Data System (ADS)

    Makkonen, Lasse

    2017-08-01

    When a three-phase contact line moves along a solid surface, the contact angle no longer corresponds to the static equilibrium angle but is larger when the liquid is advancing and smaller when the liquid is receding. The difference between the advancing and receding contact angles, i.e., the contact angle hysteresis, is of paramount importance in wetting and capillarity. For example, it determines the magnitude of the external force that is required to make a drop slide on a solid surface. Until now, fundamental origin of the contact angle hysteresis has been controversial. Here, this origin is revealed and a quantitative theory is derived. The theory is corroborated by the available experimental data for a large number of solid-liquid combinations. The theory is applied in modelling the contact angle hysteresis on a textured surface, and these results are also in quantitative agreement with the experimental data.

  18. Dual-view angle backlight module design.

    PubMed

    Chen, Bo-Tsuen; Pan, Jui-Wen

    2015-10-01

    We propose a bilayer light guide plate (BLGP) with specially designed microstructures and two light source modules to achieve an adjustable viewing angle backlight for ecofriendly displays. The dual viewing angle backlight module has a thin, simple structure and a high optical efficiency. Comparison with the conventional edge-lit backlight module shows an improvement in the on-axis luminance of the narrow viewing angle mode of 4.3 times and a decrease in the half-luminance angle of 7° in the horizontal direction. When using the wide viewing angle mode, there is an improvement in the on-axis luminance of 1.8 times and an improvement in the half-luminance angle of 54° in the horizontal direction. The uniformity of illuminance can reach 80% in each mode. The backlight optical sheet number is reduced from 5 to 1.

  19. Contact angle measurement on rough surfaces.

    PubMed

    Meiron, Tammar S; Marmur, Abraham; Saguy, I Sam

    2004-06-15

    A new method for the measurement of apparent contact angles at the global energy minimum on real surfaces has been developed. The method consists of vibrating the surface, taking top-view pictures of the drop, monitoring the drop roundness, and calculating the contact angle from the drop diameter and weight. The use of the new method has been demonstrated for various rough surfaces, all having the same surface chemistry. In order to establish the optimal vibration conditions, the proper ranges for the system parameters (i.e., drop volume, vibration time, frequency of vibration, and amplitude of vibration) were determined. The reliability of the method has been demonstrated by the fact that the ideal contact angles of all surfaces, as calculated from the Wenzel equation using the measured apparent contact angles, came out to be practically identical. This ideal contact angle has been compared with three methods of calculation from values of advancing and receding contact angles.

  20. Signature extension for sun angle, volume 1

    NASA Technical Reports Server (NTRS)

    Smith, J. A. (Principal Investigator); Berry, J. K.; Heimes, F.

    1975-01-01

    The author has identified the following significant results. Within a restricted zenith sun angle range of 35 - 50 degrees, it was empirically observed that canopy reflectance is mainly Lambertian. Reflectance changes with crop stage were simple shifts in scale in the sun angle range. It was noted that sun angle variations depend on canopy characteristics. Effects of the vegetative canopy were most pronounced at the larger solar zenith angles (20 %). The linear sun angle correction coefficients demonstrate a dependency on both crop stage (15-20 %) and crop type (10-20 %). The use of canopy reflectance modeling allowed for the generation of a simulated data set over an extremely broad envelope of sun angles.

  1. A thermodynamic model of contact angle hysteresis.

    PubMed

    Makkonen, Lasse

    2017-08-14

    When a three-phase contact line moves along a solid surface, the contact angle no longer corresponds to the static equilibrium angle but is larger when the liquid is advancing and smaller when the liquid is receding. The difference between the advancing and receding contact angles, i.e., the contact angle hysteresis, is of paramount importance in wetting and capillarity. For example, it determines the magnitude of the external force that is required to make a drop slide on a solid surface. Until now, fundamental origin of the contact angle hysteresis has been controversial. Here, this origin is revealed and a quantitative theory is derived. The theory is corroborated by the available experimental data for a large number of solid-liquid combinations. The theory is applied in modelling the contact angle hysteresis on a textured surface, and these results are also in quantitative agreement with the experimental data.

  2. Contact angle measurements under thermodynamic equilibrium conditions.

    PubMed

    Lages, Carol; Méndez, Eduardo

    2007-08-01

    The precise control of the ambient humidity during contact angle measurements is needed to obtain stable and valid data. For a such purpose, a simple low-cost device was designed, and several modified surfaces relevant to biosensor design were studied. Static contact angle values for these surfaces are lower than advancing contact angles published for ambient conditions, indicating that thermodynamic equilibrium conditions are needed to avoid drop evaporation during the measurements.

  3. High angle of attack hypersonic aerodynamics

    NASA Technical Reports Server (NTRS)

    Harloff, Gary J.

    1987-01-01

    A new aerodynamics force model is presented which is based on modified Newtonian theory and empirical correlations. The algebraic model was developed for complete vehicles from take off to orbital speeds and for large angles of attack. Predictions are compared to results for a wind tunnel model at a Mach number of 20, and the full scale Shuttle Orbiter for Mach numbers from 0.25 to 20 for angles of attack from 0 to 50 deg. The maximum shuttle orbiter lift/drag at Mach 10 and 20 is 1.85 at 20-deg angle-of-attack. Aerodynamic force predictions are made for a transatmospheric vehicle, which is a derivative of the Shuttle Orbiter, for Mach numbers from 4 to 27 at angles of attack from 5 to 40 deg. Predicted aerodynamic force data indicate that lift/drag ratios of 5.2 at Mach number 10 and 3.6 at Mach number 26 are obtainable. Changes in force coefficients with changes in: nose angle, sweep angle, and (volume exp 2/3)/planform area are quantified for Mach numbers of 10 and 26. Lift/drag ratios increase with decreasing nose angle and (volume exp 2/3)/planform area and increasing wing sweep angle. Lift/drag ratios are independent of these variables for angles of attack in excess of 20 deg at Mach 10 and 30 deg at Mach 26.

  4. Pitch Angle Survey of GOODS Spiral Galaxies

    NASA Astrophysics Data System (ADS)

    Boe, Benjamin; Kennefick, Daniel; Arkansas Galaxy Evolution Survey, Arkansas CenterSpace; Planetary Sciences

    2015-01-01

    This research looks at how the pitch angles of galaxies change over scales of cosmic time. We measure the pitch angle, or tightness of spiral winding, using a new code, Spirality. We then compare the results to those obtained from established software, 2DFFT (2 Dimensional Fast Fourier Transform). We investigate any correlation between pitch angle and redshift, or distance from Earth. Previous research indicates that the pitch angle of a galaxy correlates with its central bulge mass and the mass of its central black hole. Thus any evolution in the distribution of pitch angles could ultimately prove to be indicative of evolution in the supermassive black hole mass function. Galaxies from the Hubble GOODS (Great Observatories Origins Deep Survey) North and South were measured. We found that there was strong agreement between Spirality and 2DFFT measurements. Spirality measured the pitch angle of the GOODS galaxies with a lower error than 2DFFT on average. With both software a correlation between pitch angle and redshift was found. Spirality observed a 6.150 increase in pitch per unit redshift. The increase in pitch angle with redshift suggests that in the past galaxies had higher pitch angles, which could be indicative of lower central black hole masses (or, more directly, central bulge masses).

  5. Best Angle to Orient Two Intersecting Lines

    SciTech Connect

    Awwal, A S; Ferguson, S W; Shull, P B

    2006-07-25

    Fiducials in the form of intersecting straight lines are used to align the target in the final target chamber of the National Ignition Facility of Lawrence Livermore National Laboratory. One of the techniques used to locate these lines is the Hough transform. When two lines intersect at a 90 degree angle, it is tempting to orient the lines to horizontal and vertical directions. There are other possible angles at which the lines may be oriented. One question that arises while designing the fiducials is whether there is a preferred angle or range of angles that leads to higher accuracy. This work attempts to answer this question through detailed computer simulation.

  6. Behavior of Tilted Angle Shear Connectors

    PubMed Central

    Khorramian, Koosha; Maleki, Shervin; Shariati, Mahdi; Ramli Sulong, N. H.

    2015-01-01

    According to recent researches, angle shear connectors are appropriate to transfer longitudinal shear forces across the steel-concrete interface. Angle steel profile has been used in different positions as L-shaped or C-shaped shear connectors. The application of angle shear connectors in tilted positions is of interest in this study. This study investigates the behaviour of tilted-shaped angle shear connectors under monotonic loading using experimental push out tests. Eight push-out specimens are tested to investigate the effects of different angle parameters on the ultimate load capacity of connectors. Two different tilted angles of 112.5 and 135 degrees between the angle leg and steel beam are considered. In addition, angle sizes and lengths are varied. Two different failure modes were observed consisting of concrete crushing-splitting and connector fracture. By increasing the size of connector, the maximum load increased for most cases. In general, the 135 degrees tilted angle shear connectors have a higher strength and stiffness than the 112.5 degrees type. PMID:26642193

  7. Contact angle hysteresis on fluoropolymer surfaces.

    PubMed

    Tavana, H; Jehnichen, D; Grundke, K; Hair, M L; Neumann, A W

    2007-10-31

    Contact angle hysteresis of liquids with different molecular and geometrical properties on high quality films of four fluoropolymers was studied. A number of different causes are identified for hysteresis. With n-alkanes as probe liquids, contact angle hysteresis is found to be strongly related to the configuration of polymer chains. The largest hysteresis is obtained with amorphous polymers whereas the smallest hysteresis occurs for polymers with ordered molecular chains. This is explained in terms of sorption of liquid by the solid and penetration of liquid into the polymer film. Correlation of contact angle hysteresis with the size of n-alkane molecules supports this conclusion. On the films of two amorphous fluoropolymers with different molecular configurations, contact angle hysteresis of one and the same liquid with "bulky" molecules is shown to be quite different. On the surfaces of Teflon AF 1600, with stiff molecular chains, the receding angles of the probe liquids are independent of contact time between solid and liquid and similar hysteresis is obtained for all the liquids. Retention of liquid molecules on the solid surface is proposed as the most likely cause of hysteresis in these systems. On the other hand, with EGC-1700 films that consist of flexible chains, the receding angles are strongly time-dependent and the hysteresis is large. Contact angle hysteresis increases even further when liquids with strong dipolar intermolecular forces are used. In this case, major reorganization of EGC-1700 chains due to contact with the test liquids is suggested as the cause. The effect of rate of motion of the three-phase line on the advancing and receding contact angles, and therefore contact angle hysteresis, is investigated. For low viscous liquids, contact angles are independent of the drop front velocity up to approximately 10 mm/min. This agrees with the results of an earlier study that showed that the rate-dependence of the contact angles is an issue only

  8. The SU(2) action-angle variables

    NASA Technical Reports Server (NTRS)

    Ellinas, Demosthenes

    1993-01-01

    Operator angle-action variables are studied in the frame of the SU(2) algebra, and their eigenstates and coherent states are discussed. The quantum mechanical addition of action-angle variables is shown to lead to a noncommutative Hopf algebra. The group contraction is used to make the connection with the harmonic oscillator.

  9. [Clinical classification of variable angle exotrophy].

    PubMed

    Arroyo-Yllanes, María Estela; Osorio-González, Déborah Itzel; Pérez-Pérez, José Fernando

    2007-01-01

    Variable exotropia is determined by a series of mechanisms that provide different clinical characteristics to outline individual therapy. There is no specific categorization that can identify such an entity. A clinical classification is proposed that includes different clinical features in accordance with the mechanisms involved in the variability genesis of such exotropias. Patients with a diagnosis of variable angle exotropia without previous surgery were included. A complete ophthalmic and strabismus exploration was performed. Variability characteristics were studied and grouped by entries in the classification proposed. Ninety patients were examined from the Pediatric Ophthalmology and Strabismus Unit of the General Hospital of Mexico O.D., with a diagnosis of variable angle exotropia. The following forms of presentations were found: secondary variable angle exotropia due to neurological alteration in 32 cases (35.5%), secondary variable angle exotropia due to monocular bad vision in 19 cases (21.2%), dissociated horizontal deviation in 14 cases (15.5%), mixed variable angle exotropia in 22 cases (4.5%) and primary variable angle exotropia in 3 cases (3.33%). This classification allows categorization of all patients of variable angle exotropia into proposed categories. The most common mechanism responsible for variability is neurological alteration. Primary variable angle exotropias are rare and are present in a minimum percentage.

  10. A Climbing Class' Reinvention of Angles

    ERIC Educational Resources Information Center

    Fyhn, Anne Birgitte

    2008-01-01

    A previous study shows how a twelve-year-old girl discovers angles in her narrative from a climbing trip. Based on this research, the girl's class takes part in one day of climbing and half a day of follow-up work at school. The students mathematise their climbing with respect to angles and they express themselves in texts and drawings. Their…

  11. Nasolabial angle: a perception of treatment needs.

    PubMed

    Sukhia, Rashna Hoshang; Sukhia, Hoshang Rumi; Fida, Mubassar; Khan, Munizeh

    2012-01-01

    The nasolabial angle holds a very important position in the treatment planning process for an orthodontic case, especially in today's soft tissue paradigm. This study was therefore conducted to compare the mean preference scores for orthodontic treatment need considering the nasolabial angle among orthodontists, orthodontic patients and their parents.

  12. Effects Of Molecular Processes On Trim Angles

    NASA Technical Reports Server (NTRS)

    Park, Chul; Yoon, Seokkwan

    1991-01-01

    Report discusses preliminary calculations of effects of vibrational excitation and dissociation of air molecules on trim angle of attack on blunt body flying at suborbital speed. Intended as study of feasibility and utility of such calculations, motivated by fact that trim angle of attack at suborbital and higher speeds important aerodynamic parameter for spacecraft reentering atmosphere and for future hypersonic aerospace vehicles.

  13. Bilateral angle closure glaucoma following general anaesthesia.

    PubMed

    Raj, K Mohan; Reddy, P Arun Subhash; Kumar, Vikram Chella

    2015-04-01

    Angle closure glaucoma is one of the ophthalmic emergencies and treatment has to be given at the earliest. It is a rare complication of general anesthesia. A female patient underwent Hysterectomy under general anesthesia. Following this, patient developed bilateral angle closure glaucoma. This patient was treated with antiglaucoma medications followed by YAG laser iridotomy and patient regained vision.

  14. Classification procedure in limited angle tomography system

    SciTech Connect

    Chlewicki, W.; Baniukiewicz, P.; Chady, T.; Brykalski, A.

    2011-06-23

    In this work we propose the use of limited angle reconstruction algorithms combined with a procedure for defect detection and feature evaluation in three dimensions. The procedure consists of the following steps: acquisition of the X-ray projections, approximated limited angle 3D image reconstruction, and image preprocessing and classification.

  15. Apparent contact angle and contact angle hysteresis on liquid infused surfaces

    NASA Astrophysics Data System (ADS)

    Semprebon, Ciro; McHale, Glen; Kusumaatmaja, Halim

    We theoretically investigate the apparent contact angle and contact angle hysteresis of a droplet placed on a liquid infused surface. We show that the apparent contact angle is not uniquely defined by material parameters, but also has a strong dependence on the relative size between the droplet and its surrounding wetting ridge formed by the infusing liquid. We derive a closed form expression for the contact angle in the limit of vanishing wetting ridge, and compute the correction for small but finite ridge, which corresponds to an effective line tension term. We also predict contact angle hysteresis on liquid infused surfaces generated by the pinning of the contact lines by the surface corrugations. Our analytical expressions for both the apparent contact angle and contact angle hysteresis can be interpreted as `weighted sums' between the contact angles of the infusing liquid relative to the droplet and surrounding gas phases, where the weighting coefficients are given by ratios of the fluid surface tensions.

  16. Apparent contact angle and contact angle hysteresis on liquid infused surfaces.

    PubMed

    Semprebon, Ciro; McHale, Glen; Kusumaatmaja, Halim

    2016-12-21

    We theoretically investigate the apparent contact angle and contact angle hysteresis of a droplet placed on a liquid infused surface. We show that the apparent contact angle is not uniquely defined by material parameters, but also has a dependence on the relative size between the droplet and its surrounding wetting ridge formed by the infusing liquid. We derive a closed form expression for the contact angle in the limit of vanishing wetting ridge, and compute the correction for small but finite ridge, which corresponds to an effective line tension term. We also predict contact angle hysteresis on liquid infused surfaces generated by the pinning of the contact lines by the surface corrugations. Our analytical expressions for both the apparent contact angle and contact angle hysteresis can be interpreted as 'weighted sums' between the contact angles of the infusing liquid relative to the droplet and surrounding gas phases, where the weighting coefficients are given by ratios of the fluid surface tensions.

  17. Nanodrop contact angles from molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Ravipati, Srikanth; Aymard, Benjamin; Yatsyshin, Petr; Galindo, Amparo; Kalliadasis, Serafim

    2016-11-01

    The contact angle between three phases being in thermodynamic equilibrium is highly sensitive to the nature of the intermolecular forces as well as to various fluctuation effects. Determining the Young contact angle of a sessile drop sitting on a substrate from molecular dynamics (MD) simulations is a highly non-trivial task. Most commonly employed methods for finding droplet contact angles from MD simulation data either require large numbers of particles or are system-dependent. We propose a systematic geometry based methodology for extracting the contact angle from simulated sessile droplets by analysing an appropriately coarse-grained density field. To demonstrate the method, we consider Lennard-Jones (LJ) and SPC/E water nanodroplets of different sizes sitting on planar LJ walls. Our results are in good agreement with Young contact angle values computed employing test-area perturbation method.

  18. Investigation of Lightning Rod Shielding Angle

    NASA Astrophysics Data System (ADS)

    Nayel, Mohamed

    This paper studies those parameters affecting the shielding angle of the lightning rod (Franklin Rod) above very tall buildings. It was recommended that the shielding angle of the lightning rod is about 45°∼60°. The downward lightning leader is modeled by using discrete line charges to consider the exponential distribution of charges through the downward leader. The voltage condition used by Rizk is used to investigate the inception of the upward lightning leader. Different air conditions (relative air density and air humidity) are considered for more practical simulation. The influences of lightning parameters and lightning rod height on the shielding angle are studied. The results shows that, lightning leader parameters, lightning rod height and ground slope have series effects on the lightning rod shielding angle. Based on the results, a lightning rod shielding angle for shielding design is recommended to decrease the lightning stroke to the lightning rod.

  19. Reliable measurement of the receding contact angle.

    PubMed

    Korhonen, Juuso T; Huhtamäki, Tommi; Ikkala, Olli; Ras, Robin H A

    2013-03-26

    Surface wettability is usually evaluated by the contact angle between the perimeter of a water drop and the surface. However, this single measurement is not enough for proper characterization, and the so-called advancing and receding contact angles also need to be measured. Measuring the receding contact angle can be challenging, especially for extremely hydrophobic surfaces. We demonstrate a reliable procedure by using the common needle-in-the-sessile-drop method. Generally, the contact line movement needs to be followed, and true receding movement has to be distinguished from "pseudo-movement" occurring before the receding angle is reached. Depending on the contact angle hysteresis, the initial size of the drop may need to be surprisingly large to achieve a reliable result. Although our motivation for this work was the characterization of superhydrophobic surfaces, we also show that this method works universally ranging from hydrophilic to superhydrophobic surfaces.

  20. Contact angle hysteresis of microbead suspensions.

    PubMed

    Waghmare, Prashant R; Mitra, Sushanta K

    2010-11-16

    Microbead suspensions are often used in microfluidic devices for transporting biomolecules. An experimental investigation on the wettability of microbead suspension is presented in this study. The variation in the surface tension and the equilibrium contact angle with the change in the volume fraction of the microbead is presented here. The surface tension of the microbead suspension is measured with the pendant drop technique, whereas the dynamic contact angle measurements, i.e., advancing and receding contact angles, are measured with the sessile drop technique. An equilibrium contact angle of a suspension with particular volume fraction is determined by computing an average over the measured advancing and receding contact angles. It is observed that the surface tension and the equilibrium contact angle determined from advancing and receding contact angles vary with the magnitude of the microbeads volume fraction in the suspension. A decrease in the surface tension with an increase in the volume fraction of the microbead suspension is observed. The advancement and the recession in contact line for dynamic contact angle measurements are achieved with the motorized dosing mechanism. For microbead suspensions, the advancement of the contact line is faster as compared to the recession of the contact line for the same flow rate. The presence of microbeads assists in the advancement and the recession of the contact line of the suspension. A decrease in the equilibrium contact angles with an increase in the microbead suspension volume fraction is observed. Inclusion of microbeads in the suspension increases the wetting capability for the considered combination of the microbead suspension and substrate. Finally, empirical correlations for the surface tension and the contact angle of the suspension as a function of microbead volume fraction are proposed. Such correlations can readily be used to develop mechanistic models for the capillary transport of microbead

  1. Survival and Growth of Cottonwood Clones After Angle Planting and Base Angle Treatments

    Treesearch

    W.K. Randall; Harvey E. Kennedy

    1976-01-01

    Presently, commercial cottonwood plantations in the lower Mississippi Valley are established using vertically planted, unrooted cuttings with a flat (90°) base. Neither survival nor first-year growth of a group of six Stoneville clones was improved by angle planting or cutting base angles diagonally. For one clone, survival was significantly better when base angle was...

  2. Analysis of factors affecting angle ANB.

    PubMed

    Hussels, W; Nanda, R S

    1984-05-01

    Cephalometric analyses based on angular and linear measurements have obvious fallacies, which have been discussed in detail by Moyers and Bookstein. However, the clinical application of such an analysis by the orthodontic profession in treatment planning is widely accepted. Variations of angle ANB are commonly used to determine relative jaw relationships in most of the cephalometric evaluations. Several authors, including points A and B influences angle ANB, as does rotational growth of the upper and lower jaws. In addition, the authors point out that growth in a vertical direction (distance N to B) and an increase of the dental height (distance A to B) may contribute to changes in angle ANB. For a Class I relation (Wits = 0 mm), a mathematical formula has been developed which enables the authors to study the geometric influence of angle ANB caused by the following four effects: (1) rotation of the jaws and/or occlusal plane relative to the anterior cranial base; (2) anteroposterior position of N relative to point B, (3) vertical growth (distance N to B); (4) increase in dental height (distance A to B). It was observed that, contrary to the common belief that an ANB angle of 2 +/- 3.0 degrees is considered normal for a skeletal Class I relation, the calculated values of angle ANB will vary widely with changes in these four controlling factors under the same skeletal Class I conditions (Wits = 0 mm). Therefore, in a case under consideration, angle ANB must be corrected for these geometric effects in order to get a proper perspective of the skeletal discrepancy. This is facilitated by comparing the measured ANB angle with the corresponding ANB angle calculated by a formula for a Class I relationship. The corresponding calculated angle ANB can be taken from the tables which are based upon the formula using the same values for SNB, omega (angle between occlusal plane and anterior cranial base), b (which is distance N to B) and a (dental height measured as perpendicular

  3. Asteroid photometry: Phase-angle effects

    NASA Astrophysics Data System (ADS)

    Belskaya, I.; Shevchenko, V.

    2014-07-01

    We review available observational data on magnitude phase-angle dependencies of asteroids. The number of asteroids, for which good quality phase curves were measured, increases very slowly. At present, the data-set on magnitude-phase dependencies with a good phase-angle coverage and small scatter includes less than one hundred asteroids. Most part of these data is related to the ground-based observations of main-belt asteroids and covered the phase-angle range from 0.3--0.5 deg to 20--25 deg. The phase curves in the wider phase-angle range up to 120--140 deg were measured for ten asteroids observed by space missions and for several near-Earth asteroids. Ground-based and space-based observations are generally mutually consistent. For most of the observed phase-angle ranges, asteroid magnitude phase curves are found to be linear with a noticeable deviation at phase angles smaller than 5--7 deg due to the opposition effect and at phase angles larger than 70-80 deg due to the influence of large-scale surface features. The differences in the phase curves at large phase angles and their influence on the phase integral have not yet been thoroughly investigated. The measured linear phase coefficients of asteroids are in the range of 0.02--0.05 mag/deg. The opposition-effect amplitudes determined relatively to the extrapolation of the linear part of the phase curve do not exceeds 0.4 mag. Relatively small variations of asteroid phase curve parameters require accurate photometric observations and thorough account for lightcurve amplitude to distinguish phase-angle effects. The measured magnitude phase dependencies revealed essential differences in magnitude phase-angle behavior for asteroids of different surface composition both in the linear part and in the opposition effect range (Harris et al. 1989, Belskaya and Shevchenko 2000, Shevchenko et al. 2012). Maximal amplitude of the opposition effect occurs for moderate-albedo S- and M-type asteroids. Low-albedo asteroids

  4. Creation of the π angle standard for the flat angle measurements

    NASA Astrophysics Data System (ADS)

    Giniotis, V.; Rybokas, M.

    2010-07-01

    Angle measurements are based mainly on multiangle prisms - polygons with autocollimators, rotary encoders fo high accuracy and circular scales as the standards of the flat angle. Traceability of angle measurements is based on the standard of the plane angle - prism (polygon) calibrated at an appropriate accuracy. Some metrological institutions have established their special test benches (comparators) equipped with circular scales or rotary encoders of high accuracy and polygons with autocollimators for angle calibration purposes. Nevertheless, the standard (etalon) of plane angle - polygon has many restrictions for the transfer of angle unit - radian (rad) and other units of angle. It depends on the number of angles formed by the flat sides of the polygon that is restricted by technological and metrological difficulties related to the production and accuracy determination of the polygon. A possibility to create the standard of the angle equal to π rad or half the circle or the full angle is proposed. It can be created by the circular scale with the rotation axis of very high accuracy and two precision reading instruments, usually, photoelectric microscopes (PM), placed on the opposite sides of the circular scale using the special alignment steps. A great variety of angle units and values can be measured and its traceability ensured by applying the third PM on the scale. Calibration of the circular scale itself and other scale or rotary encoder as well is possible using the proposed method with an implementation of π rad as the primary standard angle. The method proposed enables to assure a traceability of angle measurements at every laboratory having appropriate environment and reading instruments of appropriate accuracy together with a rotary table with the rotation axis of high accuracy - rotation trajectory (runout) being in the range of 0.05 μm. Short information about the multipurpose angle measurement test bench developed is presented.

  5. Pitch angle variations in spiral galaxies

    NASA Astrophysics Data System (ADS)

    Savchenko, S. S.; Reshetnikov, V. P.

    2013-12-01

    We present a detailed photometric study and measurements of spiral arm pitch angles for a sample of 50 non-barred or weakly barred grand-design spiral galaxies selected from Sloan Digital Sky Survey. In order to find pitch angles, we used a new method based on the window Fourier analysis of their images. This method allows us not only to infer the average pitch angle, but to obtain its value as a function of galactocentric radius as well. Our main results are as follows: (1) Spiral arms of most galaxies cannot be described by a single value of the pitch angle. About 2/3 of galaxies demonstrate pitch angle variations exceeding 20 per cent. In most galaxies in the sample their pitch angle decreases by increasing the distance from the centre. (2) Pitch angle variations correlate with the properties of galaxies - with the shape of the surface brightness distribution (envelope-type or truncated disc), and with the sign of stellar disc colour gradient. (3) More luminous and bright bulges produce more tightly wound spiral arms, that is in agreement with current models for spiral arms formation.

  6. Contact angle hysteresis, adhesion, and marine biofouling.

    PubMed

    Schmidt, Donald L; Brady, Robert F; Lam, Karen; Schmidt, Dale C; Chaudhury, Manoj K

    2004-03-30

    Adhesive and marine biofouling release properties of coatings containing surface-oriented perfluoroalkyl groups were investigated. These coatings were prepared by cross-linking a copolymer of 1H,1H,2H,2H-heptadecafluorodecyl acrylate and acrylic acid with a copolymer of poly(2-isopropenyl-2-oxazoline) and methyl methacrylate at different molar ratios. The relationships between contact angle, contact angle hysteresis, adhesion, and marine biofouling were studied. Adhesion was determined by peel tests using pressure-sensitive adhesives. The chemical nature of the surfaces was studied by using X-ray photoelectron spectroscopy. Resistance to marine biofouling of an optimized coating was studied by immersion in seawater and compared to previous, less optimized coatings. The adhesive release properties of the coatings did not correlate well with the surface energies of the coatings estimated from the static and advancing contact angles nor with the amount of fluorine present on the surface. The adhesive properties of the surfaces, however, show a correlation with water receding contact angles and contact angle hysteresis (or wetting hysteresis) resulting from surface penetration and surface reconstruction. Coatings having the best release properties had both the highest cross-link density and the lowest contact angle hysteresis. An optimized coating exhibited unprecedented resistance to marine biofouling. Water contact angle hysteresis appears to correlate with marine biofouling resistance.

  7. Bayesian AVO inversion with consistent angle parameters

    NASA Astrophysics Data System (ADS)

    Li, Chao; Zhang, Jinmiao; Zhu, Zhenyu

    2017-04-01

    Amplitude versus offset (AVO) inversion has been extensively used in seismic exploration. Many different elastic parameters can be inverted by incorporating corresponding reflection coefficient approximations. Although efforts have been made to improve the accuracy of AVO inversions for years, there is still one problem that has long been ignored. In most methods, the angle in the approximation and the angle used in seismic angle gather extractions are not the same one. This inconsistency leads to inaccurate inversion results. In this paper, a Bayesian AVO inversion method with consistent angles is proposed to solve the problem and improve inversion accuracy. Firstly, a linearized P-wave reflection coefficient approximation with consistent angles is derived based on angle replacements. The equivalent form of the approximation in terms moduli and density is derived so that moduli can be inverted for reservoir characterization. Then, by convoluting it with seismic wavelets as the forward solver, a probabilistic prestack seismic inversion method with consistent angles is presented in a Bayesian scheme. The synthetic test proves that the accuracy of this method is higher than the traditional one. The real data example shows that the inversion result fits better with well log interpretation data, which verifies the feasibility of the proposed method.

  8. Globographic visualisation of three dimensional joint angles.

    PubMed

    Baker, Richard

    2011-07-07

    Three different methods for describing three dimensional joint angles are commonly used in biomechanics. The joint coordinate system and Cardan/Euler angles are conceptually quite different but are known to represent the same underlying mathematics. More recently the globographic method has been suggested as an alternative and this has proved particularly attractive for the shoulder joint. All three methods can be implemented in a number of ways leading to a choice of angle definitions. Very recently Rab has demonstrated that the globographic method is equivalent to one implementation of the joint coordinate system. This paper presents a rigorous analysis of the three different methods and proves their mathematical equivalence. The well known sequence dependence of Cardan/Euler is presented as equivalent to configuration dependence of the joint coordinate system and orientation dependence of globographic angles. The precise definition of different angle sets can be easily visualised using the globographic method using analogues of longitude, latitude and surface bearings with which most users will already be familiar. The method implicitly requires one axis of the moving segment to be identified as its principal axis and this can be extremely useful in helping define the most appropriate angle set to describe the orientation of any particular joint. Using this technique different angle sets are considered to be most appropriate for different joints and examples of this for the hip, knee, ankle, pelvis and axial skeleton are outlined.

  9. Why does acute primary angle closure happen? Potential risk factors for acute primary angle closure.

    PubMed

    Zhang, Xiulan; Liu, Yaoming; Wang, Wei; Chen, Shida; Li, Fei; Huang, Wenbin; Aung, Tin; Wang, Ningli

    Acute primary angle closure is an ocular emergency and requires immediate management to avoid blindness. Narrow anterior chamber angle, advanced age, female gender, and Asian ethnic background are considered risk factors for acute primary angle closure. The predictive power of these factors is, however, relatively poor, and many questions remain unanswered because acute primary angle closure eventually develops in only a relatively small proportion of anatomically predisposed eyes. We summarize the potential roles of various factors in the pathogenesis of acute primary angle closure. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Identification of a YAC spanning the translocation breakpoints in uterine leiomyomata, pulmonary chondroid hamartoma, and lipoma: Physical mapping of the 12q14-q15 breakpoint region in uterine leiomyomata

    SciTech Connect

    Fejzo, M.S.; Yoon, S.J.; Kucherlapati, R.S.

    1995-03-20

    Uterine leiomyomata are the most common tumors in women and can cause abnormal uterine bleeding, pelvic pain, and infertility. Approximately 200,000 hysterectomies are performed annually in the U.S. to relieve patients of the medical sequelae of these benign neoplasms. Our efforts have focused on cloning the t(12;14)(q14-q15;q23-q24) breakpoint in uterine leiomyoma to further our understanding of the biology of these tumors. Thirty-nine YACs and six cosmids mapping to 12q14-q15 have been mapped by fluorescence in situ hybridization to tumor metaphase chromosomes containing a t(12;14). One YAC spanned the translocation breakpoint and was mapped to tumor metaphases from a pulmonary chondroid hamartoma containing a t(12;14)(q14-q15;q23-q24) and a lipoma containing a t(12;15)(q15;q24); this YAC also spanned the breakpoint in these two tumors, suggesting that the same gene on chromosome 12 may be involved in the pathobiology of these distinct benign neoplasms. 41 refs., 2 figs., 1 tab.

  11. Phase-angle controller for Stirling engines

    NASA Technical Reports Server (NTRS)

    Mcdougal, A. R. (Inventor)

    1980-01-01

    An actuator includes a restraint link adapted to be connected with a pivotal carrier arm for a force transfer gear interposed between the crankshaft for an expander portion of a Stirling engine and a crankshaft for the displacer portion of the engine. The restraint link is releasably trapped hydraulic fluid for selectively establishing a phase angle relationship between the crankshaft. A second embodiment incorporates a hydraulic coupler for use in varying the phase angle of gear-coupled crank fpr a Stirling engine whereby phase angle changes are obtainable.

  12. Wide-angle vision for road views

    NASA Astrophysics Data System (ADS)

    Huang, F.; Fehrs, K.-K.; Hartmann, G.; Klette, R.

    2013-03-01

    The field-of-view of a wide-angle image is greater than (say) 90 degrees, and so contains more information than available in a standard image. A wide field-of-view is more advantageous than standard input for understanding the geometry of 3D scenes, and for estimating the poses of panoramic sensors within such scenes. Thus, wide-angle imaging sensors and methodologies are commonly used in various road-safety, street surveillance, street virtual touring, or street 3D modelling applications. The paper reviews related wide-angle vision technologies by focusing on mathematical issues rather than on hardware.

  13. Reconditioning of Cassini Narrow-Angle Camera

    NASA Image and Video Library

    2002-07-23

    These five images of single stars, taken at different times with the narrow-angle camera on NASA Cassini spacecraft, show the effects of haze collecting on the camera optics, then successful removal of the haze by warming treatments.

  14. High angle conveyors climb to the top

    SciTech Connect

    Mitchell, J.J.

    1984-11-01

    A major objective in the design of a storage facility is to have the least handling over the shortest distances and to optimize land usage by attaining the highest tons-per-acre value. The advantages of high angle conveyors become apparent when the height of lift is compared with the surface area. High angle conveyors achieve high capacities in the least amount of space. Continental Conveyor and Equipment Co., has conducted several studies that evaluate the technical and economic feasibility of using high angle conveyors in conveyor systems. A few of the high angle conveying concepts reviewed are the bucket ladder or pocket belt, belts with partitions or fin belt, and the sandwich type belt conveyors.

  15. High angle conveyors climb to the top

    SciTech Connect

    Mitchell, J.J.

    1984-11-01

    Descriptions are presented of various types of high angle conveyors, including pocket belt, fin belt, sandwich belt, snake sandwich conveyor, mechanically pressed sandwich conveyor, and pneumatically pressed sandwich conveyors. 10 references.

  16. SOLARMAX/Electron Pitch Angle Anisotropy Distributions

    NASA Technical Reports Server (NTRS)

    McKenzie, David L.; Anderson, Phillip C.

    2002-01-01

    This final research report summarizes the scientific work performed by The Aerospace Corporation on SOLARMAX/Electron Pitch Angle Anisotropy Distributions. The period of performance was from June 1, 2000 to December 31, 2001.

  17. Angle measurement with laser feedback instrument.

    PubMed

    Chen, Wenxue; Zhang, Shulian; Long, Xingwu

    2013-04-08

    An instrument for angle measurement based on laser feedback has been designed. The measurement technique is based on the principle that when a wave plate placed into a feedback cavity rotates, its phase retardation varies. Phase retardation is a function of the rotating angle of the wave plate. Hence, the angle can be converted to phase retardation. The phase retardation is measured at certain characteristic points identified in the laser outputting curve that are then modulated by laser feedback. The angle of a rotating object can be measured if it is connected to the wave plate. The main advantages of this instrument are: high resolution, compact, flexible, low cost, effective power, and fast response.

  18. A Distance and Angle Similarity Measure Method.

    ERIC Educational Resources Information Center

    Zhang, Jin; Korfhage, Robert R.

    1999-01-01

    Discusses similarity measures that are used in information retrieval to improve precision and recall ratios and presents a combined vector-based distance and angle measure to make similarity measurement more scientific and accurate. Suggests directions for future research. (LRW)

  19. Low-angle optical vortex coronagraphic scatterometer.

    PubMed

    Wan, Lingyu; Ruane, Garreth J; Swartzlander, Grover A

    2016-11-01

    The important, but difficult-to-measure zero and low-angle scattering spectrum, as well as the broader angular spectrum, was obtained by use of an optical vortex coronagraphic scatterometer (patent pending). The experimental measurements agreed well with the predictions from the Mie scattering theory. High contrast discrimination allowed us to remove the unscattered coherent illumination, revealing a low-angle superimposed scattered signal.

  20. Eliminating Deadbands In Resistive Angle Sensors

    NASA Technical Reports Server (NTRS)

    Salomon, Phil M.; Allen, Russell O.; Marchetto, Carl A.

    1992-01-01

    Proposed shaft-angle-measuring circuit provides continuous indication of angle of rotation from 0 degree to 360 degrees. Sensing elements are two continuous-rotation potentiometers, and associated circuitry eliminates deadband that occurs when wiper contact of potentiometer crosses end contacts near 0 degree position of circular resistive element. Used in valve-position indicator or similar device in which long operating life and high angular precision not required.

  1. Solar Cell Angle of Incidence Corrections

    NASA Technical Reports Server (NTRS)

    Burger, Dale R.; Mueller, Robert L.

    1995-01-01

    The Mars Pathfinder mission has three different solar arrays each of which sees changes in incidence angle during normal operation. When solar array angle of incidence effects was researched little published data was found. The small amount of-published data created a need to obtain and evaluate such data. The donation of the needed data, which was taken in the fall of 1994, was a major factor in the preparation of this paper.

  2. Contact angle hysteresis on superhydrophobic stripes.

    PubMed

    Dubov, Alexander L; Mourran, Ahmed; Möller, Martin; Vinogradova, Olga I

    2014-08-21

    We study experimentally and discuss quantitatively the contact angle hysteresis on striped superhydrophobic surfaces as a function of a solid fraction, ϕS. It is shown that the receding regime is determined by a longitudinal sliding motion of the deformed contact line. Despite an anisotropy of the texture the receding contact angle remains isotropic, i.e., is practically the same in the longitudinal and transverse directions. The cosine of the receding angle grows nonlinearly with ϕS. To interpret this we develop a theoretical model, which shows that the value of the receding angle depends both on weak defects at smooth solid areas and on the strong defects due to the elastic energy of the deformed contact line, which scales as ϕS(2)lnϕS. The advancing contact angle was found to be anisotropic, except in a dilute regime, and its value is shown to be determined by the rolling motion of the drop. The cosine of the longitudinal advancing angle depends linearly on ϕS, but a satisfactory fit to the data can only be provided if we generalize the Cassie equation to account for weak defects. The cosine of the transverse advancing angle is much smaller and is maximized at ϕS ≃ 0.5. An explanation of its value can be obtained if we invoke an additional energy due to strong defects in this direction, which is shown to be caused by the adhesion of the drop on solid sectors and is proportional to ϕS(2). Finally, the contact angle hysteresis is found to be quite large and generally anisotropic, but it becomes isotropic when ϕS ≤ 0.2.

  3. Particle chaos and pitch angle scattering

    NASA Technical Reports Server (NTRS)

    Burkhart, G. R.; Dusenbery, P. B.; Speiser, T. W.

    1995-01-01

    Pitch angle scattering is a factor that helps determine the dawn-to-dusk current, controls particle energization, and it has also been used as a remote probe of the current sheet structure. Previous studies have interpreted their results under the exception that randomization will be greatest when the ratio of the two timescales of motion (gyration parallel to and perpendicular to the current sheet) is closet to one. Recently, the average expotential divergence rate (AEDR) has been calculated for particle motion in a hyperbolic current sheet (Chen, 1992). It is claimed that this AEDR measures the degree of chaos and therefore may be thought to measure the randomization. In contrast to previous expectations, the AEDR is not maximized when Kappa is approximately equal to 1 but instead increases with decreasing Kappa. Also contrary to previous expectations, the AEDR is dependent upon the parameter b(sub z). In response to the challenge to previous expectations that has been raised by this calculation of the AEDR, we have investigated the dependence of a measure of particle pitch angle scattering on both the parameters Kappa and b(sub z). We find that, as was previously expected, particle pitch angle scattering is maximized near Kappa = 1 provided that Kappa/b(sub z) greater than 1. In the opposite regime, Kappa/b(sub z) less than 1, we find that particle pitch angle scattering is still largest when the two timescales are equal, but the ratio of the timescales is proportional to b(sub z). In this second regime, particle pitch angle scattering is not due to randomization, but is instead due to a systematic pitch angle change. This result shows that particle pitch angle scattering need not be due to randomization and indicates how a measure of pitch angle scattering can exhibit a different behavior than a measure of chaos.

  4. Nucleation of small-angle boundaries

    SciTech Connect

    Nabarro, F.R.N. |; Wilsdorf, D.K.

    1996-12-01

    The internal stresses induced by the strain gradients in an array of lattice cells delineated by low-angle dislocation boundaries are partially relieved by the creation of new low-angle boundaries. This is shown to be a first-order transition, the new boundaries having finite misorientations. The calculated misorientations both of the new boundaries and of the existing boundaries which provoke the transition agree well with observations.

  5. Angle only tracking with particle flow filters

    NASA Astrophysics Data System (ADS)

    Daum, Fred; Huang, Jim

    2011-09-01

    We show the results of numerical experiments for tracking ballistic missiles using only angle measurements. We compare the performance of an extended Kalman filter with a new nonlinear filter using particle flow to compute Bayes' rule. For certain difficult geometries, the particle flow filter is an order of magnitude more accurate than the EKF. Angle only tracking is of interest in several different sensors; for example, passive optics and radars in which range and Doppler data are spoiled by jamming.

  6. Neutron spin echo scattering angle measurement (SESAME)

    SciTech Connect

    Pynn, R.; Fitzsimmons, M.R.; Fritzsche, H.; Gierlings, M.; Major, J.; Jason, A.

    2005-05-15

    We describe experiments in which the neutron spin echo technique is used to measure neutron scattering angles. We have implemented the technique, dubbed spin echo scattering angle measurement (SESAME), using thin films of Permalloy electrodeposited on silicon wafers as sources of the magnetic fields within which neutron spins precess. With 30-{mu}m-thick films we resolve neutron scattering angles to about 0.02 deg. with neutrons of 4.66 A wavelength. This allows us to probe correlation lengths up to 200 nm in an application to small angle neutron scattering. We also demonstrate that SESAME can be used to separate specular and diffuse neutron reflection from surfaces at grazing incidence. In both of these cases, SESAME can make measurements at higher neutron intensity than is available with conventional methods because the angular resolution achieved is independent of the divergence of the neutron beam. Finally, we discuss the conditions under which SESAME might be used to probe in-plane structure in thin films and show that the method has advantages for incident neutron angles close to the critical angle because multiple scattering is automatically accounted for.

  7. Harmonic phase angles used for nanoparticle sensing.

    PubMed

    Shi, Yipeng; Khurshid, Hafsa; Ness, Dylan B; Weaver, John B

    2017-10-04

    A series of techniques have been developed to use magnetic nanoparticles as biosensors to characterize their local microenvironment. Two approaches have been used to obtain quantitative information: model based approaches and scaling based approaches. We have favored scaling based approaches, because approximations made in models can lead to limitations in the accuracy. Currently all the scaling approaches use harmonic ratios to retrieve physical parameters like temperature, viscosity and relaxation time. In this work, we showed that the phase angle of the signal at a single harmonic frequency is an alternative to the ratio. The phase angle is nanoparticle density-independent, and can be used to improve sensitivity, enabling us to measure smaller biomedical effects. With the phase angle as an example, we showed that scaling methods are general and do not depend on specific approximations. We showed that the same scaling techniques can be used with both the phase angle and harmonic ratio because they both depend on the same combinations of physical parameters. Using the phase angle improves the precision and using the combination of phase angles and harmonic ratio provides the best precision.

  8. Pressure dependence of the contact angle.

    PubMed

    Wu, Jiyu; Farouk, T; Ward, C A

    2007-06-07

    When a liquid and its vapor contact a smooth, homogeneous surface, Gibbsian thermodynamics indicates that the contact angle depends on the pressure at the three-phase line of an isothermal system. When a recently proposed adsorption isotherm for a solid-vapor interface is combined with the equilibrium conditions and the system is assumed to be in a cylinder where the liquid-vapor interface can be approximated as spherical, the contact-angle-pressure relation can be made explicit. It indicates that a range of contact angles can be observed on a smooth homogeneous surface by changing the pressure at the three-phase line, but it also indicates that the adsorption at the solid-liquid interface is negative, and leads to the prediction that the contact angle increases with pressure. The predicted dependence of the contact angle on pressure is investigated experimentally in a system that has an independent mechanism for determining when thermodynamic equilibrium is reached. The predictions are in agreement with the measurements. The results provide a possible explanation for contact angle hysteresis.

  9. Does gallbladder angle affect gallstone formation?

    PubMed Central

    Sanal, Bekir; Korkmaz, Mehmet; Zeren, Sezgin; Can, Fatma; Elmali, Ferhan; Bayhan, Zulfu

    2016-01-01

    Introduction Morphology of gallbladder varies considerably from person to person. We believe that one of the morphological variations of gallbladder is the “gallbladder angle”. Gallbladder varies also in “angle”, which, to the best of our knowledge, has never been investigated before. The purpose of this study was to investigate the impact of gallbladder angle on gallstone formation. Methods in this study, 1075 abdominal computed tomography (CT) images were retrospectively examined. Patients with completely normal gallbladders were selected. Among these patients, those with both abdominal ultrasound and blood tests were identified in the hospital records and included in the study. Based on the findings of the ultrasound scans, patients were divided into two groups as patients with gallstones and patients without gallstones. Following the measurement of gallbladder angles on the CT images, the groups were statistically evaluated. Results The gallbladder angle was smaller in patients with gallstones (49 ± 21 degrees and 53 ± 19 degrees) and the gallbladder with larger angle was 1.015 (1/0.985) times lower the risk of gallstone formation. However, these were not statistically significant (p>0,05). Conclusion A more vertically positioned gallbladder does not affect gallstone formation. However, a smaller gallbladder angle may facilitate gallstone formation in patients with the risk factors. Gallstones perhaps more easily and earlier develop in gallbladders with a smaller angle. PMID:27795762

  10. Modelling PTB's spatial angle autocollimator calibrator

    NASA Astrophysics Data System (ADS)

    Kranz, Oliver; Geckeler, Ralf D.; Just, Andreas; Krause, Michael

    2013-05-01

    The accurate and traceable form measurement of optical surfaces has been greatly advanced by a new generation of surface profilometers which are based on the reflection of light at the surface and the measurement of the reflection angle. For this application, high-resolution electronic autocollimators provide accurate and traceable angle metrology. In recent years, great progress has been made at the Physikalisch-Technische Bundesanstalt (PTB) in autocollimator calibration. For an advanced autocollimator characterisation, a novel calibration device has been built up at PTB: the Spatial Angle Autocollimator Calibrator (SAAC). The system makes use of an innovative Cartesian arrangement of three autocollimators (two reference autocollimators and the autocollimator to be calibrated), which allows a precise measurement of the angular orientation of a reflector cube. Each reference autocollimator is sensitive primarily to changes in one of the two relevant tilt angles, whereas the autocollimator to be calibrated is sensitive to both. The distance between the reflector cube and the autocollimator to be calibrated can be varied flexibly. In this contribution, we present the SAAC and aspects of the mathematical modelling of the system for deriving analytical expressions for the autocollimators' angle responses. These efforts will allow advancing the form measurement substantially with autocollimator-based profilometers and approaching fundamental measurement limits. Additionally, they will help manufacturers of autocollimators to improve their instruments and will provide improved angle measurement methods for precision engineering.

  11. Management of Primary Angle-Closure Glaucoma.

    PubMed

    Lai, Jimmy; Choy, Bonnie N K; Shum, Jennifer W H

    2016-01-01

    Primary angle-closure glaucoma (PACG) is a progressive optic nerve degeneration and is defined as a glaucomatous optic neuropathy with associated characteristic enlargement of optic disc cupping and visual field loss that is secondary to ocular hypertension caused by closure of the drainage angle. Angle closure is caused by appositional approximation or adhesion between the iris and the trabecular meshwork. The main treatment strategy for PACG lies in the reduction of intraocular pressure, reopening of the closed angle, and possible prevention of further angle closure. There is no universally agreed best surgical treatment for PACG. Trabeculectomy, goniosynechialysis (GSL), glaucoma implant, and cyclodestructive procedures are effective surgical options. Each of them plays an important role in the management of PACG with its own pros and cons. Accumulating evidence is available to show the effectiveness of visually significant and visually nonsignificant cataract extraction in the treatment of PACG. Trabeculectomy and GSL are often combined with cataract extraction, which may offer additional pressure control benefits to patients with PACG. This review article will discuss laser peripheral iridotomy, argon laser peripheral iridoplasty, and surgeries such as GSL, phacoemulsification, and phaco plus glaucoma surgeries that lower intraocular pressure and also alter the anterior segment and/or drainage angle anatomy. Currently, glaucoma implants and cyclodestruction are mainly reserved for PACG patients who have failed previous filtering operations. Their role as initial surgical treatment for PACG will not be discussed.

  12. Sharper angle, higher risk? The effect of cutting angle on knee mechanics in invasion sport athletes.

    PubMed

    Schreurs, Mervin J; Benjaminse, Anne; Lemmink, Koen A P M

    2017-08-24

    Cutting is an important skill in team-sports, but unfortunately is also related to non-contact ACL injuries. The purpose was to examine knee kinetics and kinematics at different cutting angles. 13 males and 16 females performed cuts at different angles (45°, 90°, 135° and 180°) at maximum speed. 3D kinematics and kinetics were collected. To determine differences across cutting angles (45°, 90°, 135° and 180°) and sex (female, male), a 4×2 repeated measures ANOVA was conducted followed by post hoc comparisons (Bonferroni) with alpha level set at α≤0.05a priori. At all cutting angles, males showed greater knee flexion angles than females (p<0.01). Also, where males performed all cutting angles with no differences in the amount of knee flexion -42.53°±8.95°, females decreased their knee flexion angle from -40.6°±7.2° when cutting at 45° to -36.81°±9.10° when cutting at 90°, 135° and 180° (p<0.01). Knee flexion moment decreased for both sexes when cutting towards sharper angles (p<0.05). At 90°, 135° and 180°, males showed greater knee valgus moments than females. For both sexes, knee valgus moment increased towards the sharper cutting angles and then stabilized compared to the 45° cutting angle (p<0.01). Both females and males showed smaller vGRF when cutting to sharper angles (p<0.01). It can be concluded that different cutting angles demand different knee kinematics and kinetics. Sharper cutting angles place the knee more at risk. However, females and males handle this differently, which has implications for injury prevention. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Solar cell angle of incidence corrections

    NASA Technical Reports Server (NTRS)

    Burger, Dale R.; Mueller, Robert L.

    1995-01-01

    Literature on solar array angle of incidence corrections was found to be sparse and contained no tabular data for support. This lack along with recent data on 27 GaAs/Ge 4 cm by 4 cm cells initiated the analysis presented in this paper. The literature cites seven possible contributors to angle of incidence effects: cosine, optical front surface, edge, shadowing, UV degradation, particulate soiling, and background color. Only the first three are covered in this paper due to lack of sufficient data. The cosine correction is commonly used but is not sufficient when the incident angle is large. Fresnel reflection calculations require knowledge of the index of refraction of the coverglass front surface. The absolute index of refraction for the coverglass front surface was not known nor was it measured due to lack of funds. However, a value for the index of refraction was obtained by examining how the prediction errors varied with different assumed indices and selecting the best fit to the set of measured values. Corrections using front surface Fresnel reflection along with the cosine correction give very good predictive results when compared to measured data, except there is a definite trend away from predicted values at the larger incident angles. This trend could be related to edge effects and is illustrated by a use of a box plot of the errors and by plotting the deviation of the mean against incidence angle. The trend is for larger deviations at larger incidence angles and there may be a fourth order effect involved in the trend. A chi-squared test was used to determine if the measurement errors were normally distributed. At 10 degrees the chi-squared test failed, probably due to the very small numbers involved or a bias from the measurement procedure. All other angles showed a good fit to the normal distribution with increasing goodness-of-fit as the angles increased which reinforces the very small numbers hypothesis. The contributed data only went to 65 degrees

  14. Contact angle hysteresis: study by dynamic cycling contact angle measurements and variable angle spectroscopic ellipsometry on polyimide.

    PubMed

    Hennig, A; Eichhorn, K-J; Staudinger, U; Sahre, K; Rogalli, M; Stamm, M; Neumann, A W; Grundke, K

    2004-08-03

    The phenomenon of contact angle hysteresis was studied on smooth films of polyimide, a polymer type used in the microelectronic industry, by dynamic cycling contact angle measurements based on axisymmetric drop shape analysis-profile in combination with variable angle spectroscopic ellipsometry (VASE). It was found that both advancing and receding contact angles became smaller with increasing the number of cycles and are, therefore, not a property of the dry solid alone. The changes of the wetting behavior during these dynamic cycling contact angle measurements are attributed mainly to swelling and/or liquid retention. To reveal the water-induced changes of the polymer film, the polyimide surface was studied before and after the contact with a water droplet by VASE. Both the experimental ellipsometric spectrum for Delta and that for Psi as well as the corresponding simulations show characteristic shifts due to the contact with water. The so-called effective medium approximation was applied to recover information about the thickness and effective optical constants of the polymer layer from the ellipsometrically measured values of Delta and Psi. On the basis of these results, the swelling and retention behavior of the polyimide films in contact with water droplets were discussed.

  15. Contact angle of unset elastomeric impression materials.

    PubMed

    Menees, Timothy S; Radhakrishnan, Rashmi; Ramp, Lance C; Burgess, John O; Lawson, Nathaniel C

    2015-10-01

    Some elastomeric impression materials are hydrophobic, and it is often necessary to take definitive impressions of teeth coated with some saliva. New hydrophilic materials have been developed. The purpose of this in vitro study was to compare contact angles of water and saliva on 7 unset elastomeric impression materials at 5 time points from the start of mixing. Two traditional polyvinyl siloxane (PVS) (Aquasil, Take 1), 2 modified PVS (Imprint 4, Panasil), a polyether (Impregum), and 2 hybrid (Identium, EXA'lence) materials were compared. Each material was flattened to 2 mm and a 5 μL drop of distilled water or saliva was dropped on the surface at 25 seconds (t0) after the start of mix. Contact angle measurements were made with a digital microscope at initial contact (t0), t1=2 seconds, t2=5 seconds, t3=50% working time, and t4=95% working time. Data were analyzed with a generalized linear mixed model analysis, and individual 1-way ANOVA and Tukey HSD post hoc tests (α=.05). For water, materials grouped into 3 categories at all time-points: the modified PVS and one hybrid material (Identium) produced the lowest contact angles, the polyether material was intermediate, and the traditional PVS materials and the other hybrid (EXA'lence) produced the highest contact angles. For saliva, Identium, Impregum, and Imprint 4 were in the group with the lowest contact angle at most time points. Modified PVS materials and one of the hybrid materials are more hydrophilic than traditional PVS materials when measured with water. Saliva behaves differently than water in contact angle measurement on unset impression material and produces a lower contact angle on polyether based materials. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  16. Fractal Approach in Petrology: Combining Ultra-Small Angle (USANA) and Small Angle Neutron Scattering (SANS)

    SciTech Connect

    LoCelso, F.; Triolo, F.; Triolo, A.; Lin, J.S.; Lucido, G.; Triolo, R.

    1999-10-14

    Ultra small angle neutron scattering instruments have recently covered the gap between the size resolution available with conventional intermediate angle neutron scattering and small angle neutron scattering instruments on one side and optical microscopy on the other side. Rocks showing fractal behavior in over two decades of momentum transfer and seven orders of magnitude of intensity are examined and fractal parameters are extracted from the combined USANS and SANS curves.

  17. Ocular biometry in occludable angles and angle closure glaucoma: a population based survey.

    PubMed

    George, R; Paul, P G; Baskaran, M; Ramesh, S Ve; Raju, P; Arvind, H; McCarty, C; Vijaya, L

    2003-04-01

    To compare ocular biometric values in a population based sample of eyes with occludable angles, angle closure glaucoma, and normal subjects. 2850 subjects from a population based glaucoma prevalence study underwent complete ocular examination including indentation gonioscopy. Ocular biometry was performed in all subjects classified to have occludable angles (n = 143); angle closure glaucoma (n = 22), and a random subgroup of 419 normal subjects. Ocular biometry readings between the groups were compared and statistically analysed using "t," "z," and Mann-Whitney U tests. The mean age among subjects with occludable angles (54.43 (SD 9.53) years) and angle closure glaucoma (57.45 (8.5) years) was significantly higher (p<0.001) than normal subjects (49.95 (9.95) years). Axial length was shorter (p<0.001) in the occludable angle group (22.07 (0.69) mm) compared to the normal group (22.76 (0.78) mm). Anterior chamber depth (ACD) was shallower (p<0.001) among subjects with occludable angles (2.53 (0.26) mm) than normal subjects (3.00 (0.30) mm). Lens thickness (LT) was greater (p<0.001) in people with occludable angles (4.40 (0.53) mm) compared to normal subjects (4.31 (0.31) mm). No significant difference was noted in axial length, ACD (p = 0.451), and LT (p = 0.302) between angle closure glaucoma and occludable eyes. South Indian eyes with angle closure glaucoma and occludable angles seem to have significantly shorter axial lengths, shallower anterior chambers and greater lens thickness compared to the normal group.

  18. Acoustic neuroma

    MedlinePlus

    Vestibular schwannoma; Tumor - acoustic; Cerebellopontine angle tumor; Angle tumor; Hearing loss - acoustic; Tinnitus - acoustic ... Acoustic neuromas have been linked with the genetic disorder neurofibromatosis type 2 (NF2). Acoustic neuromas are uncommon.

  19. Graphene spin valve: An angle sensor

    NASA Astrophysics Data System (ADS)

    Iqbal, Muhammad Zahir; Hussain, Ghulam; Siddique, Salma; Iqbal, Muhammad Waqas

    2017-06-01

    Graphene spin valves can be optimized for various spintronic applications by tuning the associated experimental parameters. In this work, we report the angle dependent magnetoresistance (MR) in graphene spin valve for different orientations of applied magnetic field (B). The switching points of spin valve signals show a clear shift towards higher B for each increasing angle of the applied field, thus sensing the response for respective orientation of the magnetic field. The angular variation of B shifts the switching points from ±95 G to ±925 G as the angle is varied from 0° to 90° at 300 K. The observed shifts in switching points become more pronounced (±165 G to ±1450 G) at 4.2 K for similar orientation. A monotonic increase in MR ratio is observed as the angle of magnetic field is varied in the vertical direction at 300 K and 4.2 K temperatures. This variation of B (from 0° to 90°) increases the magnitude of MR ratio from ∼0.08% to ∼0.14% at 300 K, while at 4.2 K it progresses to ∼0.39% from ∼0.14%. The sensitivity related to angular variation of such spin valve structure can be employed for angle sensing applications.

  20. LVAD Outflow Graft Angle and Thrombosis Risk.

    PubMed

    Aliseda, Alberto; Chivukula, Venkat Keshav; Mcgah, Patrick; Prisco, Anthony R; Beckman, Jennifer A; Garcia, Guilherme J M; Mokadam, Nahush A; Mahr, Claudius

    This study quantifies thrombogenic potential (TP) of a wide range of left ventricular assist device (LVAD) outflow graft anastomosis angles through state-of-the-art techniques: 3D imaged-based patient-specific models created via virtual surgery and unsteady computational fluid dynamics with Lagrangian particle tracking. This study aims at clarifying the influence of a single parameter (outflow graft angle) on the thrombogenesis associated with flow patterns in the aortic root after LVAD implantation. This is an important and poorly-understood aspect of LVAD therapy, because several studies have shown strong inter and intrapatient thrombogenic variability and current LVAD implantation strategies do not incorporate outflow graft angle optimization. Accurate platelet-level investigation, enabled by statistical treatment of outliers in Lagrangian particle tracking, demonstrates a strong influence of outflow graft anastomoses angle on thrombogenicity (platelet residence times and activation state characterized by shear stress accumulation) with significantly reduced TP for acutely-angled anastomosed outflow grafts. The methodology presented in this study provides a device-neutral platform for conducting comprehensive thrombogenicity evaluation of LVAD surgical configurations, empowering optimal patient-focused surgical strategies for long-term treatment and care for advanced heart failure patients.

  1. NORAD LOOK ANGLES AND PIO SATELLITE PACKAGE

    NASA Technical Reports Server (NTRS)

    ANONYMOUS

    1994-01-01

    This program package consists of two programs. First is the NORAD Look Angles Program, which computes satellite look angles (azimuth, elevation, and range) as well as the subsatellite points (latitude, longitude, and height). The second program in this package is the PIO Satellite Program, which computes sighting directions, visibility times, and the maximum elevation angle attained during each pass of an earth-orbiting satellite. Computations take into consideration the observing location and the effect of the earth's shadow on the satellite visibility. Input consists of a magnetic tape prepared by the NORAD Look Angles Program and punched cards containing reference Julian date, right ascension, declination, mean sidereal time at zero hours universal time of the reference date, and daily changes of these quantities. Output consists of a tabulated listing of the satellite's rise and set times, direction, and the maximum elevation angle visible from each observing location. This program has been implemented on the GE 635. The program Assembler code can easily be replaced by FORTRAN statements.

  2. Residual angle closure one year after laser peripheral iridotomy in primary angle closure suspects.

    PubMed

    Baskaran, Mani; Yang, Elizabeth; Trikha, Sameer; Kumar, Rajesh S; Wong, Hon Tym; He, Mingguang; Chew, Paul Tk; Foster, Paul J; Friedman, David; Aung, Tin

    2017-09-05

    To determine the incidence and baseline clinical and anterior segment optical coherence tomography (AS-OCT) predictors associated with residual angle closure as assessed by gonioscopy 1 year after laser peripheral iridotomy (LPI) in primary angle closure suspects (PACS). Sub-analysis of randomized controlled trial data METHODS: AS-OCT images (Visante, Carl Zeiss Meditec, Dublin, CA) from 181 PACS subjects ≥ 50 years of age, were analyzed using customized software, prior to, and 1 year after LPI. Other parameters assessed were intraocular pressure (IOP) and axial length (Axl). Residual angle closure was defined as the inability to see the posterior trabecular meshwork for at least 2 quadrants on gonioscopy after LPI. Multivariate regression analysis determined the baseline predictors of residual angle closure 1 year after LPI. The mean age of participants was 62.4 (SD 9.9) years. The majority were female (137, 75.7%) and Chinese 174, 96.1%). At 1 year post LPI, 148 (81.8%) subjects had gonioscopic residual angle closure. Univariate analysis showed that baseline Axl, anterior chamber area, anterior chamber volume, angle opening distance at 750 microns from the scleral spur and angle recess area were smaller while baseline lens vault and iris curvature were larger in residual angle closure subjects (all p<0.05). Multivariate analysis revealed that baseline iris volume (B=-0.08, P=0.035) and baseline IOP (B=0.23, p=0.032) were predictors for residual angle closure. One year after LPI, >80% of PACS had gonioscopic residual angle closure. Greater baseline iris volume and higher IOP at baseline are independent risk factors for residual gonioscopic angle closure. Copyright © 2017. Published by Elsevier Inc.

  3. Angle sensing with ferromagnetic nanowire arrays

    NASA Astrophysics Data System (ADS)

    Tannous, C.; Gieraltowski, J.

    2014-01-01

    Hysteresis loops and Ferromagnetic Resonance (FMR) linewidths of Nickel ferromagnetic nanowire arrays are measured versus angle θH between the applied magnetic field angle and the common nanowire axis. Using Preisach analysis, we extract from the hysteresis loop an interaction parameter σi that strongly depends on θH. Extending the analysis to FMR lineshapes, we deduce a strong dependence of the FMR field linewidth ΔH on θH through the interaction parameter σi. Existence of a link between static (hysteresis) and dynamic (FMR) cases through θH might be exploited in contactless absolute angle sensing devices that could compete with inductive, Hall, and magnetoresistive devices.

  4. High brightness angled cavity quantum cascade lasers

    SciTech Connect

    Heydari, D.; Bai, Y.; Bandyopadhyay, N.; Slivken, S.; Razeghi, M.

    2015-03-02

    A quantum cascade laser (QCL) with an output power of 203 W is demonstrated in pulsed mode at 283 K with an angled cavity. The device has a ridge width of 300 μm, a cavity length of 5.8 mm, and a tilt angle of 12°. The back facet is high reflection coated, and the front facet is anti-reflection coated. The emitting wavelength is around 4.8 μm. In distinct contrast to a straight cavity broad area QCL, the lateral far field is single lobed with a divergence angle of only 3°. An ultrahigh brightness value of 156 MW cm{sup −2 }sr{sup −1} is obtained, which marks the brightest QCL to date.

  5. A heterodyne interferometer for angle metrology.

    PubMed

    Hahn, Inseob; Weilert, M; Wang, X; Goullioud, R

    2010-04-01

    We have developed a compact, high-resolution, angle measurement instrument based on a heterodyne interferometer. Common-path heterodyne interferometer metrology is used to measure displacements of a reflective target surface. In the interferometer set up, an optical mask is used to sample the laser beam reflecting back from four areas on a target surface. From the relative displacement measurements of the target surface areas, we can simultaneously determine angular rotations around two orthogonal axes in a plane perpendicular to the measurement beam propagation direction. The device is used in a testbed for a tracking telescope system where pitch and yaw angle measurements of a flat mirror are performed. Angle noise measurement of the device shows 0.1 nrad/square root of Hz at 1 Hz, at a working distance of 1 m. The operation range and nonlinearity of the device when used with a flat mirror is approximately +/-0.15 mrad, and 3 microrad rms, respectively.

  6. A heterodyne interferometer for angle metrology

    SciTech Connect

    Hahn, Inseob; Weilert, M.; Wang, X.; Goullioud, R.

    2010-04-15

    We have developed a compact, high-resolution, angle measurement instrument based on a heterodyne interferometer. Common-path heterodyne interferometer metrology is used to measure displacements of a reflective target surface. In the interferometer set up, an optical mask is used to sample the laser beam reflecting back from four areas on a target surface. From the relative displacement measurements of the target surface areas, we can simultaneously determine angular rotations around two orthogonal axes in a plane perpendicular to the measurement beam propagation direction. The device is used in a testbed for a tracking telescope system where pitch and yaw angle measurements of a flat mirror are performed. Angle noise measurement of the device shows 0.1 nrad/{radical}(Hz) at 1 Hz, at a working distance of 1 m. The operation range and nonlinearity of the device when used with a flat mirror is approximately {+-}0.15 mrad, and 3 {mu}rad rms, respectively.

  7. Bicycle helmet ventilation and comfort angle dependence.

    PubMed

    Brühwiler, Paul A; Ducas, Charline; Huber, Roman; Bishop, Phillip A

    2004-09-01

    Five modern bicycle helmets were studied to elucidate some of the variations in ventilation performance, using both a heated manikin headform and human subjects (n = 7). Wind speed and head angle were varied to test their influence on the measured steady-state heat exchange (cooling power) in the skull section of the headform. The cooling power transmitted by the helmets varied from about 60% to over 90% of that of the nude headform, illustrating the range of present manufacturer designs. Angling the head forward by 30 degrees was found to provide better cooling power to the skull (up to 25%) for three of the helmets and almost equal cooling power in the remaining two cases. Comparisons of skull ventilation at these angles with human subjects strongly supported the headform results.

  8. Data for phase angle shift with frequency

    PubMed Central

    Paul, T.; Banerjee, D.; Kargupta, K.

    2016-01-01

    Phase angle shift between the current and voltage with frequency has been reported for a single phosphoric acid fuel cell in the cell temperature from 100 °C to 160 °C and the humidifier temperature from 40 °C to 90 °C. An electrochemical workbench is employed to find the shift. The figure of phase angle shift shows a peak in high humidifier temperatures. The peak in phase angle shift directs to lower frequency side with decreasing humidifier temperature. The estimation of electrochemical reaction time is also evaluated in the humidifier temperature zone from 50 °C to 90 °C. PMID:27158655

  9. Michelson interferometer for precision angle measurement.

    PubMed

    Ikram, M; Hussain, G

    1999-01-01

    An angle-measuring technique based on an optical interferometer is reported. The technique exploits a Michelson interferometric configuration in which a right-angle prism and a glass strip are introduced into a probe beam. Simultaneous rotation of both components along an axis results in an optical path difference between the reference and the probe beams. In a second arrangement two right-angle prisms and glass strips are introduced into two beams of a Michelson interferometer. The prisms and the strips are rotated simultaneously to introduce an optical path difference between the two beams. In our arrangement, optimization of various parameters makes the net optical path difference between the two beams approximately linear for a rotation as great as +/-20 degrees . Results are simulated that show an improvement of 2-3 orders of magnitude in error and nonlinearity compared with a previously reported technique.

  10. High brightness angled cavity quantum cascade lasers

    NASA Astrophysics Data System (ADS)

    Heydari, D.; Bai, Y.; Bandyopadhyay, N.; Slivken, S.; Razeghi, M.

    2015-03-01

    A quantum cascade laser (QCL) with an output power of 203 W is demonstrated in pulsed mode at 283 K with an angled cavity. The device has a ridge width of 300 μm, a cavity length of 5.8 mm, and a tilt angle of 12°. The back facet is high reflection coated, and the front facet is anti-reflection coated. The emitting wavelength is around 4.8 μm. In distinct contrast to a straight cavity broad area QCL, the lateral far field is single lobed with a divergence angle of only 3°. An ultrahigh brightness value of 156 MW cm-2 sr-1 is obtained, which marks the brightest QCL to date.

  11. Three paths toward the quantum angle operator

    SciTech Connect

    Gazeau, Jean Pierre; Szafraniec, Franciszek Hugon

    2016-12-15

    We examine mathematical questions around angle (or phase) operator associated with a number operator through a short list of basic requirements. We implement three methods of construction of quantum angle. The first one is based on operator theory and parallels the definition of angle for the upper half-circle through its cosine and completed by a sign inversion. The two other methods are integral quantization generalizing in a certain sense the Berezin–Klauder approaches. One method pertains to Weyl–Heisenberg integral quantization of the plane viewed as the phase space of the motion on the line. It depends on a family of “weight” functions on the plane. The third method rests upon coherent state quantization of the cylinder viewed as the phase space of the motion on the circle. The construction of these coherent states depends on a family of probability distributions on the line.

  12. Three paths toward the quantum angle operator

    NASA Astrophysics Data System (ADS)

    Gazeau, Jean Pierre; Szafraniec, Franciszek Hugon

    2016-12-01

    We examine mathematical questions around angle (or phase) operator associated with a number operator through a short list of basic requirements. We implement three methods of construction of quantum angle. The first one is based on operator theory and parallels the definition of angle for the upper half-circle through its cosine and completed by a sign inversion. The two other methods are integral quantization generalizing in a certain sense the Berezin-Klauder approaches. One method pertains to Weyl-Heisenberg integral quantization of the plane viewed as the phase space of the motion on the line. It depends on a family of "weight" functions on the plane. The third method rests upon coherent state quantization of the cylinder viewed as the phase space of the motion on the circle. The construction of these coherent states depends on a family of probability distributions on the line.

  13. Small Angle X-Ray Scattering Detector

    SciTech Connect

    Hessler, Jan P.

    2004-06-15

    A detector for time-resolved small-angle x-ray scattering includes a nearly constant diameter, evacuated linear tube having an end plate detector with a first fluorescent screen and concentric rings of first fiber optic bundles for low angle scattering detection and an annular detector having a second fluorescent screen and second fiber optic bundles concentrically disposed about the tube for higher angle scattering detection. With the scattering source, i.e., the specimen under investigation, located outside of the evacuated tube on the tube's longitudinal axis, scattered x-rays are detected by the fiber optic bundles, to each of which is coupled a respective photodetector, to provide a measurement resolution, i.e., dq/q, where q is the momentum transferred from an incident x-ray to an x-ray scattering specimen, of 2% over two (2) orders of magnitude in reciprocal space, i.e., qmax/qmin approx=lO0.

  14. Angle-averaged Compton cross sections

    SciTech Connect

    Nickel, G.H.

    1983-01-01

    The scattering of a photon by an individual free electron is characterized by six quantities: ..cap alpha.. = initial photon energy in units of m/sub 0/c/sup 2/; ..cap alpha../sub s/ = scattered photon energy in units of m/sub 0/c/sup 2/; ..beta.. = initial electron velocity in units of c; phi = angle between photon direction and electron direction in the laboratory frame (LF); theta = polar angle change due to Compton scattering, measured in the electron rest frame (ERF); and tau = azimuthal angle change in the ERF. We present an analytic expression for the average of the Compton cross section over phi, theta, and tau. The lowest order approximation to this equation is reasonably accurate for photons and electrons with energies of many keV.

  15. Positron Emission Mammography with Multiple Angle Acquisition

    SciTech Connect

    Mark F. Smith; Stan Majewski; Raymond R. Raylman

    2002-11-01

    Positron emission mammography (PEM) of F-18 fluorodeoxyglucose (FDG) uptake in breast tumors with dedicated detectors typically has been accomplished with two planar detectors in a fixed position with the breast under compression. The potential use of PEM imaging at two detector positions to guide stereotactic breast biopsy has motivated us to use PEM coincidence data acquired at two or more detector positions together in a single image reconstruction. Multiple angle PEM acquisition and iterative image reconstruction were investigated using point source and compressed breast phantom acquisitions with 5, 9, 12 and 15 mm diameter spheres and a simulated tumor:background activity concentration ratio of 6:1. Image reconstruction was performed with an iterative MLEM algorithm that used coincidence events between any two detector pixels on opposed detector heads at each detector position. This present study compared two acquisition protocols: 2 angle acquisition with detector angular positions of -15 and +15 degrees and 11 angle acquisition with detector positions spaced at 3 degree increments over the range -15 to +15 degrees. Three- dimensional image resolution was assessed for the point source acquisitions, and contrast and signal-to-noise metrics were evaluated for the compressed breast phantom with different simulated tumor sizes. Radial and tangential resolutions were similar for the two protocols, while normal resolution was better for the 2 angle acquisition. Analysis is complicated by the asymmetric point spread functions. Signal- to-noise vs. contrast tradeoffs were better for 11 angle acquisition for the smallest visible 9 mm sphere, while tradeoff results were mixed for the larger and more easily visible 12 mm and 15 mm diameter spheres. Additional study is needed to better understand the performance of limited angle tomography for PEM. PEM tomography experiments with complete angular sampling are planned.

  16. Positron Emission Mammography with Multiple Angle Acquisition

    SciTech Connect

    Mark F. Smith; Stan Majewski; Raymond R. Raylman

    2002-11-01

    Positron emission mammography (PEM) of F-18 fluorodeoxyglucose (FbG) uptake in breast tumors with dedicated detectors typically has been accomplished with two planar detectors in a fixed position with the breast under compression. The potential use of PEM imaging at two detector positions to guide stereotactic breast biopsy has motivated us to use PEM coincidence data acquired at two or more detector positions together in a single image reconstruction. Multiple angle PEM acquisition and iterative image reconstruction were investigated using point source and compressed breast phantom acquisitions with 5, 9, 12 and 15 mm diameter spheres and a simulated tumor:background activity concentration ratio of 6:1. Image reconstruction was performed with an iterative MLEM algorithm that used coincidence events between any two detector pixels on opposed detector heads at each detector position. This present study compared two acquisition protocols: 2 angle acquisition with detector angular positions of -15 and +15 degrees and 11 angle acquisition with detector positions spaced at 3 degree increments over the range -15 to +15 degrees. Three-dimensional image resolution was assessed for the point source acquisitions, and contrast and signal-to-noise metrics were evaluated for the compressed breast phantom with different simulated tumor sizes. Radial and tangential resolutions were similar for the two protocols, while normal resolution was better for the 2 angle acquisition. Analysis is complicated by the asymmetric point spread functions. Signal- to-noise vs. contrast tradeoffs were better for 11 angle acquisition for the smallest visible 9 mm sphere, while tradeoff results were mixed for the larger and more easily visible 12 mm and 15 mm diameter spheres. Additional study is needed to better understand the performance of limited angle tomography for PEM. PEM tomography experiments with complete angular sampling are planned.

  17. Methodology for high accuracy contact angle measurement.

    PubMed

    Kalantarian, A; David, R; Neumann, A W

    2009-12-15

    A new version of axisymmetric drop shape analysis (ADSA) called ADSA-NA (ADSA-no apex) was developed for measuring interfacial properties for drop configurations without an apex. ADSA-NA facilitates contact angle measurements on drops with a capillary protruding into the drop. Thus a much simpler experimental setup, not involving formation of a complete drop from below through a hole in the test surface, may be used. The contact angles of long-chained alkanes on a commercial fluoropolymer, Teflon AF 1600, were measured using the new method. A new numerical scheme was incorporated into the image processing to improve the location of the contact points of the liquid meniscus with the solid substrate to subpixel resolution. The images acquired in the experiments were also analyzed by a different drop shape technique called theoretical image fitting analysis-axisymmetric interfaces (TIFA-AI). The results were compared with literature values obtained by means of the standard ADSA for sessile drops with the apex. Comparison of the results from ADSA-NA with those from TIFA-AI and ADSA reveals that, with different numerical strategies and experimental setups, contact angles can be measured with an accuracy of less than 0.2 degrees. Contact angles and surface tensions measured from drops with no apex, i.e., by means of ADSA-NA and TIFA-AI, were considerably less scattered than those from complete drops with apex. ADSA-NA was also used to explore sources of improvement in contact angle resolution. It was found that using an accurate value of surface tension as an input enhances the accuracy of contact angle measurements.

  18. Magic-angle turning with double acquisition.

    PubMed

    Matsunaga, Tatsuya; Takegoshi, K

    2017-01-01

    The double-acquisition scheme for efficient data collection of hypercomplex data (the States method) of a two-dimensional experiment is adopted to magic-angle hopping (MAH) and magic-angle turning (MAT) experiments, which are powerful methods to measure the principal values of the chemical shift anisotropy (CSA) in a powder sample. It is shown that the double acquisition MAT (DAMAT) sequence realizes the S/N ratio comparable to or better than those of other variants of the MAH/MAT sequences. In addition, we show that DAMAT has preferable features that there are no spinning sidebands in the indirect dimension, and no spectral shearing is necessary.

  19. Magic-angle turning with double acquisition

    NASA Astrophysics Data System (ADS)

    Matsunaga, Tatsuya; Takegoshi, K.

    2017-01-01

    The double-acquisition scheme for efficient data collection of hypercomplex data (the States method) of a two-dimensional experiment is adopted to magic-angle hopping (MAH) and magic-angle turning (MAT) experiments, which are powerful methods to measure the principal values of the chemical shift anisotropy (CSA) in a powder sample. It is shown that the double acquisition MAT (DAMAT) sequence realizes the S/N ratio comparable to or better than those of other variants of the MAH/MAT sequences. In addition, we show that DAMAT has preferable features that there are no spinning sidebands in the indirect dimension, and no spectral shearing is necessary.

  20. Taper Angle Evolution in Taiwan Accretionary Wedge

    NASA Astrophysics Data System (ADS)

    Chen, L.; Chi, W.; Liu, C.

    2011-12-01

    Liwen Chena,b, Wu-Cheng Chia, Char-Shine Liuc aInstitute of Earth Sciences, Academia Sinica, Taipei, Taiwan bInstitute of Geosciences, National Taiwan University, Taipei, Taiwan cInstitute of Oceanography, National Taiwan University, Taipei, Taiwan The critical taper model, originally developed using onland Taiwan as an example, is governed by force balance of a horizontal compressional wedge. This model has been successfully applied to many mountainous regions around the world. Among them, Taiwan is located in an oblique collision between the Luzon Arc and the Chinese Passive margin. Previous critical taper angle studies of Taiwan are mainly focusing on utilizing land data. In this study we want to extend these studies to offshore region from the subduction zone to collision zone. Here we study the varying taper angles of the double-vergent wedge derived from 1,000 km of reflection seismic profiles in both the pro-wedge and retro-wedge locations. These profiles were collected in the last two decades. For the retro-wedge, the topography slope angle changes from 2 to 8.8 degrees; some of the steep slope suggests that some part of the retrowedge is currently in a super-critical angle state. Such dramatic changes in taper angle probably strongly affect regional sedimentary processes, including slumping, in addition to structural deformation. These complex processes might even help develop a mélange or re-open a closed basin. We are currently working on studying the taper angle evolution of the pro-wedge from subduction to arc-continent collision zone in the offshore region. Though further works are needed, our preliminary results show that the evolution of wedge angles and the geometry of the wedge are closely linked and inseparable. The structures of the subducting plate might have strong influence on the deformation style of the over-riding plate. It would be interesting to combine the angle variation with the structure interpretation of the accretionary wedge

  1. Spherical Parameterization Balancing Angle and Area Distortions.

    PubMed

    Nadeem, Saad; Su, Zhengyu; Zeng, Wei; Kaufman, Arie; Gu, Xianfeng

    2017-06-01

    This work presents a novel framework for spherical mesh parameterization. An efficient angle-preserving spherical parameterization algorithm is introduced, which is based on dynamic Yamabe flow and the conformal welding method with solid theoretic foundation. An area-preserving spherical parameterization is also discussed, which is based on discrete optimal mass transport theory. Furthermore, a spherical parameterization algorithm, which is based on the polar decomposition method, balancing angle distortion and area distortion is presented. The algorithms are tested on 3D geometric data and the experiments demonstrate the efficiency and efficacy of the proposed methods.

  2. Brewster's angle silicon wafer terahertz linear polarizer.

    PubMed

    Wojdyla, Antoine; Gallot, Guilhem

    2011-07-18

    We present a new cost-effective terahertz linear polarizer made from a stack of silicon wafers at Brewster's angle, andevaluate its performances. We show that this polarizer is wide-band, has a high extinction ratio (> 6 × 10(3)) and very small insertion losses (< 1%). We provide measurements of the temporal waveforms after linearly polarizing the THz beam and show that there is no distortion of the pulse. We compare its performances with a commercial wire-grid polarizer, and show that the Brewster's angle polarizer can conveniently be used to control the power of a terahertz beam.

  3. Angle-resolved RABBITT: theory and numerics

    NASA Astrophysics Data System (ADS)

    Hockett, Paul

    2017-08-01

    Angle-resolved (AR) RABBITT measurements offer a high information content measurement scheme, due to the presence of multiple, interfering, ionization channels combined with a phase-sensitive observable in the form of angle and time-resolved photoelectron interferograms. In order to explore the characteristics and potentials of AR-RABBITT, a perturbative 2-photon model is developed; based on this model, example AR-RABBITT results are computed for model and real systems, for a range of RABBITT schemes. These results indicate some of the phenomena to be expected in AR-RABBITT measurements, and suggest various applications of the technique in photoionization metrology.

  4. Understanding Angle and Angle Measure: A Design-Based Research Study Using Context Aware Ubiquitous Learning

    ERIC Educational Resources Information Center

    Crompton, Helen

    2015-01-01

    Mobile technologies are quickly becoming tools found in the educational environment. The researchers in this study use a form of mobile learning to support students in learning about angle concepts. Design-based research is used in this study to develop an empirically-substantiated local instruction theory about students' develop of angle and…

  5. Using Digital Technology to See Angles from Different Angles. Part 2: Openings and Turns

    ERIC Educational Resources Information Center

    Host, Erin; Baynham, Emily; McMaster, Heather

    2015-01-01

    Ever wondered how to use technology to teach angles? This article follows on from an earlier article published last year, providing a range of ideas for integrating technology and concrete materials with the teaching of angle concepts. The authors also provide a comprehensive list of free online games and learning objects that can be used to teach…

  6. Understanding Angle and Angle Measure: A Design-Based Research Study Using Context Aware Ubiquitous Learning

    ERIC Educational Resources Information Center

    Crompton, Helen

    2015-01-01

    Mobile technologies are quickly becoming tools found in the educational environment. The researchers in this study use a form of mobile learning to support students in learning about angle concepts. Design-based research is used in this study to develop an empirically-substantiated local instruction theory about students' develop of angle and…

  7. Using Digital Technology to See Angles from Different Angles. Part 2: Openings and Turns

    ERIC Educational Resources Information Center

    Host, Erin; Baynham, Emily; McMaster, Heather

    2015-01-01

    Ever wondered how to use technology to teach angles? This article follows on from an earlier article published last year, providing a range of ideas for integrating technology and concrete materials with the teaching of angle concepts. The authors also provide a comprehensive list of free online games and learning objects that can be used to teach…

  8. A fringe shadow method for measuring flapping angle and torsional angle of a dragonfly wing

    NASA Astrophysics Data System (ADS)

    Zeng, Lijiang; Matsumoto, Hirokazu; Kawachi, Keiji

    1996-05-01

    A fringe shadow (FS) method was developed for measuring the flapping angle and torsional angle of a dragonfly wing during beating motion. This new method involves two sets of fringe patterns projected onto the wing from orthogonal directions. The torsional angle is determined using the length of the shadow of the wing chord that is cast by the two sets of fringe patterns. The flapping angle is determined using the shadowgraph of the wing projected by a laser. The advantages of the FS method are its capability (i) to measure the flapping angle and torsional angle of a dragonfly wing simultaneously using only one high-speed camera and (ii) to recognize the spanwise position of a section from the number of fringes, without having to use diffuse marks that are common in current methods. The resolution of the FS method can be changed easily by adjusting the fringe spacing. The measurement results for the torsional angle and flapping angle of a dragonfly wing prove the effectiveness of the FS method in studying the flight performance of dragonflies.

  9. Spirality: Spiral arm pitch angle measurement

    NASA Astrophysics Data System (ADS)

    Shields, Douglas W.; Boe, Benjamin; Pfountz, Casey; Davis, Benjamin L.; Hartley, Matthew; Pour Imani, Hamed; Slade, Zac; Kennefick, Daniel; Kennefick, Julia

    2015-12-01

    Spirality measures spiral arm pitch angles by fitting galaxy images to spiral templates of known pitch. Written in MATLAB, the code package also includes GenSpiral, which produces FITS images of synthetic spirals, and SpiralArmCount, which uses a one-dimensional Fast Fourier Transform to count the spiral arms of a galaxy after its pitch is determined.

  10. Association between Bolton discrepancy and Angle malocclusions.

    PubMed

    Cançado, Rodrigo Hermont; Gonçalves Júnior, Waldir; Valarelli, Fabrício Pinelli; Freitas, Karina Maria Salvatore de; Crêspo, Janaina Aparecida Lima

    2015-01-01

    This study aimed to assess and compare the overall and anterior ratios of tooth size discrepancies in all Angle malocclusion groups. The following null hypothesis (H0) was tested: no difference between tooth size discrepancies (overall and anterior) would be observed among Angle malocclusion groups. The sample comprised of 711 pre-orthodontic treatment study casts of Brazilian patients with a mean age of 17.42 years selected from private practices in Brazil. The casts were divided into 3 groups according to the type of malocclusion: Class I (n = 321), Class II (n = 324), and Class III patients (n = 66). The measurement of the greatest mesiodistal width of the teeth was performed using a centesimal precision digital caliper directly on the study casts, from the distal surface of the left first molar to the distal surface of the right first molar. The overall and anterior ratios between the maxillary and mandibular teeth were evaluated using Bolton's method. The following statistical tests were applied: chi-square, independent t-test, and one-way ANOVA. Results showed that all Angle malocclusions groups exhibited a ratio compatible with those recommended by Bolton. With respect to the overall and anterior ratios among the malocclusion groups, no statistically significant differences were found. The null hypothesis was accepted because the results showed no differences in the overall and anterior ratios of tooth size discrepancies among different Angle malocclusion groups.

  11. Recent Results on the CKM Angle Alpha

    SciTech Connect

    Mihalyi, A.; /Wisconsin U., Madison

    2005-10-18

    The method to measure the CKM angle {alpha} and the modes sensitive to it are discussed. It is shown that the B {yields} {rho}{rho} decays provide the most stringent constraint on {alpha}, which is found to be {alpha} = 96{sup o} {+-} 10{sup o}(stat) {+-} 4{sup o}(syst){+-} 13{sup o}(penguin).

  12. Camber Angle Inspection for Vehicle Wheel Alignments

    PubMed Central

    Young, Jieh-Shian; Hsu, Hong-Yi; Chuang, Chih-Yuan

    2017-01-01

    This paper introduces an alternative approach to the camber angle measurement for vehicle wheel alignment. Instead of current commercial approaches that apply computation vision techniques, this study aims at realizing a micro-control-unit (MCU)-based camber inspection system with a 3-axis accelerometer. We analyze the precision of the inspection system for the axis misalignments of the accelerometer. The results show that the axes of the accelerometer can be aligned to the axes of the camber inspection system imperfectly. The calibrations that can amend these axis misalignments between the camber inspection system and the accelerometer are also originally proposed since misalignments will usually happen in fabrications of the inspection systems. During camber angle measurements, the x-axis or z-axis of the camber inspection system and the wheel need not be perfectly aligned in the proposed approach. We accomplished two typical authentic camber angle measurements. The results show that the proposed approach is applicable with a precision of ±0.015∘ and therefore facilitates the camber measurement process without downgrading the precision by employing an appropriate 3-axis accelerometer. In addition, the measured results of camber angles can be transmitted via the medium such as RS232, Bluetooth, and Wi-Fi. PMID:28165365

  13. Flare angles measured with ball gage

    NASA Technical Reports Server (NTRS)

    Cleghorn, D.; Wall, W. A.

    1968-01-01

    Precision tungsten carbide balls measure the internal angle of flared joints. Measurements from small and large balls in the flare throat to an external reference point are made. The difference in distances and diameters determine the average slope of the flare between the points of ball contact.

  14. Anterior chamber angle in the exfoliation syndrome.

    PubMed Central

    Wishart, P K; Spaeth, G L; Poryzees, E M

    1985-01-01

    The gonioscopic findings of 76 patients with the exfoliation syndrome were reviewed. A high frequency of narrowness of the anterior chamber (AC) angle was found (32%). 18% had angles considered occludable, and 14% had obvious angle-closure glaucoma as shown by the presence of peripheral anterior synechias (PAS). Increased pigmentation of the posterior trabecular meshwork (PTM) was noted in all cases. When this pigmentation was markedly asymmetrical, unilateral exfoliation with glaucoma was common in the more pigmented eye. In addition heavy angle pigmentation in the absence of exfoliation was noted in the fellow eye of patients with characteristic exfoliated material in the other eye. Increased pigmentation of the PTM may be the earliest detectable sign of the exfoliation syndrome (ES). The clinical significance of our estimating PTM pigmentation at the 12 o'clock position is discussed. In view of the accelerated optic nerve damage associated with the development of glaucoma secondary to ES, routine estimation of the pigmentation of the PTM at 12 o'clock is recommended in the hope of early detection of cases of otherwise inapparent ES. Images PMID:3966996

  15. Sensor Tracks the Sun From Any Angle

    NASA Technical Reports Server (NTRS)

    Birnbaum, M., M.; Bunker, R. L.

    1986-01-01

    Sensor system locates Sun from any angle and generates error signals to point object toward Sun and follow its motion. Sun-sensor system includes three photodetectors, each with separate field of view defined by set of apertures. As equipment rotates about axis, detectors put out time-varying signals processed by external electronics to determine rotation rate and direction to Sun.

  16. Instrument accurately measures weld angle and offset

    NASA Technical Reports Server (NTRS)

    Boyd, W. G.

    1967-01-01

    Weld angle is measured to the nearest arc minute and offset to one thousandth of an inch by an instrument designed to use a reference plane at two locations on a test coupon. A special table for computation has been prepared for use with the instrument.

  17. Camber Angle Inspection for Vehicle Wheel Alignments.

    PubMed

    Young, Jieh-Shian; Hsu, Hong-Yi; Chuang, Chih-Yuan

    2017-02-03

    This paper introduces an alternative approach to the camber angle measurement for vehicle wheel alignment. Instead of current commercial approaches that apply computation vision techniques, this study aims at realizing a micro-control-unit (MCU)-based camber inspection system with a 3-axis accelerometer. We analyze the precision of the inspection system for the axis misalignments of the accelerometer. The results show that the axes of the accelerometer can be aligned to the axes of the camber inspection system imperfectly. The calibrations that can amend these axis misalignments between the camber inspection system and the accelerometer are also originally proposed since misalignments will usually happen in fabrications of the inspection systems. During camber angle measurements, the x-axis or z-axis of the camber inspection system and the wheel need not be perfectly aligned in the proposed approach. We accomplished two typical authentic camber angle measurements. The results show that the proposed approach is applicable with a precision of ± 0.015 ∘ and therefore facilitates the camber measurement process without downgrading the precision by employing an appropriate 3-axis accelerometer. In addition, the measured results of camber angles can be transmitted via the medium such as RS232, Bluetooth, and Wi-Fi.

  18. Statistical analysis of Contact Angle Hysteresis

    NASA Astrophysics Data System (ADS)

    Janardan, Nachiketa; Panchagnula, Mahesh

    2015-11-01

    We present the results of a new statistical approach to determining Contact Angle Hysteresis (CAH) by studying the nature of the triple line. A statistical distribution of local contact angles on a random three-dimensional drop is used as the basis for this approach. Drops with randomly shaped triple lines but of fixed volumes were deposited on a substrate and their triple line shapes were extracted by imaging. Using a solution developed by Prabhala et al. (Langmuir, 2010), the complete three dimensional shape of the sessile drop was generated. A distribution of the local contact angles for several such drops but of the same liquid-substrate pairs is generated. This distribution is a result of several microscopic advancing and receding processes along the triple line. This distribution is used to yield an approximation of the CAH associated with the substrate. This is then compared with measurements of CAH by means of a liquid infusion-withdrawal experiment. Static measurements are shown to be sufficient to measure quasistatic contact angle hysteresis of a substrate. The approach also points towards the relationship between microscopic triple line contortions and CAH.

  19. Wideband Phase-Locked Angle Modulator

    NASA Technical Reports Server (NTRS)

    Nguyen, Lim

    1991-01-01

    Modified configuration for phase-locked angle modulator circuit makes possible to design filters in modulating portion of circuit independently of filter in phase-locked-loop portion. Bandwidth of phase- or frequency-modulated output not limited by low-pass nature of loop filter.

  20. Prediction of ultrasonic properties from grain angle

    Treesearch

    M.F. Kabir

    2001-01-01

    The ultrasonic properties of rubber wood were evaluated in three main symmetry axes – longitudinal (L), radial (R) and tangential direction and also at an angle rotating from the symmetry axes at different moisture content. The ultrasonic velocity were determined with a commercial ultrasonic tester of 45 kHz pulsed longitudinal waves. The experimental results were...

  1. Incidence angle normalization of radar backscatter data

    USDA-ARS?s Scientific Manuscript database

    NASA’s Soil Moisture Passive Active (SMAP) satellite (~2014) will include a radar system that will provide L-band multi-polarization backscatter at a constant incidence angle of 40º. During the pre-launch phase of the project there is a need for observations that will support the radar-based soil mo...

  2. Contact Angle Changes Induced by Immunocomplex Formation†

    PubMed Central

    Kim, Jong-Hoon; Shen, Amy Q.; Lee, Kyong-Hoon; Cangelosi, Gerard A.; Chung, Jae-Hyun

    2014-01-01

    Immunoassays analyzing interactions between antigens and antibodies can be affected by capillary action together with binding affinity. This paper studies contact-angle changes of bacterial suspensions on antibody immobilized surfaces. The capillary action and the dried pattern of the cell suspensions are analyzed and correlated with specific- and nonspecific bindings between bacteria and antibodies. PMID:24482797

  3. Partitioning Pythagorean Triangles Using Pythagorean Angles

    ERIC Educational Resources Information Center

    Swenson, Carl E.; Yandl, Andre L.

    2012-01-01

    Inside any Pythagorean right triangle, it is possible to find a point M so that drawing segments from M to each vertex of the triangle yields angles whose sines and cosines are all rational. This article describes an algorithm that generates an infinite number of such points.

  4. Partitioning Pythagorean Triangles Using Pythagorean Angles

    ERIC Educational Resources Information Center

    Swenson, Carl E.; Yandl, Andre L.

    2012-01-01

    Inside any Pythagorean right triangle, it is possible to find a point M so that drawing segments from M to each vertex of the triangle yields angles whose sines and cosines are all rational. This article describes an algorithm that generates an infinite number of such points.

  5. Raised-angle discrimination under passive finger movement.

    PubMed

    Wu, Jinglong; Yang, Jiajia; Ogasa, Takashi

    2010-01-01

    The characteristics of raised-line drawing discrimination can be defined as the sum of the discriminability of the length, curvature, and angles of the edges. The size of the angle between two edges constitutes an important feature of these tactile stimuli. In the first experiment, five standard angles (30 degrees, 60 degrees, 90 degrees, 120 degrees, and 150 degrees) and twenty comparison angles for each standard angle were used to investigate the human capacity for tactile discrimination of raised angles by passive finger movement. The subjects in this study were asked to identify the larger angle of each pair by passive finger movement. We found that the threshold doubled when the standard angle was increased from 30 degrees to 90 degrees; however, the threshold remained unchanged when the standard angle was greater than 90 degrees. In the second experiment, to investigate the influence of the endpoints on angle discriminability, we used one standard angle (60 degrees) and seven comparison angles that changed in four bisector orientations. The results indicate that cutaneous feedback from the local apex and endpoints of the angle contributed to the discrimination of acute angles. Taken together, these results suggest that, when an acute angle is presented, both local apex and endpoint informations are used, while cutaneous mechanoreceptors rely more on apex information to discriminate the angle size when an obtuse angle is presented.

  6. Compression failure of angle-ply laminates

    NASA Technical Reports Server (NTRS)

    Peel, Larry D.; Hyer, Michael W.; Shuart, Mark J.

    1991-01-01

    The present work deals with modes and mechanisms of failure in compression of angle-ply laminates. Experimental results were obtained from 42 angle-ply IM7/8551-7a specimens with a lay-up of ((plus or minus theta)/(plus or minus theta)) sub 6s where theta, the off-axis angle, ranged from 0 degrees to 90 degrees. The results showed four failure modes, these modes being a function of off-axis angle. Failure modes include fiber compression, inplane transverse tension, inplane shear, and inplane transverse compression. Excessive interlaminar shear strain was also considered as an important mode of failure. At low off-axis angles, experimentally observed values were considerably lower than published strengths. It was determined that laminate imperfections in the form of layer waviness could be a major factor in reducing compression strength. Previously developed linear buckling and geometrically nonlinear theories were used, with modifications and enhancements, to examine the influence of layer waviness on compression response. The wavy layer is described by a wave amplitude and a wave length. Linear elastic stress-strain response is assumed. The geometrically nonlinear theory, in conjunction with the maximum stress failure criterion, was used to predict compression failure and failure modes for the angle-ply laminates. A range of wave length and amplitudes were used. It was found that for 0 less than or equal to theta less than or equal to 15 degrees failure was most likely due to fiber compression. For 15 degrees less than theta less than or equal to 35 degrees, failure was most likely due to inplane transverse tension. For 35 degrees less than theta less than or equal to 70 degrees, failure was most likely due to inplane shear. For theta less than 70 degrees, failure was most likely due to inplane transverse compression. The fiber compression and transverse tension failure modes depended more heavily on wave length than on wave amplitude. Thus using a single

  7. Probe Without Moving Parts Measures Flow Angle

    NASA Technical Reports Server (NTRS)

    Corda, Stephen; Vachon, M. Jake

    2003-01-01

    The measurement of local flow angle is critical in many fluid-dynamic applications, including the aerodynamic flight testing of new aircraft and flight systems. Flight researchers at NASA Dryden Flight Research Center have recently developed, flight-tested, and patented the force-based flow-angle probe (FLAP), a novel, force-based instrument for the measurement of local flow direction. Containing no moving parts, the FLAP may provide greater simplicity, improved accuracy, and increased measurement access, relative to conventional moving vane-type flow-angle probes. Forces in the FLAP can be measured by various techniques, including those that involve conventional strain gauges (based on electrical resistance) and those that involve more advanced strain gauges (based on optical fibers). A correlation is used to convert force-measurement data to the local flow angle. The use of fiber optics will enable the construction of a miniature FLAP, leading to the possibility of flow measurement in very small or confined regions. This may also enable the tufting of a surface with miniature FLAPs, capable of quantitative flow-angle measurements, similar to attaching yarn tufts for qualitative measurements. The prototype FLAP was a small, aerodynamically shaped, low-aspect-ratio fin about 2 in. (approximately equal to 5 cm) long, 1 in. (approximately equal to 2.5 cm) wide, and 0.125 in. (approximately equal to 0.3 cm) thick (see Figure 1). The prototype FLAP included simple electrical-resistance strain gauges for measuring forces. Four strain gauges were mounted on the FLAP; two on the upper surface and two on the lower surface. The gauges were connected to form a full Wheatstone bridge, configured as a bending bridge. In preparation for a flight test, the prototype FLAP was mounted on the airdata boom of a flight-test fixture (FTF) on the NASA Dryden F-15B flight research airplane.

  8. Optimal Number of Angle Images for Calculating Anterior Angle Volume and Iris Volume Measurements

    PubMed Central

    Blieden, Lauren S.; Chuang, Alice Z.; Baker, Laura A.; Bell, Nicholas P.; Fuller, Timothy S.; Mankiewicz, Kimberly A.; Feldman, Robert M.

    2015-01-01

    Purpose. We determined the optimal number of angle images required to obtain reliable measurements of trabecular-iris circumferential volume (TICV) and iris volume (IV) using swept-source Fourier domain anterior segment optical coherence tomography (SSFD-ASOCT) scans in narrow angle eyes. Methods. Scleral spur landmarks (SSL) were manually identified on ASOCT angle images from 128 meridians from each of 24 eyes with chronic primary angle closure (PAC) spectrum of disease. The anterior and posterior corneal curves, and the anterior and posterior iris surfaces were identified automatically by the anterior chamber analysis and interpretation (ACAI) software, then manually examined and edited by the reader if required. Trabecular-iris circumferential volume at 750 μm from SSL (TICV750) and IV were subsequently calculated using varying numbers of angle images. Threshold error was determined to be less than the lower 95% confidence limit of mean absolute percent error (MAPE) of the change in TICV or IV resulting from laser peripheral iridotomy, which would be 17% for TICV and 5% for IV, based on previous studies. The optimal number of angle images was the smallest number of images where MAPE was less than this threshold for TICV and IV. Results. A total of 32 equally-spaced angle images (16 meridians) was required to estimate TICV750 and 16 angle images (8 meridians) to estimate IV. Both were within 4.6% and 1.6% of MAPE, respectively. Conclusions. It is possible to determine TICV and IV parameters reliably in narrow angles without evaluating all 128 meridians obtained with SSFD-ASOCT. PMID:25829412

  9. The Pluto System At Small Phase Angles

    NASA Astrophysics Data System (ADS)

    Verbiscer, Anne J.; Buie, Marc W.; Binzel, Richard; Ennico, Kimberly; Grundy, William M.; Olkin, Catherine B.; Showalter, Mark Robert; Spencer, John R.; Stern, S. Alan; Weaver, Harold A.; Young, Leslie; New Horizons Science Team

    2016-10-01

    Hubble Space Telescope observations of the Pluto system acquired during the New Horizons encounter epoch (HST Program 13667, M. Buie, PI) span the phase angle range from 0.06 to 1.7 degrees, enabling the measurement and characterization of the opposition effect for Pluto and its satellites at 0.58 microns using HST WFC3/UVIS with the F350LP filter, which has a broadband response and a pivot wavelength of 0.58 microns. At these small phase angles, differences in the opposition effect width and amplitude appear. The small satellites Nix and Hydra both exhibit a very narrow opposition surge, while the considerably larger moon Charon has a broader opposition surge. Microtextural surface properties derived from the shape and magnitude of the opposition surge of each surface contain a record of the collisional history of the system. We combine these small phase angle observations with those made at larger phase angles by the New Horizons Long Range Reconnaissance Imager (LORRI), which also has a broadband response with a pivot wavelength of 0.61 microns, to produce the most complete disk-integrated solar phase curves that we will have for decades to come. Modeling these disk-integrated phase curves generates sets of photometric parameters that will inform spectral modeling of the satellite surfaces as well as terrains on Pluto from spatially resolved New Horizons Ralph Linear Etalon Imaging Spectral Array (LEISA) data from 1.2 to 2.5 microns. Rotationally resolved phase curves of Pluto reveal opposition effects that only appear at phase angles less than 0.1 degree and have widths and amplitudes that are highly dependent on longitude and therefore on Pluto's diverse terrains. The high albedo region informally known as Sputnik Planum dominates the disk-integrated reflectance of Pluto on the New Horizons encounter hemisphere. These results lay the groundwork for observations at true opposition in 2018, when the Pluto system will be observable at phase angles so small that

  10. On some relations between advancing, receding and Young's contact angles.

    PubMed

    Chibowski, Emil

    2007-05-31

    Problems of experimental determination and theoretical verification of equilibrium contact angles are discussed basing on the literature data. A relationship between the advancing and receding contact angles versus the equilibrium contact angle is described and then verified using the literature contact angles determined on paraffin wax and polypropylene. Using the proposed relationship and experimentally determined equilibrium contact angles, obtained by plotting the advancing and receding contact angles versus the contact angle hysteresis or by applying vibration of the system liquid drop/solid surface, it is found that the same value of the surface free energy for paraffin wax is calculated from the contact angles of water and ethylene glycol. However, in the case of polypropylene some inconsistency appears between the equilibrium contact angles of the probe liquid used and the calculated surface free energy. More experimental data of the equilibrium contact angle are needed to verify further the relationship.

  11. Shuttle Program. Euler angles, quaternions, and transformation matrices working relationships

    NASA Technical Reports Server (NTRS)

    Henderson, D. M.

    1977-01-01

    A brief mathematical development of the relationship between the Euler angles and the transformation matrix, the quaternion and the transformation matrix, and the Euler angles and the quaternion is presented. The analysis and equations presented apply directly to current space shuttle problems. The twelve three-axis Euler transformation matrices are given as functions of the Euler angles, the equations for the quaternion as a funtion of the Euler angles, and the Euler angles as a function of the transformation matrix elements.

  12. Contact angle and contact angle hysteresis measurements using the capillary bridge technique.

    PubMed

    Restagno, Frédéric; Poulard, Christophe; Cohen, Céline; Vagharchakian, Laurianne; Léger, Liliane

    2009-09-15

    A new experimental technique is proposed to easily measure both advancing and receding contact angles of a liquid on a solid surface, with unprecedented accuracy. The technique is based on the analysis of the evolution of a capillary bridge formed between a liquid bath and a solid surface (which needs to be spherical) when the distance between the surface and the liquid bath is slowly varied. The feasibility of the technique is demonstrated using a low-energy perfluorinated surface with two different test liquids (water and hexadecane). A detailed description of both experimental procedures and computational modeling are given, allowing one to determine contact angle values. It is shown that the origin of the high accuracy of this technique relies on the fact that the contact angles are automatically averaged over the whole periphery of the contact. This method appears to be particularly adapted to the characterization of surfaces with very low contact angle hysteresis.

  13. The angle detecting inclined sensors (ADIS) systemmeasuring particle angles of incidence without position sensing detectors

    NASA Astrophysics Data System (ADS)

    Connell, J. J.; Lopate, C.; McKibben, R. B.

    2001-01-01

    We report on a novel system, the Angle Detecting Inclined Sensors (ADIS), for determining the angle of incidence of energetic charged particles. This system is particularly suited to space-based and balloon-borne instruments to study Solar Energetic Particles, Galactic Cosmic Rays and Anomalous Cosmic Rays. Such instruments are frequently constrained by limited resources in terms of mass, power and telemetry. At the same time, large detector area and acceptance angle, together with good elemental and isotopic resolution, can be critical for the required measurements. High-resolution particle identification requires that the angles of incidence of ion events in an instrument be determined. Conventional Position Sensing Detectors (PSDs) used in hodoscopes add significant complexity and require additional electronics, thus increasing instrument mass and power usage. The ADIS system overcomes many of these problems by using detector geometry in place of PSDs.

  14. Gaia: focus, straylight and basic angle

    NASA Astrophysics Data System (ADS)

    Mora, A.; Biermann, M.; Bombrun, A.; Boyadjian, J.; Chassat, F.; Corberand, P.; Davidson, M.; Doyle, D.; Escolar, D.; Gielesen, W. L. M.; Guilpain, T.; Hernandez, J.; Kirschner, V.; Klioner, S. A.; Koeck, C.; Laine, B.; Lindegren, L.; Serpell, E.; Tatry, P.; Thoral, P.

    2016-07-01

    The Gaia all-sky astrometric survey is challenged by several issues affecting the spacecraft stability. Amongst them, we find the focus evolution, straylight and basic angle variations Contrary to pre-launch expectations, the image quality is continuously evolving, during commissioning and the nominal mission. Payload decontaminations and wavefront sensor assisted refocuses have been carried out to recover optimum performance. An ESA-Airbus DS working group analysed the straylight and basic angle issues and worked on a detailed root cause analysis. In parallel, the Gaia scientists have also analysed the data, most notably comparing the BAM signal to global astrometric solutions, with remarkable agreement. In this contribution, a status review of these issues will be provided, with emphasis on the mitigation schemes and the lessons learned for future space missions where extreme stability is a key requirement.

  15. Dancing droplets: Contact angle, drag, and confinement

    NASA Astrophysics Data System (ADS)

    Benusiglio, Adrien; Cira, Nate; Prakash, Manu

    2015-11-01

    When deposited on a clean glass slide, a mixture of water and propylene glycol forms a droplet of given contact angle, when both pure liquids spread. (Cira, Benusiglio, Prakash: Nature, 2015). The droplet is stabilized by a gradient of surface tension due to evaporation that induces a Marangoni flow from the border to the apex of the droplets. The apparent contact angle of the droplets depends on both their composition and the external humidity as captured by simple models. These droplets present remarkable properties such as lack of a large pinning force. We discuss the drag on these droplets as a function of various parameters. We show theoretical and experimental results of how various confinement geometries change the vapor gradient and the dynamics of droplet attraction.

  16. Linkage studies in primary open angle glaucoma

    SciTech Connect

    Avramopoulos, D.; Grigoriadu, M.; Kitsos, G.

    1994-09-01

    Glaucoma is a leading cause of blindness worldwide. The majority of glaucoma is associated with an open, normal appearing anterior chamber angle and is termed primary open angle glaucoma (POAG, MIM 137760). It is characterized by elevated intraocular pressure and onset in middle age or later. A subset of POAG with juvenile onset has recently been linked to chromosome 1q in two families with autosomal dominant inheritance. Eleven pedigrees with autosomal dominant POG (non-juvenile-onset) have been identified in Epirus, Greece. In the present study DNA samples have been collected from 50 individuals from one large pedigree, including 12 affected individuals. Preliminary results of linkage analysis with chromosome 1 microsatellites using the computer program package LINKAGE Version 5.1 showed no linkage with the markers previously linked to juvenile-onset POAG. Further linkage analysis is being pursued, and the results will be presented.

  17. The conventions for the polarization angle

    NASA Astrophysics Data System (ADS)

    Serego Alighieri, Sperello di

    2017-02-01

    Since more than a century astronomers measure the position angle of the major axis of the polarization ellipse starting from the North direction and increasing counter-clockwise, when looking at the source. This convention has been enforced by the IAU with a Resolution in 1973. Much later the WMAP satellite, which has observed the polarization of the cosmic microwave background, has unfortunately adopted the opposite convention: the polarization position angle is measured starting from the South and increasing clockwise, when looking at the source. This opposite convention has been followed by most cosmic microwave background polarization experiments and is causing obvious problems and misunderstandings. The attempts and prospects to enforce the official IAU convention are described.

  18. The conventions for the polarization angle

    NASA Astrophysics Data System (ADS)

    de Serego Alighieri, Sperello

    2017-02-01

    Since more than a century astronomers measure the position angle of the major axis of the polarization ellipse starting from the North direction and increasing counter-clockwise, when looking at the source. This convention has been enforced by the IAU with a Resolution in 1973. Much later the WMAP satellite, which has observed the polarization of the cosmic microwave background, has unfortunately adopted the opposite convention: the polarization position angle is measured starting from the South and increasing clockwise, when looking at the source. This opposite convention has been followed by most cosmic microwave background polarization experiments and is causing obvious problems and misunderstandings. The attempts and prospects to enforce the official IAU convention are described.

  19. Picoliter water contact angle measurement on polymers.

    PubMed

    Taylor, Michael; Urquhart, Andrew J; Zelzer, Mischa; Davies, Martyn C; Alexander, Morgan R

    2007-06-19

    Water contact angle measurement is the most common method for determining a material's wettability, and the sessile drop approach is the most frequently used. However, the method is generally limited to macroscopic measurements because the base diameter of the droplet is usually greater than 1 mm. Here we report for the first time on a dosing system to dispense smaller individual droplets with control of the position and investigate whether water contact angles determined from picoliter volume water droplets are comparable with those obtained from the conventional microliter volume water droplets. This investigation was conducted on a group of commonly used polymers. To demonstrate the higher spatial resolution of wettability that can be achieved using picoliter volume water droplets, the wettability of a radial plasma polymer gradient was mapped using a 250 microm interval grid.

  20. Anisotropy angle of the DST-emissions

    NASA Astrophysics Data System (ADS)

    Cardone, F.; Duro, S.

    2014-07-01

    In our previous experiments, it has been found that an angle of asymmetry is present when the breakdown of the Lorenz invariance occurs. We want to make sure that this angle is present as a preferred direction of emission for α-rays and neutrons emitted as a result of piezonuclear reactions, or better, the reactions in deformed spacetime (DST-reactions: deformed spacetime reactions, for more details on the DST-reactions [see G. Albertini et al., Material and Process for Energy, ed. A. Mendez-Vilas (Formatex, 2013)]. For this purpose, we analyze the experiment of Ancona for α-ray emission and the experiment of Cagliari for neutrons emission. In this work, we present an example for each group of experiments. These experimental examples are significant because they show the behavior of the emissions detected in all the measures.

  1. Determination of Laser Tracker Angle Encoder Errors

    NASA Astrophysics Data System (ADS)

    Nasr, Karim M.; Hughes, Ben; Forbes, Alistair; Lewis, Andrew

    2014-08-01

    Errors in the angle encoders of a laser tracker may potentially produce large errors in long range coordinate measurements. To determine the azimuth angle encoder errors and verify their values stored in the tracker's internal error map, several methodologies were evaluated, differing in complexity, measurement time and the need for specialised measuring equipment. These methodologies are: an artefact-based technique developed by NIST; a multi-target network technique developed by NPL; and the classical precision angular indexing table technique. It is shown that the three methodologies agree within their respective measurement uncertainties and that the NPL technique has the advantages of a short measurement time and no reliance on specialised measurement equipment or artefacts.

  2. An approach to standing phase angle reduction

    SciTech Connect

    Wunderlich, S.; Fischl, R.; Nwankpa, C.O. ); Adibi, M.M. )

    1994-02-01

    This paper is part of a series presented on behalf of the System Restoration Subcommittee with the intent of focusing industry attention on power system restoration. The presence of excessive standing phase angle (SPA) differences across open circuit breakers causes significant delays in power system restoration. These angles may occur across a tie line between two systems or between two connected subsystems within a system. They must be within SPA limits before an attempt is made to close breakers to firm up the bulk power transmission system. There has been a need for an efficient methodology to serve as a guideline for reducing excessive SPA differences to allowable limits, without resorting to the raising and lowering of various generation levels on a trial and error basis. This paper describes such a methodology.

  3. Fan Stagger Angle for Dirt Rejection

    NASA Technical Reports Server (NTRS)

    Gallagher, Edward J. (Inventor); Rose, Becky E. (Inventor); Brilliant, Lisa I. (Inventor)

    2015-01-01

    A gas turbine engine includes a spool, a turbine coupled to drive the spool, a propulsor coupled to be rotated about an axis by the turbine through the spool, and a gear assembly coupled between the propulsor and the spool such that rotation of the turbine drives the propulsor at a different speed than the spool. The propulsor includes a hub and a row of propulsor blades that extend from the hub. Each of the propulsor blades has a span between a root at the hub and a tip, and a chord between a leading edge and a trailing edge. The chord forms a stagger angle alpha with the axis, and the stagger angle alpha is less than 15 deg. at a position along the propulsor blade that is within an inboard 20% of the span.

  4. Wide angle zoom for the Space Shuttle

    NASA Astrophysics Data System (ADS)

    Angenieux, J.; Debize, J.; Masson, A.

    1983-01-01

    In order to pilot and visually monitor the Canadarm operating on the Shuttle, a zoom lens with a minimum wide angle of 98 deg field of view was needed. The design of the chosen solution is presented. There are 22 lenses arranged in 4 groups allowing mechanical compensation. The range of focal lengths is 8.2 to 25 mm; the aperture is f/3.6. The weight is 1.6 kilos.

  5. Example of Weathering And Sun Angle

    NASA Image and Video Library

    1996-12-12

    The letter 'B' or perhaps the figure '8' appears to have been etched into the Mars rock at the left edge of this picture taken yesterday by NASA's Viking 1 Lander. It is believed to be an illusion caused by weathering processes and the angle of the sun as it illuminated the scene for the spacecraft camera. The object at lower left is the housing containing the surface sampler scoop. http://photojournal.jpl.nasa.gov/catalog/PIA00386

  6. Measurement of the angle alpha at BABAR

    SciTech Connect

    Perez, A.; /Orsay, LAL

    2009-06-25

    The authors present recent measurements of the CKM angle {alpha} using data collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory, operating at the {Upsilon}(4S) resonance. They present constraints on {alpha} from B {yields} {pi}{pi}, B {yields} {rho}{rho} and B {yields} {rho}{pi} decays.

  7. Black hole microstates from branes at angle

    NASA Astrophysics Data System (ADS)

    Pieri, Lorenzo

    2017-07-01

    We derive the leading g s perturbation of the SUGRA fields generated by a supersymmetric configuration of respectively 1, 2 or 4 D3-branes intersecting at an arbitrary angle via the computation of the string theory disk scattering amplitude of one massless NSNS field interacting with open strings stretched between the branes. The configuration with four branes is expected to be relevant for black hole microstate counting in four dimensions.

  8. Wireless Orbiter Hang-Angle Inclinometer System

    NASA Technical Reports Server (NTRS)

    Lucena, Angel; Perotti, Jose; Green, Eric; Byon, Jonathan; Burns, Bradley; Mata, Carlos; Randazzo, John; Blalock, Norman

    2011-01-01

    A document describes a system to reliably gather the hang-angle inclination of the orbiter. The system comprises a wireless handheld master station (which contains the main station software) and a wireless remote station (which contains the inclinometer sensors, the RF transceivers, and the remote station software). The remote station is designed to provide redundancy to the system. It includes two RF transceivers, two power-management boards, and four inclinometer sensors.

  9. Neutron Reflectivity and Grazing Angle Diffraction

    PubMed Central

    Ankner, J. F.; Majkrzak, C. F.; Satija, S. K.

    1993-01-01

    Over the last 10 years, neutron reflectivity has emerged as a powerful technique for the investigation of surface and interfacial phenomena in many different fields. In this paper, a short review of some of the work on neutron reflectivity and grazing-angle diffraction as well as a description of the current and planned neutron rcflectometers at NIST is presented. Specific examples of the characterization of magnetic, superconducting, and polymeric surfaces and interfaces are included. PMID:28053457

  10. Small-Angle Scattering on Magnetoferritin Nanoparticles

    NASA Astrophysics Data System (ADS)

    Balejčíková Petrenko, L., VI; Avdeev, MV; Garamus, VM; Almásy, L.; Kopčanský, P.

    2017-05-01

    Magnetoferritin is a synthetically prepared magnetic bio-complex, consisting of apoferritin shell and iron-based nanoparticles. Superparamagnetic behaviour, nanoscale size (about 12 nm) and biological origin allow to use magnetoferritin in various applications. In this report, we present a general overview about basic physicochemical properties of magnetoferritin, as determined by small-angle X-ray and neutron scattering experiments and some interesting references on their potential bio-applications.

  11. Contact angle hysteresis at the nanometer scale.

    PubMed

    Delmas, Mathieu; Monthioux, Marc; Ondarçuhu, Thierry

    2011-04-01

    Using atomic force microscopy with nonconventional carbon tips, the pinning of a liquid contact line on individual nanometric defects was studied. This mechanism is responsible for the occurrence of the contact angle hysteresis. The presence of weak defects which do not contribute to the hysteresis is evidenced for the first time. The dissipated energy associated with strong defects is also measured down to values in the range of kT, which correspond to defect sizes in the order of 1 nm.

  12. Lightweight Right-Angle Valve For Cryogenics

    NASA Technical Reports Server (NTRS)

    Calhoun, Richard B.

    1993-01-01

    Lightweight right-angle valve isolates pressurized liquid or gas stream from vacuum over wide range of temperatures from ambient down to cryogenic. Sized to fit tubes of types ordinarily used in cryogenic equipment. Maintains isolation, without need for manual adjustment of packing gland as pressure and temperature vary. Mass of valve less than 60 grams. Made of off-the-shelf parts and few simple custom-machined parts.

  13. Drug-induced Angle-Closure Glaucoma

    PubMed Central

    Khurana, Aruj K; Khurana, Bhawna

    2012-01-01

    Drug-induced angle-closure glaucoma is an important entity for the ophthalmologist as well as the general physician as it represents a preventable cause of potential blindness. This brief review highlights the fact that a high index of suspicion, in a susceptible individual followed by confirmation on appropriate imaging modality (UBM, ultrasound or anterior segment OCT) can alleviate the threat to sight and also help to institute appropriate therapy. PMID:27990064

  14. [Morphologic aspects of angle grinder injury].

    PubMed

    Thurner, W; Pollak, S

    1989-01-01

    Experiments were conducted on soft-tissue and bone preparations to determine the morphological characteristics of angle grinder injuries. The grinding effect of the rotating cutting-off wheel causes severances with local loss of tissue, resulting in tool-specific wound features. Superficial skin notches and (incomplete) severances of bony structures are of particular significance. Mutual trace transfer is a valuable means for determining the tool used and for interpreting the scene.

  15. On accurate determination of contact angle

    NASA Technical Reports Server (NTRS)

    Concus, P.; Finn, R.

    1992-01-01

    Methods are proposed that exploit a microgravity environment to obtain highly accurate measurement of contact angle. These methods, which are based on our earlier mathematical results, do not require detailed measurement of a liquid free-surface, as they incorporate discontinuous or nearly-discontinuous behavior of the liquid bulk in certain container geometries. Physical testing is planned in the forthcoming IML-2 space flight and in related preparatory ground-based experiments.

  16. Tool Indicates Contact Angles In Bearing Raceways

    NASA Technical Reports Server (NTRS)

    Akian, Richard A.; Butner, Myles F.

    1995-01-01

    Tool devised for use in measuring contact angles between balls and races in previously operated ball bearings. Used on both inner and outer raceways of bearings having cross-sectional widths between approximately 0.5 and 2.0 in. Consists of integral protractor mounted in vertical plane on bracket equipped with leveling screws and circular level indicator. Protractor includes rotatable indicator needle and set of disks of various sizes to fit various raceway curvatures.

  17. Relationships Between Lower Extremity Alignment and the Quadriceps Angle

    PubMed Central

    Nguyen, Anh-Dung; Boling, Michelle C.; Levine, Beverly; Shultz, Sandra J.

    2010-01-01

    Objective To determine the extent to which select lower extremity alignment characteristics of the pelvis, hip, knee, and foot are related to the Q angle. Design Descriptive cohort study design. Setting Applied Neuromechanics Research Laboratory. Participants Two hundred eighteen participants (102 males, 116 females). Assessment of Risk Factors Eight clinical measures of static alignment of the left lower extremity were measured by a single examiner to determine the impact of lower extremity alignment on the magnitude of Q angle. Main Outcome Measures Q angle, pelvic angle, hip anteversion, tibiofemoral angle, genu recurvatum, tibial torsion, navicular drop, and femur and tibia length. Results Once all alignment variables were accounted for, greater tibiofemoral angle and femoral anteversion were significant predictors of greater Q angle in both males and females. Pelvic angle, genu recurvatum, tibial torsion, navicular drop, and femur to tibia length ratio were not significant independent predictors of Q angle in males or females. Conclusions Greater femoral anteversion and tibiofemoral angle result in greater Q angle, with changes in tibiofemoral angle having a substantially greater impact on the magnitude of the Q angle compared with femoral anteversion. As such, the Q angle seems to largely represent a frontal plane alignment measure. As many knee injuries seem to result from a combination of both frontal and transverse plane motions and forces, this may in part explain why Q angle has been found to be a poor independent predictor of lower extremity injury risk. PMID:19423972

  18. Repellency of the lotus leaf: contact angles, drop retention, and sliding angles.

    PubMed

    Extrand, C W; Moon, Sung In

    2014-07-29

    Much of the modeling done on repellency and super hydrophobicity has focused on surfaces with rectilinear geometries, but their wetting behavior is simpler and can be quite different from that of repellent surfaces with curved features. In this study, we model the contact angles and sliding angles exhibited by the lotus leaf, accounting for the influence of curvature and pinning. Our estimates agree reasonably well with experimental observations.

  19. Robust angle-independent blood velocity estimation based on dual-angle plane wave imaging.

    PubMed

    Fadnes, Solveig; Ekroll, Ingvild Kinn; Nyrnes, Siri Ann; Torp, Hans; Lovstakken, Lasse

    2015-10-01

    Two-dimensional blood velocity estimation has shown potential to solve the angle-dependency of conventional ultrasound flow imaging. Clutter filtering, however, remains a major challenge for large beam-to-flow angles, leading to signal drop-outs and corrupted velocity estimates. This work presents and evaluates a compounding speckle tracking (ST) algorithm to obtain robust angle-independent 2-D blood velocity estimates for all beam-to-flow angles. A dual-angle plane wave imaging setup with full parallel receive beamforming is utilized to achieve high-frame-rate speckle tracking estimates from two scan angles, which may be compounded to obtain velocity estimates of increased robustness. The acquisition also allows direct comparison with vector Doppler (VD) imaging. Absolute velocity bias and root-mean-square (RMS) error of the compounding ST estimations were investigated using simulations of a rotating flow phantom with low velocities ranging from 0 to 20 cm/s. In a challenging region where the estimates were influenced by clutter filtering, the bias and RMS error for the compounding ST estimates were 11% and 2 cm/s, a significant reduction compared with conventional single-angle ST (22% and 4 cm/s) and VD (36% and 6 cm/s). The method was also tested in vivo for vascular and neonatal cardiac imaging. In a carotid artery bifurcation, the obtained blood velocity estimates showed that the compounded ST method was less influenced by clutter filtering than conventional ST and VD methods. In the cardiac case, it was observed that ST velocity estimation is more affected by low signal-to-noise (SNR) than VD. However, with sufficient SNR the in vivo results indicated that a more robust angle-independent blood velocity estimator is obtained using compounded speckle tracking compared with conventional ST and VD methods.

  20. Angles-Let's treat them squarely

    NASA Astrophysics Data System (ADS)

    Brownstein, K. R.

    1997-07-01

    We suggest a self-consistent treatment of the dimensions and units of the geometric quantity "angle." The method regards "angle" as a fundamental dimensional physical quantity, on a par with length, mass, time, etc. All units (whether angular or otherwise) are treated on an equal footing and balance out correctly; in particular, "radian" units need never be spuriously inserted or deleted. The method could find application in algebraic and calculus symbolic manipulation computer programs to correctly process units of physical quantities. The technique necessitates a minor modification of the relation "s=Rθ" and its consequences, rather than any modification of the units of other physical quantities (such as moment arms) as previously suggested by others. We make several important clarifying distinctions: (a) ω [SI: radṡs-1] for rotational motion (as in θ=ωt) versus Ω [SI: s-1] for simple harmonic motion [as in x=xm cos(Ωt)], (b) geometric trigonometric functions whose arguments are angles [SI: rad] versus mathematical trigonometric functions whose arguments are pure numbers, (c) simple harmonic motion versus uniform circular motion in the reference circle analogy.

  1. Association between hypodontia and Angles malocclusion.

    PubMed

    Ali, Batool; Hussain, Syed Sheeraz

    2016-10-01

    This study was planned to determine the prevalence of hypodontia in permanent dentition and to test whether an association was present between hypodontia and Angle's malocclusion. The retrospective study was conducted at a tertiary care hospital, Karachi, and comprised record of all patients visiting the orthodontic clinics of the hospital from 2005 to 2015. Orthodontic records of 790(79%) subjects, including 189(23.9%) males and 601(76.1%) females, were reviewed. Their mean age was 17 ± 5.06 years. A tooth was considered missing if no evidence of tooth germ was observed on orthopantomograms and dental casts. The total sample was distributed into three groups on the basis of Angle's classification. Chi-square test was applied to determine an association between hypodontia and Angle's malocclusion. Tooth agenesis was observed in 34(4.3%) and a statistically significant difference was found between the genders (p=0.005). A positive association was found between hypodontia and malocclusion groups. Higher frequency of missing teeth was seen in Class III malocclusion which indicates a great need for orthodontic treatment as it has a psychosocial impact on the quality of life.

  2. Head flexion angle while using a smartphone.

    PubMed

    Lee, Sojeong; Kang, Hwayeong; Shin, Gwanseob

    2015-01-01

    Repetitive or prolonged head flexion posture while using a smartphone is known as one of risk factors for pain symptoms in the neck. To quantitatively assess the amount and range of head flexion of smartphone users, head forward flexion angle was measured from 18 participants when they were conducing three common smartphone tasks (text messaging, web browsing, video watching) while sitting and standing in a laboratory setting. It was found that participants maintained head flexion of 33-45° (50th percentile angle) from vertical when using the smartphone. The head flexion angle was significantly larger (p < 0.05) for text messaging than for the other tasks, and significantly larger while sitting than while standing. Study results suggest that text messaging, which is one of the most frequently used app categories of smartphone, could be a main contributing factor to the occurrence of neck pain of heavy smartphone users. Practitioner Summary: In this laboratory study, the severity of head flexion of smartphone users was quantitatively evaluated when conducting text messaging, web browsing and video watching while sitting and standing. Study results indicate that text messaging while sitting caused the largest head flexion than that of other task conditions.

  3. Large Spin Hall Angle in Vanadium Film

    NASA Astrophysics Data System (ADS)

    Wang, Tao; Fan, Xin; Wang, Wenrui; Xie, Yunsong; Warsi, Muhammad A.; Wu, Jun; Chen, Yunpeng; Lorenz, Virginia O.; Xiao, John Q.

    We report the large spin Hall angle observed in Vanadium film with small grain size and distorted lattice parameter. The spin Hall angle is quantified by measuring current-induced spin-orbit torque in V/CoFeB bilayer using optical spin torque magnetometer based on polar magneto-optical Kerr effect (MOKE). The spin Hall angle as large as θSH = -0.071 has been observed in V/CoFeB bilayer Structural analysis, using X-ray diffraction (XRD), transmission electron microscopy (TEM) and selected area electron diffraction (SAED), confirms films grown at room temperature have very small grain size and enlarged lattice parameter. The Vanadium films with distorted crystal structure also have high resistivity (>200 μΩ cm) and long spin diffusion length (~16.3 nm) measured via spin pumping experiment. This finding of spin Hall effect enhancement in more disordered structure will provide insights for understanding and exploiting materials with strong spin orbit interaction, especially in light 3d transition metals which promise long spin diffusion length.

  4. Off-Angle Iris Correction Methods

    SciTech Connect

    Santos-Villalobos, Hector J; Thompson, Joseph T; Karakaya, Mahmut; Boehnen, Chris Bensing

    2016-01-01

    In many real world iris recognition systems obtaining consistent frontal images is problematic do to inexperienced or uncooperative users, untrained operators, or distracting environments. As a result many collected images are unusable by modern iris matchers. In this chapter we present four methods for correcting off-angle iris images to appear frontal which makes them compatible with existing iris matchers. The methods include an affine correction, a retraced model of the human eye, measured displacements, and a genetic algorithm optimized correction. The affine correction represents a simple way to create an iris image that appears frontal but it does not account for refractive distortions of the cornea. The other method account for refraction. The retraced model simulates the optical properties of the cornea. The other two methods are data driven. The first uses optical flow to measure the displacements of the iris texture when compared to frontal images of the same subject. The second uses a genetic algorithm to learn a mapping that optimizes the Hamming Distance scores between off-angle and frontal images. In this paper we hypothesize that the biological model presented in our earlier work does not adequately account for all variations in eye anatomy and therefore the two data-driven approaches should yield better performance. Results are presented using the commercial VeriEye matcher that show that the genetic algorithm method clearly improves over prior work and makes iris recognition possible up to 50 degrees off-angle.

  5. Small Angle X-Ray Scattering Detector

    DOEpatents

    Hessler, Jan P.

    2004-06-15

    A detector for time-resolved small-angle x-ray scattering includes a nearly constant diameter, evacuated linear tube having an end plate detector with a first fluorescent screen and concentric rings of first fiber optic bundles for low angle scattering detection and an annular detector having a second fluorescent screen and second fiber optic bundles concentrically disposed about the tube for higher angle scattering detection. With the scattering source, i.e., the specimen under investigation, located outside of the evacuated tube on the tube's longitudinal axis, scattered x-rays are detected by the fiber optic bundles, to each of which is coupled a respective photodetector, to provide a measurement resolution, i.e., dq/q, where q is the momentum transferred from an incident x-ray to an x-ray scattering specimen, of 2% over two (2) orders of magnitude in reciprocal space, i.e., q.sub.max /q.sub.min.congruent.100.

  6. Angle sensitive single photon avalanche diode

    SciTech Connect

    Lee, Changhyuk Johnson, Ben Molnar, Alyosha

    2015-06-08

    An ideal light sensor would provide exact information on intensity, timing, location, and angle of incoming photons. Single photon avalanche diodes (SPADs) provide such desired high (single photon) sensitivity with precise time information and can be implemented at a pixel-scale to form an array to extract spatial information. Furthermore, recent work has demonstrated photodiode-based structures (combined with micro-lenses or diffraction gratings) that are capable of encoding both spatial and angular information of incident light. In this letter, we describe the implementation of such a grating structure on SPADs to realize a pixel-scale angle-sensitive single photon avalanche diode (A-SPAD) built in a standard CMOS process. While the underlying SPAD structure provides high sensitivity, the time information of the two layers of diffraction gratings above offers angle-sensitivity. Such a unique combination of SPAD and diffraction gratings expands the sensing dimensions to pave a path towards lens-less 3-D imaging and light-field time-of-flight imaging.

  7. Constitutive modeling of contact angle hysteresis.

    PubMed

    Vedantam, Srikanth; Panchagnula, Mahesh V

    2008-05-15

    We introduce a phase field model of wetting of surfaces by sessile drops. The theory uses a two-dimensional non-conserved phase field variable to parametrize the Gibbs free energy of the three-dimensional system. Contact line tension and contact angle hysteresis arise from the gradient term in the free energy and the kinetic coefficient respectively. A significant advantage of this approach is in the constitutive specification of hysteresis. The advancing and receding angles of a surface, the liquid-vapor interfacial energy and three-phase line tension are the only required constitutive inputs to the model. We first simulate hysteresis on a smooth chemically homogeneous surface using this theory. Next we show that it is possible to study heterogeneous surfaces whose component surfaces are themselves hysteretic. We use this theory to examine the wetting of a surface containing a circular heterogeneous island. The contact angle for this case is found to be determined solely by the material properties at the contact line in accord with recent experimental data.

  8. Dynamic contact angle cycling homogenizes heterogeneous surfaces.

    PubMed

    Belibel, R; Barbaud, C; Mora, L

    2016-12-01

    In order to reduce restenosis, the necessity to develop the appropriate coating material of metallic stent is a challenge for biomedicine and scientific research over the past decade. Therefore, biodegradable copolymers of poly((R,S)-3,3 dimethylmalic acid) (PDMMLA) were prepared in order to develop a new coating exhibiting different custom groups in its side chain and being able to carry a drug. This material will be in direct contact with cells and blood. It consists of carboxylic acid and hexylic groups used for hydrophilic and hydrophobic character, respectively. The study of this material wettability and dynamic surface properties is of importance due to the influence of the chemistry and the potential motility of these chemical groups on cell adhesion and polymer kinetic hydrolysis. Cassie theory was used for the theoretical correction of contact angles of these chemical heterogeneous surfaces coatings. Dynamic Surface Analysis was used as practical homogenizer of chemical heterogeneous surfaces by cycling during many cycles in water. In this work, we confirmed that, unlike receding contact angle, advancing contact angle is influenced by the difference of only 10% of acidic groups (%A) in side-chain of polymers. It linearly decreases with increasing acidity percentage. Hysteresis (H) is also a sensitive parameter which is discussed in this paper. Finally, we conclude that cycling provides real information, thus avoiding theoretical Cassie correction. H(10)is the most sensible parameter to %A.

  9. Multi-Angle Snowflake Camera Instrument Handbook

    SciTech Connect

    Stuefer, Martin; Bailey, J

    2016-07-01

    The Multi-Angle Snowflake Camera (MASC) takes 9- to 37-micron resolution stereographic photographs of free-falling hydrometers from three angles, while simultaneously measuring their fall speed. Information about hydrometeor size, shape orientation, and aspect ratio is derived from MASC photographs. The instrument consists of three commercial cameras separated by angles of 36º. Each camera field of view is aligned to have a common single focus point about 10 cm distant from the cameras. Two near-infrared emitter pairs are aligned with the camera’s field of view within a 10-angular ring and detect hydrometeor passage, with the lower emitters configured to trigger the MASC cameras. The sensitive IR motion sensors are designed to filter out slow variations in ambient light. Fall speed is derived from successive triggers along the fall path. The camera exposure times are extremely short, in the range of 1/25,000th of a second, enabling the MASC to capture snowflake sizes ranging from 30 micrometers to 3 cm.

  10. Angle sensitive single photon avalanche diode

    NASA Astrophysics Data System (ADS)

    Lee, Changhyuk; Johnson, Ben; Molnar, Alyosha

    2015-06-01

    An ideal light sensor would provide exact information on intensity, timing, location, and angle of incoming photons. Single photon avalanche diodes (SPADs) provide such desired high (single photon) sensitivity with precise time information and can be implemented at a pixel-scale to form an array to extract spatial information. Furthermore, recent work has demonstrated photodiode-based structures (combined with micro-lenses or diffraction gratings) that are capable of encoding both spatial and angular information of incident light. In this letter, we describe the implementation of such a grating structure on SPADs to realize a pixel-scale angle-sensitive single photon avalanche diode (A-SPAD) built in a standard CMOS process. While the underlying SPAD structure provides high sensitivity, the time information of the two layers of diffraction gratings above offers angle-sensitivity. Such a unique combination of SPAD and diffraction gratings expands the sensing dimensions to pave a path towards lens-less 3-D imaging and light-field time-of-flight imaging.

  11. Quantifying foot deformation using finite helical angle.

    PubMed

    Pothrat, Claude; Goislard de Monsabert, Benjamin; Vigouroux, Laurent; Viehweger, Elke; Berton, Eric; Rao, Guillaume

    2015-10-15

    Foot intrinsic motion originates from the combination of numerous joint motions giving this segment a high adaptive ability. Existing foot kinematic models are mostly focused on analyzing small scale foot bone to bone motions which require both complex experimental methodology and complex interpretative work to assess the global foot functionality. This study proposes a method to assess the total foot deformation by calculating a helical angle from the relative motions of the rearfoot and the forefoot. This method required a limited number of retro-reflective markers placed on the foot and was tested for five different movements (walking, forefoot impact running, heel impact running, 90° cutting, and 180° U-turn) and 12 participants. Overtime intraclass correlation coefficients were calculated to quantify the helical angle pattern repeatability for each movement. Our results indicated that the method was suitable to identify the different motions as different amplitudes of helical angle were observed according to the flexibility required in each movement. Moreover, the results showed that the repeatability could be used to identify the mastering of each motion as this repeatability was high for well mastered movements. Together with existing methods, this new protocol could be applied to fully assess foot function in sport or clinical contexts.

  12. Angle-resolved optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Desjardins, Adrien Emmanuel

    Optical coherence tomography (OCT) has emerged as a powerful tool for probing the microstructure of biological tissue non-invasively at high-speed. OCT measures depth-resolved reflectance of infrared light, generating cross-sectional images non-invasively with micron-scale resolution. As with other imaging modalities that employ coherent detection, OCT images are confounded by speckle noise. Speckle imposes a grainy texture on images that reduces the signal-to-noise ratio to near unity values. As a result, it conceals subtle differences in scattering properties known to be crucial for differentiating normal from diseased tissue states. In this thesis, we developed a novel OCT modality called "Angle-Resolved OCT" in which depth scans (A-lines) are obtained simultaneously from a broad range of backscattering angles. We demonstrated that high levels of speckle reduction can be achieved by averaging the magnitudes of A-lines corresponding to the same transverse locations. With both experimental and analytic approaches, we demonstrated that this averaging method does not lead to a substantial loss in spatial resolution. We developed two different imaging systems for performing Angle-Resolved OCT. With the first system, angular data was acquired simultaneously; with the second, it was acquired sequentially. The first system had superior speckle-reduction capabilities but image quality degraded significantly with small sample movements. The second system allowed for in vivo imaging, as demonstrated with Resolved OCT systems, the speckle-reduced images showed hitherto unprecedented delineation of tissue microstructure.

  13. Manifold angles, the concept of self-similarity, and angle-enhanced bifurcation diagrams.

    PubMed

    Beims, Marcus W; Gallas, Jason A C

    2016-01-06

    Chaos and regularity are routinely discriminated by using Lyapunov exponents distilled from the norm of orthogonalized Lyapunov vectors, propagated during the temporal evolution of the dynamics. Such exponents are mean-field-like averages that, for each degree of freedom, squeeze the whole temporal evolution complexity into just a single number. However, Lyapunov vectors also contain a step-by-step record of what exactly happens with the angles between stable and unstable manifolds during the whole evolution, a big-data information permanently erased by repeated orthogonalizations. Here, we study changes of angles between invariant subspaces as observed during temporal evolution of Hénon's system. Such angles are calculated numerically and analytically and used to characterize self-similarity of a chaotic attractor. In addition, we show how standard tools of dynamical systems may be angle-enhanced by dressing them with informations not difficult to extract. Such angle-enhanced tools reveal unexpected and practical facts that are described in detail. For instance, we present a video showing an angle-enhanced bifurcation diagram that exposes from several perspectives the complex geometrical features underlying the attractors. We believe such findings to be generic for extended classes of systems.

  14. Manifold angles, the concept of self-similarity, and angle-enhanced bifurcation diagrams

    NASA Astrophysics Data System (ADS)

    Beims, Marcus W.; Gallas, Jason A. C.

    2016-01-01

    Chaos and regularity are routinely discriminated by using Lyapunov exponents distilled from the norm of orthogonalized Lyapunov vectors, propagated during the temporal evolution of the dynamics. Such exponents are mean-field-like averages that, for each degree of freedom, squeeze the whole temporal evolution complexity into just a single number. However, Lyapunov vectors also contain a step-by-step record of what exactly happens with the angles between stable and unstable manifolds during the whole evolution, a big-data information permanently erased by repeated orthogonalizations. Here, we study changes of angles between invariant subspaces as observed during temporal evolution of Hénon’s system. Such angles are calculated numerically and analytically and used to characterize self-similarity of a chaotic attractor. In addition, we show how standard tools of dynamical systems may be angle-enhanced by dressing them with informations not difficult to extract. Such angle-enhanced tools reveal unexpected and practical facts that are described in detail. For instance, we present a video showing an angle-enhanced bifurcation diagram that exposes from several perspectives the complex geometrical features underlying the attractors. We believe such findings to be generic for extended classes of systems.

  15. Aspect angle dependence of the E region irregularity velocity at large flow angles

    NASA Astrophysics Data System (ADS)

    Makarevich, R. A.; Koustov, A. V.; Senior, A.; Uspensky, M.; Honary, F.; Dyson, P. L.

    2007-11-01

    We present the Doppler velocity observations of 1-m plasma waves in the auroral E region by the Scandinavian Twin Auroral Radar Experiment (STARE) Norway VHF coherent radar in the context of simultaneous and coincident measurements of electron and ion drift velocities determined by the European Incoherent Scatter (EISCAT) tristatic radar facility. The measurements were performed in the afternoon sector (1500-2000 MLT) at seven locations along the STARE radar beam 2 with different values of the magnetic off-perpendicular (aspect) angle α between 0.48° and 2.63° and at large angles with respect to the electron background drift (θ = 55°-90°). It is demonstrated that the STARE line-of-sight velocity, normalized to the EISCAT-derived electron drift speed at large flow angles, exhibits a decrease with increasing aspect angle, and the rate of decrease is investigated as a function of the flow angle. We also compare the STARE velocity with the electron and ion drift velocity components along the STARE radar beam look direction and show that, at large aspect angles, the E region velocity is correlated (anticorrelated) with the ion (electron) drift velocity component. The results are discussed in the contexts of the linear fluid theory of the modified two-stream plasma instability and the theory of anomalous collisions.

  16. The Angle Detecting Inclined Sensors (ADIS) System: Measuring Particle Angles of Incidence without Position Sensing Detectors

    NASA Astrophysics Data System (ADS)

    Connell, J. J.; Lopate, C.; McKibben, R. B.

    2001-08-01

    We report on a novel system, the Angle Detecting Inclined Sensors (ADIS), for determining the angles of incidence of Solar energetic particles, Galactic cosmic rays and anomalous cosmic rays. This system would be especially applicable to compact high resolution energetic particle telescopes. The response of charged particle detectors varies with particle pathlength, which depends on angle of incidence. Achieving good elemental and isotopic resolution requires correcting for this effect. ADIS consists of three detectors, two of which are inclined at an angle to the telescope axis, forming the first detectors in a multi-element telescope. By comparing the signals from the ADIS detectors, and using the computable angle dependent pathlengths through the detectors, the angle of incidence may be determined. The ADIS system thus can replace hodoscopes using conventional position sensing detectors (PSD's). PSD's add significant complexity and require additional electronics, increasing instrument mass, power usage and, in many cases, telemetry requirements. We derive simple equations for the incident particle charge and trajectory. These calculations are well within the capabilities of even the slowest on-board processors. We present Monte-Carlo modeling of such an instrument to demonstrate the system's capabilities.

  17. Pair Creation at Large Inherent Angles

    SciTech Connect

    Chen, P.; Tauchi, T.; Schroeder, D.V.; /SLAC

    2007-04-25

    In the next-generation linear colliders, the low-energy e{sup +}e{sup -} pairs created during the collision of high-energy e{sup +}e{sup -} beams would cause potential deleterious background problems to the detectors. At low collider energies, the pairs are made essentially by the incoherent process, where the pair is created by the interaction of beamstrahlung photons on the individual particles in the oncoming beam. This problem was first identified by Zolotarev, et al[1]. At energies where the beamstrahlung parameter {Upsilon} lies approximately in the range 0.6 {approx}< {Upsilon} {approx}< 100, pair creation from the beamstrahlung photons is dominated by a coherent process, first noted by Chen[2]. The seriousness of this pair creation problem lies in the transverse momenta that the pair particles carry when leaving the interaction point (IP) with large angles. One source of transverse momentum is from the kick by the field of the oncoming beam which results in an outcoming angle {theta} {proportional_to} 1/{radical}x, where x is the fractional energy of the particle relative to the initial beam particle energy[2,3]. As was shown in Ref. 131, there in fact exists an energy threshold for the coherent pairs, where x{sub th} {approx}> 1/2{Upsilon}. Thus within a tolerable exiting angle, there exists an upper limit for {Upsilon} where all coherent pairs would leave the detector through the exhaust port[4]. A somewhat different analysis has been done by Schroeder[5]. In the next generation of linear colliders, as it occurs, the coherent pairs can be exponentially suppressed[2] by properly choosing the {Upsilon}({approx}< 0.6). When this is achieved, the incoherent pairs becomes dominant. Since the central issue is the transverse momentum for particles with large angles, we notice that there is another source for it. Namely, when the pair particles are created at low energies, the intrinsic angles of these pairs when produced may already be large. This issue was

  18. Angle amplifier based on multiplexed volume holographic gratings

    NASA Astrophysics Data System (ADS)

    Cao, Liangcai; Zhao, Yifei; He, Qingsheng; Jin, Guofan

    2008-03-01

    Angle amplifier of laser beam scanner is a widely used device in optical systems. Volume holographic optical elements can be applied in the angle amplifier. Compared with the traditional angle amplifier, it has the advantages of high angle resolution, high diffraction efficiency, small size, and high angle magnification and flexible design. Bragg anglewavelength- compensating recording method is introduced. Because of the Bragg compensatory relation between angle and wavelength, this device could be recorded at another wavelength. The design of the angle amplifier recording at the wavelength of 514.2nm for the working wavelength of 632.8nm is described. An optical setup for recording the angle amplifier device is designed and discussed. Experimental results in the photorefractive crystal Fe:LiNbO 3 demonstrate the feasibility of the angle amplifier scheme.

  19. Angle Closure Scoring System (ACSS)-A Scoring System for Stratification of Angle Closure Disease

    PubMed Central

    Rao, Aparna; Padhy, Debananda; Sarangi, Sarada; Das, Gopinath

    2016-01-01

    Purpose To evaluate the angle closure scoring system (ACSS) for stratifying primary angle course disease. Methods This observational cross sectional institutional study included patients with primary open angle glaucoma suspects (n = 21) and primary angle closure disease (primary angle closure, PAC, n = 63 and primary angle course glaucoma, PACG, n = 58 (defined by International society of Geographical and Epidemiological Ophthalmology, ISGEO). Two independent examiners blinded to clinical details, graded good quality pre-laser goniophotographs of the patients incorporating quadrants of peripheral anterior synechieae (PAS), non-visibility of posterior trabecular meshwork (PTM) and blotchy pigments (ranging from 1–4 quadrants), iris configuration, angle recess (sum of above depicting ACSSg) and lens thickness/axial length ratio (LT/AL), cup disc ratio and baseline intraocular pressure (IOP) to give total score (ACSSt). Result There were significant differences in ACSSg scores within the same ISGEO stage of PAC and PACG between eyes that required nil or >1medicines after laser iridotomy, p<0.001. The ACSSg was associated with need for >1 medicines in both PAC and PACG eyes, p<0.001. An ACSSg score>12 and 14 in PAC (odds ratio = 2.7(95% CI-1.7–5.9) and PACG (Odds ratio = 1.6(95%CI-1.19–2.2) predicted need for single medicines while ACSSg scores >14 and 19 predicted need for ≥2 medicines in PAC and PACG eyes, respectively. The LT/Al ratio, IOP score or cup disc score did not influence the need for medical treatment independently. Conclusion The ACSS can be a useful clinical adjunct to the ISGEO system to predict need for medicines and prognosticate each stage more accurately. PMID:27788183

  20. Angle Closure Scoring System (ACSS)-A Scoring System for Stratification of Angle Closure Disease.

    PubMed

    Rao, Aparna; Padhy, Debananda; Sarangi, Sarada; Das, Gopinath

    2016-01-01

    To evaluate the angle closure scoring system (ACSS) for stratifying primary angle course disease. This observational cross sectional institutional study included patients with primary open angle glaucoma suspects (n = 21) and primary angle closure disease (primary angle closure, PAC, n = 63 and primary angle course glaucoma, PACG, n = 58 (defined by International society of Geographical and Epidemiological Ophthalmology, ISGEO). Two independent examiners blinded to clinical details, graded good quality pre-laser goniophotographs of the patients incorporating quadrants of peripheral anterior synechieae (PAS), non-visibility of posterior trabecular meshwork (PTM) and blotchy pigments (ranging from 1-4 quadrants), iris configuration, angle recess (sum of above depicting ACSSg) and lens thickness/axial length ratio (LT/AL), cup disc ratio and baseline intraocular pressure (IOP) to give total score (ACSSt). There were significant differences in ACSSg scores within the same ISGEO stage of PAC and PACG between eyes that required nil or >1medicines after laser iridotomy, p<0.001. The ACSSg was associated with need for >1 medicines in both PAC and PACG eyes, p<0.001. An ACSSg score>12 and 14 in PAC (odds ratio = 2.7(95% CI-1.7-5.9) and PACG (Odds ratio = 1.6(95%CI-1.19-2.2) predicted need for single medicines while ACSSg scores >14 and 19 predicted need for ≥2 medicines in PAC and PACG eyes, respectively. The LT/Al ratio, IOP score or cup disc score did not influence the need for medical treatment independently. The ACSS can be a useful clinical adjunct to the ISGEO system to predict need for medicines and prognosticate each stage more accurately.