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Sample records for coherence tomographic findings

  1. Optical Coherence Tomographic Findings in Berlin′s Edema

    Directory of Open Access Journals (Sweden)

    Leila El Matri

    2010-01-01

    Full Text Available Purpose: To describe optical coherence tomography (OCT findings in a patient with Berlin′s edema following blunt ocular trauma. Case Report: A 26-year-old man presented with acute loss of vision in his left eye following blunt trauma. He underwent a complete ophthalmologic examination and OCT. Fundus examination revealed abnormal yellow discoloration in the macula. OCT disclosed thickening of outer retinal structures and increased reflectivity in the area of photoreceptor outer segments with preservation of inner retinal architecture. Re-examination was conducted one month later at the time which OCT changes resolved leading to a surprisingly normal appearance. Conclusion: OCT can be a useful tool in the diagnosis and follow-up of eyes with Berlin′s edema and may reveal ultrastructural macular changes.

  2. Swept-Source Optical Coherence Tomographic Findings of Choroidal Osteoma

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    Yuki Hayashi

    2014-07-01

    Full Text Available Purpose: To report the morphologic features of a choroidal osteoma using swept-source optical coherence tomography (SS-OCT and fundus autofluorescence (FAF. Methods: Two eyes of two cases with a choroidal osteoma were studied using SS-OCT and FAF. Results: The location of the tumor was circumpapillary without macular involvement in case 1 and juxtapapillary with macular involvement in case 2. Both cases had a mixture of calcified and decalcified areas, and a concomitant choroidal neovascularization was found in case 2. The FAF images showed decreased autofluorescence in the central decalcified regions and relatively preserved fluorescence in marginal calcified regions in both cases. SS-OCT revealed a normal inner retina and an abnormal outer retina in both cases, and subretinal fluid in case 2. The calcified regions appeared sponge-like and were multilayered in case 2. A lamellar reflective pattern was observed in the decalcified regions in case 1, and hyperreflective mound-like areas were observed in both cases. SS-OCT demonstrated hyperreflective areas above Bruch's membrane accompanied by disruption of Bruch's membrane in case 1. The chorioscleral border was visible in both cases. Conclusions: The FAF pattern in the calcified and decalcified areas of the choroidal osteoma may correspond to the different stage of tumor evolution. The SS-OCT findings indicate that choroidal osteomas can have characteristic reflective patterns and alterations of the overlying retina.

  3. Fundus autofluorescence and optical coherence tomographic findings in acute zonal occult outer retinopathy.

    Science.gov (United States)

    Fujiwara, Takamitsu; Imamura, Yutaka; Giovinazzo, Vincent J; Spaide, Richard F

    2010-09-01

    The purpose of this study was to investigate the fundus autofluorescence and optical coherence tomography findings in eyes with acute zonal occult outer retinopathy (AZOOR). A retrospective observational case series of the fundus autofluorescence and spectral domain optical coherence tomography in a series of patients with AZOOR. There were 19 eyes of 11 patients (10 women), who had a mean age of 49.1 +/- 13.9 years. Fundus autofluorescence abnormalities were seen in 17 of the 19 eyes, were more common in the peripapillary area, and were smaller in extent than the optical coherence tomography abnormalities. Nine eyes showed progression of hypoautofluorescence area during the mean follow-up of 69.7 months. The mean thickness of the photoreceptor layer at fovea was 177 microm in eyes with AZOOR, which was significantly thinner than controls (193 microm, P = 0.049). Abnormal retinal laminations were found in 12 eyes and were located over areas of loss of the photoreceptors. The subfoveal choroidal thickness was 243 microm, which is normal. Fundus autofluorescence abnormalities in AZOOR showed distinct patterns of retinal pigment epithelial involvement, which may be progressive. Thinning of photoreceptor cell layer with loss of the outer segments and abnormal inner retinal lamination in the context of a normal choroid are commonly found in AZOOR.

  4. Neuroblastoma: computed tomographic findings

    International Nuclear Information System (INIS)

    Yoon, Choon Sik; Ahn, Chang Su; Kim, Myung Jun; Oh, Ki Keun

    1994-01-01

    To evaluate the characteristic CT findings of neuroblastoma, we studied neuroblastomas. We analysed CT findings of available 25 cases among pathologically proved 51 neuroblastomas from Jan. 1983 to Sept. 1990. The most frequent site of origin is adrenal gland (40%) and the second is retroperitoneum (32%) and the third ismediastinum (16%). Characteristic CT findings are as follows: Calcifications within the tumor is detected in 86% of abdominal neuroblastomas and 50% of mediastinal origin. Hemorrhagic and necrotic changes within the tumor is noted at 86% in the tumor of abdominal origin and 25% in mediastinal neuroblastomas. Contrast enhanced study showed frequently seperated enhanced appearance with/without solid contrast enhancement. Encasements of major great vessels such as aorta and IVC with/without displacement by metastatic lymph nodes or tumor are frequently seen in 90% of abdominal neuroblastomas. Multiple lymphadenopathy are detected in 95% of abdominal neuroblastomas and 25% of mediastinal neuroblastomas. The most common organ or contiguous direct invasion is kidney in 6 cases and the next one is liver but intraspinal canal invasion is also noted in 2 cases. We concluded that diagnosis of neuroblastoma would be easily obtained in masses of pediatric group from recognition of above characteristic findings

  5. Computed tomographic findings of intracranial gliosis

    International Nuclear Information System (INIS)

    Weisberg, L.

    1981-01-01

    The clinical and computed tomographic (CT) findings in eight patients with pathological evidence of cerebral gliosis are analyzed. CT findings do not permit differentiation of gliosis from other neoplastic and non-neoplastic conditions. (orig.)

  6. Computed tomographic findings of intracranial pyogenic abscess

    International Nuclear Information System (INIS)

    Kim, S. J.; Suh, J. H.; Park, C. Y.; Lee, K. C.; Chung, S. S.

    1982-01-01

    The early diagnosis and effective treatment of brain abscess pose a difficult clinical problem. With the advent of computed tomography, however, it appears that mortality due to intracranial abscess has significantly diminished. 54 cases of intracranial pyogenic abscess are presented. Etiologic factors and computed tomographic findings are analyzed and following result are obtained. 1. The common etiologic factors are otitis media, post operation, and head trauma, in order of frequency. 2. The most common initial computed tomographic findings of brain abscess is ring contrast enhancement with surrounding brain edema. 3. The most characteristic computed tomographic finding of ring contrast enhancement is smooth thin walled ring contrast enhancement. 4. Most of thick irregular ring contrast enhancement are abscess associated with cyanotic heart disease or poor operation. 5. The most common findings of epidural and subdural empyema is crescentic radiolucent area with thin wall contrast enhancement without surrounding brain edema in convexity of brain

  7. Differences in optical coherence tomographic findings and clinical outcomes between excimer laser and cutting balloon angioplasty for focal in-stent restenosis lesions.

    Science.gov (United States)

    Nishino, Masami; Lee, Yasuharu; Nakamura, Daisuke; Yoshimura, Takahiro; Taniike, Masayuki; Makino, Nobuhiko; Kato, Hiroyasu; Egami, Yasuyuki; Shutta, Ryu; Tanouchi, Jun; Yamada, Yoshio

    2012-10-01

    In-stent restenosis (ISR), especially focal ISR, after percutaneous coronary intervention (PCI) remains one of the major clinical problems in the drug-eluting stent (DES) era. Several reports have revealed that excimer laser coronary angioplasty (ELCA) is useful for ISR; however, detailed findings after ELCA are unknown. Therefore, we investigated the condition of the neointima after ELCA for ISR with optical coherence tomography (OCT) and compared the OCT findings and clinical outcome between ELCA and cutting-balloon angioplasty (CBA). Twenty-one consecutive patients with focal ISR who underwent ELCA or CBA were enrolled. All patients underwent 12- to 15-month follow-up coronary angiography. OCT was performed immediately after successful PCI to evaluate the neointimal condition in the ISR lesion. We compared the following OCT parameters between ELCA and CBA groups: maximal thickness of remaining in-stent neointima (MTN), number of tears, minimum lumen dimension (MLD), and minimum lumen area (MLA). We also evaluated clinical outcomes, including target vessel revascularization, acute myocardial infarction, death, and stent thrombosis. MLA in the ELCA group (n = 10) was significantly larger than in the CBA group, and number of tears in the ELCA group was significantly lower than in the CBA group. A trend was shown toward lower TLR with ELCA versus CBA (10.0% vs 45.5%). OCT immediately after ELCA for ISR lesions revealed larger lumen area and smaller number of tears compared with CBA, which may support favorable effects of ELCA for focal ISR.

  8. Computed tomographic findings of cerebral arterial ectasia

    International Nuclear Information System (INIS)

    Choi, Woo Suk; Ko, Young Ho; Lim, Jae Hoon

    1987-01-01

    The computed tomographic findings of cerebral arterial ectasia in 8 patients, of which 5 cases were angiographically documented, are reported. The ecstatic arteries, located predominantly in the suprasellar and interpeduncular cisterns, appeared as serpignous, tubular structures on the unenhanced scan. The enhanced CT scan demonstrated dense, sharply defined, homogeneous intraluminal enhancement. Until recently, the diagnosis of cerebral arterial ectasia was usually established by angiography. With introduction of CT it has become possible to noninvasively identify and characterize this vascular disorder and its associated intracranial complications. The vertebrobasilar dolichoectasia may be diagnosed by CT as an extra-axial lesion in the cerebellopontine angle. It enhances in a tubular fashion after intravenous injection of contrast.

  9. Computed tomographic findings of intracerebral cysticercosis

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    Hong, Jin Kyo; Lee, Sun Wha; Kim, Ho Kyun; Ahn, Chi Yul [School of Medicine, Kyung-Hee University, Seoul (Korea, Republic of)

    1980-12-15

    Cysticercosis is a parasitic disease in which man serves as the intermediate host of Taenia Solium, the pork tapeworm. The computed tomographic findings of 25 cases of intracerebral cysticercosis proven by pathologic and/or clinical findings during past 2 years were analysed. The results were as follows; 1. The sex was 19 males and 6 females, and 56 percent of the patients were seen in fourth and fifth decades. The most common symptom was epilepsy (72%). 2. The C. T. findings in precontrast study were varied; such as ill defined low density (48%), cystic low density (20%), dilated ventricles (20%), ill defined low density with isodense nodule (18%), cystic low density with isodense mural nodule (12%) and calcification (8%). 3. The areas of involvement were 20 cases (80%) of parenchymal form, 3 cases (12%) of ventricular form and 2 cases (8%) of mixed form. 4. The contrast-enhanced 13 cases were 5 nodular, 5 ring or rim-like and 3 mixed type enhancements, while 12 cases were not enhanced. 5. C.T. scan demonstrated more precise location and extents of cerebral cysticercosis, especially in parenchymal form. It was considered to be important in determination of surgical feasibility and its approach.

  10. Computed tomographic findings of cerebral paragonimiasis

    International Nuclear Information System (INIS)

    Sung, Nak Kwan; Nam, Kyung Jin; Park, Churl Min; Eun, Chung Kie; Lee, Sun Wha

    1983-01-01

    Paragonimiasis is widely distributed in Far East and Southeast Asia, particularly in Korea. The central nervous system is the most frequent location for paragonimiasis outside the lungs. We analyzed the computed tomographic findings of 17 cases which were diagnosed pathologically and clinically as cerebral paragonimiasis. The results were as follows: 1. The ratio of male to female was 10 : 7 and about 88% of cases were under the age of 40 years. 2. The common locations of cerebral paragonimiasis were the occipital (12 cases) and temporal (11 cases) lobes. 3. Precontrast CT findings of cerebral paragonimiasis were low density with calcifications in 6 cases, low and isodensities in 4 cases, mixed densities in 3 cases, only low density in 2 cases and only calcification in 2 cases. Hydrocephalus (7 cases), mass effect (6 cases), atrophic change (6 cases) and cyst formation (3 cases) were associated. 4. The shape of calcifications in CT scan were soap-bubble or ring in 6 cases, nodular or oval in 6 cases, stipple in 4 cases and amorphous conglomerated in 2 cases. 5. The contrast -enhanced 8 cases were 5 ring or rim like, 2 nodular and 1 irregular enhancements, while 9 cases were not enhanced

  11. Computed tomographic findings of hepatocellular carcinoma

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    Eun, Chung Kie [Kyung Hee University College of Medicine, Seoul (Korea, Republic of)

    1982-09-15

    It is well known that CT is very useful in the evaluation of hepatocellular carcinoma. The computed tomographic findings of 56 patients diagnosed as hepatocellular carcinoma were reviewed and analyzed. The results were as follows: 1. The male to female ratio was 3 : 1 and the age ranged from 31 to 73 years with average age of 54 years. 2. Alpha-fetoprotein was positive in 19 out of 38 cases (50%). HBsAg was positive in 8 out of 33 cases (24%). 3. All lesions were seen as areas of low density except 1 case (0%) of isodensity, and 40 cases (72%) appeared to be solitary while 15 (26%) were multifocal. The low density was homogenous in 13 cases (24%) and inhomogenous in 42 cases (76%), and 18 cases out of 42 cases inhomogenous low density showed peripheal and/or central nodular enhancement. The additional findings were contour changes in 37 cases (66%), metastasis in 35 cases (63%), splenomegaly in 23 cases (42%) and ascities in 22 cases (39%). 4. In postcontrast scans, 41 cases (80%) out of 51 cases showed the change of density after contrast infusion. The presence and extent of tumors were better seen after contrast infusion in 30 cases (59%), better seen before contrast infusion in 11 cases (21%) and no significant difference before and after contrast infusion in 10 cases (20%). 5. The sites of involved lobe were right lobe in 38 cases (68%), left lobe in 5 cases (9%) and both lobes in 13 cases (23%). 6. 35 cases (63%) showed evidence of metastasis to regional lymph nodes, organ or tissues.

  12. Computed tomographic findings of cerebral paragonimiasis

    International Nuclear Information System (INIS)

    Bae, Weon Tae; Jung, Min Ki; Kang, Heoung Keun; Chung, Hyon De

    1988-01-01

    Authors analyzed the computed tomographic (CT) findings of 19 cases pathologically and clinically proven cerebral paragonimiasis that were performed at Chonnam University Hospital from April 1983 through March 1987. The results were as follows: 1. Male to female ratio was 15:4 and the most prevalent age group was 3rd decade (7 cases). The common symptoms were epileptic seizure (16 cases) and headache (12 cases). 2. The multiplicity of cerebral paragonimiasis was 7 of 19 cases and the distributions of lesion were occipital (11 cases), temporal (6 cases), frontal (5 cases) and parietal (5 cases) lobe. 3. The calcification on CT scan were single (7 cases) or multiple (7 cases) and the shape of calcification were nodular (10 cases), soap babble of ring (8 cases), and stippled (6 cases). The pattern of contrast enhancement were ring (5 cases) or nodular (1 case), and along the basal cistern (1 case with arachnoiditis). 4. 12 out of 13 cases, had long clinical symptoms over 3 years with calcifications, could be analyzed according to Valentine's vascular territory; 6 cases in PCA territory, 3 in MCA and 3 in ACA. 5. CT findings were noted according to the duration of symptoms; 5 cases, had symptoms less than 1 year, showed abscess (5 cases) and arachnoiditis (1 case) with brain edema, mass effect, hydrocephalus and contrast enhancement but no calcification in all. One case, had symptom of 1 year and 2 months, showed partially calcified granulomatous lesion with perifocal edema and contrast enhancement, 13 cases, had symptoms over 3 years, showed multiple calcification with brain atrophy (10 cases), but no contrast enhancement in all cases.

  13. Computed tomographic findings of traumatic intracranial lesions

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    Jeong, Seong Wook; Kim, Il Young; Lee, Byung Ho; Kim, Ki Jeoung; Yoon, Il Gyu [Soonchunhyang University College of Medicine, Seoul (Korea, Republic of)

    1985-10-15

    Traumatic intracranial lesion has been one of the most frequent and serious problem in neurosurgical pathology. Computed tomography made it possible to get prompt diagnosis and surgical intervention of intracranial lesions by its safety, fastness and accuracy. Computed tomographic scan was carried out on 1309 cases at Soonchunhyang Chunan Hospital for 15 months from October 1983 to December 1984. We have reviewed the computed tomographic scans of 264 patients which showed traumatic intracranial lesion. The result were as follows: 1. Head trauma was the most frequent diagnosed disease using computed tomographic scans (57.8%) and among 264 cases the most frequent mode of injury was traffic accident (73.9%). 2. Skull fracture was accompanied in frequency of 69.7% and it was detected in CT in 38.6%: depression fracture was more easily detected in 81%. 3. Conutercoup lesion (9.5%) was usually accompanied with temporal and occipital fracture, and it appeared in lower incidence among pediatric group. 4. Intracranial lesions of all 264 cases were generalized cerebral swelling (24.6%), subdural hematoma (22.3%), epidural hematoma (20.8%), intracerebral hematoma (6.1%), and subarachnoid hemorrhage (3.0%). 5. The shape of hematoma was usually biconvex (92.7%) in acute epidural hematoma and cresentic (100%) in acute subdural hematoma, but the most chronic the case became, they showed planoconvex and bicconvex shapes. 6. Extra-axial hematoma was getting decreased in density as time gone by. 7. Hematoma density was not in direct proportion to serum hemoglobin level as single factor.

  14. Computed tomographic findings of traumatic intracranial lesions

    International Nuclear Information System (INIS)

    Jeong, Seong Wook; Kim, Il Young; Lee, Byung Ho; Kim, Ki Jeoung; Yoon, Il Gyu

    1985-01-01

    Traumatic intracranial lesion has been one of the most frequent and serious problem in neurosurgical pathology. Computed tomography made it possible to get prompt diagnosis and surgical intervention of intracranial lesions by its safety, fastness and accuracy. Computed tomographic scan was carried out on 1309 cases at Soonchunhyang Chunan Hospital for 15 months from October 1983 to December 1984. We have reviewed the computed tomographic scans of 264 patients which showed traumatic intracranial lesion. The result were as follows: 1. Head trauma was the most frequent diagnosed disease using computed tomographic scans (57.8%) and among 264 cases the most frequent mode of injury was traffic accident (73.9%). 2. Skull fracture was accompanied in frequency of 69.7% and it was detected in CT in 38.6%: depression fracture was more easily detected in 81%. 3. Conutercoup lesion (9.5%) was usually accompanied with temporal and occipital fracture, and it appeared in lower incidence among pediatric group. 4. Intracranial lesions of all 264 cases were generalized cerebral swelling (24.6%), subdural hematoma (22.3%), epidural hematoma (20.8%), intracerebral hematoma (6.1%), and subarachnoid hemorrhage (3.0%). 5. The shape of hematoma was usually biconvex (92.7%) in acute epidural hematoma and cresentic (100%) in acute subdural hematoma, but the most chronic the case became, they showed planoconvex and bicconvex shapes. 6. Extra-axial hematoma was getting decreased in density as time gone by. 7. Hematoma density was not in direct proportion to serum hemoglobin level as single factor

  15. Computed tomographic findings of hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Jo, In Su; Jong, Woo Yung; Lee, Jong Yul; Choi, Han Yong; Kim, Bong Ki

    1987-01-01

    With Development of Computed Tomography, detection of the Hepatocellular Carcinoma are easily performed and frequently used in the world. During 15 months, from December 1985 to February 1987, 59 patients with hepatocellular carcinoma were evaluated with computed tomography in department of radiology at Wallace Memorial Baptist Hospital. The results were as follow: 1. The most prevalent age group was 5th to 7th decades, male to female ratio was 4.9:1. 2. Classification with incidence of computed tomographic appearance of the hepatocellular carcinoma were solitary type 28 cases (48%), multinodular type 24 cases (40%), and diffuse type 7 cases (12%), Association with liver cirrhosis was noted in 22 cases (38%). 3. Inhomogenous internal consistency of hepatocellular carcinoma due to central necrosis were 35 cases (60%). Portal vein invasion by hepatocellular carcinoma was noted in 15 cases (25%), and particularly most common in diffuse type 4 cases (55%). 4. On precontrast scan, all hepatocellular carcinoma were seen as area of low density except for 3 cases(0.5%) of near isodensity which turned out to be remarkable low density on postcontrast scan. 5. In solitary type, posterior segment of right lobe was most common site of involvement 12 cases (43%). In diffuse type, bilobar involvement was most common, 6 cases (85%)

  16. Computed tomographic findings in manifesting carriers of Duchenne muscular dystrophy

    NARCIS (Netherlands)

    de Visser, M.; Verbeeten, B.

    1985-01-01

    Clinical and computed tomographic (CT) findings in 3 manifesting carriers of Duchenne muscular dystrophy are reported. CT proved to be an important adjunct to the clinical examination: in all our 3 cases a decrease in density was found in various non-paretic muscles

  17. Computerized tomographic findings in children with head trauma in ...

    African Journals Online (AJOL)

    Objective: To describe the computerized tomographic findings in children with head trauma who presented at the University of Benin Teaching Hospital, Benin City, Nigeria. Methods: It is a retrospective review of patients aged 0 – 15 years with suspected intracranial injury (ICI) following head trauma, who presented for CT ...

  18. Computed tomographic findings in penetrating peptic ulcer

    International Nuclear Information System (INIS)

    Madrazo, B.L.; Halpert, R.D.; Sandler, M.A.; Pearlberg, J.L.

    1984-01-01

    Four cases of peptic ulcer penetrating the head of the pancreas were diagnosed by computed tomography (CT). Findings common to 3 cases included (a) an ulcer crater, (b) a sinus tract, and (c) enlargement of the head of the pancreas. Unlike other modalities, the inherent spatial resolution of CT allows a convenient diagnosis of this important complication of peptic ulcer disease

  19. Computed tomographic findings in progressive supranuclear palsy

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    Saitoh, H; Yoshii, F; Shinohara, Y

    1987-03-01

    CT findings of 6 patients with progressive supranuclear palsy (PSP) are described, with emphasis on their supratentorial changes in comparison with those of control subjects and patients with Parkinson's disease (PD). As estimated from CT films, the lateral ventricles, third ventricle and prepontine cistern were significantly enlarged in PSP patients compared with both controls and PD patients. It is suggested that the patients with PSP have not only infratentorial but also supratentorial lesions.

  20. Computed tomographic findings of intrahepatic peripheral cholangiocarcinoma

    International Nuclear Information System (INIS)

    Woo, Seong Ku; Suh, Soo Jhi; Kim, Ho Joon; Chun, Byung Hee

    1986-01-01

    Cholangiocarcinoma is synonymous with bile duct carcinoma, and can originate in a small intrahepatic bile duct (peripheral type), a major intrahepatic duct including the hepatic hills, an extrahepatic duct, or near the papilla of Vater (central type). In a sense bile duct carcinoma of the peripheral type is cholangiocarcinoma of the liver; it has the same gross configuration as hepatocellular carcinoma, resulting in difficulty to differentiate on the CT. The authors studied CT findings of 14 cases of pathologically proven peripheral type cholangiocarcinoma of the liver during the last 4 years. The results were as follows: 1. Of 14 cases, 8 were female and 6 were male, and the age ranged from 5th to 7th decades. 2. Preoperative clinical diagnosis were as follows: hepatoma 8 cases, abscess 5 cases and metastasis 1 case in order of frequency. 3. Diagnosis were confirmed by hepatic lobectomy in 7 cases, wedge resection in 5 cases and needle biopsy in 2 case. 4. Laboratory findings were not specific, but there were only 2 cases with elevated alpha-fetoprotein level. 5. Associated diseases were gallstones in 1 case, intrahepatic duct stones in 1 case, extrahepatic duct stones in 2 cases, acute or chronic cholecystitis in 5 cases and CS in 3 cases. 6. Angiographic and scintigraphic findings were helpful in differential diagnosis from hepatoma but ultrasonography was non-specific. 7. The number of tumor were solitary in 12 cases and multiple in 2 cases. Among solitary cases, the site of involvement of the liver were right lobe in 8 cases and left lobe in 4 cases. 8. Common CT features of the intrahepatic peripheral cholangiocinoma of the liver were irregular, inhomogeneous, occasionally peripherally enhancing, low density liver mass, frequently accompanied by diffuse or segmental dilatation of the intrahepatic bile duct. If there were normal alpha fetoprotein level, positive skin and/or stool examination for CS and diffuse or segmental dilatation of the intrahepatic duct

  1. Computed tomographic findings of intramural hematoma

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    Park, Chan Hoon; Kim, Hong; Woo, Seong Ku; Suh, Soo Jhi [Keimyung University School of Medicine, Taegu (Korea, Republic of)

    1990-10-15

    The CT findings of eleven patients with intramural hematoma of the gastrointestinal tract are presented. The most frequent site of intramural hematoma was duodenum(7/11). followed jejunum(2/11), ascending colon(2/11), stomach(1/11), and rectum(1/11). Blunt abdominal trauma was the prime etiologic factor(7/11). others included pancreatitis, iatrogenic and unknown. Intramural hematoma showed three patterns of CT characteristics: intramural mass(8/11), thickened bowel wall(1/11), and both(2/11). There were variable attenuation value of 10 cases of intramural mass; homogenous hyperdensity or hypodensity in each 3 cases, inhomogeneous or mixed density in 4 cases. Also there were peripheral lucent halo(1/10), pseudocapsule or dense rim(5/10), crescentic hyperdensity(2/10) and central hyperdense area(4/10). Associated CT features were hemoperitoneum(4), mesenteric infiltration, fatty liver, pancreatic confusion, and chronic pancreatitis. CT is the most accurate method in establishing the diagnosis or intramural hematoma, evaluating the extent of bleeding and its effect on adjacent organs, demonstrating regression after treatment, and detecting associating injury.

  2. Computed tomographic findings of intramural hematoma

    International Nuclear Information System (INIS)

    Park, Chan Hoon; Kim, Hong; Woo, Seong Ku; Suh, Soo Jhi

    1990-01-01

    The CT findings of eleven patients with intramural hematoma of the gastrointestinal tract are presented. The most frequent site of intramural hematoma was duodenum(7/11). followed jejunum(2/11), ascending colon(2/11), stomach(1/11), and rectum(1/11). Blunt abdominal trauma was the prime etiologic factor(7/11). others included pancreatitis, iatrogenic and unknown. Intramural hematoma showed three patterns of CT characteristics: intramural mass(8/11), thickened bowel wall(1/11), and both(2/11). There were variable attenuation value of 10 cases of intramural mass; homogenous hyperdensity or hypodensity in each 3 cases, inhomogeneous or mixed density in 4 cases. Also there were peripheral lucent halo(1/10), pseudocapsule or dense rim(5/10), crescentic hyperdensity(2/10) and central hyperdense area(4/10). Associated CT features were hemoperitoneum(4), mesenteric infiltration, fatty liver, pancreatic confusion, and chronic pancreatitis. CT is the most accurate method in establishing the diagnosis or intramural hematoma, evaluating the extent of bleeding and its effect on adjacent organs, demonstrating regression after treatment, and detecting associating injury

  3. Computed tomographic findings of ovarian tumors

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    Kwon, Kwi Ryeon; Lee, Ki Man; Woo, Seong Ku; Suh, Soo Jhi [Keimyung University School of Medicine, Seoul (Korea, Republic of); Kang, Duk Sik [Kyungpook National University College of Medicine, Taegu (Korea, Republic of)

    1986-08-15

    irregular-marginated, thick-walled, cystic tumors with enhancing solid lesion, septal irregularity and signs of metastasis, although there were some cases having similar features of benign. 7. Among the extrapelvic CT findings of malignant epithelial ovarian tumor, peritoneal/omental implants (11 cases: 79%) and ascites (10 cases: 71%) were the most common, and indistinct uterus (6 cases: 43%), bowel adhesion (5 cases: 36%) and pseucomyxoma peritonei (2 cases) were descending order of frequency. 8. CT features of teratoma were diagnostic having at least three more of different tissue densities among fat, water, soft tissue and calcific densities. Also there were thick wall (4 cases) and fat-fluid level (1 case). 9. In 8 cases of ovarian metastases, there were solid type tumor smaller than 10cm in 4 cases and huge cystic in 2 cases. The site of primary cancer were stomach in 4 cases, colon, cervix, endometrium and unknown in each one case. 10. In 3 cases of malignant lymphoma, the CT features were solid in appearance, smaller than 10cm and accompanied by lymphadenopathy in all cases.

  4. Tomographic findings of acute pulmonary toxoplasmosis in immunocompetent patients.

    Science.gov (United States)

    de Souza Giassi, Karina; Costa, Andre Nathan; Apanavicius, Andre; Teixeira, Fernando Bin; Fernandes, Caio Julio Cesar; Helito, Alfredo Salim; Kairalla, Ronaldo Adib

    2014-11-25

    Toxoplasmosis is one of the most common human zoonosis, and is generally benign in most of the individuals. Pulmonary involvement is common in immunocompromised subjects, but very rare in immunocompetents and there are scarce reports of tomographic findings in the literature. The aim of the study is to describe three immunocompetent patients diagnosed with acute pulmonary toxoplasmosis and their respective thoracic tomographic findings. Acute toxoplasmosis was diagnosed according to the results of serological tests suggestive of recent primary infection and the absence of an alternative etiology. From 2009 to 2013, three patients were diagnosed with acute respiratory failure secondary to acute toxoplasmosis. The patients were two female and one male, and were 38, 56 and 36 years old. Similarly they presented a two-week febrile illness and progressive dyspnea before admission. Laboratory tests demonstrated lymphocytosis, slight changes in liver enzymes and high inflammatory markers. Tomographic findings were bilateral smooth septal and peribronchovascular thickening (100%), ground-glass opacities (100%), atelectasis (33%), random nodules (33%), lymph node enlargement (33%) and pleural effusion (66%). All the patients improved their symptoms after treatment, and complete resolution of tomographic findings were found in the followup. These cases provide a unique description of the presentation and evolution of pulmonary tomographic manifestations of toxoplasmosis in immunocompetent patients. Toxoplasma pneumonia manifests with fever, dyspnea and a non-productive cough that may result in respiratory failure. In animal models, changes were described as interstitial pneumonitis with focal infiltrates of neutrophils that can finally evolve into a pattern of diffuse alveolar damage with focal necrosis. The tomographic findings are characterized as ground glass opacities, smooth septal and marked peribronchovascular thickening; and may mimic pulmonary congestion

  5. Tomographic findings of lobar consolidation in primary pulmonary tuberculosis

    International Nuclear Information System (INIS)

    Pereira, Bruno Alberto Falcao; Macedo, Solange Goncalves David de; Penna, Claudia Renata Rezende

    2009-01-01

    Objective: To describe tomographic findings of lobar consolidation as early manifestation of primary pulmonary tuberculosis. Materials and methods: The present study was developed at Hospital Municipal Jesus, Rio de Janeiro, RJ, Brazil, in the period between 2002 and 2006, retrospectively evaluating tomographic findings in four children aged from 3 to 14 months with lobar consolidation as an early manifestation of primary pulmonary tuberculosis. Results: The most frequently found radiological pattern was lobar consolidation with calcifications, cavitation and intermingle necrotic areas, associated with bulging fissure. Signs of bronchogenic dissemination and lymph node enlargement were observed in all of the four children. Consolidation with a pseudotumor aspect and masslike effect was observed in one case. Conclusion: The cases included in the present study have demonstrated that primary pulmonary tuberculosis manifested as lobar consolidation presents typical tomographic images such as cavitation, hypodense areas and calcifications intermingled with consolidation. The association with lymph node enlargement with central necrosis and signs of bronchogenic dissemination reinforce the diagnosis of tuberculosis. (author)

  6. Clinical findings in 16 patients with tomographic diagnosis of schizencephaly

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    Rodrigues, Maria do Carmo de Souza [Universidade Federal do Espirito Santo, Vitoria, ES (Brazil). Hospital Universitario Cassiano Antonio Moraes]. E-mail: rodriguesmcs@yahoo.com.br; Monteiro, Alexandra Maria Vieira [Universidade do Estado do Rio de Janeiro, RJ (Brazil). Faculdade de Ciencias Medicas; Llerena Junior, Juan Clinton [Fundacao Oswaldo Cruz, Rio de Janeiro, RJ (Brazil). Instituto Fernandes Figueira. Centro de Genetica Medica; Fernandes, Alexandre Ribeiro [Universidade Gama Filho, Rio de Janeiro, RJ (Brazil). Dept. de Pediatria

    2006-09-15

    Objective: to establish a correlation between clinical features in a group of children with tomographic diagnosis of schizencephaly and clefts extent and localization. Materials and methods: retrospective study of dossiers from the archives of Neurology and Medical Genetics Services at Instituto Fernandes Figueira/FIOCRUZ and Hospital Municipal Jesus, Rio de Janeiro, RJ, Brazil, in the period between 2000 and 2003. The study included 16 patients, nine female and seven male, with tomographic diagnosis of schizencephaly investigated for clinical findings, psychomotor development, motor/cognitive deficits and epilepsy. Results: predominance of bilateral clefts in 10:16 patients, open-lip schizencephaly type in 23:27 patients, and small lips in 11:27 patients. As regards anomalies associated with schizencephaly, pellucid septum absence was the most frequent one (10:16 patients). As regards clinical findings, 15 patients presented with developmental delay and motor deficit, six patients with cognitive deficit and ten with epilepsy. In three patients, we observed discordant clinical findings and cleft sizes, although the clefts were small, the clinical features severity was high because of other cerebral anomalies. Conclusion: the clinical features of schizencephaly are related to the size of the clefts, regardless laterality, presenting higher severity when associated with other cerebral anomalies. (author)

  7. Clinical findings in 16 patients with tomographic diagnosis of schizencephaly

    International Nuclear Information System (INIS)

    Rodrigues, Maria do Carmo de Souza; Monteiro, Alexandra Maria Vieira; Llerena Junior, Juan Clinton; Fernandes, Alexandre Ribeiro

    2006-01-01

    Objective: to establish a correlation between clinical features in a group of children with tomographic diagnosis of schizencephaly and clefts extent and localization. Materials and methods: retrospective study of dossiers from the archives of Neurology and Medical Genetics Services at Instituto Fernandes Figueira/FIOCRUZ and Hospital Municipal Jesus, Rio de Janeiro, RJ, Brazil, in the period between 2000 and 2003. The study included 16 patients, nine female and seven male, with tomographic diagnosis of schizencephaly investigated for clinical findings, psychomotor development, motor/cognitive deficits and epilepsy. Results: predominance of bilateral clefts in 10:16 patients, open-lip schizencephaly type in 23:27 patients, and small lips in 11:27 patients. As regards anomalies associated with schizencephaly, pellucid septum absence was the most frequent one (10:16 patients). As regards clinical findings, 15 patients presented with developmental delay and motor deficit, six patients with cognitive deficit and ten with epilepsy. In three patients, we observed discordant clinical findings and cleft sizes, although the clefts were small, the clinical features severity was high because of other cerebral anomalies. Conclusion: the clinical features of schizencephaly are related to the size of the clefts, regardless laterality, presenting higher severity when associated with other cerebral anomalies. (author)

  8. Alveolar echinococcosis of the liver - computed tomographic findings

    International Nuclear Information System (INIS)

    Merkle, E.; Usadel, S.; Vogel, J.; Kern, P.; Friedrich, J.M.; Brambs, H.J.

    1995-01-01

    In order to ascertain the typical computed tomographic findings of hepatic alveolar echinococcosis, 24 computed tomograms of 19 patients were evaluated. The liver was involved in all cases whereas the diaphragma was infiltrated in 32%, and the retroperioteneal area in 42%. The right liver lobe was affected in 65%. Both before and after intravenous bolus contrast medium administration, the lesions were mainly inhomogeneous and of low density; a masking of the lesions due to the contrast medium administration was not observed; the enhancement pattern was irregular. Calcifications were detected in 96% of the cases, cystic structures in 50%, and cholestasis in 54%. On the basis of the crucial finding of calcifications in combination with the other typical observations, CT seems to be very suitable for the evaluation of hepatic alveolar echinococcosis. (orig.) [de

  9. Optical coherence tomographic view of persistent primary fetal vasculature

    International Nuclear Information System (INIS)

    Shenoy, R.; Al-Kharousi, Nadia S.; Bialasiewicz, Alexander A.

    2006-01-01

    Purpose was to report on the posterior segment changes in a patient with bilateral persistent primary fetal vasculature as detected by optical coherence tomography. An 18-year-old lady with poor vision, left esotropia and bilateral posterior polar cataract was found to have dysplasia of the macula in the both eyes. Fundus fluorescein angiography, optical coherence tomography, ''A'' scan biometry and genetic work up was performed as a part of investigation. There was increase in thickness of the macular area in both the eyes (450-500mm). The left eye showed a ''sail like'' fold extending over macula, from nasal to temporal side. The tissue had the same sensitivity and thickness as inner the retinal layers (180-200). There was no detectable nerve fibre layer in the macula of either eye. Fundus fluorescein angiography was normal in the right eye, and showed hyperfluorescence at the inferior pole of the disk in the left eye corresponding to the Bergmeister papilla. There was no staining of the membrane with the dye. Evaluation of the posterior segment is important in predicting the visual outcome in patients with any from of PFV. Optical coherence tomography is an adjuvant to direct visualization and aids in further delineating posterior segment changes seen in this condition. (author)

  10. Application of THz probe radiation in low-coherent tomographs based on spatially separated counterpropagating beams

    Energy Technology Data Exchange (ETDEWEB)

    Kuritsyn, I I; Shkurinov, A P; Nazarov, M M [Department of Physics, M.V. Lomonosov Moscow State University (Russian Federation); Mandrosov, V I [Moscow Institute of Physics and Technology (State University), Dolgoprudnyi, Moscow Region (Russian Federation); Cherkasova, O P [Institute of Laser Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2013-10-31

    A principle of designing a high-resolution low-coherent THz tomograph, which makes it possible to investigate media with a high spatial resolution (in the range λ{sub 0} – 2λ{sub 0}, where λ{sub 0} is the average probe wavelength) is considered. The operation principle of this tomograph implies probing a medium by radiation with a coherence length of 8λ{sub 0} and recording a hologram of a focused image of a fixed layer of this medium using spatially separated counterpropagating object and reference beams. Tomograms of the medium studied are calculated using a temporal approach based on application of the time correlation function of probe radiation. (terahertz radiation)

  11. Computed tomographic findings in children with spastic diplegia

    International Nuclear Information System (INIS)

    Yokochi, Kenji; Horie, Masayo; Inukai, Kazuhisa; Kito, Hideyuki; Shimabukuro, Satoshi; Kodama, Kazuo.

    1989-01-01

    Computed tomographic findings of 46 children with spastic diplegia examined at nine months to three years of age corrected for preterm births were analyzed. Both the size of the lateral ventricles measured by the width of the anterior horns, and the volume of the extracerebral low-density areas were enlarged in some patiens. Both enlargements did not, however, correlate to the severity of the motor abnormality in the patients. The low-density areas of the periventricular white matter, especially adjacent to the trigone, were reduced in many children, probably due to the atrophy of the cerebral white matter having periventricular leukomalacia. The anterior expansion of the white matter reduction from the trigone corresponded to the severer motor abnormality in the children with spastic diplegia. (author)

  12. Computed tomographic findings of liver injury in adults

    International Nuclear Information System (INIS)

    Ha, Deok Gi; Lee, Hyeon Kyeong; Lee, Won Jae; Oh, Yeon Hee; Lee, Sung Hee; Yun, Jee Yeong; Lee, Tae Woo; Lee, Sung Woo; Park, Soo Soung

    1994-01-01

    We studied to compare computed tomographic(CT) findings of liver injury with management method in adults and, moreover, to present the CT basis for the management. We retrospectively reviewed CT scans of 43 adults diagnosed as liver injury during a 66 month period. Thirty-eight patients were hemodynamically stable. Thirty-two of them were managed conservatively, whereas six managed operatively. Five unstable patients underwent emergency operation. We classified CT findings according to the severity of liver injuries(ie, hematoma, laceration, and periportal tracking) and hemoperitoneum, ranging from grade 1 to 5 and from 0 to 3 +. respectively. Thus, we compared the CT classifications with their management(ie, operation rate), especially hemodynamically stable patients. Operation rates of all patients and hemodynamically stable patients were 26% and 16%, respectively. Operation rate at each grade of liver injury was low, especially in hemodynamically stable, despite relatively high operation rate in grade 4. Operation rate of 3+ homoperitoneum was 100%, including hemodynamically stable patients, in contrast to otherwise low operation rate of others. Most liver injury in adults, including grade 4, were managed conservatively, especially hemodynamically stable. Though large amount of hemoperitoneum(ie, 3+) required operation, most hemooperitoeum were managed conservatively. Thus, CT findings of liver injury is helpful in the decision for the management method

  13. Laparoscopic optical coherence tomographic imaging of human ovarian cancer

    Science.gov (United States)

    Hariri, Lida P.; Bonnema, Garret T.; Schmidt, Kathy; Korde, Vrushali; Winkler, Amy M.; Hatch, Kenneth; Brewer, Molly; Barton, Jennifer K.

    2009-02-01

    Ovarian cancer is the fourth leading cause of cancer-related death among women. If diagnosed at early stages, 5-year survival rate is 94%, but drops to 68% for regional disease and 29% for distant metastasis; only 19% of cases are diagnosed at early, localized stages. Optical coherence tomography is a recently emerging non-destructive imaging technology, achieving high axial resolutions (10-20 µm) at imaging depths up to 2 mm. Previously, we studied OCT in normal and diseased human ovary ex vivo. Changes in collagen were suggested with several images that correlated with changes in collagen seen in malignancy. Areas of necrosis and blood vessels were also visualized using OCT, indicative of an underlying tissue abnormality. We recently developed a custom side-firing laparoscopic OCT (LOCT) probe fabricated for in vivo imaging. The LOCT probe, consisting of a 38 mm diameter handpiece terminated in a 280 mm long, 4.6 mm diameter tip for insertion into the laparoscopic trocar, is capable of obtaining up to 9.5 mm image lengths at 10 µm axial resolution. In this pilot study, we utilize the LOCT probe to image one or both ovaries of 17 patients undergoing laparotomy or transabdominal endoscopy and oophorectomy to determine if OCT is capable of differentiating normal and neoplastic ovary. We have laparoscopically imaged the ovaries of seventeen patients with no known complications. Initial data evaluation reveals qualitative distinguishability between the features of undiseased post-menopausal ovary and the cystic, non-homogenous appearance of neoplastic ovary such as serous cystadenoma and endometroid adenocarcinoma.

  14. Brain computed tomographic findings in post-cardiopulmonary resuscitation patients

    International Nuclear Information System (INIS)

    Ishida, Tsuguharu; Yoshinaga, Kazumasa; Horibe, Takashi; Kokubu, Kiyokazu; Kokura, Yoshihiro; Matsui, Konosuke; Inamoto, Kazuo.

    1986-01-01

    We retrospectively assessed the brain computed tomographic (CT) findings in 22 post-cardiopulmonary resuscitation (CPR) patients excluding neonatal cases. On the basis of the CT findings, the patients were divided into two groups. Eight patients (36.4 %) had bilateral abnormal lowdensity areas in the basal ganglia (Group I). The remaining 14 patients (63.6 %) had no abnormalities in that area (Group II). In Group I, the incidence of primary cardiac arrest and duration of advanced life support (ALS) was significantly different (p < 0.05) from Group II. Sex, age, duration of basic life support (BLS), time elapsed from initiation of BLS to initial CT and from initiation of ALS to initial CT was not significantly different between the two groups. Outcome was very poor in both groups and no significant difference was noted between them. We conclude that primary cardiac arrest and long duration of ALS were predictors of abnormal bilateral low-density areas in the basal ganglia in post-CPR patients. However, their appearance was not related to outcome. (author)

  15. On the estimation of wall pressure coherence using time-resolved tomographic PIV

    Science.gov (United States)

    Pröbsting, Stefan; Scarano, Fulvio; Bernardini, Matteo; Pirozzoli, Sergio

    2013-07-01

    Three-dimensional time-resolved velocity field measurements are obtained using a high-speed tomographic Particle Image Velocimetry (PIV) system on a fully developed flat plate turbulent boundary layer for the estimation of wall pressure fluctuations. The work focuses on the applicability of tomographic PIV to compute the coherence of pressure fluctuations, with attention to the estimation of the stream and spanwise coherence length. The latter is required for estimations of aeroacoustic noise radiation by boundary layers and trailing edge flows, but is also of interest for vibro-structural problems. The pressure field is obtained by solving the Poisson equation for incompressible flows, where the source terms are provided by time-resolved velocity field measurements. Measured 3D velocity data is compared to results obtained from planar PIV, and a Direct Numerical Simulation (DNS) at similar Reynolds number. An improved method for the estimation of the material based on a least squares estimator of the velocity derivative along a particle trajectory is proposed and applied. Computed surface pressure fluctuations are further verified by means of simultaneous measurements by a pinhole microphone and compared to the DNS results and a semi-empirical model available from literature. The correlation coefficient for the reconstructed pressure time series with respect to pinhole microphone measurements attains approximately 0.5 for the band-pass filtered signal over the range of frequencies resolved by the velocity field measurements. Scaled power spectra of the pressure at a single point compare favorably to the DNS results and those available from literature. Finally, the coherence of surface pressure fluctuations and the resulting span- and streamwise coherence lengths are estimated and compared to semi-empirical models and DNS results.

  16. Optical coherence tomography findings of quinine poisoning

    Directory of Open Access Journals (Sweden)

    John Christoforidis

    2011-01-01

    Full Text Available John Christoforidis, Robert Ricketts, Theodore Loizos, Susie ChangThe Ohio State University College of Medicine, Columbus, OH, USAPurpose: To report a case of acute quinine poisoning, document acute and chronic macular changes with optical coherence tomography imaging and fluorescein angiography (FA, and to review the literature on ocular toxicity of quinine.Methods: A 32-year-old white female presented to our Emergency Department after ingesting over 7.5 g of quinine. She underwent a complete ophthalmologic examination, fluorescein angiography, Stratus time-domain optical coherence tomography (OCT, and electroretinography at 72 hours and 15 months postingestion. Stratus time-domain and Cirrus spectral-domain OCT, fundus autofluorescence, and FA were obtained at 28 months postingestion.Results: Fluorescein angiography at 72 hours postingestion revealed normal filling times and vasculature. OCT showed marked thickening of the inner retina bilaterally. At 15 and 28 months follow-up, fundus photography and fluorescein angiography demonstrated optic nerve pallor, severely attenuated retinal vessels while OCT showed inner retinal atrophy. Fundus autofluorescence did not reveal any retinal pigmentary abnormalities.Conclusions: Quinine toxicity as seen by OCT reveals increased thickness with inner retinal hyperreflectivity acutely with development of significant retinal atrophy in the long-term. Fundus autofluorescence reveals an intact retinal pigment epithelial layer at 28 months. These findings suggest that quinine poisoning may produce a direct toxic effect on the inner retina in the acute phase resulting in long-term retinal atrophy.Keywords: retinal, optical coherence tomography, quinine toxicity 

  17. Fractal analysis of en face tomographic images obtained with full field optical coherence tomography

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Wanrong; Zhu, Yue [Department of Optical Engineering, Nanjing University of Science and Technology, Jiangsu (China)

    2017-03-15

    The quantitative modeling of the imaging signal of pathological areas and healthy areas is necessary to improve the specificity of diagnosis with tomographic en face images obtained with full field optical coherence tomography (FFOCT). In this work, we propose to use the depth-resolved change in the fractal parameter as a quantitative specific biomarker of the stages of disease. The idea is based on the fact that tissue is a random medium and only statistical parameters that characterize tissue structure are appropriate. We successfully relate the imaging signal in FFOCT to the tissue structure in terms of the scattering function and the coherent transfer function of the system. The formula is then used to analyze the ratio of the Fourier transforms of the cancerous tissue to the normal tissue. We found that when the tissue changes from the normal to cancerous the ratio of the spectrum of the index inhomogeneities takes the form of an inverse power law and the changes in the fractal parameter can be determined by estimating slopes of the spectra of the ratio plotted on a log-log scale. The fresh normal and cancer liver tissues were imaged to demonstrate the potential diagnostic value of the method at early stages when there are no significant changes in tissue microstructures. (copyright 2016 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Tuberculosis of the Parotid Gland: Computed Tomographic Findings

    International Nuclear Information System (INIS)

    Wei, Y.; Xiao, J.; Pui, M.H.; Gong, Q.

    2008-01-01

    Background: Tuberculosis (TB) of the parotid gland is rare, even in endemic regions. Approximately 100 cases have been reported in the English literature. The computed tomographic (CT) features, however, have seldom been studied. Purpose: To determine the diagnostic CT features of tuberculosis of the parotid gland. Material and Methods: CT studies of four histologically proven cases of tuberculosis of the parotid gland were retrospectively reviewed. Results: A total of 15 enlarged lymph nodes were found in the superficial lobes of the parotid glands. The nodes were arranged linearly within the gland. Enhancement patterns included homogeneous enhancement (9/15, 60%), homogeneous enhancement with eccentric microcysts (3/15, 20%), and thick-walled rim enhancement with central lucency (3/15, 20%). Thickened adjacent fascial plane and platysma were seen in two patients. Ipsilateral cervical lymphadenopathy was seen in all patients. Conclusion: In patients presenting with unilateral parotid nodules, TB should be considered when linearly arranged enhancing nodules are demonstrated in the superficial lobes of the glands on CT scan

  19. Correlation of computed tomographic and magnetic resonance imaging findings in cerebral infartion

    International Nuclear Information System (INIS)

    Komatsubara, Chizuko; Chuda, Moriyoshi; Taka, Toshihiko

    1989-01-01

    We evaluated neurological findings in 75 patients of cerebral infarction, and correlated computed tomographic (CT) and magnetic resonance imaging (MRI) findings. MRI was found to have the advantage when the lesion were multiple, or in the posterior fossa. MRI demonstrates the anatomical details, and lacks the bony artifact, so it is an excellent method for identification of cerebral infarction. (author)

  20. Optical coherence tomography findings in methanol toxicity.

    Science.gov (United States)

    Klein, Kendra A; Warren, Alexis K; Baumal, Caroline R; Hedges, Thomas R

    2017-01-01

    Methanol toxicity poses a significant public health problem in developing countries, and in Southeast Asia, where the most common source of poisoning is via adulterated liquor in local drinks. Methanol toxicity can have devastating visual consequences and retinal specialists should be aware of the features of this toxic optic neuropathy. The authors report a case of severe systemic methanol toxicity and relatively mild optic neuropathy demonstrating unique retinal changes on optical coherence tomography (OCT). A previously healthy student developed ataxia, difficulty breathing and loss of consciousness hours after drinking homemade alcohol while traveling in Indonesia. She was found to have a serum pH of 6.79 and elevated methanol levels. She was treated with intravenous ethanol, methylprednisolone and sodium bicarbonate. When she awoke she had bilateral central scotomas. At presentation, she had central depression on visual field testing. OCT of the retinal nerve fiber layer (RNFL) was normal but ganglion cell layer analysis (GCL) showed highly selective loss of the nasal fibers in both eyes. Further, OCT of the macula demonstrated inner nuclear layer (INL) microcysts in the corresponding area of selective GCL loss in both eyes. The selective involvement of the papillomacular bundle fibers is common in toxic optic neuropathies and represents damage to the small caliber axons rich in mitochondria. Despite severe systemic toxicity, the relative sparing of the optic nerve in this case enabled characterization of the evolution of methanol toxicity with segmental GCL involvement and preservation of the RNFL, corresponding to the papillomacular bundle. This is the first reported case of INL microcysts in methanol optic neuropathy and supports that they are a non-specific finding, and may represent preferential damage to the papillomacular bundle.

  1. Computed tomographic findings in acute superior mesenteric arterial occlusion

    International Nuclear Information System (INIS)

    Kuwabara, Yoshiyuki; Kataoka, Makoto; Kureyama, Yasuyuki; Iwata, Hiroshi; Kashima, Taketoshi; Sinoda, Noriyuki; Sato, Atsushi; Hattori, Kohji; Masaoka, Akira

    1993-01-01

    In this study computed tomography (CT) findings were examined in 6 cases of acute superior mesenteric arterial (SMA) occlusion. With simple CT, occluded site of SMA revealed a slightly high density in 2 cases, while no findings were noted in other cases. Slightly dilated multiple loops of the intestine were confirmed in 3 cases, but no particular changes in the intestinal wall were found. As other findings, ascites and air in the portal vein were found in each one case. Contrast enhanced CT was conducted in 2 out of the 6 cases, and occluded site was visualized as spots in one case but no findings were noted in the other. The contrast enhancement effect in vessels in SMA region was examined from its root to the peripheral in this order, and the 2 cases showed common findings that the contrast enhancement effect abruptly disappeared at a point in vessels in SMA region (discontinuance). The point was consistent with the occluded site on angiography. These findings indicate that simple CT alone is difficult to offer correct diagnosis of SMA occlusion, but contrast enhanced CT is able to visualize the SMA occlusion as a discontinuance picture. It is thought that contrast enhanced CT can be a useful procedure for early diagnosis of SMA occlusion. (author)

  2. Comparative study of the macroscopic finding, conventional tomographic imaging, and computed tomographic imaging in locating the mandibular canal

    International Nuclear Information System (INIS)

    Choi, Hang Moon; You, Dong Soo

    1995-01-01

    The purpose of this study was comparison of conventional tomography with reformatted computed tomography for dental implant in locating the mandibular canal. Five dogs were used and after conventional tomographs and fitted computed tomographs were taken, four dentist traced all films. Mandibles were sectioned with 2 mm slice thickness and the sections were then radiographed (contact radiography). Each radiograpic image was traced and linear measurements were made from mandibular canal to alveolar crest, buccal cortex, lingual cortex, and inferior border. The following results were obtained; 1. Reformatted computed tomographs were exacter than conventional tomography by alveolar crest to canal length of -0.6 mm difference between real values and radiographs 2. The average measurements of buccal cortex to mandibular canal width and lingual cortex to mandibular canal width of conventional tomographs were exacter than reformatted computed tomographs, but standard deviations were higher than reformatted computed tomographs. 3. Standard deviations of reformatted computed tomographs were lower than conventional tomographs at all comparing sites 4. At reformatted computed tomography 62.5% of the measurements performed were within ±1 mm of the true value, and at conventional tomography 24.1% were. 5. Mandibular canal invisibility was 0.8% at reformatted computed tomography and 9.2% at conventional tomography. Reformatted computed tomography has been shown to be more useful radiographic technique for assessment of the mandibular canal than conventional tomography.

  3. Computer tomographic examination of the thymus. Normal and pathological findings

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, C.; Dinkel, E.; Wimmer, B.; Grosser, G.; Schildge, J.

    1987-09-01

    The diagnostic value of CT in follicular thymic hyperplasia and in thymomas in 8 patients with myasthenia gravis and in 12 patients without myasthenia gravis suffering from thymic tumors was evaluated by correlating CT-findings to surgical results and pathological-histological findings. Thymic size of the six patients with histologically proven follicular hyperplasia were scattered within the normal range, but half of them were at the upper limit. Thymic tumors were differentiated between invasive and non invasive tumors by CT staging. Solid tumors with different histology could not be further classified; the attenuation values ranging from 15-55 HU were the same in tumors, follicular hyperplasia and normal thymus.

  4. Computed tomographic findings of progressive supranuclear palsy compared with Parkinson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Yuki, Nobuhiro; Sato, Shuzo; Yuasa, Tatsuhiko; Ito, Jusuke; Miyatake, Tadashi [Niigata Univ. (Japan). School of Dentistry

    1990-10-01

    We investigated computed tomographic (CT) films of 4 pathologically documented cases of progressive supranuclear palsy (PSP) in which the clinical presentations were atypical and compared the findings with those of 15 patients with Parkinson's disease (PD). Dilatation of the third ventricle, atrophy of the midbrain tegmentum, and enlargement of the interpeduncular cistern toward the aqueduct were found to be the characteristic findings in PSP. Thus, radiological findings can be useful when the differential diagnosis between PSP and PD is clinically difficult. (author).

  5. Computed tomographic brain scan findings in Q fever encephalitis

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Aranda, F.; Romero Acebal, M.; Maestre Moreno, J.; Pachon Diaz, J.; Lopez Cortes, L.; Navarro Rodriguez, A.

    1984-07-01

    Neurological involvement in Q Fever is unusual. We present a case of encephalitis due to Coxiella Burnetii with neuroradiologic findings on CT not described previously, consisting in areas of decreased absorption coefficient in the subcortical white matter of both hemispheres, predominantly in the right. Differential diagnosis must be established from viral encephalitis, of similar clinical presentation, which may show similar CT lesions to those in this case.

  6. Ultrasonic and x-ray tomographic findings of Schistosomiasis Japonicum

    International Nuclear Information System (INIS)

    Nagata, Osamu; Uto, Koji; Sugihara, Hisayo; Takii, Masaru; Nohara, Yumiko; Tominaga, Hidetoshi; Kaji, Masaro; Koga, Teruto.

    1986-01-01

    In the present study, attempts were made to classify the ultrasonic patterns of the liver infected with Schistosoma Japonicum. The calcification and fibrosis of the liver were evaluated by comparative investigation with an ultrasonogram and computed tomography (CT). Schistosomiasis Japonica was examined in 23 patients who were more than 45 years of age. It was diagnosed by liver needle biopsy, an intracutaneous test, or autopsy. The cases with a fish scale and network pattern had attenuation of the liver on ultrasonography and were unspecific on CT. Histological findings demonstrated moderate liver fibrosis. The cases with a sieve pattern had attenuation on ultrasonography, and the CT disclosed a retractive liver and the CT number of that liver was increased. Histological findings demonstrated a severe fibrotic liver. The cases with a mottled pattern had increased reflective spotty echo with an acoustic shadow, and the CT disclosed calcification. The histological findings demonstrated a marked calcification of the eggs. The cases with a mixed pattern, which consisted of mottled and sieve based on fish scale and network, had no retraction with less increase in the CT number. These results suggest that the peculiar reflective echo pattern of Schistosomiasis Japonica was due to not only calcification but also fibrosis of the liver. (author)

  7. Computed tomographic findings in normal elderly volunteers and demented patients

    International Nuclear Information System (INIS)

    Nishino, Hideo; Ide, Hiroshi; Kurihara, Norimitsu; Tanno, Munehiko; Yamada, Hideo; Chiba, Kazuo; Kasahara, Isao; Karasawa, Akihide; Hasegawa, Kazuo.

    1988-01-01

    CT findings of demented patients with CVD (49 cases) and without CVD (51 cases) were compared with those of healthy age matched volunteers with CVD (29 cases) and without CVD (110 cases). The results were as follows. 1) About 20 % of healthy volunteers had CVD (silent stroke) and these cases should never be regarded as real healthy aged peoples. 2) In aged healthy peoples, size of lateral ventricles, sulci and Sylvian fissure were increased with aging. The degree of PVL and size of third ventricle were not increased with age. 3) Incidence of PVL was closely related with presence of CVD. In demented patients without CVD, however, PVL increased with aging. 4) In dementia the size of lateral ventricle, sulci, Sylvian fissure and third ventricle showed no correlation with aging. In general, enlargement of the lateral ventricle and Sylvian fissure were more prominent in demented peoples without CVD. 5) Atrophy in the medial temporal lobe were observed most frequently in demented peoples without CVD aged 50 to 59 years. In demented patients over 60, no difference was observed in finding of the area between those with and without CVD. (author)

  8. Computed Tomographic Findings of Acute Carbon Monoxide Posioning

    International Nuclear Information System (INIS)

    Park, Young Keun; Won, Hee Sun; Lee, Seung Ro; Hahm, Chang Kok

    1983-01-01

    Carbon monoxide (CO) is a kind of frequent toxic gas around our living lives, for common use of briquets as fuel, and its pathologic effect has been known due to mainly hypoxia and direct cytotoxicity in some part to almost all organs, especially to the brain and heart. Some authors have reported pathologic and anatomic changes of the acute of poisoning, although in a few cases, that bilaterally symmetrical lesions of the globs pallidus or cerebral white matter regarded as typical. After using computed tomography (CT), those findings have been discovered more easily and accurately. Authors analysed CT findings of 32 cases, who had a history of acute CO poisoning and performed CT at Hanyang University Hospital from May 1970 to June 1983. The results were as follows: 1. Of all 32 cases with CT scan, low density lesions were demonstrated in 28 cases (88%) and others were hemorrhage and calcified in 2(6%), respectively. 2. All lesions were seen as bilaterally symmetrical, except 2 cases of hemorrhage and 1 of low density. 3. Of all 28 cases of the low densities, 15 cases(53.6%) were located in the globs pallidus, 10(35.7%) in the cerebral white matter and 3(10.7%) in both of them. 4. Of all 113 cases of the low density lesions in the cerebral white matter, common locations were in the frontal and parietal lobes (65.6%), and more in frontal (40.6%). 5. Of all 113 cases of low density lesions in the cerebral white matter, cases of involving all of the lobes were found in only 4. 6. All of 2 cases of the calcified lesions were seen at both sides of the globs pallidus, symmetrically. 7. All of 2 cases of the hemorrhage were seen at thalamus, ventricles and head of caudate nucleus, and these locations were different from those of the low densities or calcifications.

  9. Hepatocellular carcinoma with bile duct involvement : computed Tomographic (CT) findings

    International Nuclear Information System (INIS)

    Lee, Joon Woo; Han, Joon Koo; Kim, Tae Kyoung; And others

    2000-01-01

    To describe the radiologic features of computed tomography (CT) in hepatocellular carcinoma (HCC) with bile duct involvement. We retrospectively analyzed the two phase spiral CT findings of 31 patients in whom HCC with bile duct invasion (n=3D28) or compression (n=3D3), was diagnosed. Eight of these underwent follow up CT after transarterial chemoembolization. We analyzed the size, type, location, enhancement pattern, and lipiodol retention of parenchymal and intraductal masses, as well as their lymphadenopathy. In all patients with bile duct invasion, single or multiple masses were demonstrated in the bile ducts. Intraductal masses showed the same enhancement characteristics as the parenchymal mass (kappa 0.550, p less than 0.001), and were contiguous to this mass. In 14 of 28 patients, intraductal masses filled the peripheral intrahepatic bile ducts and extended to the common bile ducts. In the other 14, the parenchymal mass extended to the area of the porta hepatis and then directly invaded the large ducts. In nine of the 28 patients, there was a hypoattenuated cleft between the intraductal mass and ductal wall. In six, a parenchymal mass was not apparent (n=3D2), or was smaller than 2cm (n=3D4). In five of eight patients (62.5%), follow-up CT after transarterial chemoembolization showed compact or partial lipiodol retention within the intraductal mass. In patients with bile duct compression, perihilar lymph nodes were noted along with the dilated intrahepatic duct but no intra ductal mass was demonstrated in the duct. Hepatocellular carcinomas cause bile duct dilatation either by direct invasion or by extrinsic compression of the bile duct with surrounding enlarged nodes. For the diagnosis of this condition, CT is helpful. (author)

  10. Intraretinal hyperreflective foci on spectral-domain optical coherence tomographic images of patients with retinitis pigmentosa

    Science.gov (United States)

    Kuroda, Masako; Hirami, Yasuhiko; Hata, Masayuki; Mandai, Michiko; Takahashi, Masayo; Kurimoto, Yasuo

    2014-01-01

    Background The purpose of this study was to observe the characteristic findings of spectral-domain optical coherence tomography (SD-OCT) images in the retinas of patients with retinitis pigmentosa and to evaluate their distribution patterns in the early and advanced stages of the disease. Methods A total of 184 patients (368 eyes) with retinitis pigmentosa were observed using SD-OCT. We studied the presence or absence of continuous inner/outer segment (IS/OS) lines, presence of thinning of the retinal pigment epithelium-Bruch’s membrane complex, and distribution patterns of hyperreflective foci in the inner and outer nuclear layers (INL and ONL). Results The IS/OS junction had partially disappeared in 275 eyes, which were at the early stage of retinitis pigmentosa (group X), whereas the junction had totally disappeared in 93, which were at the advanced stage of retinitis pigmentosa (group Y). Hyperreflective foci in the INL were observed in a significantly larger proportion of the eyes in group X than in group Y (90% versus 61%, Pretinitis pigmentosa and hyperreflective foci in the ONL were more frequently observed in the advanced stage. Hyperreflective foci may be indicative of changes in the retinal structure at each stage of retinitis pigmentosa. PMID:24591813

  11. Tomographic findings of gastric gastrointestinal stromal tumor: a 14-case study

    International Nuclear Information System (INIS)

    Pelandre, Gustavo Lemos; Djahjah, Maria Celia; Nobre, Luiz Felipe; Gasparetto, Emerson Leandro; Marchiori, Edson; Pereira, Bruno Vilhena; Valadao, Marcus; Linhares, Eduardo

    2008-01-01

    Objective: The purpose of this study was to describe the tomographic findings of gastric gastrointestinal stromal tumor. Materials and methods: Fourteen patients with histopathologically and immunohistochemically confirmed gastric gastrointestinal stromal tumors, who had already been submitted to computed tomography scans before the treatment, were evaluated in the period between January 1999 and December 2006. The following tomographic variables were analyzed: lesion topography, size/dimensions, homogeneity, contour, margins, morphology, pattern and intravenous contrast-enhancement intensity, growth pattern, invasion of adjacent organs, presence of ulceration, fistula, calcifications, mesenteric fat infiltration, lymphadenomegaly and presence of distant metastasis. Results: Tumors were found in the body (57.1%) or in the gastric fundus (42.9%), with sizes ranging between 6.0 cm and 23.0 cm (mean, 11.5 cm). Predominantly extra luminal growth was observed in 57.1% of cases and intra/extra luminal in 35.7%. Subtle contrast-enhancement was observed in 50%, moderate in 50%, and heterogeneous in 64.3% of cases. Additionally, central hypodensity was observed in 64.3%, invasion of adjacent organs in 42.9%, and hepatic metastasis in 7.2% of cases. Conclusion: In the present study, the majority of tumors were found in the gastric body, with an average size of 11.5 cm, presenting with central hypodensity, heterogeneous contrast-enhancement and predominantly extraluminal growth. (author)

  12. Comparison between computed tomographic and surgical findings in nine large-breed dogs with lumbosacral stenosis

    International Nuclear Information System (INIS)

    Jones, J.C.; Sorjonen, D.C.; Simpson, S.T.; Coates, J.R.; Lenz, S.D.; Hathcock, J.T.; Agee, M.W.; Bartels, J.E.

    1996-01-01

    In a three-year prospective study, computed tomographic (CT) and surgical findings were compared for nine large breed dogs with lumbosacral stenosis. Surgically-excised tissue was examined histologically in seven dogs and additional necropsy evaluation was performed in one dog. The CT abnormalities observed at sites of confirmed cauda equina compression were: loss of epidural fat, increased soft tissue opacity, bulging of the intervertebral disc margin, spondylosis, thecal sac displacement, narrowed intervertebral foramen, narrowed vertebral canal, thickened articular process, articular process subluxation, articular process osteophyte, and telescoped sacral lamina. The CT characteristics of lumbosacral degenerative disease and discospondylitis were similar to those described in humans. In three dogs, CT findings at the site of cauda equina compression were consistent with congenital or developmental spinal stenosis, but the method of surgical exposure precluded confirmation. Epidural fibrosis (eight dogs) and multi-level CT abnormalities (six dogs) were identified but the cause(s) and significance were unknown

  13. Correlation between presumed sinusitis-induced pain and paranasal sinus computed tomographic findings.

    Science.gov (United States)

    Mudgil, Shikha P; Wise, Scott W; Hopper, Kenneth D; Kasales, Claudia J; Mauger, David; Fornadley, John A

    2002-02-01

    The correlation between facial and/or head pain in patients clinically suspected of having sinusitis and actual localized findings on sinus computed tomographic (CT) imaging are poorly understood. To prospectively evaluate the relationship of paranasal sinus pain symptoms with CT imaging. Two hundred consecutive patients referred by otolaryngologists and internists for CT of the paranasal sinuses participated by completing a questionnaire immediately before undergoing CT. Three radiologists blinded to the patients' responses scored the degree of air/fluid level, mucosal thickening, bony reaction, and mucus retention cysts using a graded scale of severity (0 to 3 points). The osteomeatal complexes and nasolacrimal ducts were also evaluated for patency. Bivariate analysis was performed to evaluate the relationship between patients' localized symptoms and CT findings in the respective sinus. One hundred sixty-three patients (82%) reported having some form of facial pain or headache. The right temple/forehead was the most frequently reported region of maximal pain. On CT imaging the maxillary sinus was the most frequently involved sinus. Bivariate analysis failed to show any relationship between patient symptoms and findings on CT. Patients with a normal CT reported a mean 5.88 sites of facial or head pain versus 5.45 sites for patients with an abnormal CT. Patient-based responses of sinonasal pain symptoms fail to correlate with findings in the respective sinuses. CT should therefore be reserved for delineating the anatomy and degree of sinus disease before surgical intervention.

  14. Coherent eavesdropping attacks in tomographic quantum cryptography: Nonequivalence of quantum and classical key distillation

    International Nuclear Information System (INIS)

    Kaszlikowski, Dagomir; Lim, J.Y.; Englert, Berthold-Georg; Kwek, L.C.

    2005-01-01

    The security of a cryptographic key that is generated by communication through a noisy quantum channel relies on the ability to distill a shorter secure key sequence from a longer insecure one. We show that - for protocols that use quantum channels of any dimension and completely characterize them by state tomography - the noise threshold for classical advantage distillation of a specific kind is substantially lower than the threshold for quantum entanglement distillation if the eavesdropper can perform powerful coherent attacks. In marked contrast, earlier investigations had shown that the thresholds are identical for incoherent attacks on the same classical distillation scheme. It remains an open question whether other schemes for classical advantage distillation have higher thresholds for coherent eavesdropping attacks

  15. Paraquat-poisoning in the rabbit lungs: high resolution computed tomographic findings and pathologic correlation

    International Nuclear Information System (INIS)

    Lee, Kyung Soo; Kim, Eui Han; Lee, Byoung Ho; Kim, Kun Sang

    1992-01-01

    The authors evaluated high resolution computed tomographic (HRCT) findings of the isolated rabbit lungs with paraquat poisoning, and the findings were correlated with pathologic specimens. The purposes of this study are 1) to obtain the HRCT findings of the normal rabbit lung. 2) to find out if pulmonary pathology can be induced in rabbits by paraquat, and 3) to correlate the HRCT findings to those of pathology. Thirty rabbits were divided into three groups: group I included four control rabbits; group II included 16 rabbits given paraquat intraperitoneally (IP group); and group III included 10 rabbits given paraquat intravenously (IV group). The rabbits were sacrificed seven, 10, and 14 days after injection of various amount of paraquat, and then the lungs were isolated for HRCT and pathologic studies. Gross and microscopic findings of the three groups of control and paraquat-injected rabbit lungs were correlated with HRCT findings. Pulmonary congestion, mild thickening of alveolar walls and septae, and multifocal micro-atelectasis were the man pathologic findings of the lungs in both groups of the rabbits. Pulmonary hemorrhage was noted in five (31%) of 16 rabbits of IP group and three (30%) of 10 IV group. Pulmonary edema was seen in one rabbits (6%) of IP and four (40%) of IV group. Typical pulmonary fibrosis was seen in one rabbit of IP (6%) and IV (10%) group, respectively. There was no correlation between the amount of paraquat and frequency of the pulmonary pathology. Pulmonary fibrosis was seen at least one week after the paraquat injection. On HRCT, pulmonary hemorrhage and edema appeared as diffuse air-space consolidation and pulmonary fibrosis as linear or band-like opacities. However, minimal changes such as mild congestion

  16. Computed tomographic findings and histological findings of an organized chronic subdural hematoma. A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kamiya, Kazuko; Inagawa, Tetsuji; Nagasako, Ren

    1987-08-01

    As chronic subdural hematoma can be readily diagnosed by computed tomography (CT) and can be treated, there are no reports in the literature describing the CT findings of an organized chronic subdural hematoma with a long clinical course. The present case was a 53-year-old male who experienced a series of remissions and aggravations of such symptoms as right hemiparesis and consciousness disturbance for about five years. CT showed a crescent lesion in the left frontoparietal region. In the margin, an uneven, high-density area could be observed running in ward, and in the interior, an iso approx. low-density area could be seen, but no evident enhancement could be noted in either area. The patient died of liver cirrhosis, and an autopsy was performed. The hematoma was encapsulated with a very thick and hard membrane, and directly under the capsule the foci of fresh hemorrhage could be seen along the capsule. The interior of the hematoma was almost entirely organized. The clinical features of this case were considered to reflect the remissions and aggravations of symptoms due to repeated hemorrhages of the chronic subdural hematoma over an extended period.

  17. Computed Tomographic Findings and Mortality in Patients With Pneumomediastinum From Blunt Trauma.

    Science.gov (United States)

    Lee, Wayne S; Chong, Vincent E; Victorino, Gregory P

    2015-08-01

    The care of most patients with pneumomediastinum (PNM) due to trauma can be managed conservatively; however, owing to aerodigestive tract injury and other associated injuries, there is a subset of patients with PNM who are at higher risk of mortality but can be difficult to identify. To characterize computed tomographic (CT) findings associated with mortality in patients with PNM due to blunt trauma. A retrospective review of medical records from January 1, 2002, to December 31, 2011, was conducted at a university-based urban trauma center. The patients evaluated were those injured by blunt trauma and found to have PNM on initial chest CT scanning. Data analysis was performed July 2, 2013, to June 18, 2014. In-hospital mortality. During the study period, 3327 patients with blunt trauma underwent chest CT. Of these, 72 patients (2.2%) had PNM. Patients with PNM had higher Injury Severity Scores (P blunt trauma; however, CT findings of posterior PNM, air in all mediastinal compartments, and concurrent hemothorax are associated with increased mortality. These CT findings could be used as a triage tool to alert the trauma surgeon to a potentially lethal injury.

  18. Computed tomographic findings of skeletal muscles in amyotrophic lateral sclerosis (ALS)

    International Nuclear Information System (INIS)

    Takahashi, Ryosuke; Imai, Terukuni; Sadashima, Hiromichi; Matsumoto, Sadayuki; Yamamoto, Toru; Kusaka, Hirobumi; Yamasaki, Masahiro; Maya, Kiyomi; Tanabe, Masaya

    1989-01-01

    We evaluated the Computed Tomographic (CT) findings of skeletal muscles in 12 cases of amyotrophic lateral sclerosis (ALS), 1 case of spinal progressive muscular atrophy (SPMA), and 1 case of Kugelberg-Welander disease. CT examination was performed in the neck, shoulders, abdomen, pelvis, thighs, and lower legs, 15 muscles were selected for evaluation. The following muscles tended to be affected: m. transversospinalis (12 cases were abnormal), m. deltoideus (10), m. subscapularis (10), m. infraspinatus (10), mm. dorsi (12), hamstring muscles (14), m. tibialis anterior (14), and m. triceps surae (14). On the contrary, the following muscles tended to be preserved: m. sternocleidomastoideus (only 7 cases were abnormal), m. psoas major (7), m. gluteus maximus (7), m. rectus femoris (7), m. sartorius (7) and m. gracilis (6). The distribution of the muscles affected showed neither proximal nor distal dominancy. As the disease advanced, however, all the muscles became affected without any severity. CT findings of skeletal muscles in ALS were characterized by muscle atrophy and fat infiltration, which showed a patchy, linear, or moth-eaten appearance. In mildly affected cases, there was muscle atrophy without internal architectual changes. In moderately affected cases, muscle atrophy advanced and internal architectural changes (patchy, linear, and moth-eaten fat infiltration) became evident. In most advanced cases, every muscle showed a ragged appearance because of severe muscle atrophy and internal architectural changes. These findings were well distinguished from those of SPMA, which resembled the CT pattern of primary muscle diseases. (author)

  19. Computed tomographic findings of skeletal muscles in amyotrophic lateral sclerosis (ALS)

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Ryosuke; Imai, Terukuni; Sadashima, Hiromichi; Matsumoto, Sadayuki; Yamamoto, Toru; Kusaka, Hirobumi; Yamasaki, Masahiro; Maya, Kiyomi; Tanabe, Masaya (Kitano Hospital, Osaka (Japan))

    1989-04-01

    We evaluated the Computed Tomographic (CT) findings of skeletal muscles in 12 cases of amyotrophic lateral sclerosis (ALS), 1 case of spinal progressive muscular atrophy (SPMA), and 1 case of Kugelberg-Welander disease. CT examination was performed in the neck, shoulders, abdomen, pelvis, thighs, and lower legs, 15 muscles were selected for evaluation. The following muscles tended to be affected: m. transversospinalis (12 cases were abnormal), m. deltoideus (10), m. subscapularis (10), m. infraspinatus (10), mm. dorsi (12), hamstring muscles (14), m. tibialis anterior (14), and m. triceps surae (14). On the contrary, the following muscles tended to be preserved: m. sternocleidomastoideus (only 7 cases were abnormal), m. psoas major (7), m. gluteus maximus (7), m. rectus femoris (7), m. sartorius (7) and m. gracilis (6). The distribution of the muscles affected showed neither proximal nor distal dominancy. As the disease advanced, however, all the muscles became affected without any severity. CT findings of skeletal muscles in ALS were characterized by muscle atrophy and fat infiltration, which showed a patchy, linear, or moth-eaten appearance. In mildly affected cases, there was muscle atrophy without internal architectual changes. In moderately affected cases, muscle atrophy advanced and internal architectural changes (patchy, linear, and moth-eaten fat infiltration) became evident. In most advanced cases, every muscle showed a ragged appearance because of severe muscle atrophy and internal architectural changes. These findings were well distinguished from those of SPMA, which resembled the CT pattern of primary muscle diseases. (author).

  20. Novel developments in Fourier domain optical coherence tomography and nonlinear tomographic interferometry

    OpenAIRE

    Mallat, Kamel

    2014-01-01

    In this thesis we present novel methods to improve the limitations in Optical Coherence Tomography (OCT). They are divided into two parts. The first part deals with the axial resolution limitation in OCT systems. We give a description of the Fourier Domain OCT (FDOCT), and then we show theoretically how to enhance the axial resolution in a particular case of a two-layer sample where one of the two layers is moving continuously, while these two layers are separated by a distance lower than the...

  1. A case of adrenal tumour in a lion (Panthera leo: tomographic and ultrasonographic findings.

    Directory of Open Access Journals (Sweden)

    Maurizio Longo

    2015-07-01

    Full Text Available Adrenal gland tumors are common in humans and in several animal species. Studies concerning this neoplasia in human medicine indicate that clinical signs have a high variability. Adrenal adenomas can be occasionally observed in asymptomatic patients during tomographic studies while estrogen-secreting tumors, known as "feminizing adrenal tumors" (FATs, have been rarely reported. The aim of this study is to describe for the first time the Imaging findings of a captivity lion affected by a neoplastic secreting adrenal tumour. An 8 year-old male lion with progressive lack of secondary sex characteristics, disorexia and weight loss was referred to our Institution. The patient was chemically immobilized to undergo general clinical evaluation, hematologic, serum biochemical and hormonal profile, FIV and FeLV tests. Three months later a total body computed tomography and abdominal ultrasonography were performed. Liver and left adrenal lesions FNABs were performed. Imaging findings showed the presence of an extended expansive neoplastic lesion on the left adrenal gland (40x39x37 mm with right adrenal gland atrophy. Generalized hepatopathy associated with a suspected intrahepatic cholestasis was confirmed by ultrasonography. Cytological evaluation ruled out the presence of neuroendocrine cells without malignancy evidences compatible with the adenomatous nature of the lesion, associated with moderate degenerative hepatopathy. Blood tests reported an estradiol concentration of 462 ng/dl. To our knowledge, this is the first description of adrenal mass in a lion associated with secondary feminization, inappetence and high values of hematic estradiol, referable to a feminizing adrenal tumor (FAT.

  2. Correlation of tomographic findings with pulmonary function parameters in nonsmoking patients with idiopathic pulmonary fibrosis

    International Nuclear Information System (INIS)

    Lopes, Agnaldo Jose; Capone, Domenico; Mogami, Roberto; Jansen, Jose Manoel .E mail: phel.lop@uol.com.br; Cunha, Daniel Leme da; Melo, Pedro Lopes de

    2007-01-01

    Objective: To correlate tomographic findings with pulmonary function parameters in patients with idiopathic pulmonary fibrosis (IPF). Methods: A cross-sectional study was carried out, in which 30 nonsmoking patients with IPF were evaluated. Using a semiquantitative scoring system, the following high-resolution computerized tomography findings were quantified: total interstitial disease (TID), reticular abnormality/honeycombing, and ground-glass opacity (GGO). The functional variables were measured by spirometry, forced oscillation technique (FOT), helium dilution method, as well as the single-breath method of measuring diffusion capacity of the lung for carbon monoxide (DLCO). Results: Of the 30 patients studied, 18 were female, and 12 were male, with a mean age of 70.9 years. We found that TID and reticular abnormality and honeycombing correlated significantly (negative correlations) with the measurements of forced vital capacity (FVC), total lung capacity (TLC), DLCO, and dynamic respiratory compliance were found, as well as that GGO correlated significantly (and positively) with residual volume/TLC. The ratio of forced expiratory flow between 25 and 75% of FVC to FVC (FEF25-75%/FVC) correlated positively with TID, reticular abnormality/honeycombing, and GGO. Conclusion: In IPF patients, the measurements of volume, diffusion, and dynamic compliance are the physiological variables which best reflect the extent of the interstitial disease on HRCT scans. (author)

  3. Correlation of tomographic findings with pulmonary function parameters in nonsmoking patients with idiopathic pulmonary fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Agnaldo Jose; Capone, Domenico; Mogami, Roberto; Jansen, Jose Manoel [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). School of Medical Sciences].E mail: phel.lop@uol.com.br; Cunha, Daniel Leme da [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Pedro Ernesto University Hospital. Dept. of Radiology and Diagnostic Imaging; Melo, Pedro Lopes de [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. of Biology

    2007-11-15

    Objective: To correlate tomographic findings with pulmonary function parameters in patients with idiopathic pulmonary fibrosis (IPF). Methods: A cross-sectional study was carried out, in which 30 nonsmoking patients with IPF were evaluated. Using a semiquantitative scoring system, the following high-resolution computerized tomography findings were quantified: total interstitial disease (TID), reticular abnormality/honeycombing, and ground-glass opacity (GGO). The functional variables were measured by spirometry, forced oscillation technique (FOT), helium dilution method, as well as the single-breath method of measuring diffusion capacity of the lung for carbon monoxide (DLCO). Results: Of the 30 patients studied, 18 were female, and 12 were male, with a mean age of 70.9 years. We found that TID and reticular abnormality and honeycombing correlated significantly (negative correlations) with the measurements of forced vital capacity (FVC), total lung capacity (TLC), DLCO, and dynamic respiratory compliance were found, as well as that GGO correlated significantly (and positively) with residual volume/TLC. The ratio of forced expiratory flow between 25 and 75% of FVC to FVC (FEF25-75%/FVC) correlated positively with TID, reticular abnormality/honeycombing, and GGO. Conclusion: In IPF patients, the measurements of volume, diffusion, and dynamic compliance are the physiological variables which best reflect the extent of the interstitial disease on HRCT scans. (author)

  4. Computed tomographic findings and treatment of a bull with pituitary gland abscess.

    Science.gov (United States)

    Braun, Ueli; Malbon, Alexandra; Kochan, Manon; Riond, Barbara; Janett, Fredi; Iten, Cornelia; Dennler, Matthias

    2017-01-13

    In cattle, the prognosis of brain abscess is unfavourable and treatment is therefore not recommended. To the knowledge of the authors, there has been no report of successful treatment of a brain abscess in cattle.This report describes the clinical, computed tomographic and postmortem findings in a Holstein-Friesian bull with a hypophyseal abscess. The main clinical findings were generalised ataxia, ptyalism, prolapse of the tongue, dropped jaw, dysphagia, head tilt and unilateral ptosis. Cerebrospinal fluid evaluation revealed 2437 leukocytes/µl and severe pleocytosis. CT examination of the head showed a cavitary lesion consistent with an abscess in the hypophysis. Treatment consisted of gentamicin and flunixin meglumine for 3 days and amoxicillin for 40 days. The neurological signs resolved within 8 days of the start of treatment. The bull was slaughtered 11 months later because of infertility, and a postmortem examination was carried out. Histologically, a mild chronic non suppurative meningoencephalitis restricted to the ventral diencephalon was diagnosed. In addition, there was mild to moderate multifocal chronic lymphoplasmacytic hypophysitis with mild multifocal fibrosis. This case report stresses the significance of CT in confirming the clinical and laboratory diagnosis of central nervous system disorders in cattle and for localising brain lesions. Treatment of the brain abscess resulted, with respect to the central nervous disorder, in a successful outcome and was encouraging considering that most cases have an unfavourable prognosis.

  5. Anisakiasis presenting to the ED: clinical manifestations, time course, hematologic tests, computed tomographic findings, and treatment.

    Science.gov (United States)

    Takabayashi, Takeshi; Mochizuki, Toshiaki; Otani, Norio; Nishiyama, Kei; Ishimatsu, Shinichi

    2014-12-01

    The prevalence of anisakiasis is rare in the United States and Europe compared with that in Japan, with few reports of its presentation in the emergency department (ED). This study describes the clinical, hematologic, computed tomographic (CT) characteristics, and treatment in gastric and small intestinal anisakiasis patients in the ED. We retrospectively reviewed the data of 83 consecutive anisakiasis presentations in our ED between 2003 and 2012. Gastric anisakiasis was endoscopically diagnosed with the Anisakis polypide. Small intestinal anisakiasis was diagnosed based on both hematologic (Anisakis antibody) and CT findings. Of the 83 cases, 39 had gastric anisakiasis and 44 had small intestinal anisakiasis based on our diagnostic criteria. Although all patients had abdominal pain, the gastric anisakiasis group developed symptoms significantly earlier (peaking within 6 hours) than the small intestinal anisakiasis group (peaking within 48 hours), and fewer patients with gastric anisakiasis needed admission therapy (5% vs 57%, Pfindings revealed edematous wall thickening in all patients, and ascites and phlegmon of the mesenteric fat were more frequently observed in the small intestinal anisakiasis group. In the ED, early and accurate diagnosis of anisakiasis is important to treat and explain to the patient, and diagnosis can be facilitated by a history of raw seafood ingestion, evaluation of the time-to-symptom development, and classic CT findings. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. High-resolution computed tomographic findings of Aspergillus infection in lung transplant patients

    International Nuclear Information System (INIS)

    Gazzoni, Fernando Ferreira; Hochhegger, Bruno; Severo, Luiz Carlos; Marchiori, Edson; Pasqualotto, Alessandro; Sartori, Ana Paula Garcia; Schio, Sadi; Camargo, José

    2014-01-01

    Objective: The aim of this study was to assess high-resolution computed tomographic (HRCT) findings at presentation in lung transplant patients diagnosed with pulmonary Aspergillus infection. Materials and methods: We retrospectively reviewed HRCT findings from 23 patients diagnosed with pulmonary aspergillosis. Imaging studies were performed 2–5 days after the onset of symptoms. The patient sample comprised 12 men and 11 women aged 22–59 years (mean age, 43.6 years). All patients had dyspnea, tachypnea, and cough. Diagnoses were established with Platelia Aspergillus enzyme immunoassays for galactomannan antigen detection in bronchoalveolar lavage and recovery of symptoms, and HRCT findings after voriconazole treatment. The HRCT scans were reviewed independently by two observers who reached a consensus decision. Results: The main HRCT pattern, found in 65% (n = 15) of patients, was centrilobular tree-in-bud nodules associated with bronchial thickening. This pattern was described in association with areas of consolidation and ground-glass opacities in 13% (n = 3) of patients. Consolidation and ground-glass opacities were the main pattern in 22% (n = 5) of patients. The pattern of large nodules with and without the halo sign was observed in 13% (n = 3) of patients, and were associated with consolidation and ground-glass opacities in one case. Conclusion: The predominant HRCT findings in lung transplant patients with pulmonary aspergillosis were bilateral bronchial wall thickening and centrilobular opacities with the tree-in-bud pattern. Ground-glass opacities and/or bilateral areas of consolidation were also common findings. Pulmonary nodules with the halo sign were found in only 13% of patients

  7. Semi-automated software to measure luminal and stromal areas of choroid in optical coherence tomographic images.

    Science.gov (United States)

    Sonoda, Shozo; Sakamoto, Taiji; Kakiuchi, Naoko; Shiihara, Hideki; Sakoguchi, Tomonori; Tomita, Masatoshi; Yamashita, Takehiro; Uchino, Eisuke

    2018-03-01

    To determine the capabilities of "EyeGround" software in measuring the choroidal cross sectional areas in optical coherence tomographic (OCT) images. Cross sectional, prospective study. The cross-sectional area of the subfoveal choroid within a 1500 µm diameter circle centered on the fovea was measured both with and without using the EyeGround software in the OCT images. The differences between the evaluation times and the results of the measurements were compared. The inter-rater, intra-rater, inter-method agreements were determined. Fifty-one eyes of 51 healthy subjects were studied: 24 men and 27 women with an average age of 35.0 ± 8.8 years. The time for analyzing a single image was significantly shorter with the software at 3.2±1.1 min than without the software at 12.1±5.1 min (P software, the inter-rater correlation efficient was significantly high [0.997, 95% CI (0.995-0.999)], and the intra-rater correlation efficient was also significantly high [0.999, 95% CI (0.999-1.0)]. The EyeGround software can measure the choroidal area in the OCT cross sectional images with good reproducibility and in a significantly shorter times. It can be a valuable tool for analyzing the choroid.

  8. Computerized tomographic findings of hepatic fascioliasis compared with melioidosis-caused liver abscesses.

    Science.gov (United States)

    Chamadol, Nittaya; Laopaiboon, Vallop; Techasatian, Pennapa; Sukeepaisanjaroen, Wattana; Sripanuskul, Anan

    2010-07-01

    To compare the computerized tomographic (CT) findings of hepatic fascioliasis (HF) vs. melioidosis-caused liver (ML) abscesses. CT images of 15 patients with hepatic fascioliasis (HF) and 16 patients with melioidosis-caused liver (ML) abscesses were retrospectively reviewed. The authors evaluated and compared HF and ML abscesses (by chi2 and Fisher exact tests) vis-a-vis their location of liver involvement, size, shape, number margins, enhancement patterns, subcapsular lesions, internal architecture, dilatation of intrahepatic bile duct and combination with splenic abscesses. Fourteen HF patients had only liver abscesses and 1 had combined liver and splenic abscesses. Four ML patients had liver abscesses alone while 12 had combined liver and splenic abscesses (p = 0.000). Eight of the 15 HF (53.3%) and 2 of the 16 ML (12.5%) patients had subcapsular lesions (p = 0.019). The liver abscesses were round or oval with linear tracts in 8 of the 15 HF (53.3%) and none of the ML patients (p = 0.001). Between the respective HF and ML patients, there was a significant difference in those with round shaped in ML (p = 0.008), multiple and conglomerately distributed in HF (p = 0.050), multiple and discretely distributed in ML (p = 0.001) no (or minimal) peripheral contrast enhancement in HF (p = 0.011) and moderate or mark peripheral enhancement in ML (p = 0.011). The CT findings of liver abscesses that helped to differentiate hepatic fascioliasis from melioidosis liver abscesses were: their number shape, enhancement pattern, presence of subcapsular lesion (s) and co-occurrence with splenic abscesses. The diagnosis of hepatic fascioliasis by CT is suggested when the following characteristics were seen: (1) multiple, small round or oval (with linear tracts) conglomerates presenting as hypodense lesions; (2) no (or minimal) peripheral contrast enhancement; (3) subcapsular lesions; or (4) less frequent co-occurrence with splenic abscesses.

  9. Clear cell chondrosarcoma: radiographic, computed tomographic, and magnetic resonance findings in 34 patients with pathologic correlation

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Mark S.; Koyama, Takashi; Swee, Ronald G.; Inwards, Carrie Y. [Department of Radiology, Mayo Clinic, 200 First Street SW, MN 55905, Rochester (United States)

    2003-12-01

    To describe the radiographic features of clear cell chondrosarcoma (CCCS), including the computed tomographic (CT) and magnetic resonance (MR) findings, and to correlate them with the histopathologic findings. A retrospective review was carried out of 72 patients with histopathologically confirmed CCCS. Imaging studies were available for 34 patients: conventional radiographs (n=28), CT scans (n=14), and MR images (n=15). Radiographic studies were reviewed by three radiologists who rendered a consensus opinion; the studies were correlated with the histopathologic findings. Of the 34 patients with imaging studies, 30 were male and 4 were female (mean age 38.6 years; range 11-74 years). Twenty-two lesions were in long bones (15, proximal femur; 1, distal femur; 1, proximal tibia; 5, proximal humerus) and 11 were in flat bones (5, vertebra; 4, rib; 1, scapula; 1, innominate). One lesion occurred in the tarsal navicular bone. Typically, long bone lesions were located in the epimetaphysis (19/22) and were lucent with a well-defined sclerotic margin and no cortical destruction or periosteal new bone formation. More than one-third of the long bone lesions contained matrix mineralization with a characteristic chondroid appearance. Pathologic fractures were present in six long bone lesions (4, humerus; 2, femur). Lesions in the proximal humerus were more likely to have indistinct margins (4/5) and extend into the diaphysis. Flat bone lesions were typically lytic and expansile and occasionally demonstrated areas of cortical disruption. Typically, matrix mineralization, when present, was amorphous. MR imaging, when available, was superior to conventional radiographs for demonstrating the intramedullary extent of a lesion as well as soft tissue extension. CT images better delineated the presence of cortical destruction and the character of matrix mineralization patterns. CCCS lesions were typically low signal intensity on T1-weighted images and moderately or significantly

  10. Clear cell chondrosarcoma: radiographic, computed tomographic, and magnetic resonance findings in 34 patients with pathologic correlation

    International Nuclear Information System (INIS)

    Collins, Mark S.; Koyama, Takashi; Swee, Ronald G.; Inwards, Carrie Y.

    2003-01-01

    To describe the radiographic features of clear cell chondrosarcoma (CCCS), including the computed tomographic (CT) and magnetic resonance (MR) findings, and to correlate them with the histopathologic findings. A retrospective review was carried out of 72 patients with histopathologically confirmed CCCS. Imaging studies were available for 34 patients: conventional radiographs (n=28), CT scans (n=14), and MR images (n=15). Radiographic studies were reviewed by three radiologists who rendered a consensus opinion; the studies were correlated with the histopathologic findings. Of the 34 patients with imaging studies, 30 were male and 4 were female (mean age 38.6 years; range 11-74 years). Twenty-two lesions were in long bones (15, proximal femur; 1, distal femur; 1, proximal tibia; 5, proximal humerus) and 11 were in flat bones (5, vertebra; 4, rib; 1, scapula; 1, innominate). One lesion occurred in the tarsal navicular bone. Typically, long bone lesions were located in the epimetaphysis (19/22) and were lucent with a well-defined sclerotic margin and no cortical destruction or periosteal new bone formation. More than one-third of the long bone lesions contained matrix mineralization with a characteristic chondroid appearance. Pathologic fractures were present in six long bone lesions (4, humerus; 2, femur). Lesions in the proximal humerus were more likely to have indistinct margins (4/5) and extend into the diaphysis. Flat bone lesions were typically lytic and expansile and occasionally demonstrated areas of cortical disruption. Typically, matrix mineralization, when present, was amorphous. MR imaging, when available, was superior to conventional radiographs for demonstrating the intramedullary extent of a lesion as well as soft tissue extension. CT images better delineated the presence of cortical destruction and the character of matrix mineralization patterns. CCCS lesions were typically low signal intensity on T1-weighted images and moderately or significantly

  11. Spectralis optical coherence tomography findings in Welder′s maculopathy

    Directory of Open Access Journals (Sweden)

    Aniruddha Mahindrakar

    2013-01-01

    Full Text Available Welder′s maculopathy is a form of photochemical damage to the retina and is typically characterized by involvement of the outer retinal layers. Spectral domain optical coherence tomography (SD-OCT imaging was performed in three eyes of two patients with clinical findings suggestive of Welder′s maculopathy in occupational welders. A faceted foveal lesion characterized clinical examination and the SD-OCT line scans images showed a distinct discontinuity of the photoreceptor inner and outer segment (IS/OS junction. The external limiting membrane (ELM and the retinal pigment epithelial (RPE layer remained intact at the site of IS/OS defect. SD-OCT imaging offers a noninvasive way of evaluating the microstructural changes at the fovea in Welder′s maculopathy.

  12. Tomographic findings of lobar consolidation in primary pulmonary tuberculosis; Aspectos tomograficos da consolidacao lobar na tuberculose pulmonar primaria

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    Pereira, Bruno Alberto Falcao [Hopital Europeen Georges Pompidou, Paris (France); Macedo, Solange Goncalves David de [Hospital Municipal Jesus, Rio de Janeiro, RJ (Brazil). Setor de Pneumologia; Nogueira, Renata do Amaral [Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro, RJ (Brazil). Setor de Pediatria; Castiel, Lola Celeste Pantoja [Clinica Radiologica Dr. Samuel Castiel, Porto Velho, RO (Brazil); Penna, Claudia Renata Rezende [Hospital Municipal Jesus, Rio de Janeiro, RJ (Brazil). Servico de Radiologia Pediatrica], e-mail: cr-penna@uol.com.br

    2009-03-15

    Objective: To describe tomographic findings of lobar consolidation as early manifestation of primary pulmonary tuberculosis. Materials and methods: The present study was developed at Hospital Municipal Jesus, Rio de Janeiro, RJ, Brazil, in the period between 2002 and 2006, retrospectively evaluating tomographic findings in four children aged from 3 to 14 months with lobar consolidation as an early manifestation of primary pulmonary tuberculosis. Results: The most frequently found radiological pattern was lobar consolidation with calcifications, cavitation and intermingle necrotic areas, associated with bulging fissure. Signs of bronchogenic dissemination and lymph node enlargement were observed in all of the four children. Consolidation with a pseudotumor aspect and masslike effect was observed in one case. Conclusion: The cases included in the present study have demonstrated that primary pulmonary tuberculosis manifested as lobar consolidation presents typical tomographic images such as cavitation, hypodense areas and calcifications intermingled with consolidation. The association with lymph node enlargement with central necrosis and signs of bronchogenic dissemination reinforce the diagnosis of tuberculosis. (author)

  13. Spectral Domain Optical Coherence Tomography Findings in Posterior Microphthalmia

    Directory of Open Access Journals (Sweden)

    Emine Tınkır Kayıtmazbatır

    2014-05-01

    Full Text Available The retinal spectral domain optical coherence tomography (SD-OCT findings of two posterior microphthalmia cases are presented in this case report. For this purpose, the findings of two siblings aged five and seven years who presented to our clinic with the complain of far-sightedness and high hypermetropia were evaluated. Both cases diagnosed to have posterior microphthalmia demonstrated normal biomicroscopic anterior segment examination and gonioscopy findings and the axial lengths were measured to be shorter than 17mm. The SD-OCT analysis of papillomacular folds detected in fundus examination revealed contribution of only neurosensorial retina. Beneath the retinal fold, we observed bilateral cysts in the intraretinal area in one of the cases and a triangle-shaped hyporeflective space with an apex corresponding to that of the retinal fold in the subretinal area in both cases. SD-OCT is an adjunctive imaging tool for diagnosis and follow-up of degenerative changes in posterior microphthalmia. These changes may be also important for visual prognosis. (Turk J Ophthalmol 2014; 44: 240-2

  14. The computed tomographic findings of bronchogenic carcinoma presenting as a solitary peripheral pulmonary mass

    International Nuclear Information System (INIS)

    Kim, Hong; Kim, Ok Bae; Woo, Seong Ku; Suh, Soo Jhi; Kim, Sung Soo

    1985-01-01

    It is difficult to distinguish benign from malignant, ulmonary nodule by conventional roentgenologic examination. But CT makes it easier to evaluate adjacent parenchymal invasion, pleural or mediastinal extension, or early metastasis to intra- or extrathoracic lymph node as well as distant organs, although only a solitary peripheral pulmonary nodule is seen on plain radiograph. Authors reviewed CT of 22 cases of histopathologically confirmed primary lung cancer seen as a solitary peripheral pulmonary mass from May 1980 to September 1984 at Dongsan Medical Center, Keimyung University. The results are as follows: 1. The incidence was most common in the 6th decade (36%). Male to female ratio was 10 : 1 and 2 females all had bronchioloalveolar cell carcinoma. 2. The distribution of histologic cell type were as follows: squamous cell carcinoma 40%, adenocarcinoma, small cell carcinoma, bronchioloalveolar cell carcinoma and unclassified carcinoma 14% in each cases, and adenoid cystic carcinoma 4%. 3. The computed tomographic findings were as follows: a) Superior and posterior basal segments of both lower lobes were most frequently involved (68%). b) The mean diameter of the mass was 48 mm, and most common in the range of 30-49 mm in the greatest dimension (46%). c) The mean CT attenuation value was 57 H.U., and most common in the group of 41-70 H. U. (64%). d) Lymph node metastasis was found in 13 (59%) of 22 cases, and the involved nodes were as follows: hilar nodes 10 cases, paratracheal nodes 8 cases, subcarinal nodes 7 cases and extrathoracic nodes 3 cases. In 2 of 3 cases with small cell carcinoma, diffuse multiple lymph nodes were involved. e) Distant metastasis was seen relatively early in 3 cases: cerebral metastasis in 1 cases of squamous cell carcinoma, right adrenal metastasis without intrathoracic lymph node metastasis or invasion of adjacent structure in 1 case of bronchioloalveolar cell carcinoma, and liver and bone metastasis in 1 case of unclassified

  15. Histologic and tomographic findings of bone block allografts in a 4 years follow-up: a case series

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    Deluiz, Daniel; Pires, Fabio Ramoa; Tinoco, Justine Monnerat; Tinoco, Eduardo Muniz Barretto [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil); Oliveira, Luciano Santos, E-mail: d.deluiz@implanto-puc.org [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), Rio de Janeiro, RJ (Brazil); Fletcher, Paul [Department of Periodontology, Columbia University College of Dental Medicine, New York, NY (United States)

    2016-11-15

    The aim of this paper is to report histologic and tomographic findings of fresh frozen bone block allografts bearing dental implants in functional occlusion in a long-term follow-up. Four patients with implants functionally loaded for 4 years on augmented ridges requiring additional mucogingival surgery or implant placement were included in this case series. Cone-beam tomography scans were compared volumetrically between the baseline (first implant placement) and current images. Biopsies of the grafts were retrieved and sent to histological analysis. Volumetric reduction of the grafts varied from 2.1 to 7.7%. Histological evaluation demonstrated well-incorporated grafts with different degrees of remodeling. While data presented in this report are from a small sample size and do not allow definitive conclusions, the biopsies of the grafted sites were very similar to the host's native bone. Remodeling of the cortical portion of the allografts seems to take longer than the cancellous portion. The presence of unincorporated graft remains did not impair the implant success or the health of the surrounding tissues. This is the first time histologic and tomographic long term data of bone allograft have been made available in dentistry. (author)

  16. Histologic and tomographic findings of bone block allografts in a 4 years follow-up: a case series

    International Nuclear Information System (INIS)

    Deluiz, Daniel; Pires, Fabio Ramoa; Tinoco, Justine Monnerat; Tinoco, Eduardo Muniz Barretto; Oliveira, Luciano Santos; Fletcher, Paul

    2016-01-01

    The aim of this paper is to report histologic and tomographic findings of fresh frozen bone block allografts bearing dental implants in functional occlusion in a long-term follow-up. Four patients with implants functionally loaded for 4 years on augmented ridges requiring additional mucogingival surgery or implant placement were included in this case series. Cone-beam tomography scans were compared volumetrically between the baseline (first implant placement) and current images. Biopsies of the grafts were retrieved and sent to histological analysis. Volumetric reduction of the grafts varied from 2.1 to 7.7%. Histological evaluation demonstrated well-incorporated grafts with different degrees of remodeling. While data presented in this report are from a small sample size and do not allow definitive conclusions, the biopsies of the grafted sites were very similar to the host's native bone. Remodeling of the cortical portion of the allografts seems to take longer than the cancellous portion. The presence of unincorporated graft remains did not impair the implant success or the health of the surrounding tissues. This is the first time histologic and tomographic long term data of bone allograft have been made available in dentistry. (author)

  17. Applying GRADE-CERQual to qualitative evidence synthesis findings-paper 4: how to assess coherence.

    Science.gov (United States)

    Colvin, Christopher J; Garside, Ruth; Wainwright, Megan; Munthe-Kaas, Heather; Glenton, Claire; Bohren, Meghan A; Carlsen, Benedicte; Tunçalp, Özge; Noyes, Jane; Booth, Andrew; Rashidian, Arash; Flottorp, Signe; Lewin, Simon

    2018-01-25

    The GRADE-CERQual (Grading of Recommendations Assessment, Development and Evaluation-Confidence in Evidence from Reviews of Qualitative research) approach has been developed by the GRADE working group. The approach has been developed to support the use of findings from qualitative evidence syntheses in decision-making, including guideline development and policy formulation. CERQual includes four components for assessing how much confidence to place in findings from reviews of qualitative research (also referred to as qualitative evidence syntheses): (1) methodological limitations, (2) relevance, (3) coherence and (4) adequacy of data. This paper is part of a series providing guidance on how to apply CERQual and focuses on CERQual's coherence component. We developed the coherence component by searching the literature for definitions, gathering feedback from relevant research communities and developing consensus through project group meetings. We tested the CERQual coherence component within several qualitative evidence syntheses before agreeing on the current definition and principles for application. When applying CERQual, we define coherence as how clear and cogent the fit is between the data from the primary studies and a review finding that synthesises that data. In this paper, we describe the coherence component and its rationale and offer guidance on how to assess coherence in the context of a review finding as part of the CERQual approach. This guidance outlines the information required to assess coherence, the steps that need to be taken to assess coherence and examples of coherence assessments. This paper provides guidance for review authors and others on undertaking an assessment of coherence in the context of the CERQual approach. We suggest that threats to coherence may arise when the data supporting a review finding are contradictory, ambiguous or incomplete or where competing theories exist that could be used to synthesise the data. We expect the

  18. Surgical approach and optic coherence tomographic evaluation of optic disc anomaly in association with serous macular detachment.

    Science.gov (United States)

    Güven, Dilek; Balcıoğlu, Nihal; Türker, Cağrı; Baydar, Yasemin; Sendül, Yekta

    2013-12-01

    Serous macular detachment (SMD) may accompany optic disc pit (ODP) and cause visual loss if untreated. We want to present different therapeutic approaches and interesting optical coherence tomography (OCT) findings in three consecutive cases. In this case series, two patients with SMD and one patient with partial macular detachment and inferior retinal detachment accompanying ODP were evaluated before and after surgical intervention clinically and by spectral-domain OCT. The patients were 44 (case 1), 22 (case 2) and 24 (case 3) years old. Pars plana vitrectomy (PPV) + silicone oil + laser, PPV + sulfur hexafluoride gas (SF6) + laser and pneumatic retinopexy were applied, respectively. The patients were followed for 18, 15 and 14 months. Preoperative best-corrected visual acuities (BCVAs) were 5/100, 7/10 and counting fingers at 1 m. Vision improved in all cases with resolution of subretinal fluid. Final BCVAs were 3/10, 10/10 and 1/10, respectively. OCT images revealed optic disc anomaly details and changes after surgical intervention, photoreceptor outer segment alterations at the detached area and macular surface changes. Surgical intervention should be tailored individually in cases with SMD. OCT is efficient for in vivo evaluation of this pathological condition and anatomical outcomes of surgery.

  19. Clinical observations of the brain abscesses, especially on the computed tomographic brain scan findings

    International Nuclear Information System (INIS)

    Kitano, Masahiko; Kuroda, Ryotaro; Yamada, Yasufumi; Yorimae, Akira; Akai, Fumiharu; Watanabe, Masaru; Nakatani, Jiro; Ioku, Masahiko

    1988-01-01

    Fifteen cases with pyogenic brain abscess were experienced in our clinic during the last 7 years. The records of these patients were examined to evaluate the clinical stage and the result of several treatments. In 12 operative cases, diagnosis was made by fluid aspirated from the abscess. Bacteria were cultured from the fluid in 5 among these cases. In 3 other non-operative patients, diagnosis was based on computed tomographic (CT) brain scans and laboratory studies. Each volume of the brain abscess and surrounding brain edema was measured on serial CT scans to evaluate the clinical stage and the abscess evolution. In symptoms and signs, it has been thought that one of the factors contributing to mortality was the level of consciousness. In this study, the disturbance of consciousness did not correlate with the size of abscess, but with that of edema. The cases reported here were divided into 3 groups according to the volume of abscess and of edema on initial CT scans. The cases of group A had small surrounding edema ( 50 ml) and small abscess ( 25 ml). The group A had slight change in the clinical status and the size of edema, but the others had severe change. Three phase changes in edema size were seen in the group B regardless of therapeutic modalities ; showing almost constant increase in first 2 weeks, great decrease in second 2 weeks and moderate decrease following these 4 weeks. In the group C, however, these phases were seen only in early operation cases. (J.P.N.)

  20. Thoracic computerized tomographic (CT findings in 2009 influenza A (H1N1 virus infection in Isfahan, Iran

    Directory of Open Access Journals (Sweden)

    Mojtaba Rostami

    2011-01-01

    Full Text Available Background: Pandemic 2009 H1N1 influenza A virus arrived at Isfahan in August 2009. The virus is still circulating in the world. The abnormal thoracic computerized tomographic (CT scan findings vary widely among the studies of 2009 H1N1 influenza. We evaluated the thoracic CT findings in patients with 2009 H1N1 virus infection to describe findings compared to previously reported findings, and to suggest patterns that may be suggestive for 2009 influenza A (H1N1 in an appropriate clinical setting. Methods: Retrospectively, the archive of all patients with a diagnosis of 2009 H1N1 influenza A were reviewed, in Al-Zahra Hospital in Isfahan, central Iran, between September 23 rd 2009 to February 20 th 2010. Out of 216 patients with confirmed 2009 influenza A (H1N1 virus, 26 cases with abnormal CT were enrolled in the study. Radiologic findings were characterized by the type and pattern of opacities and zonal distribution. Results: Patchy infiltration (34.6%, lobar consolidation (30.8%, and interstitial infiltration (26.9% with airbronchogram (38.5% were the predominant findings in our patients. Bilateral distribution was seen in 80.8% of the patients. Only one patient (3.8% showed ground-glass opacity, predominant radiographic finding in the previous reports and severe acute respiratory syndrome (SARS. Conclusions: The most common thoracic CT findings in pandemic H1N1 were patchy infiltration, lobar consolidation, and interstitial infiltration with airbronchogram and bilateral distribution. While these findings can be associated with other infections; they may be suggestive to 2009 influenza A (H1N1 in the appropriate clinical setting. Various radiographic patterns can be seen in thoracic CT scans of the influenza patients. Imaging findings are nonspecific.

  1. Optical Coherence Tomography Findings in Patients With Stent Thrombosis.

    Science.gov (United States)

    Cuesta, Javier; Rivero, Fernando; Bastante, Teresa; García-Guimaraes, Marcos; Antuña, Paula; Alvarado, Teresa; Navarrete, Gonzalo; Benedicto, Amparo; Alfonso, Fernando

    2017-12-01

    Stent thrombosis (ST) is a rare but potentially serious complication. Optical coherence tomography (OCT) provides high-resolution images and additional information to angiography in the study of this event. Prospective study of patients with ST undergoing reintervention with OCT imaging. The study included a total of 40 consecutive patients with ST. Mean age was 69 ± 13 years and 83% were male. Early ST (≤ 30 days) was observed in 16 patients and late ST (> 30 days) in 24 patients. Stent thrombosis occurred in 17 bare-metal stents and 23 drug-eluting stents. In 34 patients (85%), adequate OCT images were obtained at the time of the ST. The predominant mechanism in early ST was stent malapposition (39%). In late ST, high frequencies of uncovered (46%) and malapposed struts (17%) were observed, especially in patients with drug-eluting stents. Furthermore, the presence of neoatherosclerosis was very high (67%) in patients with late ST. After intervention, improvements were observed in malapposition length and the amount of residual thrombus. OCT allows identification of the underlying mechanisms potentially involved in ST. This imaging modality is helpful in guiding reintervention in these patients, which improves the area and length of malapposition, as well as the maximal residual thrombus area. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  2. Type and location of findings in dental panoramic tomographs in 7-12-year-old orthodontic patients.

    Science.gov (United States)

    Pakbaznejad Esmaeili, Elmira; Ekholm, Marja; Haukka, Jari; Waltimo-Sirén, Janna

    2016-01-01

    The Radiation and Nuclear Safety Authority in Finland has paid attention to the large numbers of dental panoramic tomographs (DPTs), particularly in 7-12-year-old children. The majority of these radiographs are taken for orthodontic reasons. Because of the high radiosensitivity of children, the size of the irradiated field should be carefully chosen to yield the necessary diagnostic information at the lowest possible dose. The purpose of the present study was, therefore, to assess the outcome of DPTs within this age group in terms of type and location of pathological findings. It was also hypothesized that DPTs of orthodontic patients rarely display unrestored caries. Four hundred and forty-one DPTs, taken of 7-12-year-old children in 2010-2014, were randomly sampled. The 413 of them (94%) that had been taken for orthodontic reasons were analysed. All pathologic findings were restricted to the tooth-bearing area and there was no pathology in the bone structure or any incidental findings in the region of temporomandibular joint. Unlike hypothesized, 27% of the orthodontic DPTs showed caries in deciduous teeth and 16% in permanent teeth. A sub-sample of 229 DPTs, analysed for developmental dental and occlusal problems, most commonly displayed crowding (50%), positional anomalies and local problems with tooth eruption (32%), as well as hyperodontia (15%). Inclusion of only the actual area of interest in the image field should be considered case-specifically as a means to reduce the radiation dose.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-03-15

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

  4. Fundus autofluorescence and optical coherence tomography findings in thiamine responsive megaloblastic anemia.

    Science.gov (United States)

    Ach, Thomas; Kardorff, Rüdiger; Rohrschneider, Klaus

    2015-01-01

    To report ophthalmologic fundus autofluorescence and spectral domain optical coherence tomography findings in a patient with thiamine responsive megaloblastic anemia (TRMA). A 13-year-old girl with genetically proven TRMA was ophthalmologically (visual acuity, funduscopy, perimetry, electroretinogram) followed up over >5 years. Fundus imaging also included autofluorescence and spectral domain optical coherence tomography. During a 5-year follow-up, visual acuity and visual field decreased, despite a special TRMA diet. Funduscopy revealed bull's eye appearance, whereas fundus autofluorescence showed central and peripheral hyperfluorescence and perifoveal hypofluorescence. Spectral domain optical coherence tomography revealed affected inner segment ellipsoid band and irregularities in the retinal pigment epithelium and choroidea. Autofluorescence and spectral domain optical coherence tomography findings in a patient with TRMA show retinitis pigmentosa-like retina, retinal pigment epithelium, and choroid alterations. These findings might progress even under special TRMA diet, indispensable to life. Ophthalmologist should consider TRMA in patients with deafness and ophthalmologic disorders.

  5. Electroencephalographic and computed X-ray tomographic findings in 99 Japanese cases of herpes simplex encephalitis

    International Nuclear Information System (INIS)

    Kamei, Satoshi; Takasu, Toshiaki; Tamura, Masato; Otani, Sugishi.

    1988-01-01

    This is a retrospective analysis of electroencephalograms (EEG) and computed tomograms (CT) obtained from 99 Japanese patients with herpes simplex encephalitis (HSE). Abnormal findings of EEG were seen in 89 patients (99 %). Focal abnormality, which was frequently detected in the first EEG recording, was seen in 68 patients (76 %). Periodic synchronous discharge was observed in 25 patients (28 %). There were abnormal findings on CT in 88 patients (81 %). Low and high density areas were seen in 64 patients (73 %) and 26 patients (37 %), respectively, with the most frequent site being the temporal lobe. Mass effect was demonstrated in 33 patients (37 %). Electroencephalography detected the abnormal findings earlier than CT during the early stage of HSE in many instances. There was concordance between EEG and CT in the detection of HSE lesions in 45 patients (58 %). (Namekawa, K.)

  6. Computed tomographic findings in cerebral palsy: Analysis of hemisphere and lateral ventricular volume

    International Nuclear Information System (INIS)

    Cho, Seoung Hwan; Kim, Hak Jin; Sol, Chang Hyo; Kim, Byung Soo

    1989-01-01

    Authors analysed the CT findings of 28 cerebral palsy patients at Pusan National University Hospital from January, 1984 to December, 1987. Volumes of hemispheres, lateral ventricles and paranchymes were measured in patients who showed no remarkable abnormality on CT film, and compared with those of normal control group. 1. Among the 28 cerebral palsy patients, there were 6 cases of diffuse atrophy in CT findings, and unilateral atrophy in 2 cases and encephalomalacia and diffuse white matter low density in 1 case and generalized symmetrical white matter low density in 1 case, but remaining 18 cases had no specific abnormal finding on CT. 2. Difference in volumes of brain parenchyma and lateral ventricles of each hemisphere was greater than that of control group. 3. There were more enlarged lateral ventricles and prominent unilateral brain atrophy in 18 cases of cerebral palsy who showed no specific abnormality on CT as compared with normal control group

  7. Computer tomographic findings in portal hypertension due to cirrhosis of the liver. Pt. 1

    International Nuclear Information System (INIS)

    Koester, O.; Kunz, R.; Fischer, P.; Lackner, K.; Koischwitz, D.; Bonn Univ.

    1983-01-01

    The CT findings in 80 patients with confirmed portal hypertension due to intrahepatic block were analysed retrospectively. The findings included ascites, hypo-dense areas in the liver, nodular or irregular liver contour, the inability of define intrahepatic portal vessels with narrow window settings, the so-called ''kissing'' sign and evidence of hepato-fugal collaterals and thickning of the wall of the oesophagus. Electronic measurements of various organs (liver, spleen) and vessel diameters (portal vein, superior mesenteric vein) provide parameters which permit classification of patients into the cirrhotic group, as compared with a control group. The statistical significance of this classification was checked by the Kolmogoroff-Smirnoff test. (orig.)

  8. Computer tomographic findings in portal hypertension due to cirrhosis of the liver. Pt. 1

    Energy Technology Data Exchange (ETDEWEB)

    Koester, O; Kunz, R; Fischer, P; Lackner, K; Koischwitz, D

    1983-06-01

    The CT findings in 80 patients with confirmed portal hypertension due to intrahepatic block were analysed retrospectively. The findings included ascites, hypo-dense areas in the liver, nodular or irregular liver contour, the inability of define intrahepatic portal vessels with narrow window settings, the so-called ''kissing'' sign and evidence of hepato-fugal collaterals and thickening of the wall of the oesophagus. Electronic measurements of various organs (liver, spleen) and vessel diameters (portal vein, superior mesenteric vein) provide parameters which permit classification of patients into the cirrhotic group, as compared with a control group. The statistical significance of this classification was checked by the Kolmogoroff-Smirnoff test.

  9. Correlation of MR tomographic findings and microvascular decompression treatment of the neurovascular compressions of the cranial nerves

    International Nuclear Information System (INIS)

    Liu Zengsheng; Chen Xiangmin; Sun Yiyan; Fang Ming; Wang Ping; Guan Yong; Sun Miao

    2010-01-01

    Objective: To explore the correlation of the operation effects of the miorovascular decompression (MVD) and the findings on magnetic resonance tomographie angiography (MRTA) in patients of neurovascular compression of the cranial nerves. Methods: Two hundred and twenty three patients treated with the microvascular decompression were analyzed retrospectively. They were grouped and graded according to the vessel compression on the cranial nerves. The compression were grouped as none, moderate and severe, and the operation effects were graded as I (complete relief), II (partial relief) and III ( no relief). The operation effects grades were correlated according to the compression groups by Kruskal-Wallis test and the operation effects between each two of the groups were compared using Nemenyi test. P 2 =16.84 and P<0.05. The mean rank of the non-compression, the moderate and the severe group was 134.21,102.37 and 110.4, respectively. The difference of the mean ranks between the non-compression group and the moderate group was 31.84, and between the non-compression and the severe group was 24.17, respectively, where P<0.05 both. Conclusions: There was close relationship between the findings on magnetic resonance tomographic angiography and the operation effects of the MVD. The operation effects of patients with moderate and severe vessel compression were much better than the non-compression group. MRTA is helpful for MVD surgical indication and its prognosis. (authors)

  10. Clinical and high-resolution computed tomographic findings in five patients with pulmonary tuberculosis who developed respiratory failure following chemotherapy

    International Nuclear Information System (INIS)

    Akira, Masanori; Sakatani, Mitsunori

    2001-01-01

    AIM: The purpose of this study was to describe the clinical and high-resolution computed tomographic (HRCT) findings in patients with pulmonary tuberculosis who developed respiratory failure after starting chemotherapy. MATERIALS AND METHODS: The clinical records, chest radiographs, and HRCT findings in five patients with non-miliary pulmonary tuberculosis who developed respiratory failure after starting chemotherapy were reviewed. RESULTS: Chest radiographs taken early in the course of acute respiratory failure showed progression of the original lesions with (n = 4) or without (n = 1) new areas of opacity away from the site of the original lesions. HRCT demonstrated widespread ground-glass attenuation with a reticular pattern as well as segmental or lobar consolidation with cavitation and nodules, consistent with active tuberculous foci in all five cases. Prominent interlobular septal thickening was seen in two cases. Four of the five patients had received corticosteroids. Of these five, two died and three recovered with continued corticosteroid therapy. Transbronchial biopsy in three cases showed evidence of acute alveolar damage. CONCLUSION: In selected patients with tuberculosis who develop respiratory failure following the initiation of antituberculous therapy, HRCT may be a helpful adjunct to clinical evaluation in differentiating hypersensitivity reactions (presumed to be due to the release of mycobacterial antigens) from other pulmonary complications. Akira, M. and Sakatani, M. (2001)

  11. Imaging in blunt cardiac injury: Computed tomographic findings in cardiac contusion and associated injuries.

    Science.gov (United States)

    Hammer, Mark M; Raptis, Demetrios A; Cummings, Kristopher W; Mellnick, Vincent M; Bhalla, Sanjeev; Schuerer, Douglas J; Raptis, Constantine A

    2016-05-01

    Blunt cardiac injury (BCI) may manifest as cardiac contusion or, more rarely, as pericardial or myocardial rupture. Computed tomography (CT) is performed in the vast majority of blunt trauma patients, but the imaging features of cardiac contusion are not well described. To evaluate CT findings and associated injuries in patients with clinically diagnosed BCI. We identified 42 patients with blunt cardiac injury from our institution's electronic medical record. Clinical parameters, echocardiography results, and laboratory tests were recorded. Two blinded reviewers analyzed chest CTs performed in these patients for myocardial hypoenhancement and associated injuries. CT findings of severe thoracic trauma are commonly present in patients with severe BCI; 82% of patients with ECG, cardiac enzyme, and echocardiographic evidence of BCI had abnormalities of the heart or pericardium on CT; 73% had anterior rib fractures, and 64% had pulmonary contusions. Sternal fractures were only seen in 36% of such patients. However, myocardial hypoenhancement on CT is poorly sensitive for those patients with cardiac contusion: 0% of right ventricular contusions and 22% of left ventricular contusions seen on echocardiography were identified on CT. CT signs of severe thoracic trauma are frequently present in patients with severe BCI and should be regarded as indirect evidence of potential BCI. Direct CT findings of myocardial contusion, i.e. myocardial hypoenhancement, are poorly sensitive and should not be used as a screening tool. However, some left ventricular contusions can be seen on CT, and these patients could undergo echocardiography or cardiac MRI to evaluate for wall motion abnormalities. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

    Hymel, K.P.; Rumack, C.M.; Hay, T.C.; Strain, J.D.; Jenny, C.

    1997-01-01

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

  13. Carotid ultrasonographic and brain computerized tomographic findings in patients with vascular ocular syndromes

    Energy Technology Data Exchange (ETDEWEB)

    Iwamoto, Toshihiko; Matsushima, Chikage; Shimizu, Souichirou; Takasaki, Masaru; Iwasaki, Takuya; Usui, Masahiko [Tokyo Medical Coll. (Japan)

    2002-02-01

    To clarify the characteristics of cerebrovascular lesions in subtypes of vascular ocular syndrome, including amaurosis fugax (AF), retinal artery occlusion (RAO), and retinal vein occlusion (RVO), 93 patients with vascular ocular syndrome were studied by means of carotid ultrasonography (US) and brain computerized tomography (CT). The subjects comprised 21 patients with AF, 37 with RAO, and 35 with RVO who were sequentially given these diagnoses by the department of ophthalmology. On the basis of US findings, carotid lesions were defined as the presence of plaque or stenotic changes. CT findings were assessed for the presence and distribution of low-density areas (LDAs). Mean age was similar in each group, ranging from 64.5 to 67.4 years. The RAO group had high rates of men, hypertension, and smokers. US showed that the prevalence of carotid lesions ipsilateral to the affected eye was high in the RAO group and that severe stenosis and ulcerated plaque were present in 28.6% of the AF group and 45.9% of the RAO group. On CT examination, cerebral infarctions appeared as LDAs in about 10% of the patients in each group, and the incidence and distribution of LDAs were similar. Of 13 patients with cerebral infarction, only 2 were presumably due to carotid lesions; the others had a variety of causes. The discrepancy between US and CT findings was attributed to the small number of patients with cerebral infarction, since most patients had visual defects as an initial symptom. Our results suggest that extracranial carotid lesions, considered to be a major risk factor for stroke, should be carefully assessed in patients with AF or RAO to prevent further stroke. (author)

  14. Whole body computed tomographic findings of each one case with primary aldosteronism and Cushing syndrome

    International Nuclear Information System (INIS)

    Kamata, Shuji; Kawamura, Koro; Nakamura, Motoyuki

    1980-01-01

    We here report each one case with primary aldosteronism (male, 28 years old) and Cushing syndrome (female, 37 years old). Both of the cases showed characteristic clinical signs of hypertension and typical laboratory findings of adreno-hormonal assays. In performance of whole body computed tomography, clear pictures of tumorous adenomas in both cases were taken and the sizes of adenomas in picture were completely same as the masses obtained by the lateral adrenectomies. As a result, the whole body computed tomography is very useful to diagnose the diseases of adrenal adenoma and hyperplasia. (author)

  15. Computed tomographic findings in dogs and cats with temporomandibular joint disorders: 58 cases (2006–2011)

    Science.gov (United States)

    Arzi, Boaz; Cissell, Derek D.; Verstraete, Frank J. M.; Kass, Philip H.; DuRaine, Grayson D.; Athanasiou, Kyriacos A.

    2013-01-01

    Objective To describe CT findings in dogs and cats with temporomandibular joint (TMJ) disorders. Design Retrospective case-series. Animals 41 dogs and 17 cats. Procedures Medical records and CT images of the skull were reviewed for dogs and cats that were examined at a dentistry and oral surgery specialty practice between 2006 and 2011. Results Of 142 dogs and 42 cats evaluated, 41 dogs and 17 cats had CT findings consistent with a TMJ disorder. In dogs, the most common TMJ disorder was osteoarthritis; however, in most cases, there were other TMJ disorders present in addition to osteoarthritis. Osteoarthritis was more frequently identified at the medial aspect rather than the lateral aspect of the TMJ, whereas the frequency of osteoarthritic involvement of the dorsal and ventral compartments did not differ significantly. In cats, fractures were the most common TMJ disorder, followed by osteoarthritis. Clinical signs were observed in all dogs and cats with TMJ fractures, dysplasia, ankylosis, luxation, and tumors; however, only 4 of 15 dogs and 2 of 4 cats with osteoarthritis alone had clinical signs. Conclusions and Clinical Relevance Results indicated that TMJ disorders are frequently present in combination. Osteoarthritis was the most common TMJ disorder in dogs and the second most common TMJ disorder in cats. Computed tomography should be considered as a tool for the diagnosis of TMJ disorders in dogs and cats with suspected orofacial disorders and pain. PMID:23234284

  16. Impact of Cardiac Computed Tomographic Angiography Findings on Planning of Cancer Therapy in Patients with Concomitant Structural Heart Disease

    Directory of Open Access Journals (Sweden)

    Iyad N. Daher

    2011-01-01

    Full Text Available Background. Exclusion of underlying coronary artery disease (CAD is essential in the diagnosis of chemotherapy-induced cardiomyopathy. Presence and severity of CAD can also impact the choice of therapy in cancer patients. The value of cardiac computed tomographic angiography (CCTA in this setting has not been reported. Methods. We collected data on the clinical presentation and indications for CCTA performed from January to December 2008 at the University of Texas MD Anderson Cancer Center (MDACC. All examinations were performed using a 64-detector scanner. CCTA results and subsequent treatment decisions were examined. Results. A total of 80 patients underwent CCTA during the study period for the following indications (not mutually exclusive: cardiomyopathy of unknown etiology in 33 pts (41.3%, chest pain in 32 (40.0%, abnormal stress test in 16 (20.0%, abnormal cardiac markers in 8 (10.0%, suspected cardiac mass or thrombus in 7 (8.8%. Chemotherapy-induced cardiomyopathy was diagnosed in 18 pts (22.5%. Severe CAD was detected in 22 pts (27.5%; due to concomitant advanced cancer or patient refusal, only 12 underwent coronary angiogram. Of these, 4 pts (5% of total underwent coronary artery bypass grafting. A total of 41 pts (51.3% had their cancer management altered based on CCTA findings. Conclusion. CCTA is useful in evaluating cancer pts with structural heart disease and can have an impact on the management of cancer and cardiac disease.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-04-01

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

  18. Postmortem computed tomographic (PMCT) findings of pericardial effusion due to acute aortic dissection

    International Nuclear Information System (INIS)

    Shiotani, Seiji; Watanabe, Ko; Kohno, Mototsugu; Ohashi, Noriyoshi; Nakayama, Hidetsugu; Yamazaki, Kentaro

    2004-01-01

    The purpose of this study was to describe the appearance of pericardial effusion in deceased acute aortic dissection patients using postmortem computed tomography (PMCT). PMCT examinations were performed within 2 hours of death in 30 patients with pericardial effusion due to aortic dissection who arrived at our hospital in a state of cardiopulmonary arrest. Pericardial effusion in 18 of 30 patients (60%) showed double concentric rings on PMCT with striking differences in density, a low-density outer ring along the pericardium and a high-density inner ring on the epicardial surface (hyperdense armored heart). Pericardial effusion in two patients (7%) showed a high-density fluid level (hypostasis). Pericardial effusion in the remaining 10 patients (33%) showed no such stratification. A ''hyperdense armored heart'' is the most frequently seen PMCT finding in deceased cases of pericardial effusion due to acute aortic dissection. (author)

  19. Computed tomographical findings of skeletal muscles in rimmed vacuole type distal myopathy

    International Nuclear Information System (INIS)

    Kunimoto, Masanari; Kawai, Mitsuru; Goto, Jun; Nakano, Imaharu

    1987-01-01

    Skeletal muscle CT scans of three patients with biopsy-proven rimmed vacuole type distal myopathy(RVDM) from two unrelated families showed unique involvement pattern of the lower extremities. Parents of the patients in both families are first cousins. T.Y. is a 36-year-old woman who noticed mild difficulty in walking at 34 years of age. Now she shows waddling but still indpendent gait. Manual muscle test (MMT) revealed the following results: fair (3+/5) for hip flexion, 3 for hip extension, 3 for knee flexion, normal (5/5) for knee extension, poor (2/5) for ankle dorsi-flexion, good (4/5) for ankle plantar flexion. T.M., a 34-year-old younger sister of T.Y., started dragging her feet on gait at age 27. She could walk neither on toes nor heels. At present, she can walk only with support. MMT showed the following: 3- and trace (1/5) for hip flexion and extension, 3- and 4 for knee flexion and extension, 1 for ankle plantar- and dorsiflexion. K.W., a 33-year-old woman, began to drag her foot tips in walk and became unable to walk on toes at age 21. The leg weakness progressed into the wheelchair-ridden state at age 30. MMT gave the following results: 1 for hip flexion and extension, 2 and 4 for knee flexion and extension, zero for plantar- and dorsi-flexion. The most impressive CT findings common to these three patients are prominent contrast between the quadriceps muscles and the adductor- and hamstring-group: the former is markedly well preserved even in the most advanced patient (K.W.) while the latter are diffusely and severely affected even in the least affected patient (T.Y.). This finding well coincides with the results of MMT: the knee extensor (quadriceps muscles) fairly well keeps its strength even in the most advanced patient but the knee flexors (adductors and hamstrings) are definitely affected in the early stage of the condition. (J.P.N.)

  20. Computed tomographical findings of skeletal muscles in rimmed vacuole type distal myopathy

    Energy Technology Data Exchange (ETDEWEB)

    Kunimoto, Masanari; Kawai, Mitsuru; Goto, Jun; Nakano, Imaharu

    1987-03-01

    Skeletal muscle CT scans of three patients with biopsy-proven rimmed vacuole type distal myopathy(RVDM) from two unrelated families showed unique involvement pattern of the lower extremities. Parents of the patients in both families are first cousins. T.Y. is a 36-year-old woman who noticed mild difficulty in walking at 34 years of age. Now she shows waddling but still indpendent gait. Manual muscle test (MMT) revealed the following results: fair (3+/5) for hip flexion, 3 for hip extension, 3 for knee flexion, normal (5/5) for knee extension, poor (2/5) for ankle dorsi-flexion, good (4/5) for ankle plantar flexion. T.M., a 34-year-old younger sister of T.Y., started dragging her feet on gait at age 27. She could walk neither on toes nor heels. At present, she can walk only with support. MMT showed the following: 3- and trace (1/5) for hip flexion and extension, 3- and 4 for knee flexion and extension, 1 for ankle plantar- and dorsiflexion. K.W., a 33-year-old woman, began to drag her foot tips in walk and became unable to walk on toes at age 21. The leg weakness progressed into the wheelchair-ridden state at age 30. MMT gave the following results: 1 for hip flexion and extension, 2 and 4 for knee flexion and extension, zero for plantar- and dorsi-flexion. The most impressive CT findings common to these three patients are prominent contrast between the quadriceps muscles and the adductor- and hamstring-group: the former is markedly well preserved even in the most advanced patient (K.W.) while the latter are diffusely and severely affected even in the least affected patient (T.Y.). This finding well coincides with the results of MMT: the knee extensor (quadriceps muscles) fairly well keeps its strength even in the most advanced patient but the knee flexors (adductors and hamstrings) are definitely affected in the early stage of the condition. (J.P.N.).

  1. Spectral domain optical coherence tomography findings in tamoxifen retinopathy--a case report.

    Science.gov (United States)

    Nair, Sandhya Narayanan; Anantharaman, Giridhar; Gopalakrishnan, Mahesh; Vyas, Jyothiprakash

    2013-01-01

    To report spectral domain optical coherence tomography findings in a case of typical tamoxifen retinopathy. In this observational case report, a patient with tamoxifen retinopathy was imaged with spectral domain optical coherence tomography and fundus auto fluorescence. Spectral domain optical coherence tomography showed numerous hyperreflective spots within the retina, mainly in the inner retinal layers in both the eyes. The external limiting membrane, the Inner Segment-Outer Segment junction, and the photoreceptors were not discernable at the fovea in the right eye. In the left eye, there was foveal atrophy with total loss of photoreceptors. The autofluorescent images showed macular hypofluorescence with foveal hyperfluorescence. Spectral domain optical coherence tomography demonstrated abnormalities in the outer retinal layers in tamoxifen retinopathy. There were also characteristic alterations in the autofluorescence pattern at the macula in tamoxifen retinopathy.

  2. Tomographic reconstruction of melanin structures of optical coherence tomography via the finite-difference time-domain simulation

    Science.gov (United States)

    Huang, Shi-Hao; Wang, Shiang-Jiu; Tseng, Snow H.

    2015-03-01

    Optical coherence tomography (OCT) provides high resolution, cross-sectional image of internal microstructure of biological tissue. We use the Finite-Difference Time-Domain method (FDTD) to analyze the data acquired by OCT, which can help us reconstruct the refractive index of the biological tissue. We calculate the refractive index tomography and try to match the simulation with the data acquired by OCT. Specifically, we try to reconstruct the structure of melanin, which has complex refractive indices and is the key component of human pigment system. The results indicate that better reconstruction can be achieved for homogenous sample, whereas the reconstruction is degraded for samples with fine structure or with complex interface. Simulation reconstruction shows structures of the Melanin that may be useful for biomedical optics applications.

  3. Echocardiographic and non-gated computed tomographic findings of intrapericardial tumor and mediastinal tumor adjacent to the heart

    International Nuclear Information System (INIS)

    Ueda, Minoru; Yamada, Nobuyuki; Saito, Daiji; Haraoka, Shoichi; Tanetani, Setsuro.

    1981-01-01

    Echocardiographic and computed tomographic findings of a case of intrapericardial tumor are reported, and two other cases of mediastinal tumor are presented in a discussion of the differential diagnosis of intrapericardial from mediastinal tumors. Case report: A 7-year-old male complained of cough and dyspnea. Cardiomegaly had been pointed out at a mass X-ray examination about a month prior to the admission. Two-dimensional echocardiography revealed a massive anterior pericardial effusion and a fist-sized tumor with cystic structure. The tumor pushed the heart backward at the level of the aortic root. Non-gated computed tomography of the chest disclosed the size and location of the tumor, but failed to clarify the internal structure. The patient underwent successful removal of a tumor, 12 x 10 x 8 cm in size and 350 g in weight, originating from the left atrial wall. Histologically, the tumor was a fibrosarcomatous mesothelioma. Usually, an intrapericardial tumor is easily suspected by echocardiography by the presence of pericardial effusion, although there have been a few reports of intrapericardial tumors without pericardial effusion. Echocardiographic diagnosis of the intrapericardial tumor is difficult in such cases. Identification of the pericardium is necessary to diagnose whether a tumor is intra- or extrapericardial. This identification, however, is not always easy by echocardiography when the ultrasonic beams become tangent to the pericardium. The pericardium between the tumor and the heart could not be identified by echocardiography in our two cases of mediastinal tumor. Computed tomography is helpful in diagnosing the size and location of a mediastinal tumor. (author)

  4. Ocular coherence tomographic examination of postoperative foveal architecture after scleral buckling vs vitrectomy for macular off retinal detachment.

    LENUS (Irish Health Repository)

    Gibran, S K

    2012-02-03

    AIMS: This pilot study uses Optical Coherence Tomography (OCT) imaging to compare the difference in foveal architecture after successful retinal detachment (RD) surgery by scleral buckling or pars plana vitrectomy (PPV). METHODS: Prospective recruitment of patients with macular off RDs. Detachment surgery was undertaken by scleral buckling, external drainage, and air injection (group 1) or by PPV (group 2). Postoperatively patients had clinical examinations and OCT at 1, 3, 6, and 12 months. If abnormalities persisted, a further OCT was obtained at 18 months. RESULTS: Retinal reattachment, including clinical macular reattachment, was achieved in all cases within 24 h postoperatively. In group 1 (n=22), postoperative OCT showed persistent foveal detachment in 63% of cases (n=14) at 1 and 3 months. At 6 and 12 months, 36% (n=8) and 9% (n=2) had a persistent foveal detachment, respectively, and at 18 months, foveal detachment eventually. In group 2 (n=21), postoperative OCT showed an attached fovea in all cases; however, foveal thickening suggesting intraretinal oedema was present in all cases. The oedematous appearance of retina on OCT settled in 1-3 months. No foveal abnormality was seen at 6 and 12 months postoperatively. CONCLUSIONS: A high proportion of patients with successful retinal reattachment surgery by scleral buckling had foveal detachments postoperatively. No cases who had PPV had foveal detachments; however, transient retinal oedema was evident in all cases. The aetiology of these changes is unknown and warrants further investigation, as there is the potential of a long-term effect on vision.

  5. Middle east respiratory syndrome-corona virus infection: A case report of sieral computed tomographic findings in a young male patient

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Won Jin; Lee, Ki Nam; Kang, Eun Ju; Lee, Hyuck [Dong A University Hospital, Busan (Korea, Republic of)

    2016-02-15

    Radiologic findings of Middle East respiratory syndrome (MERS), a novel coronavirus infection, have been rarely reported. We report a 30-year-old male presented with fever, abdominal pain, and diarrhea, who was diagnosed with MERS. A chest computed tomographic scan revealed rapidly developed multifocal nodular consolidations with ground-glass opacity halo and mixed consolidation, mainly in the dependent and peripheral areas. After treatment, follow-up imaging showed that these abnormalities markedly decreased but fibrotic changes developed.

  6. Comparison between a New Optical Biometry Device and an Anterior Segment Optical Coherence Tomographer for Measuring Central Corneal Thickness and Anterior Chamber Depth

    Directory of Open Access Journals (Sweden)

    Jinhai Huang

    2016-01-01

    Full Text Available Purpose. To compare between a new optical biometer (AL-Scan, Nidek Co., Aichi, Japan and an anterior segment optical coherence tomographer (Visante AS-OCT, Carl Zeiss Meditec, Dublin, USA for measuring central corneal thickness (CCT, anterior chamber depth (ACD, and aqueous depth (AD. Methods. Sixty-three eyes of 63 normal subjects were examined with AL-Scan and Visante AS-OCT in this prospective study. One eye per subject was measured three times with both devices to record their CCT, ACD, and AD. All procedures were performed by the same operator. Agreement between the two devices was assessed using paired t-tests, Bland-Altman plots, and 95% limits of agreement (LoA. Results. The mean CCT, ACD, and AD measured by AL-Scan were 538.59±27.37 μm, 3.70±0.30 mm, and 3.16±0.30 mm, respectively. The mean values obtained by the Visante OCT were 536.14±26.61 μm for CCT, 3.71±0.29 mm for ACD, and 3.17±0.29 mm for AD. The mean CCT by the AL-Scan was higher than that obtained by the Visante AS-OCT (difference = 2.45±6.07 μm, P<0.05. The differences in ACD and AD measurements were not statistically significant. The 95% LoA of CCT, ACD, and AD were between −9.44 and 14.35 μm, −0.15 and 0.12 mm, and −0.15 and 0.12 mm, respectively. Conclusions. Since these two devices were comparable for measuring CCT, ACD, and AD, their results can be interchangeably used in the clinic.

  7. Surgical treatment and optical coherence tomographic evaluation for accidental laser-induced full-thickness macular holes.

    Science.gov (United States)

    Qi, Y; Wang, Y; You, Q; Tsai, F; Liu, W

    2017-07-01

    PurposeTo report OCT appearance and surgical outcomes of full-thickness macular holes (MHs) accidentally caused by laser devices.Patients and methodsThis retrospective case series included 11 eyes of 11 patients with laser-induced MHs treated by pars plana vitrectomy, internal limiting membrane (ILM) peeling, and gas or silicone oil tamponade. Evaluations included a full ophthalmic examination, macular spectral-domain optical coherence tomography (SD-OCT), and fundus photography. Main outcome measures is MH closure and final visual acuity; the secondary outcome was the changes of retinal pigment epithelium and photoreceptor layer evaluated by sequential post-operative SD-OCT images.ResultsFive patients were accidentally injured by a yttrium aluminum garnet (YAG) laser and six patients by handheld laser. MH diameters ranged from 272 to 815 μm (mean, 505.5±163.0 μm) preoperatively. Best-corrected visual acuity (BCVA) improved from a mean of 0.90 logMAR (range, counting finger-8/20) preoperatively to a mean of 0.34 logMAR (range, a counting finger-20/20) postoperatively (P=0.001, t=4.521). Seven of 11 patients (63.6%) achieved a BCVA better than 10/20. Ten patients had a subfoveal hyperreflectivity and four patients had a focal choroidal depression subfoveal preoperatively. At the last follow-up, all 11 eyes demonstrated the following: closure of the macular hole, variable degrees of disruption of external limiting membrane (ELM) and outer photoreceptor ellipsoid and interdigitation bands. In 10 eyes, the disruption was in the form of focal defects in the outer retina. After surgery, the subfoveal hyperreflectivity and focal choroidal depression remained.ConclusionAccidental laser-induced full-thickness macular holes can be successfully closed with surgery. Inadvertent retinal injury from laser devices, especially handheld laser injury has occurred with increasing frequency in recent years. However, there is a paucity of data regarding these types of injuries

  8. Transient spectral domain optical coherence tomography findings in classic MEWDS: a case report.

    Science.gov (United States)

    Lavigne, Luciana Castro; Isaac, David Leonardo Cruvinel; Duarte Júnior, José Osório; Avila, Marcos Pereira de

    2014-01-01

    The purpose of this study was to describe a patient with multiple evanescent white dot syndrome (MEWDS) who presented with classic retinal findings and transient changes in outer retinal anatomy. A 20-year-old man presented with mild blurred vision in the left eye, reporting flu-like symptoms 1 week before the visual symptoms started. Fundus examination of the left eye revealed foveal granularity and multiple scattered spots deep to the retina in the posterior pole. Fluorescein angiography and indocyanine green angiography showed typical MEWDS findings. Spectral Domain Optical Coherence Tomography has shown transient changes in outer retinal anatomy with disappearance of inner segment-outer segment junction and mild attenuation of external limiting membrane. Six months later, Spectral Domain Optical Coherence Tomography has shown complete resolution with recovery of normal outer retinal aspect.

  9. Gross, computed tomographic and histological findings in mandibular cheek teeth extracted from horses with clinical signs of pulpitis due to apical infection.

    Science.gov (United States)

    Casey, M B; Pearson, G R; Perkins, J D; Tremaine, W H

    2015-09-01

    The most prevalent type of equine dental pulpitis due to apical infection is not associated with coronal fractures or periodontal disease. The pathogenesis of this type of pulpitis is not fully understood. Computed tomography (CT) is increasingly used to investigate equine dental disorders. However, gross, tomographic and histopathological changes in equine dental pulpitis have not been compared previously. To compare gross, CT and histological appearances of sectioned mandibular cheek teeth extracted from horses with clinical signs of pulpitis without coronal fractures or periodontal disease. To contribute to understanding the pathogenesis of equine dental pulpitis. Descriptive study using diseased and healthy teeth. Mandibular cheek teeth extracted from horses with clinical signs of pulpitis (cases), and from cadavers with no history of dental disease (controls), were compared using CT in the transverse plane at 1 mm intervals. Teeth were then sectioned transversely, photographed and processed for histopathological examination. Tomographs were compared with corresponding gross and histological sections. Cement, dentine and bone had similar ranges of attenuation (550-2000 Hounsfield Units, HU) in tomographs but could be differentiated from pulp (-400 to 500 HU) and enamel (> 2500 HU). Twelve discrete dental lesions were identified grossly, 10 of which were characterised histologically. Reactive and reparative dentinogenesis and extensive pulpar mineralisation, previously undescribed, were identified. Pulpar oedema, neutrophilic inflammation, cement and enamel defects, and reactive cemental deposition were also observed. The CT and pathological findings corresponded well where there was mineralised tissue deposited, defects in mineralised tissue, or food material in the pulpar area. Pulpar and dentinal necrosis and cement destruction, evident grossly and histologically, did not correspond to CT changes. Computed tomography is useful for identifying deposition and

  10. Optical Coherence Tomographic and Visual Results at Six Months after Transitioning to Aflibercept for Patients on Prior Ranibizumab or Bevacizumab Treatment for Exudative Age-Related Macular Degeneration (An American Ophthalmological Society Thesis)

    Science.gov (United States)

    Chan, Clement K.; Jain, Atul; Sadda, Srinivas; Varshney, Neeta

    2014-01-01

    Purpose: To study optical coherence tomographic (OCT) results and vision at 6 months after transition (post-Tx) from intravitreal bevacizumab and/or ranibizumab to aflibercept for treatment of neovascular age-related macular degeneration (nAMD). The null hypothesis was the lack of improvements in OCT metrics and vision outcome in study eyes at 6 months after transitioning from bevacizumab or ranibizumab to aflibercept. Methods: This retrospective study assessed 6 monthly OCT (Cirrus) data after transitioning to aflibercept for eyes on prior Legacy-ranibizumab, Legacy-bevacizumab, or mixed treatment for nAMD. Outcome measures were subretinal fluid (SRF), cystoid macular edema (CME), pigment epithelial detachment (PED) heights and volumes, central 1- and 3-mm subfield, Macular Volume, and best spectacle and pinhole visual acuity (VA). A single masked investigator performed all OCT measurements. Results: One hundred eighty-nine eyes in 172 patients in Legacy-bevacizumab (95 eyes), Legacy-ranibizumab (84 eyes), or Mixed Group(10 eyes) were switched to aflibercept and followed for 6 months. Significant post-Tx reductions were noted in SRF/CME heights and volumes (all P<.001). Similar findings were noted for PED heights (122.8 μm vs 79.4 μm) and PED volumes (all P<.001). Post-Tx VA was better (20/43 vs 20/51, P<.001). There were no differences between Legacy-bevacizumab and Legacy-ranibizumab groups in OCT and VA changes. Post-Tx VA, SRF/CME, and PED heights and volumes were improved for Nonresponders (suboptimal response to bevacizumab/ranibizumab) (P=.001 to <.001), but not Responders (good responses to same). The only adverse event was a retinal pigment epithelial tear in one eye. Conclusions: Significant improvements in vision and OCT metrics developed in Nonresponders but not in Responders. Post-Tx VA and OCT measures were similar for eyes on prior bevacizumab or ranibizumab. Post-Tx adverse events were uncommon. PMID:25646034

  11. Clamshell tomograph

    International Nuclear Information System (INIS)

    Derenzo, S. E.; Budinger, Th. F.

    1984-01-01

    In brief, the invention is a tomograph modified to be in a clamshell configuration so that the ring or rings may be moved to multiple sampling positions. The tomograph includes an array of detectors arranged in successive adjacent relative locations along a closed curve in a first position in a selected plane, and means for securing the detectors in the relative locations in a first sampling position. The securing means is movable in the plane in two sections and pivotable at one point and only one point to enable movement of at least one of the sections to a second sampling position out of the closed curve so that the ends of the section which are opposite the point are moved apart a predetermined space

  12. Tomographic array

    International Nuclear Information System (INIS)

    1976-01-01

    The configuration of a tomographic array in which the object can rotate about its axis is described. The X-ray detector is a cylindrical screen perpendicular to the axis of rotation. The X-ray source has a line-shaped focus coinciding with the axis of rotation. The beam is fan-shaped with one side of this fan lying along the axis of rotation. The detector screen is placed inside an X-ray image multiplier tube

  13. Tomographic array

    International Nuclear Information System (INIS)

    1976-01-01

    A tomographic array with the following characteristics is described. An X-ray screen serving as detector is placed before a photomultiplier tube which itself is placed in front of a television camera connected to a set of image processors. The detector is concave towards the source and is replacable. Different images of the object are obtained simultaneously. Optical fibers and lenses are used for transmission within the system

  14. Computer tomographs

    International Nuclear Information System (INIS)

    Niedzwiedzki, M.

    1982-01-01

    Physical foundations and the developments in the transmission and emission computer tomography are presented. On the basis of the available literature and private communications a comparison is made of the various transmission tomographs. A new technique of computer emission tomography ECT, unknown in Poland, is described. The evaluation of two methods of ECT, namely those of positron and single photon emission tomography is made. (author)

  15. Differences in clinical features and computed tomographic findings between embolic and non-embolic acute ischemic stroke. A quantitative differential diagnosis

    International Nuclear Information System (INIS)

    Takano, Kentaro; Yamaguchi, Takenori; Minematsu, Kazuo; Sawada, Tohru; Omae, Teruo

    1998-01-01

    A diagnosis based on the presumed mechanism of stroke onset is useful for management strategies in acute ischemic stroke. Ninety-two patients with embolic (cardiac or artery-to-artery) and 107 with non-embolic (thrombotic or hemodynamic) stroke were diagnosed on strict cerebral angiographic criteria alone. To clearly discriminate between these two groups, the neurological and computed tomographic (CT) findings were then compared. Rapidity of onset, vomiting, urinary incontinence, level of consciousness, cervical bruit, anisocoria, tongue deviation, sensory disturbance, and CT findings (location of hypodense area, findings of brain edema and hemorrhagic transformation) were discriminatory factors between the two groups (p<0.01). According to these 11 items, we prepared a numerical table for quantitative differential diagnosis. A diagnostic accuracy of 98.9% for embolic and 87.9% for non-embolic stroke in internal verification, and 90.0% and 82.9%, respectively, in external verification was observed. The differences in clinical features and CT findings between embolic and non-embolic stroke may reflect the pathophysiological mechanisms of the occlusive process of cerebral artery as well as the extent and severity of ischemia. (author)

  16. Differences in clinical features and computed tomographic findings between embolic and non-embolic acute ischemic stroke. A quantitative differential diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Takano, Kentaro; Yamaguchi, Takenori; Minematsu, Kazuo; Sawada, Tohru; Omae, Teruo [National Cardiovascular Center, Suita, Osaka (Japan)

    1998-02-01

    A diagnosis based on the presumed mechanism of stroke onset is useful for management strategies in acute ischemic stroke. Ninety-two patients with embolic (cardiac or artery-to-artery) and 107 with non-embolic (thrombotic or hemodynamic) stroke were diagnosed on strict cerebral angiographic criteria alone. To clearly discriminate between these two groups, the neurological and computed tomographic (CT) findings were then compared. Rapidity of onset, vomiting, urinary incontinence, level of consciousness, cervical bruit, anisocoria, tongue deviation, sensory disturbance, and CT findings (location of hypodense area, findings of brain edema and hemorrhagic transformation) were discriminatory factors between the two groups (p<0.01). According to these 11 items, we prepared a numerical table for quantitative differential diagnosis. A diagnostic accuracy of 98.9% for embolic and 87.9% for non-embolic stroke in internal verification, and 90.0% and 82.9%, respectively, in external verification was observed. The differences in clinical features and CT findings between embolic and non-embolic stroke may reflect the pathophysiological mechanisms of the occlusive process of cerebral artery as well as the extent and severity of ischemia. (author)

  17. Retinal pigment epithelium findings in patients with albinism using wide-field polarization-sensitive optical coherence tomography.

    Science.gov (United States)

    Schütze, Christopher; Ritter, Markus; Blum, Robert; Zotter, Stefan; Baumann, Bernhard; Pircher, Michael; Hitzenberger, Christoph K; Schmidt-Erfurth, Ursula

    2014-11-01

    To investigate pigmentation characteristics of the retinal pigment epithelium (RPE) in patients with albinism using wide-field polarization-sensitive optical coherence tomography compared with intensity-based spectral domain optical coherence tomography and fundus autofluorescence imaging. Five patients (10 eyes) with previously genetically diagnosed albinism and 5 healthy control subjects (10 eyes) were imaged by a wide-field polarization-sensitive optical coherence tomography system (scan angle: 40 × 40° on the retina), sensitive to melanin contained in the RPE, based on the polarization state of backscattered light. Conventional intensity-based spectral domain optical coherence tomography and fundus autofluorescence examinations were performed. Retinal pigment epithelium-pigmentation was analyzed qualitatively and quantitatively based on depolarization assessed by polarization-sensitive optical coherence tomography. This study revealed strong evidence of polarization-sensitive optical coherence tomography to specifically image melanin in the RPE. Depolarization of light backscattered by the RPE in patients with albinism was reduced compared with normal subjects. Heterogeneous RPE-specific depolarization characteristics were observed in patients with albinism. Reduction of depolarization observed in the light backscattered by the RPE in patients with albinism corresponds to expected decrease of RPE pigmentation. The degree of depigmentation of the RPE is possibly associated with visual acuity. Findings suggest that different albinism genotypes result in heterogeneous levels of RPE pigmentation. Polarization-sensitive optical coherence tomography showed a heterogeneous appearance of RPE pigmentation in patients with albinism depending on different genotypes.

  18. Fundus Autofluorescence and Optical Coherence Tomography Findings in Branch Retinal Vein Occlusion

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    Tetsuju Sekiryu

    2012-01-01

    Full Text Available Purpose. To describe the findings of fundus autofluorescence (FAF and optical coherence tomography (OCT in patients with branch retinal vein occlusion (BRVO. Methods. In this institutional, retrospective, observational case series, FAF was evaluated in 65 eyes with BRVO in 64 consecutive patients and compared with visual acuity, OCT findings, and other clinical observations. Results. Five types of autofluorescence appeared during the course of BRVO: (1 petaloid-shaped hyperautofluorescence in the area of macular edema and (2 hyperautofluorescence coincident with yellow subretinal deposits. (3 Diffuse hyperautofluorescence appeared within the area of serous retinal detachment (SRD and OCT showed precipitates on the undersurface of the retina in 5/5 of these eyes (100%. (4 The area of vein occlusion showed diffuse hyperautofluorescence after resolution of the retinal bleeding. (5 Hard exudates exhibited hyper- or hypoautofluorescence. OCT indicated that most of the hard exudates with hyperautofluorescence were located on the retinal pigment epithelium. Conclusions. Hyperautofluorescence associated with subretinal fluid or hard exudate appeared in the subretinal space. This type of hyperautofluorescence may be attributed to blood cell or macrophages. FAF and OCT are noninvasive modalities that provide additional information regarding macular edema due to BRVO.

  19. Optical coherence tomography and fundus autofluorescence findings in presumed congenital simple retinal pigment epithelium hamartoma

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    Baskaran, Prabu

    2017-10-01

    Full Text Available Aim: Presumed congenital simple retinal pigment epithelium hamartoma is a rare benign lesion of the macula that mimics congenital hypertrophy of the retinal pigment epithelium (RPE and combined hamartoma of the retina and the RPE; newer imaging modalities can help in diagnosis. We report three patients with presumed congenital simple RPE hamartoma, and describe the enhanced-depth imaging optical coherence tomography (EDI-OCT and fundus autofluorescence (FAF findings. Methods: Two patients were asymptomatic; one had an intraocular foreign body in addition to the hamartoma. All had a similar jet black, elevated lesion in the macula, sparing the fovea. EDI-OCT showed a characteristic hyperreflective layer with complete optical shadowing of the deeper layers; FAF showed pronounced hypoautofluorescence of the lesion. Conclusion: Multimodal imaging with FAF and EDI-OCT can help to differentiate simple RPE hamartoma from similar RPE lesions, and may serve as a useful adjunct to clinical diagnosis of this rare tumor. We present the second largest series of presumed congenital simple RPE hamartoma, and – to the best of our knowledge – the first report of FAF findings of this tumor.

  20. Computed tomographic findings in dogs with head trauma and development of a novel prognostic computed tomography-based scoring system.

    Science.gov (United States)

    Chai, Orit; Peery, Dana; Bdolah-Abram, Tali; Moscovich, Efrat; Kelmer, Efrat; Klainbart, Sigal; Milgram, Joshua; Shamir, Merav H

    2017-09-01

    OBJECTIVE To characterize CT findings and outcomes in dogs with head trauma and design a prognostic scale. ANIMALS 27 dogs admitted to the Koret School Veterinary Teaching Hospital within 72 hours after traumatic head injury that underwent CT imaging of the head. PROCEDURES Data were extracted from medical records regarding dog signalment, history, physical and neurologic examination findings, and modified Glasgow coma scale scores. All CT images were retrospectively evaluated by a radiologist unaware of dog status. Short-term (10 days after trauma) and long-term (≥ 6 months after trauma) outcomes were determined, and CT findings and other variables were analyzed for associations with outcome. A prognostic CT-based scale was developed on the basis of the results. RESULTS Cranial vault fractures, parenchymal abnormalities, or both were identified via CT in 24 of 27 (89%) dogs. Three (11%) dogs had only facial bone fractures. Intracranial hemorrhage was identified in 16 (59%) dogs, cranial vault fractures in 15 (56%), midline shift in 14 (52%), lateral ventricle asymmetry in 12 (44%), and hydrocephalus in 7 (26%). Hemorrhage and ventricular asymmetry were significantly and negatively associated with short- and long-term survival, respectively. The developed 7-point prognostic scale included points for hemorrhage, midline shift or lateral ventricle asymmetry, cranial vault fracture, and depressed fracture (1 point each) and infratentorial lesion (3 points). CONCLUSIONS AND CLINICAL RELEVANCE The findings reported here may assist in determining prognoses for other dogs with head trauma. The developed scale may be useful for outcome assessment of dogs with head trauma; however, it must be validated before clinical application.

  1. Favorable effect of optimal lipid-lowering therapy on neointimal tissue characteristics after drug-eluting stent implantation: qualitative optical coherence tomographic analysis.

    Science.gov (United States)

    Jang, Ji-Yong; Kim, Jung-Sun; Shin, Dong-Ho; Kim, Byeong-Keuk; Ko, Young-Guk; Choi, Donghoon; Jang, Yangsoo; Hong, Myeong-Ki

    2015-10-01

    Serial follow-up optical coherence tomography (OCT) was used to evaluate the effect of optimal lipid-lowering therapy on qualitative changes in neointimal tissue characteristics after drug-eluting stent (DES) implantation. DES-treated patients (n = 218) who received statin therapy were examined with serial follow-up OCT. First and second follow-up OCT evaluations were performed approximately 6 and 18 months after the index procedure, respectively. Patients were divided into two groups, based on the level of low-density lipoprotein-cholesterol (LDL-C), which was measured at the second follow-up. The optimal lipid-lowering group (n = 121) had an LDL-C reduction of ≥50% or an LDL-C level ≤70 mg/dL, and the conventional group (n = 97). Neointimal characteristics were qualitatively categorized as homogeneous or non-homogeneous patterns using OCT. The non-homogeneous group included heterogeneous, layered, or neoatherosclerosis patterns. Qualitative changes in neointimal tissue characteristics between the first and second follow-up OCT examinations were assessed. Between the first and second follow-up OCT procedures, the neointimal cross-sectional area increased more substantially in the conventional group (0.4 mm(2) vs. 0.2 mm(2) in the optimal lipid-lowering group, p = 0.01). The neointimal pattern changed from homogeneous to non-homogeneous less often in the optimal lipid-lowering group (1.3%, 1/77, p < 0.001) than in the conventional group (15.3%, 11/72, p = 0.44). Optimal LDL-C reduction was an independent predictor for the prevention of neointimal pattern change from homogeneous to non-homogeneous (odds ratio: 0.05, 95% confidence interval: 0.01∼0.46, p = 0.008). Our findings suggest that an intensive reduction in LDL-C levels can prevent non-homogeneous changes in the neointima and increases in neointimal cross-sectional area compared with conventional LDL-C controls. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. Acute Retinal Pigment Epitheliitis: Spectral Domain Optical Coherence Tomography, Fluorescein Angiography, and Autofluorescence Findings

    Directory of Open Access Journals (Sweden)

    Tuğba Aydoğan

    2015-01-01

    Full Text Available A 17-year-old presented with central and paracentral scotomas in his right eye for one week. There was no remarkable medical or ocular history. Blood analyses were within normal range. At presentation both eyes’ best-corrected visual acuities were 20/20. Slit-lamp examination result was normal. Fundus examination revealed yellow-white hypopigmented areas in the macula. Fluorescein angiography (FA showed hypofluorescence surrounded by ring of hyperfluorescence. Fundus autofluorescence (FAF was slightly increased. Spectral domain optical coherence tomography (SD-OCT showed disruption of IS/OS junction with expansion of abnormal hyperreflectivity from retinal pigment epithelium to the outer nuclear layer (ONL. One month later fundus examination showed disappearance of the lesions. FA revealed transmission hyperfluorescence. FAF showed increased autofluorescence and pigment clumping. Hyperreflective band in SD-OCT disappeared. Loss of photoreceptor segment layers was observed in some of the macular lesions. The diagnosis of acute retinal pigment epitheliitis can be challenging after disappearance of fundus findings. FA, FAF, and SD-OCT are important tests for diagnosis after resolution of the disease.

  3. In Vivo Confocal Microscopy and Anterior Segment Optic Coherence Tomography Findings in Ocular Ochronosis

    Directory of Open Access Journals (Sweden)

    Elif Demirkilinc Biler

    2015-01-01

    Full Text Available Purpose. To report clinical and in vivo confocal microscopy (IVCM findings of two patients with ocular ochronosis secondary due to alkaptonuria. Materials and Methods. Complete ophthalmologic examinations, including IVCM (HRT II/Rostock Cornea Module, Heidelberg, Germany, anterior segment optical coherence tomography (AS-OCT (Topcon 3D spectral-domain OCT 2000, Topcon Medical Systems, Paramus, NJ, USA, corneal topography (Pentacam, OCULUS Optikgeräte GmbH, Wetzlar, Germany, and anterior segment photography, were performed. Results. Biomicroscopic examination showed bilateral darkly pigmented lesions of the nasal and temporal conjunctiva and episclera in both patients. In vivo confocal microscopy of the lesions revealed prominent degenerative changes, including vacuoles and fragmentation of collagen fibers in the affected conjunctival lamina propria and episclera. Hyperreflective pigment granules in different shapes were demonstrated in the substantia propria beneath the basement membrane. AS-OCT of Case 1 demonstrated hyporeflective areas. Fundus examination was within normal limits in both patients, except tilted optic discs with peripapillary atrophy in one of the patients. Corneal topography, thickness, and macular OCT were normal bilaterally in both cases. Conclusion. The degenerative and anatomic changes due to ochronotic pigment deposition in alkaptonuria can be demonstrated in detail with IVCM and AS-OCT. Confocal microscopic analysis in ocular ochronosis may serve as a useful adjunct in diagnosis and monitoring of the disease progression.

  4. Diagnostic value of computed tomographic findings of nutcracker syndrome: Correlation with renal venography and renocaval pressure gradients

    International Nuclear Information System (INIS)

    Kim, Kyung Won; Cho, Jeong Yeon; Kim, Seung Hyup; Yoon, Jeong-Hee; Kim, Dae Sik; Chung, Jin Wook; Park, Jae Hyung

    2011-01-01

    Purpose: To evaluate the diagnostic values of CT findings of nutcracker syndrome (NCS). Methods and materials: Twenty seven subjects that underwent CT and renal venography, were divided into three groups based on the venographic renocaval pressure gradient (PG) and collateral veins of the left renal vein (LRV): non-compensated NCS patients with PG ≥ 3 mm Hg (group 1, n = 12), partially compensated NCS patients with borderline PG (1 2 test). Mean values of all quantitative CT parameters differed significantly only between groups 1 and 3 (P < .05, one-way ANOVA test). For differentiating the non-compensated NCS from the control group, the beak sign showed 91.7% sensitivity and 88.9% specificity. Of the various CT parameters, the beak sign and LRV diameter ratio of ≥4.9 showed the greatest diagnostic accuracy (AUC 0.903, ROC analysis). Conclusion: Beak sign of the LRV and CT findings can be useful in diagnosing the non-compensated NCS.

  5. Tomographic and functional findings in severe COPD: comparison between the wood smoke-related and smoking-related disease

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Garcia, Mauricio; Maldonado Gomez, Dario; Torres-Duque, Carlos A.; Barrero, Margarita; Jaramillo Villegas, Claudia; Perez, Juan Manuel; Varon, Humberto [Colombian Pulmonology Foundation, Bogota (Colombia); Department of Radiology and Diagnostic Imaging, Children' s Cardiology Foundation, Cardiology Institute, Bogota (Colombia)

    2013-11-01

    Objective: Wood smoke exposure is a risk factor for COPD. For a given degree of airway obstruction, the reduction in DLCO is smaller in individuals with wood smoke-related COPD than in those with smoking-related COPD, suggesting that there is less emphysema in the former. The objective of this study was to compare HRCT findings between women with wood smoke-related COPD and women with smoking-related COPD. Methods: Twenty-two women with severe COPD (FEV1/FVC ratio < 70% and FEV1 < 50%) were divided into two groups: those with wood smoke-related COPD (n = 12) and those with smoking-related COPD (n = 10). The two groups were compared regarding emphysema scores and airway involvement (as determined by HRCT); and functional abnormalities-spirometry results, DLCO, alveolar volume (VA), the DLCO/VA ratio, lung volumes, and specific airway resistance (sRaw). Results: There were no significant differences between the two groups in terms of FEV1, sRaw, or lung hyperinflation. Decreases in DLCO and in the DLCO/VA ratio were greater in the smoking-related COPD group subjects, who also had higher emphysema scores, in comparison with the wood smoke-related COPD group subjects. In the wood smoke-related COPD group, HRCT scans showed no significant emphysema, the main findings being peribronchial thickening, bronchial dilation, and subsegmental atelectasis. Conclusions: Female patients with severe wood smoke-related COPD do not appear to develop emphysema, although they do show severe airway involvement. The reduction in DLCO and VA, with a normal DLCO/VA ratio, is probably due to severe bronchial obstruction and incomplete mixing of inspired gas during the determination of single-breath DLCO. (author)

  6. Tomographic and functional findings in severe COPD: comparison between the wood smoke-related and smoking-related disease

    International Nuclear Information System (INIS)

    Gonzalez-Garcia, Mauricio; Maldonado Gomez, Dario; Torres-Duque, Carlos A.; Barrero, Margarita; Jaramillo Villegas, Claudia; Perez, Juan Manuel; Varon, Humberto

    2013-01-01

    Objective: Wood smoke exposure is a risk factor for COPD. For a given degree of airway obstruction, the reduction in DLCO is smaller in individuals with wood smoke-related COPD than in those with smoking-related COPD, suggesting that there is less emphysema in the former. The objective of this study was to compare HRCT findings between women with wood smoke-related COPD and women with smoking-related COPD. Methods: Twenty-two women with severe COPD (FEV1/FVC ratio < 70% and FEV1 < 50%) were divided into two groups: those with wood smoke-related COPD (n = 12) and those with smoking-related COPD (n = 10). The two groups were compared regarding emphysema scores and airway involvement (as determined by HRCT); and functional abnormalities—spirometry results, DLCO, alveolar volume (VA), the DLCO/VA ratio, lung volumes, and specific airway resistance (sRaw). Results: There were no significant differences between the two groups in terms of FEV1, sRaw, or lung hyperinflation. Decreases in DLCO and in the DLCO/VA ratio were greater in the smoking-related COPD group subjects, who also had higher emphysema scores, in comparison with the wood smoke-related COPD group subjects. In the wood smoke-related COPD group, HRCT scans showed no significant emphysema, the main findings being peribronchial thickening, bronchial dilation, and subsegmental atelectasis. Conclusions: Female patients with severe wood smoke-related COPD do not appear to develop emphysema, although they do show severe airway involvement. The reduction in DLCO and VA, with a normal DLCO/VA ratio, is probably due to severe bronchial obstruction and incomplete mixing of inspired gas during the determination of single-breath DLCO. (author)

  7. Computer tomographic findings in alcoholism

    Energy Technology Data Exchange (ETDEWEB)

    Agnoli, A.L.; Tzavaras, N.; Reisig, L. (Giessen Univ. (Germany, F.R.). Abt. Neuroradiologie)

    1980-05-01

    The normal variations in the size of the ventricular systems was determined on technically satisfactory computer tomograms in 275 patients who were psychologically and neurologically normal. Ages range from one to 80 years and the data classified in decades. A physiological increase in the width of the ventricular system was found after the 50sup(t)sup(h) year. The normal patients, who acted as a control group, were compared with 65 alcoholics. A significant increase in size (simple variance) was found in alcoholics after the fourth decade, as compared with normals. Correlation between the width of the ventricular system and cerebral function, and between liver damage and the ventricular system could not be established.

  8. 6C polarization analysis - seismic direction finding in coherent noise, automated event identification, and wavefield separation

    Science.gov (United States)

    Schmelzbach, C.; Sollberger, D.; Greenhalgh, S.; Van Renterghem, C.; Robertsson, J. O. A.

    2017-12-01

    Polarization analysis of standard three-component (3C) seismic data is an established tool to determine the propagation directions of seismic waves recorded by a single station. A major limitation of seismic direction finding methods using 3C recordings, however, is that a correct propagation-direction determination is only possible if the wave mode is known. Furthermore, 3C polarization analysis techniques break down in the presence of coherent noise (i.e., when more than one event is present in the analysis time window). Recent advances in sensor technology (e.g., fibre-optical, magnetohydrodynamic angular rate sensors, and ring laser gyroscopes) have made it possible to accurately measure all three components of rotational ground motion exhibited by seismic waves, in addition to the conventionally recorded three components of translational motion. Here, we present an extension of the theory of single station 3C polarization analysis to six-component (6C) recordings of collocated translational and rotational ground motions. We demonstrate that the information contained in rotation measurements can help to overcome some of the main limitations of standard 3C seismic direction finding, such as handling multiple arrivals simultaneously. We show that the 6C polarisation of elastic waves measured at the Earth's free surface does not only depend on the seismic wave type and propagation direction, but also on the local P- and S-wave velocities just beneath the recording station. Using an adaptation of the multiple signal classification algorithm (MUSIC), we demonstrate how seismic events can univocally be identified and characterized in terms of their wave type. Furthermore, we show how the local velocities can be inferred from single-station 6C data, in addition to the direction angles (inclination and azimuth) of seismic arrivals. A major benefit of our proposed 6C method is that it also allows the accurate recovery of the wave type, propagation directions, and phase

  9. Infrared imaging and spectral-domain optical coherence tomography findings correlate with microperimetry in acute macular neuroretinopathy: a case report

    Directory of Open Access Journals (Sweden)

    Grover Sandeep

    2011-10-01

    Full Text Available Abstract Introduction Spectral-domain optical coherence tomography findings in a patient with acute macular neuroretinopathy, and correlation with functional defects on microperimetry, are presented. Case presentation A 25-year old Caucasian woman presented with bitemporal field defects following an upper respiratory tract infection. Her visual acuity was 20/20 in both eyes and a dilated fundus examination revealed bilateral hyperpigmentary changes in the papillomacular bundle. Our patient underwent further evaluation with spectral-domain optical coherence tomography, infrared and fundus autofluorescence imaging. Functional changes were assessed by microperimetry. Infrared imaging showed the classic wedge-shaped defects and spectral-domain optical coherence tomography exhibited changes at the inner segment-outer segment junction, with a thickened outer plexiform layer overlying these areas. Fluorescein and indocyanine green angiography did not demonstrate any perfusion defects or any other abnormality. Microperimetry demonstrated focal elevation in threshold correlating with the wedge-shaped defects in both eyes. Conclusion Spectral-domain optical coherence tomography findings provide new evidence of the involvement of the outer plexiform layer of the retina in acute macular neuroretinopathy.

  10. A Comparison of Computed Tomographic, Radiographic, Gross and Histological, Dental, and Alveolar Findings in 30 Abnormal Cheek Teeth from Equine Cadavers.

    Science.gov (United States)

    Liuti, Tiziana; Smith, Sionagh; Dixon, Padraic M

    2017-01-01

    Equine cheek teeth disorders, especially pulpar/apical infections, can have very serious consequences due to the frequent extension of infection to the supporting bones and/or adjacent paranasal sinuses. Limited studies have assessed the accuracy of computed tomographic (CT) imaging in the diagnosis of these disorders, and no study has directly compared imaging and pathological findings of the alveoli of diseased equine cheek teeth. To validate the accuracy of CT and radiographic imaging of cheek teeth disorders by comparing CT and radiographic imaging, gross and histological findings in abnormal cheek teeth and their alveoli extracted from equine cadaver heads. Ex vivo original study. Fifty-four cadaver heads from horses with unknown histories that had died or been euthanized on humane grounds obtained from a rendering plant had radiography, CT imaging, and gross pathological examinations performed. Based on imaging and gross examination findings, 30 abnormal cheek teeth (26 maxillary and 4 mandibular) identified in 26 heads were extracted along with their dental alveoli where possible, and further CT imaging, gross, and histological examinations were performed. Eight maxillary cheek teeth (including four with attached alveolar bone) from these heads, that were normal on gross and CT examinations, were used as controls. Gross pathological and histological examinations indicated that 28/30 teeth, including two supernumerary teeth, had pulpar/apical infection, including pulpar and apical changes. A further supernumerary and a dysplastic tooth were also identified. Abnormal calcified tissue architecture was present in all three supernumerary and in the dysplastic tooth. CT imaging strongly indicated the presence of pulpar/apical infection in 27 of the 28 (96.4%) pulpar/apically infected teeth, including the presence of intrapulpar gas ( N  = 19/28), apical clubbing ( N  = 20), periapical halo ( N  = 4), root lysis or fragmentation ( N  = 7), and

  11. Optical coherence tomography findings and retinal changes after vitrectomy for optic disc pit maculopathy

    Directory of Open Access Journals (Sweden)

    Gaurav Sanghi

    2014-01-01

    Full Text Available Purpose : To study the optical coherence tomography (OCT patterns in optic disc pit maculopathy and retinal changes after vitreous surgery. Materials and Methods : Retrospective review of consecutive cases with optic disc pit maculopathy seen at two tertiary eye institutes from January 2005 to June 2009. Results : Twenty-four eyes of 23 patients are included. The presenting visual acuity ranged from 20/400 to 20/20 (median:20/80. The median age at presentation was 24 years (range, 6-57 years. Optical coherence tomography demonstrated a combination of retinoschisis and outer layer detachment (OLD in 19 (79.17% eyes, OLD only in 3 (12.5% eyes and retinoschisis only in 2 (8.33% eyes. An obvious communication (outer layer hole between the schisis and OLD was seen in 14 (73.68% of the 19 eyes with both features. Of the 21 eyes with retinoschisis, schisis was present in multiple layers in 15 (71.43% and single layer in 6 (28.57% eyes. Eleven eyes underwent pars plana vitrectomy including creation of posterior vitreous detachment (PVD, fluid-air exchange, low intensity laser photocoagulation at the temporal edge of the optic disc pit and non-expansile perfluoropropane gas (14% injection. Five (45.45% of 11 eyes undergoing vitrectomy had complete resolution and 4 (36.36% eyes had partial resolution of maculopathy. Visual acuity improved in 8 (72.72% of 11 eyes. Conclusion : Optical coherence tomography demonstrates multiple layer schisis and outer layer detachment as main features of optic disc pit maculopathy. Vitrectomy with PVD induction, laser photocoagulation and gas tamponade results in anatomical and visual improvement in most cases with optic disc pit maculopathy.

  12. [Fluorescein angiography and optical coherence tomography findings in central fundus of myopic patients].

    Science.gov (United States)

    Avetisov, S E; Budzinskaya, M V; Zhabina, O A; Andreeva, I V; Plyukhova, A A; Kobzova, M V; Musaeva, G M

    2015-01-01

    Myopia prevalence grows alike in many countries, including Russia, regardless of geographical and population conditions. to assess fundus changes in myopic patients at different ocular axial lengths by means of modern diagnostic tools. The study enrolled 97 patients (194 eyes) aged 45 ± 20.17 years with myopia of different degrees. Besides a standard ophthalmic examination, all patients underwent fundus fluorescein angiography and optical coherence tomography. The occurrence of retinal pigment epithelium (RPE) atrophy (diffuse or focal) has been shown to increase with increasing ocular axial length. Only 27 eyes (28.1%) appeared intact. As myopia progression implies axial growth of the eye, it is associated with a more severe decrease in choroid, RPE, and photoreceptor layer thicknesses: the longer the anterior-posterior axis, the thinner the above mentioned fundus structures. Age-related changes in the fundus are also likely to be more pronounced in longer axes. Myopic traction maculopathy, which in our case appeared the main cause of increased retinal thickness, was diagnosed in 105 eyes, "outer" macular retinoschisis--in 40 eyes. Thus, modern diagnostic tools, such as fluorescein angiography and optical coherence tomography, enable objective assessment of the central fundus.

  13. Spectral-domain optical coherence tomography findings of the macula in 500 consecutive patients with uveitis.

    Science.gov (United States)

    Grajewski, R S; Boelke, A C; Adler, W; Meyer, S; Caramoy, A; Kirchhof, B; Cursiefen, C; Heindl, L M

    2016-11-01

    PurposeTo analyze the macular structure in a large series of consecutive patients with different types of uveitis using spectral-domain optical coherence tomography (SD-OCT).Patients and methodsFive hundred eyes of 500 consecutive patients with anterior, intermediate, posterior, and panuveitis underwent standardized macular examination using SD-OCT. Central retinal thickness (CRT), macular volume (MV), and presence of cystoid macular edema (CME), diffuse macular edema (DME), serous retinal detachment (SRD), epiretinal membrane with (ERM+) and without (ERM-) retinal surface wrinkling were determined.ResultsThe anatomic location of inflammation affected significantly CRT and MV (Pmacula is recommended for all uveitis patients. CRT, MV, and the incidence of CME were highest in intermediate and panuveitis.

  14. SILDENAFIL CITRATE INDUCED RETINAL TOXICITY-ELECTRORETINOGRAM, OPTICAL COHERENCE TOMOGRAPHY, AND ADAPTIVE OPTICS FINDINGS.

    Science.gov (United States)

    Yanoga, Fatoumata; Gentile, Ronald C; Chui, Toco Y P; Freund, K Bailey; Fell, Millie; Dolz-Marco, Rosa; Rosen, Richard B

    2018-02-27

    To report a case of persistent retinal toxicity associated with a high dose of sildenafil citrate intake. Single retrospective case report. A 31-year-old white man with no medical history presented with complaints of bilateral multicolored photopsias and erythropsia (red-tinted vision), shortly after taking sildenafil citrate-purchased through the internet. Patient was found to have cone photoreceptor damage, demonstrated using electroretinogram, optical coherence tomography, and adaptive optics imaging. The patient's symptoms and the photoreceptor structural changes persisted for several months. Sildenafil citrate is a widely used erectile dysfunction medication that is typically associated with transient visual symptoms in normal dosage. At high dosage, sildenafil citrate can lead to persistent retinal toxicity in certain individuals.

  15. Unusual optical coherence tomography and fundus autofluorescence findings of eclipse retinopathy

    Directory of Open Access Journals (Sweden)

    Kun-Hsien Li

    2012-01-01

    Full Text Available A 63-year-old female patient complained of dimness in the central field of vision in the left eye after viewing an annular partial eclipse without adequate eye protection on 22 July 2009. Fundoscopy showed a wrinkled macular surface. Fundus autofluorescence study revealed well-demarcated hyperautofluorescence at the fovea. Optical coherence tomography demonstrated tiny intraretinal cysts. Fluorescein angiography and indocyanine green angiography were unremarkable. Epimacular membrane developed in the following month with deteriorated vision. Vitrectomy, epiretinal membrane and internal limiting membrane peeling were performed. Vision was restored to 20/20 after the operation. Direct sun-gazing may damage the retinal structures resulting in macular inflammation and increased focal metabolism, which explains the hyperautofluorescence. It may also induce epimacular membrane. Fundus autofluorescence might represent a useful technique to detect subtle solar-induced injuries of the retina. The visual prognosis is favorable but prevention remains the mainstay of treatment. Public health education is mandatory in reducing visual morbidity.

  16. Diabetic retinal pigment epitheliopathy: fundus autofluorescence and spectral-domain optical coherence tomography findings.

    Science.gov (United States)

    Kang, Eui Chun; Seo, Yuri; Byeon, Suk Ho

    2016-10-01

    To describe the characteristics of an unfamiliar disease entity, diabetic retinal pigment epitheliopathy (DRPE), using fundus autofluorescence (FAF) and spectral-domain optical coherence tomography (SD-OCT). This retrospective study included 17 eyes from 10 proliferative diabetic retinopathy (PDR) patients with granular hypo-autofluorescence and/or variable hyper-autofluorescence on FAF (DRPE group) and 17 eyes from 10 age- and sex-matched PDR patients without abnormal autofluorescence (PDR group). Eyes with diabetic macular edema were excluded. Visual acuity (VA), retinal thickness (RT), and choroidal thickness (CT) were compared between the groups. Eyes in the DRPE group had worse logMAR VA than eyes in the PDR group (0.369 ± 0.266 vs. 0.185 ± 0.119; P = 0.026). The thickness of the retinal pigment epithelium plus the inner segment/outer segment of the photoreceptors was reduced to a greater degree in the DRPE group than the PDR group (P retina showed no differences between the two groups. CT was significantly thicker in the DRPE group than in the PDR group (329.00 ± 33.76 vs. 225.62 ± 37.47 μm; P retina, and thicker choroid in comparison with eyes with PDR. Alterations of autofluorescence on FAF and changes in the outer retinal thickness and CT on SD-OCT can be helpful for differentiating DRPE in patients with PDR.

  17. Advances in tomographic PIV

    NARCIS (Netherlands)

    Novara, M.

    2013-01-01

    This research deals with advanced developments in 3D particle image velocimetry based on the tomographic PIV technique (Tomo-PIV). The latter is a relatively recent measurement technique introduced by Elsinga et al. in 2005, which is based on the tomographic reconstruction of particle tracers in

  18. Tomographic PIV: principles and practice

    International Nuclear Information System (INIS)

    Scarano, F

    2013-01-01

    A survey is given of the major developments in three-dimensional velocity field measurements using the tomographic particle image velocimetry (PIV) technique. The appearance of tomo-PIV dates back seven years from the present review (Elsinga et al 2005a 6th Int. Symp. PIV (Pasadena, CA)) and this approach has rapidly spread as a versatile, robust and accurate technique to investigate three-dimensional flows (Arroyo and Hinsch 2008 Topics in Applied Physics vol 112 ed A Schröder and C E Willert (Berlin: Springer) pp 127–54) and turbulence physics in particular. A considerable number of applications have been achieved over a wide range of flow problems, which requires the current status and capabilities of tomographic PIV to be reviewed. The fundamental aspects of the technique are discussed beginning from hardware considerations for volume illumination, imaging systems, their configurations and system calibration. The data processing aspects are of uppermost importance: image pre-processing, 3D object reconstruction and particle motion analysis are presented with their fundamental aspects along with the most advanced approaches. Reconstruction and cross-correlation algorithms, attaining higher measurement precision, spatial resolution or higher computational efficiency, are also discussed. The exploitation of 3D and time-resolved (4D) tomographic PIV data includes the evaluation of flow field pressure on the basis of the flow governing equation. The discussion also covers a-posteriori error analysis techniques. The most relevant applications of tomo-PIV in fluid mechanics are surveyed, covering experiments in air and water flows. In measurements in flow regimes from low-speed to supersonic, most emphasis is given to the complex 3D organization of turbulent coherent structures. (topical review)

  19. Tomographic scanning apparatus

    International Nuclear Information System (INIS)

    1981-01-01

    Details are given of a tomographic scanning apparatus, with particular reference to a multiplexer slip ring means for receiving output from the detectors and enabling interfeed to the image reconstruction station. (U.K.)

  20. Tomographic scanning apparatus

    International Nuclear Information System (INIS)

    1981-01-01

    Details are presented of a tomographic scanning apparatus, its rotational assembly, and the control and circuit elements, with particular reference to the amplifier and multiplexing circuits enabling detector signal calibration. (U.K.)

  1. Tomographic scanning apparatus

    International Nuclear Information System (INIS)

    1981-01-01

    This patent specification relates to a tomographic scanning apparatus using a fan beam and digital output signal, and particularly to the design of the gas-pressurized ionization detection system. (U.K.)

  2. Tomographic scanning apparatus

    International Nuclear Information System (INIS)

    1981-01-01

    This patent specification describes a tomographic scanning apparatus, with particular reference to the adjustable fan beam and its collimator system, together with the facility for taking a conventional x-radiograph without moving the patient. (U.K.)

  3. Pressure spectra from single-snapshot tomographic PIV

    NARCIS (Netherlands)

    Schneiders, J.F.G.; Avallone, F.; Pröbsting, S.; Ragni, D.; Scarano, F.

    2018-01-01

    The power spectral density and coherence of temporal pressure fluctuations are obtained from low-repetition-rate tomographic PIV measurements. This is achieved by extension of recent single-snapshot pressure evaluation techniques based upon the Taylor’s hypothesis (TH) of frozen turbulence and

  4. Parental expectations, experiences and reactions, sense of coherence and grade of anxiety related to routine ultrasound examination with normal findings during pregnancy.

    Science.gov (United States)

    Ekelin, M; Crang Svalenius, E; Larsson, A-K; Nyberg, P; Marsál, K; Dykes, A-K

    2009-10-01

    To investigate parents' expectations, experiences and reactions, sense of coherence and anxiety before and after a second-trimester routine ultrasound examination, with normal findings. Before and after ultrasound questionnaires including the scales parents' expectations, experiences and reactions to routine ultrasound examination (PEER-U state of mind index), sense of coherence (SOC) and state and trait anxiety inventory (STAI), were sent to a 1-year cohort of women and their partners. Replies received were 2183. Both parents had significantly less worried state of mind (PEER-U) after the examination than before. Women had a lower grade of state anxiety after than before, but for men there was no significant change. Before the ultrasound, women had a higher degree of worried state of mind, as well as a higher grade of state and trait anxiety and a lower sense of coherence, than men. The women showed a greater reduction in worried state of mind than the men after the ultrasound examination. There were no significant differences in sense of coherence before and after ultrasound. Women and men are affected in their psychological well-being in relation to a routine ultrasound examination, but their sense of coherence remains stable.

  5. Mobile 3D tomograph

    International Nuclear Information System (INIS)

    Illerhaus, Bernhard; Goebbels, Juergen; Onel, Yener; Sauerwein, Christoph

    2008-01-01

    Mobile tomographs often have the problem that high spatial resolution is impossible owing to the position or setup of the tomograph. While the tree tomograph developed by Messrs. Isotopenforschung Dr. Sauerwein GmbH worked well in practice, it is no longer used as the spatial resolution and measuring time are insufficient for many modern applications. The paper shows that the mechanical base of the method is sufficient for 3D CT measurements with modern detectors and X-ray tubes. CT measurements with very good statistics take less than 10 min. This means that mobile systems can be used, e.g. in examinations of non-transportable cultural objects or monuments. Enhancement of the spatial resolution of mobile tomographs capable of measuring in any position is made difficult by the fact that the tomograph has moving parts and will therefore have weight shifts. With the aid of tomographies whose spatial resolution is far higher than the mechanical accuracy, a correction method is presented for direct integration of the Feldkamp algorithm [de

  6. An analysis of peripheral small lung carcinomas less than 20 mm in diameter in non-adenocarcinomas and carcinoids. Computed tomographic findings based on radiologic-pathologic correlation

    International Nuclear Information System (INIS)

    Tanaka, Gaku; Yamada, Kouzo; Oshita, Fumihiro; Nomura, Ikuo; Noda, Kazumasa; Nakayama, Haruhiko; Mitsuda, Aki; Kameda, Youichi; Yamakido, Michio

    2000-01-01

    With the introduction of computed tomography (CT) for chest screening in recent years, more cases of resected peripheral small lung carcinomas have been reported. Many of these were adenocarcinomas. To focus on CT findings of peripheral non-adenocarcinoma nodules, we performed a retrospective analysis based on radiographic-pathologic correlations. We analyzed CT findings based on the pathology of peripheral small lung carcinomas, excluding the histological type of adenocarcinomas. We compared our findings with those observed in adenocarcinomas. We reviewed 28 peripheral small lung carcinoma nodules less than 20 mm in diameter, including 13 squamous cell carcinomas, 4 small cell carcinomas, 2 adeno- squamous cell carcinomas, 1 large cell carcinoma, and 8 carcinoids. The carcinomas were classified into two different patterns; non-adenocarcinomas excluding carcinoids, and carcinoids. Both were solid-density types on high-resolution CT (HR-CT) images. The HR-CT findings regarding the shape and number of notching, and the presence or absence of ground glass opacity (GGO) were different between non-adenocarcinomas excluding carcinoids and adenocarcinomas. On the other hand, the HR-CT findings regarding spiculations, GGO and pleural indentations, and the absence of bronchial compression were different between carcinoids and adenocarcinomas. The shape characteristics and internal and marginal analysis on HR-CT images can contribute to the differential diagnosis of the histological type of peripheral small lung carcinomas. (author)

  7. Findings of Optical Coherence Tomography of Retinal Nerve Fiber Layer in Two Common Types of Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Gholamali Yousefipour

    2016-06-01

    Full Text Available Multiple sclerosis (MS is the most prevalent disease caused by the inflammatory demyelinating process that causes progressive nervous system degeneration over the time. Optical Coherence Tomography (OCT is a non-invasive optical imaging technology, which can measure the thickness of retinal nerve fiber layer as well as the diameter of the macula. The purpose of the study is evaluation OCT findings in two common types of multiple sclerosis. For doing the cross-sectional study, 63 patients with two prevalent types of multiple sclerosis (35 patients with Relapse Remitting Multiple Sclerosis (RRMS and 28 patients with Secondary Progressive Multiple Sclerosis (SPMS were evaluated for 6 months. Exclusion criteria of the study were a history of optic neuritis, suffering from diabetes mellitus, hypertension, ocular disease, and the presence of other neurologic degenerative diseases. Then, the thickness of retinal nerve fiber layer (RNFL, as well as thickness and volume of the macula, were measured in the patients using OCT technology. The disability rate of patients was evaluated according to Expanded Disability Status Scale (EDSS. Finally, data was analyzed by means of SPSS software. Overall, 35 patients with RRMS (with mean age of 32.37+10.01, average disease period of 3.81+3.42 and mean EDSS of 1.84+0.45 and 28 patients with SPMS (with mean age of 39.21+9.33, average disease period of 11.32+5.87 and mean EDSS of 5.12+1.46 were assessed and compared in terms of retinal nerve fiber layer and size and thickness of macula. In all of these sections, the thicknesses were smaller in SPMS patients than patients with RRMS. But, there was a significant difference in total thickness (81.82µm versus 96.03µm with P=0.04 and thickness of temporal sector (54.5 µm versus 69.34 µm with P=0.04 of retinal nerve fiber layer and macular size at the superior sector of external ring (1.48 mm³ versus 1.58 mm³ with P=0.03, and nasal sector of external ring surrounding

  8. Optical Coherence Tomography

    DEFF Research Database (Denmark)

    Fercher, A.F.; Andersen, Peter E.

    2017-01-01

    Optical coherence tomography (OCT) is a technique that is used to peer inside a body noninvasively. Tissue structure defined by tissue absorption and scattering coefficients, and the speed of blood flow, are derived from the characteristics of light remitted by the body. Singly backscattered light...... detected by partial coherence interferometry (PCI) is used to synthesize the tomographic image coded in false colors. A prerequisite of this technique is a low time-coherent but high space-coherent light source, for example, a superluminescent diode or a supercontinuum source. Alternatively, the imaging...... technique can be realized by using ultrafast wavelength scanning light sources. For tissue imaging, the light source wavelengths are restricted to the red and near-infrared (NIR) region from about 600 to 1300 nm, the so-called therapeutic window, where absorption (μa ≈ 0.01 mm−1) is small enough. Transverse...

  9. Tomographic scanning apparatus

    International Nuclear Information System (INIS)

    1981-01-01

    Details are given of a tomographic scanning apparatus, with particular reference to the means of adjusting the apparent gain of the signal processing means for receiving output signals from the detectors, to compensate for drift in the gain characteristics, including means for passing a reference signal. (U.K.)

  10. Pulmonary vessel segmentation utilizing curved planar reformation and optimal path finding (CROP) in computed tomographic pulmonary angiography (CTPA) for CAD applications

    Science.gov (United States)

    Zhou, Chuan; Chan, Heang-Ping; Kuriakose, Jean W.; Chughtai, Aamer; Wei, Jun; Hadjiiski, Lubomir M.; Guo, Yanhui; Patel, Smita; Kazerooni, Ella A.

    2012-03-01

    Vessel segmentation is a fundamental step in an automated pulmonary embolism (PE) detection system. The purpose of this study is to improve the segmentation scheme for pulmonary vessels affected by PE and other lung diseases. We have developed a multiscale hierarchical vessel enhancement and segmentation (MHES) method for pulmonary vessel tree extraction based on the analysis of eigenvalues of Hessian matrices. However, it is difficult to segment the pulmonary vessels accurately under suboptimal conditions, such as vessels occluded by PEs, surrounded by lymphoid tissues or lung diseases, and crossing with other vessels. In this study, we developed a new vessel refinement method utilizing curved planar reformation (CPR) technique combined with optimal path finding method (MHES-CROP). The MHES segmented vessels straightened in the CPR volume was refined using adaptive gray level thresholding where the local threshold was obtained from least-square estimation of a spline curve fitted to the gray levels of the vessel along the straightened volume. An optimal path finding method based on Dijkstra's algorithm was finally used to trace the correct path for the vessel of interest. Two and eight CTPA scans were randomly selected as training and test data sets, respectively. Forty volumes of interest (VOIs) containing "representative" vessels were manually segmented by a radiologist experienced in CTPA interpretation and used as reference standard. The results show that, for the 32 test VOIs, the average percentage volume error relative to the reference standard was improved from 32.9+/-10.2% using the MHES method to 9.9+/-7.9% using the MHES-CROP method. The accuracy of vessel segmentation was improved significantly (pvolume between the automated segmentation and the reference standard was improved from 0.919 to 0.988. Quantitative comparison of the MHES method and the MHES-CROP method with the reference standard was also evaluated by the Bland-Altman plot. This preliminary

  11. Enhanced depth imaging optical coherence tomography and fundus autofluorescence findings in bilateral choroidal osteoma: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Erol, Muhammet Kazim; Coban, Deniz Turgut; Ceran, Basak Bostanci; Bulut, Mehmet, E-mail: muhammetkazimerol@gmail.com [Kazim Erol. Antalya Training and Research Hospital, Ophthalmology Department, Antalya (Turkey)

    2013-11-01

    The authors present enhanced depth imaging optical coherence tomography (EDI OCT) and fundus autofluorescence (FAF) characteristics of a patient with bilateral choroidal osteoma and try to make a correlation between two imaging techniques. Two eyes of a patient with choroidal osteoma underwent complete ophthalmic examination. Enhanced depth imaging optical coherence tomography revealed a cage-like pattern, which corresponded to the calcified region of the tumor. Fundus autofluorescence imaging of the same area showed slight hyperautofluorescence. Three different reflectivity patterns in the decalcified area were defined. In the areas of subretinal fluid, outer segment elongations similar to central serous chorioretinopathy were observed. Hyperautofluorescent spots were evident in fundus autofluorescence in the same area. Calcified and decalcified portions of choroidal osteoma as well as the atrophy of choriocapillaris demonstrated different patterns with enhanced depth imaging and fundus autofluorescence imaging. Both techniques were found to be beneficial in the diagnosis and follow-up of choroidal osteoma. (author)

  12. Enhanced depth imaging optical coherence tomography and fundus autofluorescence findings in bilateral choroidal osteoma: a case report

    International Nuclear Information System (INIS)

    Erol, Muhammet Kazim; Coban, Deniz Turgut; Ceran, Basak Bostanci; Bulut, Mehmet

    2013-01-01

    The authors present enhanced depth imaging optical coherence tomography (EDI OCT) and fundus autofluorescence (FAF) characteristics of a patient with bilateral choroidal osteoma and try to make a correlation between two imaging techniques. Two eyes of a patient with choroidal osteoma underwent complete ophthalmic examination. Enhanced depth imaging optical coherence tomography revealed a cage-like pattern, which corresponded to the calcified region of the tumor. Fundus autofluorescence imaging of the same area showed slight hyperautofluorescence. Three different reflectivity patterns in the decalcified area were defined. In the areas of subretinal fluid, outer segment elongations similar to central serous chorioretinopathy were observed. Hyperautofluorescent spots were evident in fundus autofluorescence in the same area. Calcified and decalcified portions of choroidal osteoma as well as the atrophy of choriocapillaris demonstrated different patterns with enhanced depth imaging and fundus autofluorescence imaging. Both techniques were found to be beneficial in the diagnosis and follow-up of choroidal osteoma. (author)

  13. Enhanced depth imaging optical coherence tomography and fundus autofluorescence findings in bilateral choroidal osteoma: a case report

    Directory of Open Access Journals (Sweden)

    Muhammet Kazim Erol

    2013-06-01

    Full Text Available The authors present enhanced depth imaging optical coherence tomography (EDI OCT and fundus autofluorescence (FAF characteristics of a patient with bilateral choroidal osteoma and try to make a correlation between two imaging techniques. Two eyes of a patient with choroidal osteoma underwent complete ophthalmic examination. Enhanced depth imaging optical coherence tomography revealed a cage-like pattern, which corresponded to the calcified region of the tumor. Fundus autofluorescence imaging of the same area showed slight hyperautofluorescence. Three different reflectivity patterns in the decalcified area were defined. In the areas of subretinal fluid, outer segment elongations similar to central serous chorioretinopathy were observed. Hyperautofluorescent spots were evident in fundus autofluorescence in the same area. Calcified and decalcified portions of choroidal osteoma as well as the atrophy of choriocapillaris demonstrated different patterns with enhanced depth imaging and fundus autofluorescence imaging. Both techniques were found to be beneficial in the diagnosis and follow-up of choroidal osteoma.

  14. Ictal technetium-99m ethyl cysteinate dimer single-photon emission tomographic findings and propagation of epileptic seizure activity in patients with extratemporal epilepsies

    International Nuclear Information System (INIS)

    Noachtar, S.; Arnold, S.; Werhahn, K.J.; Yousry, T.A.; Tatsch, K.

    1998-01-01

    We investigated the influence of the propagation of extratemporal epileptic seizure activity on the regional increase in cerebral blood flow, which is usually associated with epileptic seizure activity. Forty-two consecutive patients with extratemporal epilepsies were prospectively evaluated. All patients underwent ictal SPET studies with simultaneous electroencephalography (EEG) and video recordings of habitual seizures and imaging studies including cranial magnetic resonance imaging and positron emission tomography with 2-[ 18 F]-fluoro-2 deoxy-d-glucose. Propagation of epilptic seizure activity (PESA) was defined as the absence of hyperperfusion on ictal ECD SPET in the lobe of seizure onset, but its presence in another ipsilateral or contralateral lobe. Observers analysing the SPET images were not informed of the other results. PESA was observed in 8 of the 42 patients (19%) and was ipsilateral to the seizure onset in five (63%) of these eight patients. The time between clinical seizure onset and injection of the ECD tracer ranged from 14 to 61 s (mean 34 s). Seven patients (88%) with PESA had parieto-occipital epilepsy and one patient had a frontal epilepsy. PESA was statistically more frequent in patients with parieto-occipital lobe epilepsies (58%) than in the remaining extratemporal epilepsy syndromes (3%) (P<0.0002). These findings indicate that ictal SPET studies require simultaneous EEG-video recordings in patients with extratemporal epilepsies. PESA should be considered when interpreting ictal SPET studies in these patients. Patients with PESA are more likely to have parieto-occipital lobe epilepsy than seizure onset in other extratemporal regions. (orig./MG) (orig.)

  15. Optical coherence tomography and autofluorescence findings in chronic phototoxic maculopathy secondary to snow-reflected solar radiation

    Directory of Open Access Journals (Sweden)

    Dhananjay Shukla

    2015-01-01

    Full Text Available A professional mountain trekker presented with gradual, moderate visual decline in one eye. The subnormal vision could not be explained by the examination of anterior and posterior segment of either eye, which was unremarkable. Optical coherence tomography and autofluorescence imaging revealed subtle defects in the outer retina, which correlated with the extent of visual disturbance. A novel presentation of retinal phototoxicity due to indirect solar radiation reflected from snow in inadequately protected eyes of a chronically exposed subject is reported.

  16. Optical coherence tomography and autofluorescence findings in chronic phototoxic maculopathy secondary to snow-reflected solar radiation.

    Science.gov (United States)

    Shukla, Dhananjay

    2015-05-01

    A professional mountain trekker presented with gradual, moderate visual decline in one eye. The subnormal vision could not be explained by the examination of anterior and posterior segment of either eye, which was unremarkable. Optical coherence tomography and autofluorescence imaging revealed subtle defects in the outer retina, which correlated with the extent of visual disturbance. A novel presentation of retinal phototoxicity due to indirect solar radiation reflected from snow in inadequately protected eyes of a chronically exposed subject is reported.

  17. MACULAR ATROPHY FINDINGS BY OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY COMPARED WITH FUNDUS AUTOFLUORESCENCE IN TREATED EXUDATIVE AGE-RELATED MACULAR DEGENERATION.

    Science.gov (United States)

    Takasago, Yukari; Shiragami, Chieko; Kobayashi, Mamoru; Osaka, Rie; Ono, Aoi; Yamashita, Ayana; Tsujikawa, Akitaka; Hirooka, Kazuyuki

    2017-11-28

    To compare the areas of choriocapillaris (CC) nonperfusion and macular atrophy (MA) in treated exudative age-related macular degeneration. This was a prospective, observational, cross-sectional study. Forty-four eyes exhibiting MA (42 patients with age-related macular degeneration), with a dry macula, underwent fundus autofluorescence and optical coherence tomography angiography. The area of MA detected by fundus autofluorescence and CC nonperfusion detected by optical coherence tomography angiography was measured using image analysis software. The rates of concordance between the MA and CC nonperfusion areas were calculated. We qualitatively and quantitatively compared the areas of MA and CC nonperfusion in age-related macular degeneration eyes. The mean areas of MA and CC nonperfusion were 5.95 ± 4.50 mm and 10.66 ± 7.05 mm, respectively (paired t-test, P autofluorescence matching optical coherence tomography angiography showed that the CC nonperfusion area was almost included in the MA area. The mean concordance rate for the MA area inside the CC nonperfusion area was 87.7 ± 13.9%. The MA and CC nonperfusion areas markedly overlapped. The area of CC nonperfusion correlated with the MA area. Choroidal ischemia might be involved in the pathogenesis of MA in treated age-related macular degeneration.This is an open access article distributed under the Creative Commons Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

  18. X-ray Tomographic Microscopy at TOMCAT

    Energy Technology Data Exchange (ETDEWEB)

    Marone, F; Hintermueller, C; McDonald, S; Abela, R; Mikuljan, G; Isenegger, A; Stampanoni, M, E-mail: federica.marone@psi.c [Swiss Light Source, Paul Scherrer Institut, 5232 Villigen (Switzerland)

    2009-09-01

    Synchrotron-based X-ray Tomographic Microscopy is a powerful technique for fast non-destructive, high resolution quantitative volumetric investigations on diverse samples. At the TOMCAT (TOmographic Microscopy and Coherent rAdiology experimenTs) beamline at the Swiss Light Source, synchrotron light is delivered by a 2.9 T superbend. The main optical component, a Double Crystal Multilayer Monochromator, covers an energy range between 8 and 45 keV. The standard TOMCAT detector offers field of views ranging from 0.75x0.75 mm{sup 2} up to 12.1x12.1 mm{sup 2} with a pixel size of 0.37 {mu}m and 5.92 {mu}m, respectively. In addition to routine measurements, which exploit the absorption contrast, the high coherence of the source also enables phase contrast tomography, implemented with two complementary techniques (Modified Transport of Intensity approach and Grating Interferometry). Typical acquisition times for a tomogram are in the order of few minutes, ensuring high throughput and allowing for semi-dynamical investigations. Raw data are automatically post-processed online and full reconstructed volumes are available shortly after a scan with minimal user intervention.

  19. Axial tomographic scanner

    International Nuclear Information System (INIS)

    1976-01-01

    An axial tomographic system is described comprising axial tomographic means for collecting sets of data corresponding to the transmission or absorption of a number of beams of penetrating radiation through a planar slice of an object. It includes means to locate an object to be analyzed, a source and detector for directing one or more beams of penetrating radiation through the object from the source to the detector, and means to rotate (and optionally translate) the source as well as means to process the collected sets of data. Data collection, data processing, and data display can each be conducted independently of each other. An additional advantage of the system described is that the raw data (i.e., the originally collected data) are not destroyed by the data processing but instead are retained intact for further reference or use, if needed

  20. Tomographic method and apparatus

    International Nuclear Information System (INIS)

    Moore, R.M.

    1981-01-01

    A tomographic x-ray machine has a camera and film-plane section which move about a primary axis for imaging a selected cross-section of an anatomical member onto the film. A ''scout image'' of the member is taken at right angles to the plane of the desired cross-section to indicate the cross-section's angle with respect to the primary axis. The film plane is then located at the same angle with respect to a film cassette axis as the selected cross-section makes with the primary axis. The film plane and the cross-section are then maintained in parallel planes throughout motion of the camera and film plane during tomographic radiography. (author)

  1. Typical computer tomographic findings in neurofibromatosis

    International Nuclear Information System (INIS)

    Allgayer, B.; Reiser, M.; Kramann, B.

    1984-01-01

    Three pateints with neurofibromatosis (Recklinghausen's disease) were examined by computer tomography. In this way, the exact extent and localisation of the neurofibromatous tumours could be demonstrated. In one patient, CT provided evidence of malignant change; this was verified histologically. The appearances of neurofibromatosis associated with elephantiasis is described. In each patient, treatment was significantly influenced by computer tomography. (orig.) [de

  2. Typical computer tomographic findings in neurofibromatosis

    Energy Technology Data Exchange (ETDEWEB)

    Allgayer, B.; Reiser, M.; Kramann, B.

    1984-06-01

    Three pateints with neurofibromatosis (Recklinghausen's disease) were examined by computer tomography. In this way, the exact extent and localisation of the neurofibromatous tumours could be demonstrated. In one patient, CT provided evidence of malignant change; this was verified histologically. The appearances of neurofibromatosis associated with elephantiasis is described. In each patient, treatment was significantly influenced by computer tomography.

  3. Computed tomographic findings in carcinoma of cervix

    International Nuclear Information System (INIS)

    Kim, Kyung Hee; Lee, Jae Moon; Bahk, Yong Whee

    1985-01-01

    Accurate staging as well as diagnosis of cervix carcinoma is of paramount importance in planning treatment. Cervical smear cytologic studies have increased the detection rate of cervix carcinoma, but current radiologic techniques are limited in staging cervix carcinoma and precise visualization of lymphnodal metastasis. The CT scan can display the precise transaxial anatomical structures, permitting us not only to know the tumor size, shape and its extent but also lymphnodal enlargement in the pelvic cavity and around the abdominal aorta and secondary changes of the kidney. The authors have tested the usefulness of CT in staging cervix carcinoma and detecting lymphatic involvement by analysis of 24 cases diagnosed by CT and confirmed histologically at St. Mary's hospital during the period from October 1982 to May 1984. The conclusions are as follows: 1. The accuracy of CT in staging of cervix carcinoma was 79%. 2. The accuracy of CT diagnosis of lymphatic involvement was 87.5%, sensitivity was 85.7%, and specificity was 88.2%

  4. Computed tomographic findings in pancreatic pathology

    International Nuclear Information System (INIS)

    Frija, J.; Laval-Jeantet, M.; Larde, D.; Mathieu, D.

    1986-01-01

    Computed tomography (CT) is actually the most suitable examination for the study of the pancreas. The evolution during the life of its thickness is studied. For the same age group pancreas sharpens from the head to the body and the tail. Pancreas progressively sharpens during the life. The comparison of the efficacy of the other imaging modalities is studied. The indications of the radiological examinations of the pancreas are evaluated during acute and chronic pancreatitis, pseudocysts, adenocarcinoma of the pancreas and endocrine tumors of the pancreas [fr

  5. Lung cancer, analysis of the most frequent tomographic findings and histopathological correlation, in patients with primary pulmonary neoplasia diagnosed during the years 2011 and 2012, at the Hospital San Juan de Dios

    International Nuclear Information System (INIS)

    Cruz Romero, Cinthia

    2013-01-01

    Tomographic images, specifically the contrasted chest tomographies, were examined in patients diagnosed in patients diagnosed with lung cancer at the Hospital San Juan de Dios during the years 2011 and 2012. The primitive tomographic behavior of lung cancer was evaluated in order to determine and characterize its presentation pattern. Each histological type of lung cancer was determined. The stage of lung cancer was classified according to the International System of Staging Tumor, Node and Metastasis. An analysis of the incidence and stage of lung cancer at the time of diagnosis was made, evidencing the fundamental role of chest tomography in the screening, diagnosis, management and control of patients with primary pulmonary neoplasia [es

  6. Industrial dynamic tomographic reconstruction

    International Nuclear Information System (INIS)

    Oliveira, Eric Ferreira de

    2016-01-01

    The state of the art methods applied to industrial processes is currently based on the principles of classical tomographic reconstructions developed for tomographic patterns of static distributions, or is limited to cases of low variability of the density distribution function of the tomographed object. Noise and motion artifacts are the main problems caused by a mismatch in the data from views acquired in different instants. All of these add to the known fact that using a limited amount of data can result in the presence of noise, artifacts and some inconsistencies with the distribution under study. One of the objectives of the present work is to discuss the difficulties that arise from implementing reconstruction algorithms in dynamic tomography that were originally developed for static distributions. Another objective is to propose solutions that aim at reducing a temporal type of information loss caused by employing regular acquisition systems to dynamic processes. With respect to dynamic image reconstruction it was conducted a comparison between different static reconstruction methods, like MART and FBP, when used for dynamic scenarios. This comparison was based on a MCNPx simulation as well as an analytical setup of an aluminum cylinder that moves along the section of a riser during the process of acquisition, and also based on cross section images from CFD techniques. As for the adaptation of current tomographic acquisition systems for dynamic processes, this work established a sequence of tomographic views in a just-in-time fashion for visualization purposes, a form of visually disposing density information as soon as it becomes amenable to image reconstruction. A third contribution was to take advantage of the triple color channel necessary to display colored images in most displays, so that, by appropriately scaling the acquired values of each view in the linear system of the reconstruction, it was possible to imprint a temporal trace into the regularly

  7. Tomographic scanning apparatus

    International Nuclear Information System (INIS)

    Abele, M.

    1983-01-01

    A computerized tomographic scanning apparatus suitable for diagnosis and for improving target identification in stereotactic neurosurgery is described. It consists of a base, a source of penetrating energy, a detector which produces scanning signals and detector positioning means. A frame with top and bottom arms secures the detector and source to the top and bottom arms respectively. A drive mechanism rotates the frame about an axis along which the frame may also be moved. Finally, the detector may be moved relative to the bottom arm in a direction contrary to the rotation of the frame. (U.K.)

  8. “En-Face” Spectral-Domain Optical Coherence Tomography Findings in Multiple Evanescent White Dot Syndrome

    Directory of Open Access Journals (Sweden)

    Flore De bats

    2014-01-01

    Full Text Available Purpose. The recent use of “en-face” enhanced-depth imaging spectral-domain optical coherence tomography (EDI SD-OCT helps distinguish the retinal layers involved in the physiopathology of multiple evanescent white dot syndrome (MEWDS. Methods. Four patients presenting with MEWDS underwent a comprehensive ocular examination including C-scan (“en-face” EDI SD-OCT at the initial visit and during follow-up. Results. C-scans combined with the other multimodal imaging enabled the visualization of retinal damage. Acute lesions appeared as diffuse and focal disruptions occurring in the ellipsoid and interdigitation zones. The match between autofluorescence imaging, indocyanine green angiography, and “en-face” OCT helped identify the acute microstructural damages in the outer retina further than the choroid. Follow-up using “en-face” EDI-OCT revealed progressive and complete recovery of the central outer retinal layers. Conclusion. “En-face” EDI SD-OCT identified the site of initial damage in MEWDS as the photoreceptors and the interdigitation layers rather than the choroid. Moreover, “en-face” OCT is helpful in the follow-up of these lesions by being able to show the recovery of the outer retinal layers.

  9. Retinal pigment epithelial changes in chronic Vogt-Koyanagi-Harada disease: fundus autofluorescence and spectral domain optical coherence tomography findings

    Science.gov (United States)

    Vasconcelos-Santos, Daniel V.; Sohn, Elliott H.; Sadda, Srinivas; Rao, Narsing A.

    2009-01-01

    Purpose To determine whether fundus autofluorescence (FAF) and spectral-domain optical coherence tomography (SD-OCT) imaging allows better assessment of RPE and outer retina (OR) in subjects with chronic VKH compared to examination and angiography alone. Methods Cross-sectional analysis of a series of seven consecutive patients with chronic VKH undergoing FAF and SD-OCT. Chronic VKH was defined as during >3 months. Color fundus photographs were correlated to FAF and SD-OCT images. The images were later correlated to fluorescein angiography (FA) and indocyanine green angiography (ICG-A). Results All patients had sunset glow fundus, which resulted in no apparent corresponding abnormality on FAF or SD-OCT. Lesions with decreased autofluorescence signal were observed in 11 eyes (85%), being associated with loss of the RPE and involvement of OR on SD-OCT. In 5 eyes (38%) some of these lesions were very subtle on clinical examination but easily detected by FAF. Lesions with increased autofluorescence signal were seen in 8 eyes (61.5%), showing variable involvement of the OR on SD-OCT and corresponding clinically to areas of RPE proliferation and cystoid macular edema. Conclusion Combined use of FAF and SD-OCT imaging allowed noninvasive delineation of RPE/OR changes in patients with chronic VKH, which were consistent with previous histopathological reports. Some of these changes were not apparent on clinical examination. PMID:20010321

  10. High resolution tomographic instrument development

    International Nuclear Information System (INIS)

    1992-01-01

    Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefited greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational

  11. High resolution tomographic instrument development

    Energy Technology Data Exchange (ETDEWEB)

    1992-08-01

    Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefited greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational.

  12. High resolution tomographic instrument development

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefited greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational.

  13. Characteristic optical coherence tomography findings in patients with primary vitreoretinal lymphoma: a novel aid to early diagnosis.

    Science.gov (United States)

    Barry, Robert J; Tasiopoulou, Anastasia; Murray, Philip I; Patel, Praveen J; Sagoo, Mandeep S; Denniston, Alastair K; Keane, Pearse A

    2018-01-06

    The diagnosis of primary vitreoretinal lymphoma (PVRL) poses significant difficulties; presenting features are non-specific and confirmation usually necessitates invasive vitreoretinal biopsy. Diagnosis is often delayed, resulting in increased morbidity and mortality. Non-invasive imaging modalities such as spectral domain optical coherence tomography (SD-OCT) offer simple and rapid aids to diagnosis. We present characteristic SD-OCT images of patients with biopsy-positive PVRL and propose a number of typical features, which we believe are useful in identifying these lesions at an early stage. Medical records of all patients attending Moorfields Eye Hospital between April 2010 and April 2016 with biopsy-positive PVRL were reviewed. Pretreatment SD-OCT images were collected for all eyes and were reviewed independently by two researchers for features suggestive of PVRL. Pretreatment SD-OCT images of 32 eyes of 22 patients with biopsy-proven PVRL were reviewed. Observed features included hyper-reflective subretinal infiltrates (17/32), hyper-reflective infiltration in inner retinal layers (6/32), retinal pigment epithelium (RPE) undulation (5/32), clumps of vitreous cells (5/32) and sub-RPE deposits (3/32). Of these, the hyper-reflective subretinal infiltrates have an appearance unique to PVRL, with features not seen in other diseases. We have identified a range of SD-OCT features, which we believe to be consistent with a diagnosis of PVRL. We propose that the observation of hyper-reflective subretinal infiltrates as described is highly suggestive of PVRL. This case series further demonstrates the utility of SD-OCT as a non-invasive and rapid aid to diagnosis, which may improve both visual outcomes and survival of patients with intraocular malignancies such as PVRL. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  14. High-resolution Fourier-Domain Optical Coherence Tomography and Microperimetric Findings After Macula-off Retinal Detachment Repair

    Science.gov (United States)

    Smith, Allison J.; Telander, David G.; Zawadzki, Robert J.; Choi, Stacey S.; Morse, Lawrence S.; Werner, John S.; Park, Susanna S.

    2009-01-01

    Objective To evaluate the morphologic changes in the macula of subjects with repaired macula-off retinal detachment (RD) using high-resolution Fourier-domain optical coherence tomography (FD OCT) and to perform functional correlation in a subset of patients using microperimetry (MP-1). Design Prospective observational case series. Participants Seventeen eyes from 17 subjects who had undergone anatomically successful repair for macula-off, rhegmatogenous RD at least 3 months earlier and without visually significant maculopathy on funduscopy. Methods FD OCT with axial and transverse resolution of 4.5 μm and 10 to 15 μm, respectively, was used to obtain rapid serial B-scans of the macula, which were compared with that from Stratus OCT. The FD OCT B-scans were used to create a 3-dimensional volume, from which en face C-scans were created. Among 11 patients, MP-1 was performed to correlate morphologic changes with visual function. Main Outcome Measures Stratus OCT scans, FD OCT scans, and MP-1 data. Results Stratus OCT and FD OCT images of the macula were obtained 3 to 30 months (mean 7 months) postoperatively in all eyes. Although Stratus OCT revealed photoreceptor disruption in 2 eyes (12%), FD OCT showed photoreceptor disruption in 13 eyes (76%). This difference was statistically significant (Pmacula-off RD repair is a common abnormality in the macula that is detected better with FD OCT than Stratus OCT. A good correlation between MP-1 abnormality and presence of photoreceptor disruption or subretinal fluid on FD OCT demonstrates that these anatomic abnormalities contribute to decreased visual function after successful repair. PMID:18672289

  15. Computerized tomographic system

    International Nuclear Information System (INIS)

    Godbarsen, R.; Barrett, D.M.; Garrott, P.M.; Foley, L.E.; Redington, R.W.; Lambert, T.W.; Edelheit, L.S.

    1981-01-01

    A computerized tomographic system for examining human breasts is described in detail. Conventional X-ray scanning apparatus has difficulty in achieving the levels of image definition and examination speeds required for mass screening. A novel method of scanning successive layers of the breast with a rotating X-ray beam is discussed and details of the control circuitry and sequence steps are given. The method involves immersing the breast in an inner fluid (e.g. water) filled container which is stationary during an examination and is surrounded by a large outer container which is also filled with the fluid; the inner and outer containers are always maintained at a constant height and the X-ray absorption across the fan-shaped beam is as close as possible to constant. (U.K.)

  16. Emission computed tomograph

    International Nuclear Information System (INIS)

    Hirose, Y.; Kanno, I.; Koga, K.; Miura, S.; Uemura, K.

    1981-01-01

    Emission computed tomograph wherein a pluralty of detectors surround an object to be examined so as to detect x- or gamma radiation emitted by said object. In front of each of said detectors there is provided a collimator which comprises a pair of main plates and a subsidiary plate interposed therebetween. The plates are made of a material capable of blocking penetration of the radiation therethrough and so supported as to be swingable over an angle sufficient to cover the whole of said object. The plates of all the collimators are simultaneously swung to the same side and at the same angular speed thereby to change the direction of incidence of said radiation on each of said detectors

  17. Tomographic examination table

    International Nuclear Information System (INIS)

    Redington, R.W.; Henkes, J.L.

    1979-01-01

    Equipment is described for positioning and supporting patients during tomographic mammography using X-rays. The equipment consists of a table and fabric slings which permit the examination of a downward, pendant breast of a prone patient by allowing the breast to pass through a aperture in the table into a fluid filled container. The fluid has an X-ray absorption coefficient similar to that of soft human tissue allowing high density resolution radiography and permitting accurate detection of breast tumours. The shape of the equipment and the positioning of the patient allow the detector and X-ray source to rotate 360 0 about a vertical axis through the breast. This permits the use of relatively simple image reconstruction algorithms and a divergent X-ray geometry. (UK)

  18. High-throughput full-automatic synchrotron-based tomographic microscopy

    International Nuclear Information System (INIS)

    Mader, Kevin; Marone, Federica; Hintermueller, Christoph; Mikuljan, Gordan; Isenegger, Andreas; Stampanoni, Marco

    2011-01-01

    At the TOMCAT (TOmographic Microscopy and Coherent rAdiology experimenTs) beamline of the Swiss Light Source with an energy range of 8-45 keV and voxel size from 0.37 (micro)m to 7.4 (micro)m, full tomographic datasets are typically acquired in 5 to 10 min. To exploit the speed of the system and enable high-throughput studies to be performed in a fully automatic manner, a package of automation tools has been developed. The samples are automatically exchanged, aligned, moved to the correct region of interest, and scanned. This task is accomplished through the coordination of Python scripts, a robot-based sample-exchange system, sample positioning motors and a CCD camera. The tools are suited for any samples that can be mounted on a standard SEM stub, and require no specific environmental conditions. Up to 60 samples can be analyzed at a time without user intervention. The throughput of the system is dependent on resolution, energy and sample size, but rates of four samples per hour have been achieved with 0.74 (micro)m voxel size at 17.5 keV. The maximum intervention-free scanning time is theoretically unlimited, and in practice experiments have been running unattended as long as 53 h (the average beam time allocation at TOMCAT is 48 h per user). The system is the first fully automated high-throughput tomography station: mounting samples, finding regions of interest, scanning and reconstructing can be performed without user intervention. The system also includes many features which accelerate and simplify the process of tomographic microscopy.

  19. Tomographic multiphase flow measurement

    International Nuclear Information System (INIS)

    Sætre, C.; Johansen, G.A.; Tjugum, S.A.

    2012-01-01

    Measurement of multiphase flow of gas, oil and water is not at all trivial and in spite of considerable achievements over the past two decades, important challenges remain (). These are related to reducing measurement uncertainties arising from variations in the flow regime, improving long term stability and developing new means for calibration, adjustment and verification of the multiphase flow meters. This work focuses on the first two issues using multi gamma beam (MGB) measurements for identification of the type of flow regime. Further gamma ray tomographic measurements are used for reference of the gas/liquid distribution. For the MGB method one Am-241 source with principal emission at 59.5 keV is used because this relatively low energy enables efficient collimation and thereby shaping of the beams, as well as compact detectors. One detector is placed diametrically opposite the source whereas the second is positioned to the side so that this beam is close to the pipe wall. The principle is then straight forward to compare the measured intensities of these detectors and through that identify the flow pattern, i.e. the instantaneous cross-sectional gas-liquid distribution. The measurement setup also includes Compton scattering measurements, which can provide information about the changes in the water salinity for flow segments with high water liquid ratio and low gas fractions. By measuring the transmitted intensity in short time slots (<100ms), rapid regime variations are revealed. From this we can select the time sections suitable for salinity measurements. Since the salinity variations change at the time scale of hours, a running average can be performed to increase the accuracy of the measurements. Recent results of this work will be presented here. - Highlights: ► Multiphase flow gas-fraction and flow regime measurements by multi gamma ray beams. ► High-speed gamma ray tomograph as reference for the flow pattern and gas fraction. ► Dual modality

  20. Tomographic multiphase flow measurement

    Energy Technology Data Exchange (ETDEWEB)

    Saetre, C., E-mail: camilla@ift.uib.no [Department of Physics and Technology, University of Bergen (Norway); Michelsen Centre for Industrial Measurement Science and Technology (Norway); Johansen, G.A. [Department of Physics and Technology, University of Bergen (Norway); Michelsen Centre for Industrial Measurement Science and Technology (Norway); Tjugum, S.A. [Michelsen Centre for Industrial Measurement Science and Technology (Norway); Roxar Flow Measurement, Bergen (Norway)

    2012-07-15

    Measurement of multiphase flow of gas, oil and water is not at all trivial and in spite of considerable achievements over the past two decades, important challenges remain (). These are related to reducing measurement uncertainties arising from variations in the flow regime, improving long term stability and developing new means for calibration, adjustment and verification of the multiphase flow meters. This work focuses on the first two issues using multi gamma beam (MGB) measurements for identification of the type of flow regime. Further gamma ray tomographic measurements are used for reference of the gas/liquid distribution. For the MGB method one Am-241 source with principal emission at 59.5 keV is used because this relatively low energy enables efficient collimation and thereby shaping of the beams, as well as compact detectors. One detector is placed diametrically opposite the source whereas the second is positioned to the side so that this beam is close to the pipe wall. The principle is then straight forward to compare the measured intensities of these detectors and through that identify the flow pattern, i.e. the instantaneous cross-sectional gas-liquid distribution. The measurement setup also includes Compton scattering measurements, which can provide information about the changes in the water salinity for flow segments with high water liquid ratio and low gas fractions. By measuring the transmitted intensity in short time slots (<100ms), rapid regime variations are revealed. From this we can select the time sections suitable for salinity measurements. Since the salinity variations change at the time scale of hours, a running average can be performed to increase the accuracy of the measurements. Recent results of this work will be presented here. - Highlights: Black-Right-Pointing-Pointer Multiphase flow gas-fraction and flow regime measurements by multi gamma ray beams. Black-Right-Pointing-Pointer High-speed gamma ray tomograph as reference for the flow

  1. Computed tomographic study in children with microcephaly

    International Nuclear Information System (INIS)

    Ito, Masatoshi; Okuno, Takehiko; Mikawa, Haruki

    1989-01-01

    Computed tomographic (CT) brain scanning was performed on fifty-eight infants and children with microcephaly. CT scans were useful for detecting unsuspected brain lesions and for diagnosing underlying diseases. The head size did not correlate with the CT findings, the degree of mental retardation, or the existence of motor disturbance or epilepsy. On the other hand, the CT findings were correlated with the degree of mental retardation, and the existence of motor disturbance or epilepsy. CT scans were useful for determining the prognosis of the microcephaly. (author)

  2. Three dimensional reconstruction of tomographic images of the retina

    International Nuclear Information System (INIS)

    Glittenberg, C.; Zeiler, F.; Falkner, C.; Binder, S.; Povazay, B.; Hermann, B.; Drexler, W.

    2007-01-01

    The development of a new display system for the three-dimensional visualization of tomographic images in ophthalmology. Specifically, a system that can use stacks of B-mode scans from an ultrahigh resolution optical tomography examination to vividly display retinal specimens as three-dimensional objects. Several subroutines were programmed in the rendering and raytracing program Cinema 4D XL 9.102 Studio Bundle (Maxon Computer Inc., Friedrichsburg, Germany), which could process stacks of tomographic scans into three-dimensional objects. Ultrahigh resolution optical coherence tomography examinations were performed on patients with various retinal pathologies and post processed with the subroutines that had been designed. All ultrahigh resolution optical coherence tomographies were performed with a titanium: sapphire based ultra broad bandwidth (160 nm) femtosecond laser system (INTEGRAL, Femtolasers Productions GmbH. Vienna Austria) with an axial resolution of 3 μm. A new three dimensional display system for tomographic images in ophthalmology was developed, which allows a highly vivid display of physiological and pathological structures of the retina. The system also distinguishes itself through its high interactivity and adaptability. This new display system allows the visualization of physiological and pathological structures of the retina in a new way, which will give us new insight into their morphology and development. (author) [de

  3. Topological Properties of Spatial Coherence Function

    International Nuclear Information System (INIS)

    Ji-Rong, Ren; Tao, Zhu; Yi-Shi, Duan

    2008-01-01

    The topological properties of the spatial coherence function are investigated rigorously. The phase singular structures (coherence vortices) of coherence function can be naturally deduced from the topological current, which is an abstract mathematical object studied previously. We find that coherence vortices are characterized by the Hopf index and Brouwer degree in topology. The coherence flux quantization and the linking of the closed coherence vortices are also studied from the topological properties of the spatial coherence function

  4. Tomographic imaging system

    International Nuclear Information System (INIS)

    Hayakawa, T.; Horiba, I.; Kohno, H.; Nakaya, C.; Sekihara, K.; Shiono, H.; Tomura, T.; Yamamoto, S.; Yanaka, S.

    1980-01-01

    A tomographic imaging system comprising: irradiating means for irradating a cross-section of an object under consideration with radiation rays from plural directions; detector means for detecting the radiation rays transmitted through the cross-section of said object to produce an output signal; first memory means for storing the output signal of said detector means; and an image jreconstructing section for performing a convolution integral operation on the contents of said first memory means by means of a first weighting function to reconstruct a three-dimensional image of the cross-section of said object, said image reconstructing section including (I) second memory means for storing a second weighting function, said second weighting function being provided with a predetermined positive and negative (N-1)th order when the output signal of said detector means produced by the irradiation of the cross-section of said object from one of said plural directions is sampled by N points, the value of the (N-1)th order of said second weighting function being an integration of said first weighting function from the (N-1)th order to positive infinity and the value of -(N-1)th order of said second weighting function being an integration of said first weighting function from the -(N-1)th order to negative infinity, (II) control means for successively reading out the contents of said first and second memory means, and (III) operational means for performing multiplying and summing operations on the read-out contents of said first and second memory means, said operational means producing the product of the values fo the (N-1)th and -(N-1)th orders of said second weighting function and a component of the output signal of said detector means relating to the radiation rays free from the absorption thereof by said object

  5. Experimental demonstration of a Hadamard gate for coherent state qubits

    Energy Technology Data Exchange (ETDEWEB)

    Tipsmark, Anders; Laghaout, Amine; Andersen, Ulrik L. [Department of Physics, Technical University of Denmark, Fysikvej, DK-2800 Kgs. Lyngby (Denmark); Dong, Ruifang [Quantum Frequency Standards Division, National Time Service Center (NTSC), Chinese Academy of Sciences, 710600 Lintong, Shaanxi (China); Department of Physics, Technical University of Denmark, Fysikvej, DK-2800 Kgs. Lyngby (Denmark); Marek, Petr [Department of Optics, Palacky University, 17. listopadu 12, CZ-77146 Olomouc (Czech Republic); Jezek, Miroslav [Department of Optics, Palacky University, 17. listopadu 12, CZ-77146 Olomouc (Czech Republic); Department of Physics, Technical University of Denmark, Fysikvej, DK-2800 Kgs. Lyngby (Denmark)

    2011-11-15

    We discuss and make an experimental test of a probabilistic Hadamard gate for coherent state qubits. The scheme is based on linear optical components, nonclassical resources, and the joint projective action of a photon counter and a homodyne detector. We experimentally characterize the gate for the coherent states of the computational basis by full tomographic reconstruction of the transformed output states. Based on the parameters of the experiment, we simulate the fidelity for all coherent state qubits on the Bloch sphere.

  6. Experimental demonstration of a Hadamard gate for coherent state qubits

    DEFF Research Database (Denmark)

    Tipsmark, Anders; Dong, Ruifang; Laghaout, Amine

    2011-01-01

    We discuss and make an experimental test of a probabilistic Hadamard gate for coherent state qubits. The scheme is based on linear optical components, nonclassical resources, and the joint projective action of a photon counter and a homodyne detector. We experimentally characterize the gate for t...... for the coherent states of the computational basis by full tomographic reconstruction of the transformed output states. Based on the parameters of the experiment, we simulate the fidelity for all coherent state qubits on the Bloch sphere....

  7. Computerized tomographic diagnosis of basal skull fracture

    International Nuclear Information System (INIS)

    Tanaka, Tokutaro; Shimoyama, Ichiro; Endoh, Mitsutoshi; Ninchoji, Toshiaki; Uemura, Kenichi.

    1984-01-01

    The diagnosis of basal skull fractures used to be difficult, particularly on the basis of routine skull roentgenography alone. We have now examined the diagnostic value of conventional computerized tomography in basal skull fractures. We studied 82 cases clinically diagnosed as basal skull fractures. We examined them based on at least one of the following computerized tomographic criteria for basal skull fractures: 1) fracture line(s), 2) intracranial air, 3) fluid in the paranasal sinuses, and 4) fluid in the middle ear, including the mastoid air cells. The signs of the fracture line and of the intracranial air are definite indications of basal skull fracture, but the signs of fluid in the paranasal sinuses and/or in the middle ear are not definite. When combined, however, with such other clinical signs as black eye, Battle's sign, CSF leakage, CSF findings, and profuse nasal or ear bleeding, the diagnosis is more reliable. Seventy cases (85.4%) in this series had basal skull fractures according to our computerized tomographic criteria. Among them , 26 cases (31.7%) were diagnosed with fracture lines, 17 cases (20.7%) with intracranial air, 16 cases (19.5%) with fluid in the paranasal sinuses, 10 cases (12.2%) with fluid in the middle ear, and one case (1.2%) with fluid in both. Twelve cases (14.6%) of the 82 cases clinically diagnosed as basal skull fractures could not have been diagnosed on our computerized tomographic criteria alone. We diagnosed them because of CSF leakage, CSF findings, surgical findings, etc. (author)

  8. Computer tomographic diagnosis of echinococcosis

    Energy Technology Data Exchange (ETDEWEB)

    Haertel, M.; Fretz, C.; Fuchs, W.A.

    1980-08-01

    The computer tomographic appearances and differential diagnosis in 22 patients with echinococcosis are described; of these, twelve were of the cystic and ten of the alveolar type. The computer tomographic appearances are characterised by the presence of daughter cysts (66%) within the sharply demarkated parasitic cyst of water density. In the absence of daughter cysts, a definite aetiological diagnosis cannot be made, although there is a tendency to clasification of the occassionally multiple echinococcus cysts. The computer tomographic appearances of advanced alveolar echinococcosis are characterised by partial collequative necrosis, with clacification around the necrotic areas (90%). The absence of CT evidence of partial necrosis and calsification of the pseudotumour makes it difficult to establish a specific diagnosis. The conclusive and non-invasive character of the procedure and its reproducibility makes computer tomography the method of choice for the diagnosis and follow-up of echinococcosis.

  9. Harmonic scalpel versus electrocautery for harvest of radial artery conduits: Reduced risk of spasm and intimal injury on optical coherence tomography

    Science.gov (United States)

    Brazio, Philip S.; Laird, Patrick C.; Xu, Chenyang; Gu, Junyan; Burris, Nicholas S.; Brown, Emile N.; Kon, Zachary N.; Poston, Robert S.

    2009-01-01

    Objective Vasospasm is the primary obstacle to widespread adoption of the radial artery as a conduit in coronary artery bypass grafting. We used optical coherence tomography, a catheter-based intravascular imaging modality, to measure the degree of radial artery spasm induced by means of harvest with electrocautery or a harmonic scalpel in patients undergoing coronary artery bypass grafting. Methods Radial arteries were harvested from 44 consecutive patients with a harmonic scalpel (n = 15) or electrocautery (n = 29). Vessels were imaged before harvesting and after removal from the arm, with saphenous vein tracts serving as internal controls. Optical coherence tomographic findings for the degree of harvesting-induced injury were validated against histologic measures. Results Optical coherence tomographic measures of endovascular dimensions and injury correlated strongly with histologic findings. Mean luminal volume, a measure of vasospasm, decreased significantly less after harvesting with a harmonic scalpel (9% ± 7%) than with electrocautery (35% ± 6%, P = .015). Completely intact intima was present in 11 (73%) of 15 radial arteries harvested with a harmonic scalpel (73%) compared with 9 of 29 arteries harvested by means of electrocautery (31%, P = .011). Intraoperative flow measurements and patency rates at 5 days postoperatively were not significantly different among groups. Conclusions Optical coherence tomography provides a level of speed and accuracy for quantifying endothelial injury and vasospasm that has not been described for any other modality, suggesting potential as an intraoperative quality assurance tool. Our optical coherence tomographic findings suggest that the harmonic scalpel induces less spasm and intimal injury compared with electrocautery. PMID:19026820

  10. Pressure spectra from single-snapshot tomographic PIV

    Science.gov (United States)

    Schneiders, Jan F. G.; Avallone, Francesco; Pröbsting, Stefan; Ragni, Daniele; Scarano, Fulvio

    2018-03-01

    The power spectral density and coherence of temporal pressure fluctuations are obtained from low-repetition-rate tomographic PIV measurements. This is achieved by extension of recent single-snapshot pressure evaluation techniques based upon the Taylor's hypothesis (TH) of frozen turbulence and vortex-in-cell (VIC) simulation. Finite time marching of the measured instantaneous velocity fields is performed using TH and VIC. Pressure is calculated from the resulting velocity time series. Because of the theoretical limitations, the finite time marching can be performed until the measured flow structures are convected out of the measurement volume. This provides a lower limit of resolvable frequency range. An upper limit is given by the spatial resolution of the measurements. Finite time-marching approaches are applied to low-repetition-rate tomographic PIV data of the flow past a straight trailing edge at 10 m/s. Reference results of the power spectral density and coherence are obtained from surface pressure transducers. In addition, the results are compared to state-of-the-art experimental data obtained from time-resolved tomographic PIV performed at 10 kHz. The time-resolved approach suffers from low spatial resolution and limited maximum acquisition frequency because of hardware limitations. Additionally, these approaches strongly depend upon the time kernel length chosen for pressure evaluation. On the other hand, the finite time-marching approaches make use of low-repetition-rate tomographic PIV measurements that offer higher spatial resolution. Consequently, increased accuracy of the power spectral density and coherence of pressure fluctuations are obtained in the high-frequency range, in comparison to the time-resolved measurements. The approaches based on TH and VIC are found to perform similarly in the high-frequency range. At lower frequencies, TH is found to underestimate coherence and intensity of the pressure fluctuations in comparison to time-resolved PIV

  11. Optical Coherence Tomographic Imaging and Delivery for Surgical Guidance

    National Research Council Canada - National Science Library

    Fujimoto, James G

    2004-01-01

    .... OCT can thus function as a type of "optical biopsy," enabling imaging of tissue with resolution approaching conventional biopsy and histopathology, but without the need to remove and process specimens...

  12. Tomographic methods in nuclear medicine

    International Nuclear Information System (INIS)

    Ahluwalia, B.D.

    1989-01-01

    This book is a review of the various approaches to tomographic imaging that have been pursued in nuclear medicine. The evolution of single photon emission computed tomography (SPECT) is discussed in detail, and the major classes of instrumentation are represented. A section on positron emission tomography is also included, but is rather brief and may serve only as a general introduction

  13. Original circuitry for TOHR tomograph

    International Nuclear Information System (INIS)

    Cuzon, J.C.; Pinot, L.

    1999-01-01

    Having industrialization in mind, a specific electronics for a high resolution tomograph is designed out of the usual standards of nuclear physics. All the information are converted in the time domain and a fast processor, in front of the data acquisition, carries out the time and energy coincidences. (authors)

  14. Coherence in Industrial Transformation

    DEFF Research Database (Denmark)

    Jørgensen, Ulrik; Lauridsen, Erik Hagelskjær

    2003-01-01

    The notion of coherence is used to illustrate the general finding, that the impact of environmental management systems and environmental policy is highly dependent of the context and interrelatedness of the systems, procedures and regimes established in society....

  15. Computer tomographic and sonographic diagnosis of echinococcus

    Energy Technology Data Exchange (ETDEWEB)

    Schulze, K.; Huebener, K.H.; Klott, K.; Jenss, H.; Baehr, R. (Tuebingen Univ. (Germany, F.R.). Medizinisches Strahleninstitut und Roentgenabteilung; Tuebingen Univ. (Germany, F.R.). Medizinische Klinik; Tuebingen Univ. (Germany, F.R.). Chirurgische Klinik und Poliklinik)

    1980-05-01

    In 33 patients (18 cystic echinococci, 15 alveolar) both methods produced the following findings which could be correlated with the pathological results: single or multi-centric lesions, sharp or indefinite demarkation and abnormalities in the shape and size of the liver. The sonographic findings were analysed with respect to the echo characteristics, whereas the computer tomographically demonstrated lesions were examined densitometrically in order to show calcification. Both methods demonstrate the pathological changes satisfactorily. Computer tomography is more effective in alveolar echinococcus lesions by showing the different types of calcification, whereas sonography provides a more accurate picture of the internal structure of the cysts in cystic echinococcus. Comparison of the methods in 19 patients examined by both showed a high accuracy in each method, but sonography was relatively poor in demonstrating lesions in the spleen.

  16. Computed tomographic appearances of cherubism

    Energy Technology Data Exchange (ETDEWEB)

    Bianchi, S D; Boccardi, A; Mela, F; Romagnoli, R

    1987-01-01

    The computed tomographic (CT) aspects of six cases of cherubism are described. Through its optimal representation of the lesions, CT enabled certain characteristics of this disease to be substantiated, namely, limitation of the process to the bones of the jaw and primarily superficial development of the mandibular lesions, coupled with an unusual mandibular condylar impairment. Moreover, the composition of this series permitted investigation of the condition in its several stages of progression.

  17. Directional fine structure in absorption of white x rays: A tomographic interpretation

    International Nuclear Information System (INIS)

    Korecki, P.; Szymonski, M.; Tolkiehn, M.; Novikov, D. V.; Materlik, G.

    2006-01-01

    We discuss directional fine structure in absorption of white x rays for tomographic imaging of crystal structure at the atomic level. The interference between a direct x-ray beam and the secondary waves coherently scattered inside a specimen modifies the total wave field at the position of the absorbing atoms. For a white x-ray beam, the wave field variations cancel out by energy integration for all directions, except for the near forward scattering components, coinciding with the incident beam. Therefore, two-dimensional patterns of the angular-dependent fine structure in absorption of white x rays can be interpreted as real-space projections of atomic structure. In this work, we present a theory describing the directional fine structure in white x-ray absorption and a tomographic approach for crystal structure retrieval developed on its basis. The tomographic algorithm is applied to the experimental x-ray absorption data recorded for GaP crystals

  18. Rotating positron tomographs revisited

    International Nuclear Information System (INIS)

    Townsend, D.; Defrise, M.; Geissbuhler, A.

    1994-01-01

    We have compared the performance of a PET scanner comprising two rotating arrays of detectors with that of the more conventional stationary-ring design. The same total number of detectors was used in each, and neither scanner had septa. For brain imaging, we find that the noise-equivalent count rate is greater for the rotating arrays by a factor of two. Rotating arrays have a sensitivity profile that peaks in the centre of the field of view, both axially and transaxially. In the transaxial plane, this effect offsets to a certain extent the decrease in the number of photons detected towards the centre of the brain due to self-absorption. We have also compared the performance of a rotating scanner to that of a full-ring scanner with the same number of rings. We find that a full-ring scanner with an axial extent of 16.2 cm (24 rings) is a factor of 3.5 more sensitive than a rotating scanner with 40% of the detectors and the same axial extent. (Author)

  19. Drug eluting stents trapping intramural hematoma in spontaneous coronary artery dissection and healing pattern at six months: Optical coherence tomography findings

    Energy Technology Data Exchange (ETDEWEB)

    Poon, Karl, E-mail: karlkpoon@gmail.com; Incani, Alexander; Small, Andrew; Raffel, O. Christopher

    2013-05-15

    Spontaneous coronary artery dissections (SCAD) are often difficult to diagnose and manage. Intravascular imaging such as optical coherence tomography (OCT) improves diagnosis and may assist in management. Recent data suggest that percutaneous coronary interventions (PCI) in in SCAD are associated with poor outcomes. This report provides striking OCT images of potential complications associated with PCI in SCAD, as well as demonstrates medium term OCT data in residual hematoma healing and stent coverage in SCAD.

  20. Investigation of a turbulent spot and a tripped turbulent boundary layer flow using time-resolved tomographic PIV

    NARCIS (Netherlands)

    Schröder, A.; Geisler, R.; Elsinga, G.E.; Scarano, F.; Dierksheide, U.

    2007-01-01

    In this feasibility study the tomographic PIV technique has been applied to time resolved PIV recordings for the study of the growth of a turbulent spot in a laminar flat plate boundary layer and to visualize the topology of coherent flow structures within a tripped turbulent flat plate boundary

  1. Segmentation-DrivenTomographic Reconstruction

    DEFF Research Database (Denmark)

    Kongskov, Rasmus Dalgas

    such that the segmentation subsequently can be carried out by use of a simple segmentation method, for instance just a thresholding method. We tested the advantages of going from a two-stage reconstruction method to a one stage segmentation-driven reconstruction method for the phase contrast tomography reconstruction......The tomographic reconstruction problem is concerned with creating a model of the interior of an object from some measured data, typically projections of the object. After reconstructing an object it is often desired to segment it, either automatically or manually. For computed tomography (CT...

  2. Computer tomographic examinations in epilepsy

    International Nuclear Information System (INIS)

    De Villiers, J.F.K.

    1984-01-01

    Epileptic patients that was examined at the Universitas Hospital (Bloemfontein) by means of computerized tomography for the period July 1978 - December 1980, are divided into two groups: a) Patients with general epilepsy of convulsions - 507; b) Patients with vocal or partial epilepsy - 111. The method of examination and the results for both general and vocal epilepsy are discussed. A degenerative state was found in 35% of the positive computer tomographic examinations in general epilepsy and 22% of the positive examinations for vocal epilepsy. The purpose of the article was to explain the circumstances that can be expected when a epileptic patient is examined by means of computerized tomography

  3. Ovarian metastases: Computed tomographic appearances

    International Nuclear Information System (INIS)

    Megibow, A.J.; Hulnick, D.H.; Bosniak, M.A.; Balthazar, E.J.

    1985-01-01

    Computed tomographic scans of 34 patients with ovarian metastases were reviewed to assess the radiographic appearances and to correlate these with the primary neoplasms. Primary neoplasms were located in the colon (20 patients), breast (six), stomach (five), small bowel (one), bladder (one), and Wilms tumor of the kidney (one). The radiographic appearance of the metastatic lesions could be described as predominantly cystic (14 lesions), mixed (12 lesions), or solid (seven lesions). The cystic and mixed lesions tended to be larger in overall diameter than the solid. The metastases from gastric carcinoma appeared solid in four of five cases. The metastases from the other neoplasms had variable appearances simulating primary ovarian carcinoma

  4. Modeling light–tissue interaction in optical coherence tomography systems

    DEFF Research Database (Denmark)

    Andersen, Peter E.; Jørgensen, Thomas Martini; Thrane, Lars

    2015-01-01

    Optical coherence tomography (OCT) performs high-resolution, cross-sectional tomographic imaging of the internal tissue microstructure by measuring backscattered or backreflected light. The scope of this chapter is to present analytical and numerical models that are able to describe light-tissue ...

  5. Experimental generation of optical coherence lattices

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yahong; Cai, Yangjian, E-mail: serpo@dal.ca, E-mail: yangjiancai@suda.edu.cn [College of Physics, Optoelectronics and Energy and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006 (China); Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province and Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University, Suzhou 215006 (China); Ponomarenko, Sergey A., E-mail: serpo@dal.ca, E-mail: yangjiancai@suda.edu.cn [Department of Electrical and Computer Engineering, Dalhousie University, Halifax, Nova Scotia B3J 2X4 (Canada)

    2016-08-08

    We report experimental generation and measurement of recently introduced optical coherence lattices. The presented optical coherence lattice realization technique hinges on a superposition of mutually uncorrelated partially coherent Schell-model beams with tailored coherence properties. We show theoretically that information can be encoded into and, in principle, recovered from the lattice degree of coherence. Our results can find applications to image transmission and optical encryption.

  6. Stratus optical coherence tomography findings in patients with retinopathy of prematurity Tomografia de coerência óptica em pacientes com retinopatia da prematuridade

    Directory of Open Access Journals (Sweden)

    Aline do Lago

    2007-02-01

    Full Text Available PURPOSE: To describe morphological features of the macula in patients with retinopathy of prematurity. METHODS: Twelve premature babies with retinopathy of prematurity grades I, II and III underwent dilated fundus examination and optical coherence tomography evaluation. RESULTS: In all thirteen eyes of the twelve premature patients optical coherence tomography revealed a condensed retinal pigmented epithelial layer in the macular-foveal area shown by increased reflectivity. In these eyes the retinal layers were not well differentiated. Foveal depression was clearly evident in 23%. CONCLUSIONS: In premature patients with retinopathy of prematurity, optical coherence tomography revealed poorly differentiated layers in the macular region with increased reflectivity in retinal pigmented epithelial-choriocapillaris zone.OBJETIVO: Descrever os aspectos morfológicos da mácula em pacientes com retinopatia da prematuridade (ROP. MÉTODOS: Doze pacientes com retinopatia da prematuridade graus I, II and III foram submetidos a mapeamento de retina e avaliação por tomografia de coerência óptica. RESULTADOS: Em todos os treze olhos de 12 pacientes a tomografia de coerência óptica mostrou a camada do epitélio pigmentar hiperrefletiva, sendo a área macular com maior intensidade. Nesses olhos as camadas da retina não estavam totalmente diferenciadas. A depressão foveal ficou claramente evidente pela tomografia de coerência óptica em 23%. CONCLUSÃO: Nos pacientes prematuros com retinopatia da prematuridade, a tomografia de coerência óptica mostrou as camadas da retina pouco diferenciadas com aumento da refletividade na área macular do complexo epitélio retiniano pigmentar-coriocapilar.

  7. Precision of quantum tomographic detection of radiation

    Energy Technology Data Exchange (ETDEWEB)

    D' Ariano, G.M. (Dipartimento di Fisica ' ' Alessandro Volta' ' , Via A. Bassi 6, I-27100, Pavia (Italy) Istituto Nazionale di Fisica Nucleare, Sezione di Pavia, Via A. Bassi 6, I-27100, Pavia (Italy)); Macchiavello, Chiara (Dipartimento di Fisica ' ' Alessandro Volta' ' , Via A. Bassi 6, I-27100, Pavia (Italy)); Paris, M.G.A. (Dipartimento di Fisica ' ' Alessandro Volta' ' , Via A. Bassi 6, I-27100, Pavia (Italy))

    1994-11-21

    Homodyne tomography provides an experimental technique for reconstructing the density matrix of the radiation field. Here we analyze the tomographic precision in recovering observables like the photon number, the quadrature, and the phase. We show that tomographic reconstruction, despite providing a complete characterization of the state of the field, is generally much less efficient than conventional detection techniques. ((orig.))

  8. Precision of quantum tomographic detection of radiation

    International Nuclear Information System (INIS)

    D'Ariano, G.M.; Macchiavello, Chiara; Paris, M.G.A.

    1994-01-01

    Homodyne tomography provides an experimental technique for reconstructing the density matrix of the radiation field. Here we analyze the tomographic precision in recovering observables like the photon number, the quadrature, and the phase. We show that tomographic reconstruction, despite providing a complete characterization of the state of the field, is generally much less efficient than conventional detection techniques. ((orig.))

  9. Coherent detectors

    International Nuclear Information System (INIS)

    Lawrence, C R; Church, S; Gaier, T; Lai, R; Ruf, C; Wollack, E

    2009-01-01

    Coherent systems offer significant advantages in simplicity, testability, control of systematics, and cost. Although quantum noise sets the fundamental limit to their performance at high frequencies, recent breakthroughs suggest that near-quantum-limited noise up to 150 or even 200 GHz could be realized within a few years. If the demands of component separation can be met with frequencies below 200 GHz, coherent systems will be strong competitors for a space CMB polarization mission. The rapid development of digital correlator capability now makes space interferometers with many hundreds of elements possible. Given the advantages of coherent interferometers in suppressing systematic effects, such systems deserve serious study.

  10. Coherent detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, C R [M/C 169-327, Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Church, S [Room 324 Varian Physics Bldg, 382 Via Pueblo Mall, Stanford, CA 94305-4060 (United States); Gaier, T [M/C 168-314, Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Lai, R [Northrop Grumman Corporation, Redondo Beach, CA 90278 (United States); Ruf, C [1533 Space Research Building, The University of Michigan, Ann Arbor, MI 48109-2143 (United States); Wollack, E, E-mail: charles.lawrence@jpl.nasa.go [NASA/GSFC, Code 665, Observational Cosmology Laboratory, Greenbelt, MD 20771 (United States)

    2009-03-01

    Coherent systems offer significant advantages in simplicity, testability, control of systematics, and cost. Although quantum noise sets the fundamental limit to their performance at high frequencies, recent breakthroughs suggest that near-quantum-limited noise up to 150 or even 200 GHz could be realized within a few years. If the demands of component separation can be met with frequencies below 200 GHz, coherent systems will be strong competitors for a space CMB polarization mission. The rapid development of digital correlator capability now makes space interferometers with many hundreds of elements possible. Given the advantages of coherent interferometers in suppressing systematic effects, such systems deserve serious study.

  11. Quantum coherence: Reciprocity and distribution

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Asutosh, E-mail: asukumar@hri.res.in [Harish-Chandra Research Institute, Allahabad-211019 (India); Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094 (India)

    2017-03-18

    Quantum coherence is the outcome of the superposition principle. Recently, it has been theorized as a quantum resource, and is the premise of quantum correlations in multipartite systems. It is therefore interesting to study the coherence content and its distribution in a multipartite quantum system. In this work, we show analytically as well as numerically the reciprocity between coherence and mixedness of a quantum state. We find that this trade-off is a general feature in the sense that it is true for large spectra of measures of coherence and of mixedness. We also study the distribution of coherence in multipartite systems by looking at monogamy-type relation–which we refer to as additivity relation–between coherences of different parts of the system. We show that for the Dicke states, while the normalized measures of coherence violate the additivity relation, the unnormalized ones satisfy the same. - Highlights: • Quantum coherence. • Reciprocity between quantum coherence and mixedness. • Distribution of quantum coherence in multipartite quantum systems. • Additivity relation for distribution of quantum coherence in Dicke and “X” states.

  12. Memories of Holocaust-related traumatic experiences, sense of coherence, and survivors' subjective well-being in late life: some puzzling findings.

    Science.gov (United States)

    Zeidner, Moshe; Aharoni-David, Eynat

    2015-01-01

    This study explores the nexus of relationships between memories of Holocaust-related early traumatic events, survivors' sense of coherence (SOC), and subjective well-being (SWB) in late life. The basic design of this study, based 106 survivors (54% female), was cross-sectional. Participants underwent an extensive in-depth clinical interview relating to their Holocaust experiences and responded to measures of SOC and SWB. These data provided no evidence for the moderating or "buffering" effect of SOC but showed support for indirect effects of SOC in the relationship between memory traces of specific traumatic experiences and adaptive outcomes. The results of the present study provide support for Antonovsky's salutogenic perspective. It is highly plausible that survivors who underwent severe experiences during the Holocaust period were forced to call upon all their inner strengths and coping resources,and that their success in doing so and also surviving this horrendous period, might have contributed to the development of a stronger sense of meaning and coherence, which, in turn lead to a better sense of mental health as they approach the final season of their lives.

  13. Influence of HeartMath quick coherence technique on ...

    African Journals Online (AJOL)

    ... of high psychophysiological coherence, decreased feelings of sadness and increased feelings of peacefulness. Psychophysiological and emotional state findings are discussed in relation to health and sport psychology, theory and practice. Keywords: Biofeedback, physiological coherence, Quick Coherence Technique, ...

  14. Effect of ranibizumab on high-speed indocyanine green angiography and minimum intensity projection optical coherence tomography findings in neovascular age-related macular degeneration.

    Science.gov (United States)

    Nicholson, Benjamin P; Nigam, Divya; Toy, Brian; Stetson, Paul F; Agrón, Elvira; Jacobs-El, Naima; Cunningham, Denise; Cukras, Catherine; Wong, Wai; Wiley, Henry; Chew, Emily; Ferris, Frederick; Meyerle, Catherine B

    2015-01-01

    The purpose of this 1-year prospective study was to investigate how induction/pro re nata ranibizumab intravitreal treatment of eyes with neovascular age-related macular degeneration affects the anatomy of choroidal neovascularization (CNV) and the overlying outer retinal tissue. High-speed indocyanine green (HS-ICG) angiography measurements provided quantification of the CNV size in 60 patients followed for 1 year. Minimum intensity projection optical coherence tomography (MinIP OCT), a novel algorithm assessing minimum optical intensity between the internal limiting membrane and retinal pigment epithelium, measured the area of outer retinal disruption overlying the CNV. Fluorescein angiography was also assessed to evaluate late retinal leakage. After 1 year, the mean area of CNV measured with indocyanine green angiography decreased by 5.8%. The mean area of MinIP OCT of outer retinal disruption overlying the CNV decreased by 4.2%. Mean area of fluorescein angiography leakage decreased by 6.3%. Both the area of outer retinal disruption measured with MinIP OCT and the area of leakage on fluorescein angiography typically exceeded the area of CNV on indocyanine green angiography at baseline and 1 year. Choroidal neovascularization treated with induction/pro re nata intravitreal ranibizumab for 1 year essentially remained static. Minimum intensity projection optical coherence tomography suggests that the area of outer retinal disruption overlying the CNV may be greater than the CNV itself and often correlates with the leakage area on fluorescein angiography. Additionally, there was minimal change in the area of outer retinal disruption on MinIP OCT even when fluid resolved. Measurements of the extent of CNV lesions based on indocyanine green angiography and MinIP OCT may provide useful outcome variables to help assess the CNV complex longitudinally and warrant further validation.

  15. Ictal technetium-99 m ethyl cysteinate dimer single-photon emission tomographic findings in epileptic patients with polymicrogyria syndromes: A subtraction of ictal-interictal SPECT coregistered to MRI study

    International Nuclear Information System (INIS)

    Wichert-Ana, Lauro; Mazzoncini de Azevedo-Marques, Paulo; Santos, Antonio C.; Araujo, David; Ferrari Oliveira, Lucas; Fernandes, Regina M.F.; Velasco, Tonicarlo R.; Sakamoto, Americo C.; Kato, Mery; Muxfeldt Bianchin, Marino

    2008-01-01

    To describe the ictal technetium-99 m-ECD SPECT findings in polymicrogyria syndromes (PMG) during epileptic seizures. We investigated 17 patients with PMG syndromes during presurgical workup, which included long-term video-electroencephalographic (EEG) monitoring, neurological and psychiatry assessments, invasive EEG, and the subtraction of ictal-interictal SPECT coregistered to magnetic resonance imaging (MRI) (SISCOM). The analysis of the PMG cortex, using SISCOM, revealed intense hyperperfusion in the polymicrogyric lesion during epileptic seizures in all patients. Interestingly, other localizing investigations showed heterogeneous findings. Twelve patients underwent epilepsy surgery, three achieved seizure-freedom, five have worthwhile improvement, and four patients remained unchanged. Our study strongly suggests the involvement of PMG in seizure generation or early propagation. Both conventional ictal single-photon emission computed tomography (SPECT) and SISCOM appeared as the single contributive exam to suggest the localization of the epileptogenic zone. Despite the limited number of resective epilepsy surgery in our study (n = 9), we found a strong prognostic role of SISCOM in predicting surgical outcome. This result may be of great value on surgical decision-making of whether or not the whole or part of the PMG lesion should be surgically resected. (orig.)

  16. Ictal technetium-99 m ethyl cysteinate dimer single-photon emission tomographic findings in epileptic patients with polymicrogyria syndromes: A subtraction of ictal-interictal SPECT coregistered to MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Wichert-Ana, Lauro [University of Sao Paulo, Center for Epilepsy Surgery, Department of Neurology, Psychiatry and Clinical Psychology, Ribeirao Preto (Brazil); Hospital das Clinicas, USP, Centro de Cirurgia de Epilepsia, CIREP, Ribeirao Preto, SP (Brazil); Mazzoncini de Azevedo-Marques, Paulo; Santos, Antonio C.; Araujo, David [University of Sao Paulo, Center for Imaging Science and Medical Physics, Department of Internal Medicine, Ribeirao Preto (Brazil); Ferrari Oliveira, Lucas [Federal University of Pelotas, Informatics Department, Pelotas, RS (Brazil); Fernandes, Regina M.F.; Velasco, Tonicarlo R.; Sakamoto, Americo C. [University of Sao Paulo, Center for Epilepsy Surgery, Department of Neurology, Psychiatry and Clinical Psychology, Ribeirao Preto (Brazil); Kato, Mery [University of Sao Paulo, Division of Nuclear Medicine, Department of Internal Medicine from the Ribeirao Preto Medical School, Ribeirao Preto (Brazil); Muxfeldt Bianchin, Marino [Rio Grande do Sul Federal University, Neurology Division, HCPA, Porto Alegre, RS (Brazil)

    2008-06-15

    To describe the ictal technetium-99 m-ECD SPECT findings in polymicrogyria syndromes (PMG) during epileptic seizures. We investigated 17 patients with PMG syndromes during presurgical workup, which included long-term video-electroencephalographic (EEG) monitoring, neurological and psychiatry assessments, invasive EEG, and the subtraction of ictal-interictal SPECT coregistered to magnetic resonance imaging (MRI) (SISCOM). The analysis of the PMG cortex, using SISCOM, revealed intense hyperperfusion in the polymicrogyric lesion during epileptic seizures in all patients. Interestingly, other localizing investigations showed heterogeneous findings. Twelve patients underwent epilepsy surgery, three achieved seizure-freedom, five have worthwhile improvement, and four patients remained unchanged. Our study strongly suggests the involvement of PMG in seizure generation or early propagation. Both conventional ictal single-photon emission computed tomography (SPECT) and SISCOM appeared as the single contributive exam to suggest the localization of the epileptogenic zone. Despite the limited number of resective epilepsy surgery in our study (n = 9), we found a strong prognostic role of SISCOM in predicting surgical outcome. This result may be of great value on surgical decision-making of whether or not the whole or part of the PMG lesion should be surgically resected. (orig.)

  17. X-ray tomographic apparatus

    International Nuclear Information System (INIS)

    Walters, R.G.

    1982-01-01

    An x-ray tomographic system consists of a radiation source such as gamma or x radiation which produces a fan-shaped beam. The fan is wide enough to encompass the patient circle. The system further includes means for rotating the radiation source about the patient for less than a full rotation, and detectors for detecting the radiation at positions that surround the patient by 180 0 plus the angle of the fan beam plus the angle between adjacent fan detectors. Attenuation data from the detectors is sorted into detector fans of attenuation data, then processed. The convolved data is back-projected into an image memory and displayed on a video monitor

  18. Tomographic anthropomorphic models. Pt. 1

    International Nuclear Information System (INIS)

    Veit, R.; Zankl, M.; Petoussi, N.; Mannweiler, E.; Drexler, G.; Williams, G.

    1989-01-01

    The first generation of heterogenoeous anthropomorphic mathematical models to be used in dose calculations was the MIRD-5 adult phantom, followed by the pediatric MIRD-type phantoms and by the GSF sex-specific phantoms ADAM and EVA. A new generation of realistic anthropomorphic models is now introduced. The organs and tissues of these models consist of a well defined number of volume elements (voxels), derived from computer tomographic (CT) data; consequently, these models were named voxel or tomographic models. So far two voxel models of real patients are available: one of an 8 week old baby and of a 7 year old child. For simplicity, the model of the baby will be referred to as BABY and that of the child as CHILD. In chapter 1 a brief literature review is given on the existing mathematical models and their applications. The reasons that lead to the construction of the new CT models is discussed. In chapter 2 the technique is described which allows to convert any physical object into computer files to be used for dose calculations. The technique which produces three dimensional reconstructions of high resolution is discussed. In chapter 3 the main characteristics of the models of the baby and child are given. Tables of organ masses and volumes are presented together with three dimensional images of some organs and tissues. A special mention is given to the assessment of bone marrow distribution. Chapter 4 gives a short description of the Monte Carlo code used in conjunction with the models to calculate organ and tissue doses resulting from photon exposures. Some technical details concerning the computer files which describe the models are also given. (orig./HP)

  19. Tomographical properties of uniformly redundant arrays

    International Nuclear Information System (INIS)

    Cannon, T.M.; Fenimore, E.E.

    1978-01-01

    Recent work in coded aperture imaging has shown that the uniformly redundant array (URA) can image distant planar radioactive sources with no artifacts. The performance of two URA apertures when used in a close-up tomographic imaging system is investigated. It is shown that a URA based on m sequences is superior to one based on quadratic residues. The m sequence array not only produces less obnoxious artifacts in tomographic imaging, but is also more resilient to some described detrimental effects of close-up imaging. It is shown that in spite of these close-up effects, tomographic depth resolution increases as the source is moved closer to the detector

  20. Volitional Control of Neuromagnetic Coherence

    Directory of Open Access Journals (Sweden)

    Matthew D Sacchet

    2012-12-01

    Full Text Available Coherence of neural activity between circumscribed brain regions has been implicated as an indicator of intracerebral communication in various cognitive processes. While neural activity can be volitionally controlled with neurofeedback, the volitional control of coherence has not yet been explored. Learned volitional control of coherence could elucidate mechanisms of associations between cortical areas and its cognitive correlates and may have clinical implications. Neural coherence may also provide a signal for brain-computer interfaces (BCI. In the present study we used the Weighted Overlapping Segment Averaging (WOSA method to assess coherence between bilateral magnetoencephalograph (MEG sensors during voluntary digit movement as a basis for BCI control. Participants controlled an onscreen cursor, with a success rate of 124 of 180 (68.9%, sign-test p < 0.001 and 84 out of 100 (84%, sign-test p < 0.001. The present findings suggest that neural coherence may be volitionally controlled and may have specific behavioral correlates.

  1. Computerized tomographic studies in cerebral palsy

    International Nuclear Information System (INIS)

    Sugie, Yoko

    1981-01-01

    Computed tomographic (CT) findings in 200 children with cerebral palsy (CP) were analysed from the viewpoint of clinical manifestations, disease complications and etiological factors. CT scans of 135 cases (67.5%) were found to be abnormal and there were 14 (7%) borderline cases. The major abnormality found on CT scans was cerebral atrophy. Other important changes included focal or diffuse low density area in the brain tissue, congenital malformation, and cerebellar atrophy. From the clinical point of view, a large number of patients with spastic tetraplegia and spastic diplegia showed highly abnormal CT scans. On the other hand, in patients with spastic monoplegia, spastic paraplegia, and athetotic type, CT findings were normal or revealed only minor cerebral atrophy. Most children showing asymmetric clinical symptoms had corresponding asymmetric CT abnormalities which included ventricular enlargement, low density area in the brain tissue, and hemispherical volume. There was a significant correlation between the severity of physical impairment and the extent of CT abnormalities. Severely affected children had grossly abnormal CT scans such as hydranencephaly, polycystic change, and extensive cerebral atrophy. In the patients complicated with epilepsy, the incidence and severity of abnormal CT were higher than those of non-epileptic patients. Mentally retarded patients had variable enlargement of the subarachnoidal space depending on the severity of their mental retardation. Patients with suspected postnatal etiology also had high incidence of severe CT abnormality. CT scan is a valuable tool for evaluating patients with CP and in some cases, possible etiology of the disease may be discovered. (author)

  2. From tomographic images to fault heterogeneities

    Directory of Open Access Journals (Sweden)

    A. Amato

    1994-06-01

    Full Text Available Local Earthquake Tomography (LET is a useful tool for imaging lateral heterogeneities in the upper crust. The pattern of P- and S-wave velocity anomalies, in relation to the seismicity distribution along active fault zones. can shed light on the existence of discrete seismogenic patches. Recent tomographic studies in well monitored seismic areas have shown that the regions with large seismic moment release generally correspond to high velocity zones (HVZ's. In this paper, we discuss the relationship between the seismogenic behavior of faults and the velocity structure of fault zones as inferred from seismic tomography. First, we review some recent tomographic studies in active strike-slip faults. We show examples from different segments of the San Andreas fault system (Parkfield, Loma Prieta, where detailed studies have been carried out in recent years. We also show two applications of LET to thrust faults (Coalinga, Friuli. Then, we focus on the Irpinia normal fault zone (South-Central Italy, where a Ms = 6.9 earthquake occurred in 1980 and many thousands of attershock travel time data are available. We find that earthquake hypocenters concentrate in HVZ's, whereas low velocity zones (LVZ’ s appear to be relatively aseismic. The main HVZ's along which the mainshock rupture bas propagated may correspond to velocity weakening fault regions, whereas the LVZ's are probably related to weak materials undergoing stable slip (velocity strengthening. A correlation exists between this HVZ and the area with larger coseismic slip along the fault, according to both surface evidence (a fault scarp as high as 1 m and strong ground motion waveform modeling. Smaller wave-length, low-velocity anomalies detected along the fault may be the expression of velocity strengthening sections, where aseismic slip occurs. According to our results, the rupture at the nucleation depth (~ 10-12 km is continuous for the whole fault lenoth (~ 30 km, whereas at shallow depth

  3. Compact Positron Tomograph for Prostate Imaging

    National Research Council Canada - National Science Library

    Huber, Jennifer

    2004-01-01

    The goal of this project is to construct a functioning compact positron tomograph, whose geometry is optimized for detecting prostate tumors with molecular tracers such as 11Ccholine (carbon-11 choline...

  4. Compact Positron Tomograph for Prostate Imaging

    National Research Council Canada - National Science Library

    Huber, Jennifer S

    2005-01-01

    The goal of this project is to construct a functioning compact positron tomograph, whose geometry is optimized for detecting prostate tumors with molecular tracers such as 11Ccholine (carbon-11 choline...

  5. Precision tomographic analysis of reactor fuels

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong Deok; Lee, Chang Hee; Kim, Jong Soo; Jeong, Jwong Hwan; Nam, Ki Yong

    2001-03-01

    For the tomographical assay, search of current status, analysis of neutron beam characteristics, MCNP code simulation, sim-fuel fabrication, neutron experiment for sim-fuel, multiaxes operation system design were done. In sensitivity simulation, the reconstruction results showed the good agreement. Also, the scoping test at ANL was very helpful for actual assay. Therefore, the results are applied for HANARO tomographical system setup and consecutive next research.

  6. Precision tomographic analysis of reactor fuels

    International Nuclear Information System (INIS)

    Lee, Yong Deok; Lee, Chang Hee; Kim, Jong Soo; Jeong, Jwong Hwan; Nam, Ki Yong

    2001-03-01

    For the tomographical assay, search of current status, analysis of neutron beam characteristics, MCNP code simulation, sim-fuel fabrication, neutron experiment for sim-fuel, multiaxes operation system design were done. In sensitivity simulation, the reconstruction results showed the good agreement. Also, the scoping test at ANL was very helpful for actual assay. Therefore, the results are applied for HANARO tomographical system setup and consecutive next research

  7. Dynamic coherent backscattering mirror

    Energy Technology Data Exchange (ETDEWEB)

    Zeylikovich, I.; Xu, M., E-mail: mxu@fairfield.edu [Physics Department, Fairfield University, Fairfield, CT 06824 (United States)

    2016-02-15

    The phase of multiply scattered light has recently attracted considerable interest. Coherent backscattering is a striking phenomenon of multiple scattered light in which the coherence of light survives multiple scattering in a random medium and is observable in the direction space as an enhancement of the intensity of backscattered light within a cone around the retroreflection direction. Reciprocity also leads to enhancement of backscattering light in the spatial space. The random medium behaves as a reciprocity mirror which robustly converts a diverging incident beam into a converging backscattering one focusing at a conjugate spot in space. Here we first analyze theoretically this coherent backscattering mirror (CBM) phenomenon and then demonstrate the capability of CBM compensating and correcting both static and dynamic phase distortions occurring along the optical path. CBM may offer novel approaches for high speed dynamic phase corrections in optical systems and find applications in sensing and navigation.

  8. Retinal pigment epithelial changes in chronic Vogt-Koyanagi-Harada disease: fundus autofluorescence and spectral domain-optical coherence tomography findings.

    Science.gov (United States)

    Vasconcelos-Santos, Daniel V; Sohn, Elliott H; Sadda, Srinivas; Rao, Narsing A

    2010-01-01

    The purpose of this study was to determine whether fundus autofluorescence (FAF) and spectral domain-optical coherence tomography (SD-OCT) imaging allow better assessment of retinal pigment epithelium and the outer retina in subjects with chronic Vogt-Koyanagi-Harada disease compared with examination and angiography alone. A cross-sectional analysis of a series of seven consecutive patients with chronic Vogt-Koyanagi-Harada disease undergoing FAF and SD-OCT was conducted. Chronic disease was defined as duration of intraocular inflammation >3 months. Color fundus photographs were correlated to FAF and SD-OCT images. The images were later correlated to fluorescein angiography and indocyanine green angiography. All patients had sunset glow fundus, which resulted in no apparent corresponding abnormality on FAF or SD-OCT. Lesions with decreased autofluorescence signal were observed in 11 eyes (85%), being associated with loss of the retinal pigment epithelium and involvement of the outer retina on SD-OCT. In 5 eyes (38%), some of these lesions were very subtle on clinical examination but easily detected by FAF. Lesions with increased autofluorescence signal were seen in 8 eyes (61.5%), showing variable involvement of the outer retina on SD-OCT and corresponding clinically to areas of retinal pigment epithelium proliferation and cystoid macular edema. Combined use of FAF and SD-OCT imaging allowed noninvasive delineation of retinal pigment epithelium/outer retina changes in patients with chronic Vogt-Koyanagi-Harada disease, which were consistent with previous histopathologic reports. Some of these changes were not apparent on clinical examination.

  9. On a novel low cost high accuracy experimental setup for tomographic particle image velocimetry

    International Nuclear Information System (INIS)

    Discetti, Stefano; Ianiro, Andrea; Astarita, Tommaso; Cardone, Gennaro

    2013-01-01

    This work deals with the critical aspects related to cost reduction of a Tomo PIV setup and to the bias errors introduced in the velocity measurements by the coherent motion of the ghost particles. The proposed solution consists of using two independent imaging systems composed of three (or more) low speed single frame cameras, which can be up to ten times cheaper than double shutter cameras with the same image quality. Each imaging system is used to reconstruct a particle distribution in the same measurement region, relative to the first and the second exposure, respectively. The reconstructed volumes are then interrogated by cross-correlation in order to obtain the measured velocity field, as in the standard tomographic PIV implementation. Moreover, differently from tomographic PIV, the ghost particle distributions of the two exposures are uncorrelated, since their spatial distribution is camera orientation dependent. For this reason, the proposed solution promises more accurate results, without the bias effect of the coherent ghost particles motion. Guidelines for the implementation and the application of the present method are proposed. The performances are assessed with a parametric study on synthetic experiments. The proposed low cost system produces a much lower modulation with respect to an equivalent three-camera system. Furthermore, the potential accuracy improvement using the Motion Tracking Enhanced MART (Novara et al 2010 Meas. Sci. Technol. 21 035401) is much higher than in the case of the standard implementation of tomographic PIV. (paper)

  10. Tomographic PIV: particles versus blobs

    International Nuclear Information System (INIS)

    Champagnat, Frédéric; Cornic, Philippe; Besnerais, Guy Le; Plyer, Aurélien; Cheminet, Adam; Leclaire, Benjamin

    2014-01-01

    We present an alternative approach to tomographic particle image velocimetry (tomo-PIV) that seeks to recover nearly single voxel particles rather than blobs of extended size. The baseline of our approach is a particle-based representation of image data. An appropriate discretization of this representation yields an original linear forward model with a weight matrix built with specific samples of the system’s point spread function (PSF). Such an approach requires only a few voxels to explain the image appearance, therefore it favors much more sparsely reconstructed volumes than classic tomo-PIV. The proposed forward model is general and flexible and can be embedded in a classical multiplicative algebraic reconstruction technique (MART) or a simultaneous multiplicative algebraic reconstruction technique (SMART) inversion procedure. We show, using synthetic PIV images and by way of a large exploration of the generating conditions and a variety of performance metrics, that the model leads to better results than the classical tomo-PIV approach, in particular in the case of seeding densities greater than 0.06 particles per pixel and of PSFs characterized by a standard deviation larger than 0.8 pixels. (paper)

  11. Computed tomographic findings of splenic injury and correlation with treatment

    International Nuclear Information System (INIS)

    Kim, Dong Jin; Koh, Joo Yaul; Kim, Myung Soon; Hong, In Soo; Cho, Whi Youl; Sung, Ki Joon

    1990-01-01

    According to recently reported classification, 46 patients with blunt splenic trauma were evaluate preoperatively with computed tomography(CT). Injures were graded I through IV and describe as capsular or subcapsular disruptions without parenchymal injury(3 patients); capsular and parenchymal injuries(23 patients); injuries involving hilum(3 patients); and fragmentation(17 patients). Nineteen patients were managed conservatively and 27 patients were managed surgically. Twelve patients(47%) out of those with Type I or Type II were managed surgically including five hemodynamically unstable patients and seven hemodynamically stable patients with associated injuries and unknown surgical criteria. On the other hand hemodynamically stable patients(25%) out of those with Type III or Type IV were managed surgically. The amount of hemoperitoneum was graded into small, moderate and large; small in three patients, moderate in 39 patients, and large in two patients. The amount of hemoperitoneum in patients with conservative treatment was moderate in 16 patients and large in one patient. And the amount of hemoperitoneum in patients with operative treatment was small in three patients, moderate in 23 patients and large in one patient. We concluded that CT was accurate method of determining the extent of splenic injury and evaluation of hemoperitoneum, but treatment choice should be based on the hemodynamic status of patients rather than the type of injury or the amount of hemoperitoneum by CT

  12. Computed tomographic findings of splenic injury and correlation with treatment

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Jin; Koh, Joo Yaul; Kim, Myung Soon; Hong, In Soo; Cho, Whi Youl; Sung, Ki Joon [Yonsei University Wonju College of Medicine, Wonju (Korea, Republic of)

    1990-12-15

    According to recently reported classification, 46 patients with blunt splenic trauma were evaluate preoperatively with computed tomography(CT). Injures were graded I through IV and describe as capsular or subcapsular disruptions without parenchymal injury(3 patients); capsular and parenchymal injuries(23 patients); injuries involving hilum(3 patients); and fragmentation(17 patients). Nineteen patients were managed conservatively and 27 patients were managed surgically. Twelve patients(47%) out of those with Type I or Type II were managed surgically including five hemodynamically unstable patients and seven hemodynamically stable patients with associated injuries and unknown surgical criteria. On the other hand hemodynamically stable patients(25%) out of those with Type III or Type IV were managed surgically. The amount of hemoperitoneum was graded into small, moderate and large; small in three patients, moderate in 39 patients, and large in two patients. The amount of hemoperitoneum in patients with conservative treatment was moderate in 16 patients and large in one patient. And the amount of hemoperitoneum in patients with operative treatment was small in three patients, moderate in 23 patients and large in one patient. We concluded that CT was accurate method of determining the extent of splenic injury and evaluation of hemoperitoneum, but treatment choice should be based on the hemodynamic status of patients rather than the type of injury or the amount of hemoperitoneum by CT.

  13. Computed tomographic findings of early subacute sclerosing panencephalitis

    International Nuclear Information System (INIS)

    Pedersen, H.; Wulff, C.H.; Rigshospitalet, Copenhagen

    1982-01-01

    Computed tomography of the brain (CT) was carried out at the early stages of subacute sclerosing panencephalitis (SSPE) in three children. The lateral ventricles were very small and the hemispheric sulci and interhemispheric fissures were not visible in all three patients in contrast to severe atrophy found at a later stage in one patient. The early CT abnormalities were revealed at the same time as the titres of measles antibodies in blood and cerebrospinal fluid were elevated, and the characteristic periodic complexes in the electroencephalogram established the diagnosis of SSPE. The CT changes indicating brain swelling reflect the reactive changes of this slow virus infection. (orig.)

  14. Dynamic enhanced computed tomographic findings of a perirenal capillary hemangioma

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jung Min; Kim, Sang Won; Kim, Hyun Cheol; Yang, Dal Mo; Ryu, Jung Kyu; Lim, Sung Jig [Kyung Hee University Hospital at Gangdong, Seoul (Korea, Republic of)

    2016-05-15

    Hemangiomas are benign mesenchymal neoplasms that rarely occur in the kidney and perirenal space. Perirenal hemangiomas can mimic the appearance of exophytic renal cell carcinoma or various retroperitoneal tumors. We report a case of perirenal hemangioma detected by dynamic enhanced computed tomography in a 43-year-old female.

  15. Coherence and Sense of Coherence

    DEFF Research Database (Denmark)

    Dau, Susanne

    2014-01-01

    Constraints in the implementation of models of blended learning can be explained by several causes, but in this paper, it is illustrated that lack of sense of coherence is a major factor of these constraints along with the referential whole of the perceived learning environments. The question exa...

  16. Emerging tomographic methods within the petroleum industry

    International Nuclear Information System (INIS)

    Johansen, Geir Anton

    2013-01-01

    Since industrial process tomography was introduced as a concept almost two decades ago, the considerable progress within a large variety of sensing modalities has to a large extent been technology driven. Industrial tomography applications may be divided into three categories: 1) Laboratory systems, 2) Field equipment for diagnostics and mapping purposes, and 3) Permanently installed systems. Examples on emerging methods on all categories will be presented, either from R and D at the University of Bergen and/or our industrial partners. Most developments are within the first category, where tomographs are used to provide better understanding of various processes such as pipe flow, separators, mixers and reactors. Here tomographic data is most often used to provide better process knowledge, for reference measurements and validation and development of process models, and finally for development for instruments and process equipment. The requirement here may be either high spatial resolution or high temporal resolution, or combinations of these. Tomographic field measurements are applied to either to inspect processes or equipment on a regular base or at faulty or irregular operation, or to map multicomponent systems such petroleum reservoirs, their structure and the distribution gas, oil and water within them. The latter will only be briefly touched upon here. Tomographic methods are increasingly being used for process and equipment diagnostics. The requirements vary and solutions based on repetition of single measurements, such as in column scanning, to full tomographic systems where there is sufficiently space or access. The third category is tomographic instruments that are permanently installed in situ in a process. These need not provide full tomographic images and instruments with fewer views are often preferred to reduce complexity and increase the instrument reliability. (author)

  17. Computed tomographic study of 50 patients with hypodense hepatic injuries in childhood

    International Nuclear Information System (INIS)

    Pereira, Ines Minniti Rodrigues; Alvares, Beatriz Regina; Baracat, Jamal; Martins, Daniel Lahan; Pereira, Ricardo Minniti Rodrigues

    2006-01-01

    Objective: To describe the different tomographic findings in hypodense hepatic lesions in children and its differential diagnosis. Materials and methods: computed tomographic studies were obtained from 50 patients (age range: 0-16 years) with low-density liver lesions previously diagnosed by ultrasound. Images were made before and after administration of intravenous contrast medium. Image findings were analyzed and afterwards correlated with anatomopathological diagnosis. Results: forty-seven of 50 cases were confirmed, 30 by anatomopathological diagnosis. Most of then were benign lesions, hemangioma in 20%. Such lesions presented a homogeneous contrast absorption, mainly at the delayed phase, differing from malignant lesions. Metastasis was the most frequently found malignant lesion (18%). Conclusion: computed tomographic study is of great value in complementing the diagnosis of hypodense hepatic lesions in children, and must follow ultrasound diagnosis as a routine procedure. (author)

  18. Development of an integrated optical coherence tomography-gas nozzle system for surgical laser ablation applications: preliminary findings of in situ spinal cord deformation due to gas flow effects.

    Science.gov (United States)

    Wong, Ronnie; Jivraj, Jamil; Vuong, Barry; Ramjist, Joel; Dinn, Nicole A; Sun, Cuiru; Huang, Yize; Smith, James A; Yang, Victor X D

    2015-01-01

    Gas assisted laser machining of materials is a common practice in the manufacturing industry. Advantages in using gas assistance include reducing the likelihood of flare-ups in flammable materials and clearing away ablated material in the cutting path. Current surgical procedures and research do not take advantage of this and in the case for resecting osseous tissue, gas assisted ablation can help minimize charring and clear away debris from the surgical site. In the context of neurosurgery, the objective is to cut through osseous tissue without damaging the underlying neural structures. Different inert gas flow rates used in laser machining could cause deformations in compliant materials. Complications may arise during surgical procedures if the dura and spinal cord are damaged by these deformations. We present preliminary spinal deformation findings for various gas flow rates by using optical coherence tomography to measure the depression depth at the site of gas delivery.

  19. Introduction to curved rotary tomographic apparatus 'TOMOREX'

    International Nuclear Information System (INIS)

    Kubota, Kazuo; Shinojima, Masayasu; Kohirasawa, Hideo; Tokui, Mitsuru

    1980-01-01

    In recent years, panorama X-ray photographic method is widely used for the X-ray diagnosis of teeth, jawbones and faces. One type based on the principle of tomography is curved surface rotary tomographic method utilizing fine-gap X-ray beam. With the synchronous rotation of an X-ray tube and a photographic film around a face, describing a U-shaped tomographic plane along a dental arch, an upper or lower jawbone is photographed. In the ''TOMOREX'' belonging to this type, is different tomographic planes are available, so that by selecting any position in advance, the part can be photographed. Furthermore, patients can be subjected to examination as laid on a stretcher. The mechanism and equipment, and the photographic method for eye sockets, cheekbones, upper jaw cavities and stereoscopic images are described. (J.P.N.)

  20. First experience with a mobile computed tomograph in the USSR

    International Nuclear Information System (INIS)

    Portnoj, L.M.

    1989-01-01

    Utilization experience of mobile computerized tomograph mounted in the bus is presented. Problems concerning staff, selection of medical base institutes etc are considered. Efficiency of mobile computerized tomographes in revealing different diseases is pointed out

  1. Coherent Baryogenesis

    CERN Document Server

    Garbrecht, B; Schmidt, M G; Garbrecht, Bjorn; Prokopec, Tomislav; Schmidt, Michael G.

    2004-01-01

    We propose a new baryogenesis scenario based on coherent production and mixing of different fermionic species. The mechanism is operative during phase transitions, at which the fermions acquire masses via Yukawa couplings to scalar fields. Baryon production is efficient when the mass matrix is nonadiabatically varying, nonsymmetric and when it violates CP and B-L directly, or some other charges that are eventually converted to B-L. We first consider a toy model, which involves two mixing fermionic species, and then a hybrid inflationary scenario embedded in a supersymmetric Pati-Salam GUT. We show that, quite generically, a baryon excess in accordance with observation can result.

  2. Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Pier Alberto Testoni

    2007-01-01

    Full Text Available Optical coherence tomography (OCT is an optical imaging modality that performs high-resolution, cross-sectional, subsurface tomographic imaging of the microstructure of tissues. The physical principle of OCT is similar to that of B-mode ultrasound imaging, except that it uses infrared light waves rather than acoustic waves. The in vivo resolution is 10–25 times better (about 10 µm than with high-frequency ultrasound imaging, but the depth of penetration is limited to 1–3 mm, depending on tissue structure, depth of focus of the probe used, and pressure applied to the tissue surface. In the last decade, OCT technology has evolved from an experimental laboratory tool to a new diagnostic imaging modality with a wide spectrum of clinical applications in medical practice, including the gastrointestinal tract and pancreatico-biliary ductal system. OCT imaging from the gastrointestinal tract can be done in humans by using narrow-diameter, catheter-based probes that can be inserted through the accessory channel of either a conventional front-view endoscope, for investigating the epithelial structure of the gastrointestinal tract, or a side-view endoscope, inside a standard transparent ERCP (endoscopic retrograde cholangiopancreatography catheter, for investigating the pancreatico-biliary ductal system. The esophagus and esophagogastric junction have been the most widely investigated organs so far; more recently, duodenum, colon, and the pancreatico-biliary ductal system have also been extensively investigated. OCT imaging of the gastrointestinal wall structure is characterized by a multiple-layer architecture that permits an accurate evaluation of the mucosa, lamina propria, muscularis mucosae, and part of the submucosa. The technique may therefore be used to identify preneoplastic conditions of the gastrointestinal tract, such as Barrett's epithelium and dysplasia, and evaluate the depth of penetration of early-stage neoplastic lesions. OCT imaging

  3. Arbitrary layer tomographic method and apparatus

    International Nuclear Information System (INIS)

    Kato, H.; Ishida, M.

    1984-01-01

    Many two-dimensional X-ray projection distribution images obtained by exposing an object to X-rays in various directions are once stored in positions different from one another in a stimulable phosphor sheet or respectively in many stimulable phosphor sheets. The stimulable phosphor sheet or sheets are then scanned with stimulating rays, and the light emitted thereby from the stimulable phosphor sheet or sheets is photoelectrically read out to obtain electric signals representing the X-ray projection distribution images. The electric signals are processed to obtain a tomographic image of an arbitrary tomographic layer of the object

  4. Directly Measuring the Degree of Quantum Coherence using Interference Fringes

    Science.gov (United States)

    Wang, Yi-Tao; Tang, Jian-Shun; Wei, Zhi-Yuan; Yu, Shang; Ke, Zhi-Jin; Xu, Xiao-Ye; Li, Chuan-Feng; Guo, Guang-Can

    2017-01-01

    Quantum coherence is the most distinguished feature of quantum mechanics. It lies at the heart of the quantum-information technologies as the fundamental resource and is also related to other quantum resources, including entanglement. It plays a critical role in various fields, even in biology. Nevertheless, the rigorous and systematic resource-theoretic framework of coherence has just been developed recently, and several coherence measures are proposed. Experimentally, the usual method to measure coherence is to perform state tomography and use mathematical expressions. Here, we alternatively develop a method to measure coherence directly using its most essential behavior—the interference fringes. The ancilla states are mixed into the target state with various ratios, and the minimal ratio that makes the interference fringes of the "mixed state" vanish is taken as the quantity of coherence. We also use the witness observable to witness coherence, and the optimal witness constitutes another direct method to measure coherence. For comparison, we perform tomography and calculate l1 norm of coherence, which coincides with the results of the other two methods in our situation. Our methods are explicit and robust, providing a nice alternative to the tomographic technique.

  5. Tomographic analysis of CBF in cerebral infarction

    International Nuclear Information System (INIS)

    Segawa, Hiromu; Kimura, Kazumoto; Ueda, Yuichi; Nagai, Masakatsu; Yoshimasu, Norio.

    1983-01-01

    Cerebral perfusion was examined in various types of occlusive disease by computed tomographic CBF method. The method utilized has several advantages over conventional studies using isotope, providing high resolution images in a direct relation to CT anatomy. Ten representative cases were presented from 25 consective cases of occlusive disease studied by this method. The method included inhalation of 40 to 60% xenon with serial CT scanning for 25 min. K (build-up rate), lambda (partition coefficient) and CBF values were calculated from ΔHU for each pixel and ΔXe in expired air, based on Fick's principle, and displayed on CRT as K-, lambda- and CBF-map separately. CBF for gray matter of normal control was 82 +- 11 ml/100 gm/min and that for white matter was 24 +- 5 ml/100 gm/min. The ischemic threshold for gray matter appeared to be approximately 20 ml/100 gm/min, as blood flow in focus of complete infarction was below this level. Blood flow between 20 - 30 ml/ 100 gm/min caused some change on CT, such as localized atrophy, cortical thinning, loss of distinction between gray and white matter and decreased or increased density, which were considered to be compatible with pathological changes of laminar necrosis or gliosis with neuronal loss. In a case with occlusion of middle cerebral artery with subsequent recanalization, causing hemorrhagic infarct, hyperemia was observed in the infarcted cortex that was enhanced by iodine. Periventricular lucency observed in two cases, where blood flow was decreased below threshold, could be classified as ''watershed infarction'' mainly involving white matter. In moyamoya disease, blood flow in the anterior circulation was decreased near ischemic level, whereas that in basal ganglia and territory of posterior cerebral artery was fairly preserved, which was compatible with general angiographic finding of this disease. (author)

  6. Quantum coherence and correlations in quantum system

    Science.gov (United States)

    Xi, Zhengjun; Li, Yongming; Fan, Heng

    2015-01-01

    Criteria of measure quantifying quantum coherence, a unique property of quantum system, are proposed recently. In this paper, we first give an uncertainty-like expression relating the coherence and the entropy of quantum system. This finding allows us to discuss the relations between the entanglement and the coherence. Further, we discuss in detail the relations among the coherence, the discord and the deficit in the bipartite quantum system. We show that, the one-way quantum deficit is equal to the sum between quantum discord and the relative entropy of coherence of measured subsystem. PMID:26094795

  7. A novel clinical multimodal multiphoton tomograph for AF, SHG, CARS imaging, and FLIM

    Science.gov (United States)

    Weinigel, Martin; Breunig, Hans Georg; König, Karsten

    2014-02-01

    We report on a flexible nonlinear medical tomograph with multiple miniaturized detectors for simultaneous acquisition of two-photon autofluorescence (AF), second harmonic generation (SHG) and coherent anti-Stokes Raman scattering (CARS) images. The simultaneous visualization of the distribution of endogenous fluorophores NAD(P)H, melanin and elastin, SHG-active collagen and as well as non-fluorescent lipids within human skin in vivo is possible. Furthermore, fluorescence lifetime images (FLIM) can be generated using time-correlated single photon counting.

  8. Computed tomographic appearances of sternocostoclavicular hyperostosis

    Energy Technology Data Exchange (ETDEWEB)

    Chigira, Masaki; Shimizu, Toru (Gunma Univ. (Japan). Dept. of Orthopaedic Surgery)

    1989-08-01

    Computed tomographical analysis of sternocostoclavicular hyperostosis was performed in 27 patients. In the earliest stage hyperostosis occurred around the cartilaginous portion of the first ribs. The sternoclavicular joint space was preserved even in the late stage III of the disorder. It is also suggested that perichondritis and periostitis play important roles in the etiology of this disorder. (orig./GDG).

  9. Computed tomographic appearances of sternocostoclavicular hyperostosis

    International Nuclear Information System (INIS)

    Chigira, Masaki; Shimizu, Toru

    1989-01-01

    Computed tomographical analysis of sternocostoclavicular hyperostosis was performed in 27 patients. In the earliest stage hyperostosis occurred around the cartilaginous portion of the first ribs. The sternoclavicular joint space was preserved even in the late stage III of the disorder. It is also suggested that perichondritis and periostitis play important roles in the etiology of this disorder. (orig./GDG)

  10. Tomographic image reconstruction using training images

    DEFF Research Database (Denmark)

    Soltani, Sara; Andersen, Martin Skovgaard; Hansen, Per Christian

    2017-01-01

    We describe and examine an algorithm for tomographic image reconstruction where prior knowledge about the solution is available in the form of training images. We first construct a non-negative dictionary based on prototype elements from the training images; this problem is formulated within...

  11. Photon emission tomographic apparatus and method

    International Nuclear Information System (INIS)

    Blum, A.S.

    1983-01-01

    Tomographic imaging system employs large area, collimated scintillation detector rotated around radiation emitting subject. Detector support rotates with an inner ring inside a stationary outer ring. Counterbalanced detector support arm is forced by spring action to cause collimator face to follow body contour as detector rotates around the body, thereby reducing collimator to subject distance to improve system resolution. Includes adjustable subject support system

  12. Case Report: Unusual computed tomographic features of ...

    African Journals Online (AJOL)

    A case report of a 57-year old woman who presented with signs and symptoms of intracranial mass. Computed tomographic (CT) and clinical features were unusual and suggestive of a parasaggital Meningioma. However an accurate diagnosis of a tuberculoma was made at surgery and histopathological examination.

  13. Quantum probability measures and tomographic probability densities

    NARCIS (Netherlands)

    Amosov, GG; Man'ko, [No Value

    2004-01-01

    Using a simple relation of the Dirac delta-function to generalized the theta-function, the relationship between the tomographic probability approach and the quantum probability measure approach with the description of quantum states is discussed. The quantum state tomogram expressed in terms of the

  14. The bar coil for NMR tomograph

    International Nuclear Information System (INIS)

    Bogorodzki, P.; Piatkowski, A.; Wasielewski, J.

    1995-01-01

    The bar coil (bi-planar) for the NMR tomograph, designed for medical diagnostics, has been described. The tests of coil shown that it generates good homogenous magnetic field in a big volume what results in improving of the signal-to-noise ratio

  15. Decomposition of time-resolved tomographic PIV

    NARCIS (Netherlands)

    Schmid, P.J.; Violato, D.; Scarano, F.

    2012-01-01

    An experimental study has been conducted on a transitional water jet at a Reynolds number of Re = 5,000. Flow fields have been obtained by means of time-resolved tomographic particle image velocimetry capturing all relevant spatial and temporal scales. The measured threedimensional flow fields have

  16. Connections model for tomographic images reconstruction

    International Nuclear Information System (INIS)

    Rodrigues, R.G.S.; Pela, C.A.; Roque, S.F. A.C.

    1998-01-01

    This paper shows an artificial neural network with an adequately topology for tomographic image reconstruction. The associated error function is derived and the learning algorithm is make. The simulated results are presented and demonstrate the existence of a generalized solution for nets with linear activation function. (Author)

  17. Results of work of neurological clinic in first year of computer tomograph application

    Energy Technology Data Exchange (ETDEWEB)

    Volejnik, V; Nettl, S; Heger, L [Karlova Univ., Hradec Kralove (Czechoslovakia). Lekarska Fakulta

    1980-11-01

    The results are analyzed of one year's use of a computer tomograph (CT) by a department of neurology. Detailed comparisons with corresponding PEG and CT findings showed the accuracy of CT examinations in the descriptions of the width of the subarachnoid spaces and of the ventricular system. The advantages of CT are assessed from the medical, economic, and ethical points of view.

  18. Results of work of neurological clinic in first year of computer tomograph application

    International Nuclear Information System (INIS)

    Volejnik, V.; Nettl, S.; Heger, L.

    1980-01-01

    The results are analyzed of one year's use of a computer tomograph (CT) by a department of neurology. Detailed comparisons with corresponding PEG and CT findings showed the accuracy of CT examinations in the descriptions of the width of the subarachnoid spaces and of the ventricular system. The advantages of CT are assessed from the medical, economic, and ethical points of view. (author)

  19. Dense velocity reconstruction from tomographic PTV with material derivatives

    Science.gov (United States)

    Schneiders, Jan F. G.; Scarano, Fulvio

    2016-09-01

    A method is proposed to reconstruct the instantaneous velocity field from time-resolved volumetric particle tracking velocimetry (PTV, e.g., 3D-PTV, tomographic PTV and Shake-the-Box), employing both the instantaneous velocity and the velocity material derivative of the sparse tracer particles. The constraint to the measured temporal derivative of the PTV particle tracks improves the consistency of the reconstructed velocity field. The method is christened as pouring time into space, as it leverages temporal information to increase the spatial resolution of volumetric PTV measurements. This approach becomes relevant in cases where the spatial resolution is limited by the seeding concentration. The method solves an optimization problem to find the vorticity and velocity fields that minimize a cost function, which includes next to instantaneous velocity, also the velocity material derivative. The velocity and its material derivative are related through the vorticity transport equation, and the cost function is minimized using the limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) algorithm. The procedure is assessed numerically with a simulated PTV experiment in a turbulent boundary layer from a direct numerical simulation (DNS). The experimental validation considers a tomographic particle image velocimetry (PIV) experiment in a similar turbulent boundary layer and the additional case of a jet flow. The proposed technique (`vortex-in-cell plus', VIC+) is compared to tomographic PIV analysis (3D iterative cross-correlation), PTV interpolation methods (linear and adaptive Gaussian windowing) and to vortex-in-cell (VIC) interpolation without the material derivative. A visible increase in resolved details in the turbulent structures is obtained with the VIC+ approach, both in numerical simulations and experiments. This results in a more accurate determination of the turbulent stresses distribution in turbulent boundary layer investigations. Data from a jet

  20. Tomographic study of temporomandibular joints before orthodontic treatment

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Ki Jeong [Kyung Hee Univ. College of Dentistry, Seoul (Korea, Republic of)

    2001-12-15

    To determine whether there is a relationship between abnormal temporomandibular joint radiographic findings and age or gender in a sample of preorthodontic patients. Individualized corrected sagittal tomographs of 188 temporomandibular joints in 94 preorthodontic patients, aged 11 to 29 years, were taken and viewed by an observer blinded to clinical records. The study population was divided into 2 aged groups (11-15 years and 16-29 years) for comparative purpose. Temporomandibular joint radiographic findings were classified as normal or abnormal. There was no difference in ratio of abnormal to normal findings between the both aged groups. The frequency of osseous abnormalities was similar with that of abnormalities of condylar position. Abnormalities in CP and JS were most frequent in all aged groups. There is no significant difference between ages or genders for temporomandibular joint radiographic abnormalities.

  1. Entropic cohering power in quantum operations

    Science.gov (United States)

    Xi, Zhengjun; Hu, Ming-Liang; Li, Yongming; Fan, Heng

    2018-02-01

    Coherence is a basic feature of quantum systems and a common necessary condition for quantum correlations. It is also an important physical resource in quantum information processing. In this paper, using relative entropy, we consider a more general definition of the cohering power of quantum operations. First, we calculate the cohering power of unitary quantum operations and show that the amount of distributed coherence caused by non-unitary quantum operations cannot exceed the quantum-incoherent relative entropy between system of interest and its environment. We then find that the difference between the distributed coherence and the cohering power is larger than the quantum-incoherent relative entropy. As an application, we consider the distributed coherence caused by purification.

  2. Tomographic Constraints on High-Energy Neutrinos of Hadronuclear Origin.

    Science.gov (United States)

    Ando, Shin'ichiro; Tamborra, Irene; Zandanel, Fabio

    2015-11-27

    Mounting evidence suggests that the TeV-PeV neutrino flux detected by the IceCube telescope has mainly an extragalactic origin. If such neutrinos are primarily produced by a single class of astrophysical sources via hadronuclear (pp) interactions, a similar flux of gamma-ray photons is expected. For the first time, we employ tomographic constraints to pinpoint the origin of the IceCube neutrino events by analyzing recent measurements of the cross correlation between the distribution of GeV gamma rays, detected by the Fermi satellite, and several galaxy catalogs in different redshift ranges. We find that the corresponding bounds on the neutrino luminosity density are up to 1 order of magnitude tighter than those obtained by using only the spectrum of the gamma-ray background, especially for sources with mild redshift evolution. In particular, our method excludes any hadronuclear source with a spectrum softer than E^{-2.1} as a main component of the neutrino background, if its evolution is slower than (1+z)^{3}. Starburst galaxies, if able to accelerate and confine cosmic rays efficiently, satisfy both spectral and tomographic constraints.

  3. Correlação dos achados tomográficos com parâmetros de função pulmonar na fibrose pulmonar idiopática em não fumantes Correlation of tomographic findings with pulmonary function parameters in nonsmoking patients with idiopathic pulmonary fibrosis

    Directory of Open Access Journals (Sweden)

    Agnaldo José Lopes

    2007-12-01

    Full Text Available OBJETIVO: Correlacionar os achados tomográficos com os parâmetros de função pulmonar em portadores de fibrose pulmonar idiopática (FPI. MÉTODOS: Foi realizado um estudo de corte transversal, em que foram avaliados 30 pacientes não tabagistas, portadores de FPI. Utilizando um sistema de escore semiquantitativo, os seguintes achados na tomografia computadorizada de alta resolução (TCAR foram quantificados: extensão total da doença intersticial (Tot, infiltrado reticular e faveolamento (Ret+Fav, e opacidade em vidro fosco (Vif. As variáveis funcionais foram mensuradas através de espirometria, técnica de oscilações forçadas (TOF, método da diluição com hélio e método da respiração única para medir a capacidade de difusão do monóxido de carbono (DLCO. RESULTADOS: Dos 30 pacientes estudados, 18 eram mulheres e 12 eram homens, com média de idade de 70,9 anos. Foram encontradas correlações significativas de Tot e Ret+Fav com as medidas de capacidade vital forçada (CVF, capacidade pulmonar total (CPT, DLCO e complacência dinâmica do sistema respiratório (correlações negativas, e de Vif com volume residual/CPT (correlação positiva. A relação fluxo expiratório forçado entre 25 e 75% da CVF/CVF (FEF25-75%/CVF correlacionou-se positivamente com Tot, Ret+Fav e Vif. CONCLUSÕES: Em portadores de FPI, as medidas de volume, difusão e complacência dinâmica são as variáveis fisiológicas que melhor refletem a extensão da doença intersticial na TCAR.OBJECTIVE: To correlate tomographic findings with pulmonary function parameters in patients with idiopathic pulmonary fibrosis (IPF. METHODS: A cross-sectional study was carried out, in which 30 nonsmoking patients with IPF were evaluated. Using a semiquantitative scoring system, the following high-resolution computerized tomography (HRCT findings were quantified: total interstitial disease (TID, reticular abnormality/honeycombing, and ground-glass opacity (GGO. The

  4. The Human Mind As General Problem Solver, Is Observed To Find ``Best'' Solutions, That Correspond To Highest Mental Coherence: Will Discuss ``sing Glass Type Theory'' of Princeton Physicist J J Hopfield, Points To How Best Use Our Own Human Mind!!

    Science.gov (United States)

    Gurr, Henry

    2014-03-01

    Princeton Physicist J. J. Hopfield's Mathematical Model of the Mammalian Brain, (Similar To Ising Glass Model of a crystal of magnetic spin particles) says our Brain-Work for Memory, Perception, Language, Thinking, etc, (Even the AHA-EUREKA-Flash Of Insight Type Problem Solving), is achieved by our massively inter-connected CNS Neurons ... working together ... MINIMIZING an analog of physical energy ... thus yielding Optimal Solutions: These ``best'' answers, correspond to highest mental coherence, for most facets organism response, beit mental (eg: perception, memory, ideas, thinking, etc) or physical-muscular-actions (eg speaking, tool using, trail following, etc). Our brain is this way, because living creature, MUST be evolved, so they will find & use the best actions, for survival!!! Our human heritage, is to instantly compute near optimal future plans, (mental & physical-muscular), and be able to accomplish plans reliably & efficiently. If you know of book or articles in these topic areas, please email to HenryG--USCA.edu How to work well, with your own ``self'', called mind-body, will follow!! Conjectures: Who is the ``I'' that appears to make decisions? Am ``I'' the master of my domain? Is there an ``I'' or am ``I'' merely an illusion of reality.

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

    International Nuclear Information System (INIS)

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

    1980-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-06-01

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

  7. Central nervous system leukemia and lymphoma: computed tomographic manifestations

    International Nuclear Information System (INIS)

    Pagani, J.J.; Libshitz, H.I.; Wallace, S.; Hayman, L.A.

    1981-01-01

    Computed tomographic (CT) abnormalities in the brain were identified in 31 of 405 patients with leukemia or lymphoma. Abnormalities included neoplastic masses (15), hemorrhage (nine), abscess (two), other brain tumors (four), and methotrexate leukoencephalopathy (one). CT was normal in 374 patients including 148 with meningeal disease diagnosed by cerebrospinal fluid cytologic examination. Prior to treatment, malignant masses were isodense or of greater density with varying amounts of edema. Increase in size or number of the masses indicated worsening. Response to radiation and chemotherapy was manifested by development of a central low density region with an enhancing rim. CT findings correlated with clinical and cerebrospinal fluid findings. The differential diagnosis of the various abnormalities is considered

  8. Coherent states in quaternionic quantum mechanics

    Science.gov (United States)

    Adler, Stephen L.; Millard, Andrew C.

    1997-05-01

    We develop Perelomov's coherent states formalism to include the case of a quaternionic Hilbert space. We find that, because of the closure requirement, an attempted quaternionic generalization of the special nilpotent or Weyl group reduces to the normal complex case. For the case of the compact group SU(2), however, coherent states can be formulated using the quaternionic half-integer spin matrices of Finkelstein, Jauch, and Speiser, giving a nontrivial quaternionic analog of coherent states.

  9. Present state and development of positron tomographs

    International Nuclear Information System (INIS)

    Allemand, R.; Gariod, R.; Laval, M.; Tournier, F.

    1979-01-01

    This document presents the main characteristics of positron tomographs and analyses the relative importance of the parameters to be taken into consideration in the design of a tomograph: on the one hand, the physical parameters linked to the measurement of the annihilation photons by time coincidence and, on the other, the geometrical and technological parameters of prime importance in minimizing the many spurious effects. The last part endeavours to show this sort of instrumentation has evolved. Using the results obtained in our laboratory by mathematical simulation, the expected advantages are presented on the picture quality of the time of flight measurement of annihilation photons. Where the physical aspects of this method are concerned, the advantage of using cesium fluoride as scintillator is demonstrated [fr

  10. The computed tomographic appearances of cherubism

    International Nuclear Information System (INIS)

    Bianchi, S.D.; Boccardi, A.; Mela, F.; Romagnoli, R.

    1987-01-01

    The computed tomographic (CT) aspects of six cases of cherubism are described. Through its optimal representation of the lesions, CT enabled certain characteristics of this disease to be substantiated, namely, limitation of the process to the bones of the jaw and primarily superficial development of the mandibular lesions, coupled with an unusual mandibular condylar impairment. Moreover, the composition of this series permitted investigation of the condition in its several stages of progression. (orig.)

  11. Tomographic scanning apparatus with ionization detector means

    International Nuclear Information System (INIS)

    1981-01-01

    This patent specification describes a tomographic scanning apparatus using a fan beam and digital output signal. Particular reference is made to the gas-pressurized ionization detector chamber, consisting of an array of side-by-side elongate ionization detection cells, the principal axis of each of the said cells being oriented along a radius extending towards the radiation source, and connection means for applying potentials across the cells for taking their output signals. (U.K.)

  12. Tomographic extreme-ultraviolet spectrographs: TESS.

    Science.gov (United States)

    Cotton, D M; Stephan, A; Cook, T; Vickers, J; Taylor, V; Chakrabarti, S

    2000-08-01

    We describe the system of Tomographic Extreme Ultraviolet (EUV) SpectrographS (TESS) that are the primary instruments for the Tomographic Experiment using Radiative Recombinative Ionospheric EUV and Radio Sources (TERRIERS) satellite. The spectrographs were designed to make high-sensitivity {80 counts/s)/Rayleigh [one Rayleigh is equivalent to 10(6) photons/(4pi str cm(2)s)}, line-of-sight measurements of the oi 135.6- and 91.1-nm emissions suitable for tomographic inversion. The system consists of five spectrographs, four identical nightglow instruments (for redundancy and added sensitivity), and one instrument with a smaller aperture to reduce sensitivity and increase spectral resolution for daytime operation. Each instrument has a bandpass of 80-140 nm with approximately 2- and 1-nm resolution for the night and day instruments, respectively. They utilize microchannel-plate-based two-dimensional imaging detectors with wedge-and-strip anode readouts. The instruments were designed, fabricated, and calibrated at Boston University, and the TERRIERS satellite was launched on 18 May 1999 from Vandenberg Air Force Base, California.

  13. Tomographic visualization of stress corrosion cracks in tubing

    International Nuclear Information System (INIS)

    Morris, R.A.; Kruger, R.P.; Wecksung, G.W.

    1979-06-01

    A feasibility study was conducted to determine the possibility of detecting and sizing cracks in reactor cooling water tubes using tomographic techniques. Due to time and financial constraints, only one tomographic reconstruction using the best technique available was made. The results indicate that tomographic reconstructions can, in fact, detect cracks in the tubing and might possibly be capable of measuring the depth of the cracks. Limits of detectability and sensitivity have not been determined but should be investigated in any future work

  14. Low-dose computed tomographic imaging in orbital trauma

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, A.; Whitehouse, R.W. (Manchester Univ. (United Kingdom). Dept. of Diagnostic Radiology)

    1993-08-01

    The authors review findings in 75 computed tomographic (CT) examinations of 66 patients with orbital trauma who were imaged using a low-radiation-dose CT technique. Imaging was performed using a dynamic scan mode and exposure factors of 120 kVp and 80 mAs resulting in a skin dose of 11 mGy with an effective dose-equivalent of 0.22 mSv. Image quality was diagnostic in all cases and excellent in 73 examinations. Soft-tissue abnormalities within the orbit including muscle adhesions were well demonstrated both on primary axial and reconstructed multiplanar images. The benefits of multiplanar reconstructions are stressed and the contribution of soft-tissue injuries to symptomatic diplopia examined. (author).

  15. Cohering power of quantum operations

    Energy Technology Data Exchange (ETDEWEB)

    Bu, Kaifeng, E-mail: bkf@zju.edu.cn [School of Mathematical Sciences, Zhejiang University, Hangzhou 310027 (China); Kumar, Asutosh, E-mail: asukumar@hri.res.in [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211019 (India); Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094 (India); Zhang, Lin, E-mail: linyz@zju.edu.cn [Institute of Mathematics, Hangzhou Dianzi University, Hangzhou 310018 (China); Wu, Junde, E-mail: wjd@zju.edu.cn [School of Mathematical Sciences, Zhejiang University, Hangzhou 310027 (China)

    2017-05-18

    Highlights: • Quantum coherence. • Cohering power: production of quantum coherence by quantum operations. • Study of cohering power and generalized cohering power, and their comparison for differentmeasures of quantum coherence. • Operational interpretation of cohering power. • Bound on cohering power of a generic quantum operation. - Abstract: Quantum coherence and entanglement, which play a crucial role in quantum information processing tasks, are usually fragile under decoherence. Therefore, the production of quantum coherence by quantum operations is important to preserve quantum correlations including entanglement. In this paper, we study cohering power–the ability of quantum operations to produce coherence. First, we provide an operational interpretation of cohering power. Then, we decompose a generic quantum operation into three basic operations, namely, unitary, appending and dismissal operations, and show that the cohering power of any quantum operation is upper bounded by the corresponding unitary operation. Furthermore, we compare cohering power and generalized cohering power of quantum operations for different measures of coherence.

  16. Computer tomographic investigation of ancient Egyptian mummies

    International Nuclear Information System (INIS)

    Huebner, K.H.; Pahl, W.M.; Tuebingen Univ.

    1981-01-01

    Radiological and computer tomographic examinations of Egyptian mummies have been carried out at the Institute of Anthropology and Human Genetics from 1975 to 1978. These have demonstrated the value of CT in medical archaeology. It enables one to study the soft tissues, the skin (if bandaged), the muscles and any organs retained in situ for magical or religious reason. Measurements of attenuation values indicate the materials which were used for mummifying the skin and organs. Characteristic examples are described and the early results of these examinations are discussed. (orig.) [de

  17. Computer tomographic investigation of ancient Egyptian mummies

    Energy Technology Data Exchange (ETDEWEB)

    Huebner, K H; Pahl, W M

    1981-08-01

    Radiological and computer tomographic examinations of Egyptian mummies have been carried out at the Institute of Anthropology and Human Genetics from 1975 to 1978. These have demonstrated the value of CT in medical archaeology. It enables one to study the soft tissues, the skin (if bandaged), the muscles and any organs retained in situ for magical or religious reason. Measurements of attenuation values indicate the materials which were used for mummifying the skin and organs. Characteristic examples are described and the early results of these examinations are discussed.

  18. An intragastric trichobezoar: computerised tomographic appearance.

    Directory of Open Access Journals (Sweden)

    Morris B

    2000-04-01

    Full Text Available A 26-year-old lady presented with a history of abdominal pain and distension since two months. The ultrasound examination showed an epigastric mass, which was delineated as a filling defect in the stomach on barium studies. The computerised tomographic scan showed a gastric mass with pockets of air in it, without post-contrast enhancement. This case highlights the characteristic appearance on computerised tomography of a bezoar within the stomach, a feature that is not commonly described in medical literature.

  19. Partially coherent imaging and spatial coherence wavelets

    International Nuclear Information System (INIS)

    Castaneda, Roman

    2003-03-01

    A description of spatially partially coherent imaging based on the propagation of second order spatial coherence wavelets and marginal power spectra (Wigner distribution functions) is presented. In this dynamics, the spatial coherence wavelets will be affected by the system through its elementary transfer function. The consistency of the model with the both extreme cases of full coherent and incoherent imaging was proved. In the last case we obtained the classical concept of optical transfer function as a simple integral of the elementary transfer function. Furthermore, the elementary incoherent response function was introduced as the Fourier transform of the elementary transfer function. It describes the propagation of spatial coherence wavelets form each object point to each image point through a specific point on the pupil planes. The point spread function of the system was obtained by a simple integral of the elementary incoherent response function. (author)

  20. Asymmetry and coherence weight of quantum states

    Science.gov (United States)

    Bu, Kaifeng; Anand, Namit; Singh, Uttam

    2018-03-01

    The asymmetry of quantum states is an important resource in quantum information processing tasks such as quantum metrology and quantum communication. In this paper, we introduce the notion of asymmetry weight—an operationally motivated asymmetry quantifier in the resource theory of asymmetry. We study the convexity and monotonicity properties of asymmetry weight and focus on its interplay with the corresponding semidefinite programming (SDP) forms along with its connection to other asymmetry measures. Since the SDP form of asymmetry weight is closely related to asymmetry witnesses, we find that the asymmetry weight can be regarded as a (state-dependent) asymmetry witness. Moreover, some specific entanglement witnesses can be viewed as a special case of an asymmetry witness—which indicates a potential connection between asymmetry and entanglement. We also provide an operationally meaningful coherence measure, which we term coherence weight, and investigate its relationship to other coherence measures like the robustness of coherence and the l1 norm of coherence. In particular, we show that for Werner states in any dimension d all three coherence quantifiers, namely, the coherence weight, the robustness of coherence, and the l1 norm of coherence, are equal and are given by a single letter formula.

  1. Experience of computed tomographic myelography and discography in cervical problem

    Energy Technology Data Exchange (ETDEWEB)

    Nakatani, Shigeru; Yamamoto, Masayuki; Uratsuji, Masaaki; Suzuki, Kunio; Matsui, Eigo [Hyogo Prefectural Awaji Hospital, Sumoto, Hyogo (Japan); Kurihara, Akira

    1983-06-01

    CTM (computed tomographic myelography) was performed on 15 cases of cervical lesions, and on 5 of them, CTD (computed tomographic discography) was also made. CTM revealed the intervertebral state, and in combination with CTD, providing more accurate information. The combined method of CTM and CTD was useful for soft disc herniation.

  2. Terahertz wave tomographic imaging with a Fresnel lens

    Institute of Scientific and Technical Information of China (English)

    S. Wang; X.-C. Zhang

    2003-01-01

    We demonstrate three-dimensional tomographic imaging using a Fresnel lens with broadband terahertz pulses. Objects at various locations along the beam propagation path are uniquely imaged on the same imaging plane using a Fresnel lens with different frequencies of the imaging beam. This procedure allows the reconstruction of an object's tomographic contrast image by assembling the frequency-dependent images.

  3. Tomographs based on non-conventional radiation sources and methods

    International Nuclear Information System (INIS)

    Barbuzza, R.; Fresno, M. del; Venere, Marcelo J.; Clausse, Alejandro; Moreno, C.

    2000-01-01

    Computer techniques for tomographic reconstruction of objects X-rayed with a compact plasma focus (PF) are presented. The implemented reconstruction algorithms are based on stochastic searching of solutions of Radon equation, using Genetic Algorithms and Monte Carlo methods. Numerical experiments using actual projections were performed concluding the feasibility of the application of both methods in tomographic reconstruction problem. (author)

  4. On Longitudinal Spectral Coherence

    DEFF Research Database (Denmark)

    Kristensen, Leif

    1979-01-01

    It is demonstrated that the longitudinal spectral coherence differs significantly from the transversal spectral coherence in its dependence on displacement and frequency. An expression for the longitudinal coherence is derived and it is shown how the scale of turbulence, the displacement between ...... observation sites and the turbulence intensity influence the results. The limitations of the theory are discussed....

  5. Computerized tomographic in non-destructive testing

    International Nuclear Information System (INIS)

    Lopes, R.T.

    1988-01-01

    The process of computerized tomography has been developed for medical imaging purposes using tomographs with X-ray, and little attention has been given to others possibles applications of technique, because of its cost. As an alternative for the problem, we constructed a Tomographic System (STAC-1), using gamma-rays, for nonmedical applications. In this work we summarize the basic theory of reconstructing images using computerized tomography and we describe the considerations leading to the development of the experimental system. The method of reconstruction image implanted in the system is the filtered backprojection or convolution, with a digital filters system to carried on a pre-filtering in the projections. The experimental system is described, with details of control and the data processing. An alternative and a complementary system, using film as a detector is shown in preliminary form . This thesis discuss and shows the theorical and practical aspects, considered in the construction of the STAC-1, and also its limitations and apllications [pt

  6. Mesooptical microscope as a tomographical device

    International Nuclear Information System (INIS)

    Soroko, L.M.

    1989-01-01

    It is shown that there are at least four regions which are common for the mesooptical microscopes, on the one hand, and for the reconstructed tomography, on the other hand. The following characteristics of the mesooptical microscope show the tomographical properties: the structure of the output data concerning the orientation and the position in space of the straight-line objects going at small angles with the perpendicular to the given tomographic plane, the behaviour of the two-dimensional fourier-transform of the straight-line object in the course of the rotation of this object with respect to the specified axis in space, the scanning algorithm of the nuclear emulsion volume by the fence-like illuminated region in the mesooptical microscope for searching for particle tracks going parallel to the optical axis of the microscope, and, finally, the fact that the mesooptical images of the straight-line particle tracks with a common vertex in the nuclear emulsion lie on the sinogram. 12 refs.; 16 figs

  7. Bone densitometry with the computer tomograph

    International Nuclear Information System (INIS)

    Weiss, T.

    1978-01-01

    This work tests the usefulness of the EMI head scanner MARK I for a quantitative detection of ossary mineral content. Twenty-three concentration levels of a aqueous K 2 HPO 4 -solution were positioned by means of a special clamping device at the EMI-scanner and examined at tubevoltages of 100, 120 and 140 kV. This produces an almost linear dependence between CT-unit and sample concentration, whereby it shows that the measured special element densities of samples with the same densities vary in dependence with the voltage. The examination of an anotomical fore-arm preperate served as a statement for the reproductability of computer tomographic densitometry at non-moving biological objects. The test of reproductability of bone densitometry measurements under clinical conditions was made on the occation of the six time examinations of the right hand fore-arm bone of a young dummy. Furthermore densitometric examination were made at the fore-arm shelton of 40 long-time dialysis patients in the age levels between 17 and 67 years. The reproductability of the technique presented here is at least not better with the EMI-head-scanner MARK I used here. A change is possible by using the new whole body tomographs. (orig./MG) [de

  8. Optical coherence tomography findings after chronic total occlusion interventions: Insights from the “AngiographiC evaluation of the everolimus-eluting stent in chronic Total occlusions” (ACE-CTO) study (NCT01012869)

    Energy Technology Data Exchange (ETDEWEB)

    Sherbet, Daniel P.; Christopoulos, Georgios; Karatasakis, Aris; Danek, Barbara Anna; Kotsia, Anna; Navara, Rachita; Michael, Tesfaldet T.; Roesle, Michele; Rangan, Bavana V.; Haagen, Donald [VA North Texas Healthcare System and University of Texas Southwestern Medical Center, Dallas, TX (United States); Garcia, Santiago [Minneapolis VA Healthcare System and University of Minnesota, Minneapolis, MN (United States); Maniu, Calin [Bon Secours Health System, Suffolk, VA (United States); Pershad, Ashish [Banner Good Samaritan Medical Center, Phoenix, AZ (United States); Abdullah, Shuaib M.; Hastings, Jeffrey L.; Kumbhani, Dharam J.; Luna, Michael; Addo, Tayo; Banerjee, Subhash [VA North Texas Healthcare System and University of Texas Southwestern Medical Center, Dallas, TX (United States); Brilakis, Emmanouil S., E-mail: esbrilakis@gmail.com [VA North Texas Healthcare System and University of Texas Southwestern Medical Center, Dallas, TX (United States)

    2016-10-15

    Background: There is limited information on optical coherence tomography (OCT) findings after percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs). OCT allows high resolution imaging that can enhance understanding of the vascular response after stenting of chronically occluded vessels. Methods: The Angiographic Evaluation of the Everolimus-Eluting Stent in Chronic Total Occlusions (ACE-CTO) study collected angiographic and clinical outcomes from 100 patients undergoing CTO PCI with the everolimus-eluting stent (EES). OCT was performed 8-months post stenting in 62 patients. Every third frame was analyzed throughout the course of the stented arterial segment. Lumen contours were semi-automatically traced and stent struts were manually delineated, with automatic measurement of the strut to lumen distance. Struts on the luminal side of the lumen contour were classified as malapposed if the distance to the lumen contour exceeded 0.108 mm. Results: A total of 44,450 struts in 6047 frames were analyzed, of which 4113 9.3%, 95% confidence intervals [CI] 9.0% to 9.5%) were malapposed and 1230 (2.8%, 95% CI 2.6% to 2.9%) were uncovered. Fifty-five of 62 patients (88.7%, 95% CI 78.5% to 98.4%) had at least one malapposed stent strut and 50 patients (80.7%, 95% CI 69.2% to 88.6%) had at least one uncovered stent strut. Mean strut-intimal thickness of the apposed and malapposed struts was 0.126 ± 0.140 mm and − 0.491 ± 0.440 mm, respectively. Conclusion: High rates of stent strut malapposition and incomplete stent strut coverage were observed after CTO PCI using EES, highlighting unique challenges associated with stent implantation in CTOs. - Highlights: • Percutaneous coronary intervention with drug-eluting stents for chronic total occlusion is associated with a 40% rate of binary in-stent restenosis at 8 months • Of patients who receive a drug eluting stent for a chronic total occlusion 88.7% will have stent strut malapposition and 80.7% will

  9. Analytic coherent states for generalized potentials

    International Nuclear Information System (INIS)

    Nieto, M.M.; Simmons, L.M. Jr.

    1978-01-01

    A prescription is given for finding coherent states in generalized potentials. By coherent states is meant states which in time follow the motion that a classical particle would. This prescription is based upon finding those natural classical variables which vary as the sine and the cosine of the classical ω/sub c/t. As an example, the symmetric Rosen--Morse potential is discussed in detail

  10. Clinical and tomographic aspects of macular microholes

    International Nuclear Information System (INIS)

    Novelli, Fernando Jose de; Maia Junior, Otacilio de Oliveira; Garrido Neto, Theodomiro; Takahashi, Walter Yukihiko

    2009-01-01

    Purpose: To describe the clinical aspects and evaluate optical coherence tomography of macular microholes. Methods: Seven patients were assessed (8 eyes) with microholes of the macula. All patients underwent complete eye examination, fundus photography, fluorescent angiography and OCT-3 imaging. Results: Ages ranged from 26 to 69 years. Six patients were female (85.7%) and five of them had microhole in the right eye. The presenting symptom was decrease in visual acuity (71.3%) and central scotoma in (14.3%). Five eyes (71.4%) had no defects shown by fluorescent angiography. A defect in the outer retina was demonstrated in all eyes on optical coherence tomography. The lesions were nonprogressive. Conclusion: Macular microholes are small lamellar defects in the outer retina. The condition is nonprogressive, generally unilateral and compatible with good visual acuity. Fundus biomicroscopy associated with an optical coherence tomography are the main elements in the diagnosis and study of this pathology. (author)

  11. Teleportation of a Coherent Superposition State Via a nonmaximally Entangled Coherent Xhannel

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ We investigate the problemm of teleportation of a superposition coherent state with nonmaximally entangled coherent channel. Two strategies are considered to complete the task. The first one uses entanglement concentration to purify the channel to a maximally entangled one. The second one teleports the state through the nonmaximally entangled coherent channel directly. We find that the probabilities of successful teleportations for the two strategies are depend on the amplitudes of the coherent states and the mean fidelity of teleportation using the first strategy is always less than that of the second strategy.

  12. Radiographic and tomographic aspects of meningeal hemangiosarcoma in a German Shepherd dog with clinical signs of cauda equina sindrome

    International Nuclear Information System (INIS)

    Pinto, A.C.B. de C.F.; Ferrigno, C.R.A.; Matera, J.M.; Torres, L.N.; Sinhorini, I.L.; Cortopassi, S.R.G.; Hage, M.C.F.N.S.

    2007-01-01

    Hemangiosarcoma is a highly malignant neoplasia derived from the endothelial cell line and, therefore, can arise in any tissue with blood vessels. A case of a rare meningeal site of hemangiosarcoma in an eight-year old German Shepherd dog with clinical signs of cauda equina sindrome is described. The diagnosis was made based on clinical, radiographic, tomographic and histopathological findings [pt

  13. Tomographic anthropomorphic models. Pt. 2. Organ doses from computed tomographic examinations in paediatric radiology

    International Nuclear Information System (INIS)

    Zankl, M.; Panzer, W.; Drexler, G.

    1993-11-01

    This report provides a catalogue of organ dose conversion factors resulting from computed tomographic (CT) examinations of children. Two radiation qualities and two exposure geometries were simulated as well as the use of asymmetrical beams. The use of further beam shaping devices was not considered. The organ dose conversion factors are applicable to babies at the age of ca. 2 months and to children between 5 and 7 years but can be used for other ages as well with the appropriate adjustments. For the calculations, the patients were represented by the GSF tomographic anthropomorphic models BABY and CHILD. The radiation transport in the body was simulated using a Monte Carlo method. The doses are presented as conversion factors of mean organ doses per air kerma free in air on the axis of rotation. Mean organ dose conversion factors are given per organ and per scanned body section of 1 cm height. The mean dose to an organ resulting from a particular CT examination can be estimated by summing up the contributions to the organ dose from all relevant sections. To facilitate the selection of the appropriate sections, a table is given which relates the tomographic models' coordinates to certain anatomical landmarks in the human body. (orig.)

  14. Collimated trans-axial tomographic scintillation camera

    International Nuclear Information System (INIS)

    1980-01-01

    The objects of this invention are first to reduce the time required to obtain statistically significant data in trans-axial tomographic radioisotope scanning using a scintillation camera. Secondly, to provide a scintillation camera system to increase the rate of acceptance of radioactive events to contribute to the positional information obtainable from a known radiation source without sacrificing spatial resolution. Thirdly to reduce the scanning time without loss of image clarity. The system described comprises a scintillation camera detector, means for moving this in orbit about a cranial-caudal axis relative to a patient and a collimator having septa defining apertures such that gamma rays perpendicular to the axis are admitted with high spatial resolution, parallel to the axis with low resolution. The septa may be made of strips of lead. Detailed descriptions are given. (U.K.)

  15. Collimated trans-axial tomographic scintillation camera

    International Nuclear Information System (INIS)

    1980-01-01

    The principal problem in trans-axial tomographic radioisotope scanning is the length of time required to obtain meaningful data. Patient movement and radioisotope migration during the scanning period can cause distortion of the image. The object of this invention is to reduce the scanning time without degrading the images obtained. A system is described in which a scintillation camera detector is moved to an orbit about the cranial-caudal axis relative to the patient. A collimator is used in which lead septa are arranged so as to admit gamma rays travelling perpendicular to this axis with high spatial resolution and those travelling in the direction of the axis with low spatial resolution, thus increasing the rate of acceptance of radioactive events to contribute to the positional information obtainable without sacrificing spatial resolution. (author)

  16. Computerized tomographic scanner with shaped radiation filter

    International Nuclear Information System (INIS)

    Carlson, R.W.; Walters, R.G.

    1981-01-01

    The invention comprises a shaped filter and a filter correction circuitry for computerized tomographic scanners. The shaped filter is a generally u-shaped block of filter material which is adapted to be mounted between the source of radiation and the scan circle. The u-shaped block has a parabolic recess. The filter material may be beryllium, aluminum, sulphur, calcium, titanium, erbium, copper, and compounds including oxides and alloys thereof. The filter correction circuit comprises a first filter correction profile adding circuit for adding a first scaler valve to each intensity valve in a data line. The data line is operated on by a beam hardness correction polynomial. After the beam hardness polynomial correction operation, a second filter correction circuit adds a second filter correction profile consisting of a table of scalor values, one corresponding to each intensity reading in the data line

  17. Occult fractures of the knee: tomographic evaluation

    International Nuclear Information System (INIS)

    Apple, J.S.; Martinez, S.; Allen, N.B.; Caldwell, D.S.; Rice, J.R.

    1983-01-01

    Seven adults with painful effusions of the knee were examined for occult fractures using pluridirectional tomograph in the coronal and lateral planes. Six patients (ages 50 to 82 years) were osteopenic and gave histories ranging from none to mild trauma; one 26-year-old man was not osteopenic and had severe trauma. In all cases, routine radiographs were interpreted as negative, but tomography demonstrated a fracture. Five fractures were subchondral. Bone scans in 2 patients were positive. The authors conclude that osteopenic patients with a painful effusion of the knee should be considered to have an occult fracture. While bone scans may be helpful, tomography is recommended as the procedure of choice to define the location and extent of the fracture

  18. Axial tomographic system for radiation diagnoses

    International Nuclear Information System (INIS)

    Crowther, T.J.

    1977-01-01

    The axial tomographic scanner consists of a source of hard radiation passing a fan shaped beam through a plane layer of the body under examination, a detector, and driving systems for the sequential displacement and rotation of the radiation source and the detector. The diagnosis is made by means of a data processing system offering extensive time overlap capability of the individual system functions. The data sets from transmission or absorption are processed in three independent subsystems, i.e., the scanning system, the processing system and the display system. The systems are made up of well-known modules, e.g., Nova 1200 or Eclipse 5200. Hence, as a result of the independent design of the data system, raw data will not be lost in case of faults in some subsystem. (DG) [de

  19. Tomographic PIV behind a prosthetic heart valve

    Science.gov (United States)

    Hasler, D.; Landolt, A.; Obrist, D.

    2016-05-01

    The instantaneous three-dimensional velocity field past a bioprosthetic heart valve was measured using tomographic particle image velocimetry. Two digital cameras were used together with a mirror setup to record PIV images from four different angles. Measurements were conducted in a transparent silicone phantom with a simplified geometry of the aortic root. The refraction indices of the silicone phantom and the working fluid were matched to minimize optical distortion from the flow field to the cameras. The silicone phantom of the aorta was integrated in a flow loop driven by a piston pump. Measurements were conducted for steady and pulsatile flow conditions. Results of the instantaneous, ensemble and phase-averaged flow field are presented. The three-dimensional velocity field reveals a flow topology, which can be related to features of the aortic valve prosthesis.

  20. E-learn Computed Tomographic Angiography

    DEFF Research Database (Denmark)

    Havsteen, Inger; Christensen, Anders; Nielsen, Jens K

    2012-01-01

    BACKGROUND: Computed tomographic angiography (CTA) is widely available in emergency rooms to assess acute stroke patients. To standardize readings and educate new readers, we developed a 3-step e-learning tool based on the test-teach-retest methodology in 2 acute stroke scenarios: vascular...... occlusion and "spot sign" in acute intracerebral hemorrhage. We hypothesized that an e-learning program enhances reading skills in physicians of varying experience. METHODS: We developed an HTML-based program with a teaching segment and 2 matching test segments. Tests were taken before and after...... sign correctly 69% before versus 92% after teaching (P = .009) and reported a median self-perceived diagnostic certainty of 50% versus 75% (P = .030). Self-perceived diagnostic certainty revealed no significant increase for vascular occlusion. CONCLUSIONS: The e-learning program is a useful educational...

  1. Advanced Ultrasonic Tomograph of Children's Bones

    Science.gov (United States)

    Lasaygues, Philippe; Lefebvre, Jean-Pierre; Guillermin, Régine; Kaftandjian, Valérie; Berteau, Jean-Philippe; Pithioux, Martine; Petit, Philippe

    This study deals with the development of an experimental device for performing ultrasonic computed tomography (UCT) on bone in pediatric degrees. The children's bone tomographs obtained in this study, were based on the use of a multiplexed 2-D ring antenna (1 MHz and 3 MHz) designed for performing electronic and mechanical scanning. Although this approach is known to be a potentially valuable means of imaging objects with similar acoustical impedances, problems arise when quantitative images of more highly contrasted media such as bones are required. Various strategies and various mathematical procedures for modeling the wave propagation based on Born approximations have been developed at our laboratory, which are suitable for use with pediatric cases. Inversions of the experimental data obtained are presented.

  2. Computed tomographic investigations on intraventricular hematomas

    International Nuclear Information System (INIS)

    Laber-Szillat, S.

    1982-01-01

    This work investigated in 106 patients with intraventricular hematomas all the known factors which can have an influence on prognosis: age, sex, anamnesis of the patients, size, extent and localization of the intracranial bleeding, underlying angiopathy and differences between arterial and venous and spontaneous and traumatic bleedings. It was shown that the state of mind was the deciding prognostic factor, whereby viligance was the cumulative expression of all other investigated influences. A computed tomography (CT) examination is deciding in the question of operative hydrocephalus care. In 13 patients it was further shown, how clearly CT results and brain dissection allowed themselves to be compared. The computed tomographic examination method is best suited to achieve even physiological and more extensive prognostic possibilities. (orig.) [de

  3. Computed tomographic evaluation of the altered pancreas in dog and cat

    International Nuclear Information System (INIS)

    Posch, B.

    2002-11-01

    Eighteen dogs and 12 cats of varying breed, age and sex underwent a computed tomographic study of the pancreas. Length, diameter and density of each lobe of the pancreas were measured. Further, the gained results were compared to the information established by the clinical examination, sonography, haematology and histology. Contrast CT improved evaluation of the pancreas in all cases of normal life controls. CT criteria such as changes in size, density, delimitation of the pancreas and the peripancreatic structures were analyzed. Increased pancreatic size was seen in inflammatory as well as in neoplastic diseases. There were no reliable computed tomographic criteria to differentiate pancreatic neoplasia from inflammation without peripancreatic findings. Ultrasonography proved to be a good screening method in this study: sonographic and computed tomographic results correlated in all cases with the exception of 5 cases. In contrast to ultrasonography CT could differentiate normal pancreas from pancreas atrophy. Computed tomography was superior to sonography in determining the full extent of pancreatic and peripancreatic signs due to the good overview and overall image of the abdominal structures. Serum chemistry of a- amylase and lipase were obtained in 28 animals. Assays of serum lipase and a- amylase activities were only able to detect acute pancreatitis in half of the canine cases. Despite morphological alterations detected with the help of sonography or CT, there were no significant increases in a- amylase and lipase in cats. Following computed tomography the pancreas of 10 animals was examined pathohistologically. With the exception of 2 cases the computed tomographic results correlated with the pathohistological findings. In conclusion, computed tomography (CT) proved to be a valuable method to evaluate the localization, the full extent and the seriousness of pancreatic lesions. (author)

  4. Coherent states in quaternionic quantum mechanics

    International Nuclear Information System (INIS)

    Adler, S.L.; Millard, A.C.

    1997-01-01

    We develop Perelomov close-quote s coherent states formalism to include the case of a quaternionic Hilbert space. We find that, because of the closure requirement, an attempted quaternionic generalization of the special nilpotent or Weyl group reduces to the normal complex case. For the case of the compact group SU(2), however, coherent states can be formulated using the quaternionic half-integer spin matrices of Finkelstein, Jauch, and Speiser, giving a nontrivial quaternionic analog of coherent states. copyright 1997 American Institute of Physics

  5. Non-rigid registration of tomographic images with Fourier transforms

    International Nuclear Information System (INIS)

    Osorio, Ar; Isoardi, Ra; Mato, G

    2007-01-01

    Spatial image registration of deformable body parts such as thorax and abdomen has important medical applications, but at the same time, it represents an important computational challenge. In this work we propose an automatic algorithm to perform non-rigid registration of tomographic images using a non-rigid model based on Fourier transforms. As a measure of similarity, we use the correlation coefficient, finding that the optimal order of the transformation is n = 3 (36 parameters). We apply this method to a digital phantom and to 7 pairs of patient images corresponding to clinical CT scans. The preliminary results indicate a fairly good agreement according to medical experts, with an average registration error of 2 mm for the case of clinical images. For 2D images (dimensions 512x512), the average running time for the algorithm is 15 seconds using a standard personal computer. Summarizing, we find that intra-modality registration of the abdomen can be achieved with acceptable accuracy for slight deformations and can be extended to 3D with a reasonable execution time

  6. Electromagnetic spatial coherence wavelets

    International Nuclear Information System (INIS)

    Castaneda, R.; Garcia-Sucerquia, J.

    2005-10-01

    The recently introduced concept of spatial coherence wavelets is generalized for describing the propagation of electromagnetic fields in the free space. For this aim, the spatial coherence wavelet tensor is introduced as an elementary amount, in terms of which the formerly known quantities for this domain can be expressed. It allows analyzing the relationship between the spatial coherence properties and the polarization state of the electromagnetic wave. This approach is completely consistent with the recently introduced unified theory of coherence and polarization for random electromagnetic beams, but it provides a further insight about the causal relationship between the polarization states at different planes along the propagation path. (author)

  7. Polarization sensitive optical coherence tomography in dentistry

    International Nuclear Information System (INIS)

    Dichtl, S.

    1998-01-01

    Optical coherence tomography (OCT) is a noninvasive and noncontact technique for obtaining cross-sectional images of biologic structure, which was initially introduced to depict the transparent tissue of the eye. It employs the partial coherence properties of a light source to image structures with high resolution (< 20 (m). Recently, this technique has also been applied in turbid media. This tomographic imaging is analogous to conventional ultrasound B mode imaging, except that OCT measures the intensity of backreflected infrared light rather than acoustical waves. First applications, of OCT in dentistry for diagnosing periodontal disease have been reported by Colston et al. presenting in vitro OCT images of the dental and periodontal tissues of porcine premolar teeth. In this work, the feasibility of polarisation sensitive OCT for dental material is suggested. In contrast with conventional OCT, where the magnitude of backscattered light as a function of depth is imaged, backscattered light is used to image the magnitude of the birefringence in the sample as a function of depth. Partial loss of birefringence is known to be an early indication of incipient caries or tissue thermal damage. Applying this technique for caries diagnosis or guidance regarding optimal dosimetry for thermally mediated laser therapeutic procedures, polarisation sensitive OCT would represent a promising new technology for dentistry. (author)

  8. Tomographic Approach in Three-Orthogonal-Basis Quantum Key Distribution

    International Nuclear Information System (INIS)

    Liang Wen-Ye; Yin Zhen-Qiang; Chen Hua; Li Hong-Wei; Chen Wei; Han Zheng-Fu; Wen Hao

    2015-01-01

    At present, there is an increasing awareness of some three-orthogonal-basis quantum key distribution protocols, such as, the reference-frame-independent (RFI) protocol and the six-state protocol. For secure key rate estimations of these protocols, there are two methods: one is the conventional approach, and another is the tomographic approach. However, a comparison between these two methods has not been given yet. In this work, with the general model of rotation channel, we estimate the key rate using conventional and tomographic methods respectively. Results show that conventional estimation approach in RFI protocol is equivalent to tomographic approach only in the case of that one of three orthogonal bases is always aligned. In other cases, tomographic approach performs much better than the respective conventional approaches of the RFI protocol and the six-state protocol. Furthermore, based on the experimental data, we illustrate the deep connections between tomography and conventional RFI approach representations. (paper)

  9. Radiographic test phantom for computed tomographic lung nodule analysis

    International Nuclear Information System (INIS)

    Zerhouni, E.A.

    1987-01-01

    This patent describes a method for evaluating a computed tomograph scan of a nodule in a lung of a human or non-human animal. The method comprises generating a computer tomograph of a transverse section of the animal containing lung and nodule tissue, and generating a second computer tomograph of a test phantom comprising a device which simulates the transverse section of the animal. The tissue simulating portions of the device are constructed of materials having radiographic densities substantially identical to those of the corresponding tissue in the simulated transverse section of the animal and have voids therein which simulate, in size and shape, the lung cavities in the transverse section and which contain a test reference nodule constructed of a material of predetermined radiographic density which simulates in size, shape and position within a lung cavity void of the test phantom the nodule in the transverse section of the animal and comparing the respective tomographs

  10. Computed tomographic determination of tracheal dimensions in children and adolescents

    International Nuclear Information System (INIS)

    Griscom, N.T.

    1982-01-01

    A computed tomographic system for determining the internal diameters, cross-sectional area, and length of the trachea in children and adolescents was developed. Intraluminal volumes were calculated from these measurements.The results of 18 analyses are reported

  11. Image interface in Java for tomographic reconstruction in nuclear medicine

    International Nuclear Information System (INIS)

    Andrade, M.A.; Silva, A.M. Marques da

    2004-01-01

    The aim of this study is to implement a software for tomographic reconstruction of SPECT data from Nuclear Medicine with a flexible interface design, cross-platform, written in Java. Validation tests were performed based on SPECT simulated data. The results showed that the implemented algorithms and filters agree with the theoretical context. We intend to extend the system by implementing additional tomographic reconstruction techniques and Java threads, in order to provide simultaneously image processing. (author)

  12. Tomographic imaging of subducted lithosphere below northwest Pacific island arcs

    Science.gov (United States)

    Van Der Hilst, R.; Engdahl, R.; Spakman, W.; Nolet, G.

    1991-01-01

    The seismic tomography problem does not have a unique solution, and published tomographic images have been equivocal with regard to the deep structure of subducting slabs. An improved tomographic method, using a more realistic background Earth model and surf ace-reflected as well as direct seismic phases, shows that slabs beneath the Japan and Izu Bonin island arcs are deflected at the boundary between upper and lower mantle, whereas those beneath the northern Kuril and Mariana arcs sink into the lower mantle.

  13. Multimodal imaging findings in 'hyper-early' stage MEWDS.

    Science.gov (United States)

    Cahuzac, Armelle; Wolff, Benjamin; Mathis, Thibaud; Errera, Marie-Hélène; Sahel, José-Alain; Mauget-Faÿsse, Martine

    2017-10-01

    To describe a new stage of multiple evanescent white dot syndrome (MEWDS), occurring at a very early phase of the disease. Retrospective analysis of clinical, angiographic and tomographic findings in four patients with 'hyper-early' stage MEWDS. In four patients seen within 1 week of the onset of symptoms, fundus analysis revealed macular granity and the classic yellow-white dots, some having no corresponding hyperautofluorescent pattern. Spectral-domain optical coherence tomography (SD-OCT) showed central foveal disruption of the ellipsoid zone (EZ) and interdigitation layer with a hyper-reflective dome-shaped lesion. In two patients, fluorescein angiography (FA) revealed an intermediate hypofluorescent perimacular halo, whereas late indocyanine green angiography (ICGA) showed a hyperfluorescent halo as well as the classic MEWDS features. After a few days, the EZ disruption appeared complete on OCT and fundus autofluorescence (FAF) in all patients. Visual acuity, OCT and FAF findings had fully recovered within 3 months. We have shown a new feature of MEWDS on FAF, OCT, FA and ICGA, corresponding to a very early stage of the disease. 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/.

  14. Optical coherence tomography in otolaryngology: original results and review of the literature

    Science.gov (United States)

    Bibas, Athanasios G.; Podoleanu, Adrian Gh.; Cucu, Radu G.; Dobre, George M.; Odell, Edward; Boxer, Aaron B.; O'Connors, Alec F.; Gleeson, Michael J.

    2004-07-01

    Optical coherence tomography is a diagnostic imaging technique allowing two dimensional tomographic imaging of tissue architecture. This is a review article on the use of optical coherence tomography in Otolaryngology including original images from human laryngeal tissue and temporal bones (cochlea) in our laboratory. Tissue specimens from normal larynges were imaged with an 850 nm OCT system. Our results showed good correlation between OCT image s and the corresponding haematoxylin-eosin stained histology sections in the normal larynx. Human temporal bones were also imaged using an 1300 nm OCT system. Limited morphological details were obtained due to the high scattering properties of the bony labyrinth.

  15. NONINVASIVE DIAGNOSIS OF BLADDER CANCER BY CROSS-POLARIZATION OPTICAL COHERENCE TOMOGRAPHY: A BLIND STATISTICAL STUDY

    Directory of Open Access Journals (Sweden)

    O. S. Streltsova

    2014-07-01

    Full Text Available Whether cross-polarization (CP optical coherence tomography (OCT could be used to detect early bladder cancer was ascertained; it was compared with traditional OCT within the framework of blind (closed clinical statistical studies. One hundred and sixteen patients with local nonexophytic (flat pathological processes of the bladder were examined; 360 CP OCT images were obtained and analyzed. The study used an OCT 1300-U CP optical coherence tomographer. CP OCT showed a high (94% sensitivity and a high (84% specificity in the identification of suspected nonexophytic areas in the urinary bladder.

  16. Tomographic Aspects of Advanced Active Pulmonary Tuberculosis and Evaluation of Sequelae following Treatment

    Directory of Open Access Journals (Sweden)

    Rafael Barcelos Capone

    2017-01-01

    Full Text Available Objectives. To evaluate tomographic changes in pulmonary tuberculosis (TB, degree of agreement among three radiologists regarding tomographic diagnoses, and sequelae following treatment. Methods. Cross-sectional and descriptive study of 74 TB patients confirmed by sputum culture and chest computed tomography before (CT1 and 6 months after (CT2 drug therapy. Results were performed by three radiologists blinded to clinical and laboratory results. Results. Main findings in CT1 included nodules indicating the presence of a tree-in-bud pattern in 93% of cases, ill-defined nodules in 84% of cases, consolidation in 77% of cases, architectural distortion in 71% of cases, cavitary lesions in 62% of cases, and ground glass opacities in 37% of cases. Airway involvement, characterized by increased thickness and dilatation of the bronchial walls, occurred in 93% of cases. Pleural involvement occurred in 54%. There was an agreement on active TB among the three radiologists in 85% of cases. The results in CT2 indicated the presence of architectural distortion in 91% of cases and cylindrical bronchiectasis in 86%. Conclusions. The study established a tomographic pattern for diagnosis of active TB characterized by the presence of airway nodules, consolidation, architectural distortion, and cavitary lesions, and an almost complete degree of agreement (Kappa was observed among the radiologists (0.85. CT after treatment assists in defining the cure.

  17. Radiographic and tomographic study of the elbow joint in dogs

    International Nuclear Information System (INIS)

    Sendyk-Grunkraut, Alessandra; Martin, Claudia M.; Souza, Alexandre N.A.; Patricio, Geni Cristina F.; Lorigados, Carla A.B.; Matera, Julia M.; Fonseca-Pinto, Ana C.B.C.

    2017-01-01

    Elbow dysplasia disease includes an united anconeal process, fragmented medial coronoid process, osteochondrosis of humeral trochlea, articular incongruity and degenerative joint disease. The aim of this study was to present detailed morphologic and morphometric aspects of the elbow joint in dog in clinical and correlate with radiographic and tomographic (CT) exam. Inter-observer variation for articular incongruity measurements by CT, comparative analysis in the radiographic exam, angle in ulnar notch and its comparative analysis between radiographic and tomographic agreement examination in 44 elbow of dogs with different ages were evaluated. The statistics analyses included the kappa coefficient and interclass correlation and Fischer's test and McNemar's test. It was evidenced that individual performance of each radiographic incidence had poor agreement with the tomographic exam, suggesting that the accomplishment of more than two radiograph views are needed. There was no agreement between the three evaluators in the ulnar notch angle at radiographic and tomographic exams. However, there was good/moderate agreement for articular incongruity measurement in the sagittal plane between evaluators. It was possible to conclude that none of the five radiographic incidences was better than the others for radiographic analysis because each incidence had a better identification of a particular elbow compartment; measurements at the tomographic exam to evaluate radioulnar incongruity had no reproductiveness in the frontal plane, but in sagittal plan had a good/moderate agreement between observers and the angle in ulnar notch presented no repeatability at radiographic exam and no reproductiveness at tomographic exam. (author)

  18. Gamma Ray Tomographic Scan Method for Large Scale Industrial Plants

    International Nuclear Information System (INIS)

    Moon, Jin Ho; Jung, Sung Hee; Kim, Jong Bum; Park, Jang Geun

    2011-01-01

    The gamma ray tomography systems have been used to investigate a chemical process for last decade. There have been many cases of gamma ray tomography for laboratory scale work but not many cases for industrial scale work. Non-tomographic equipment with gamma-ray sources is often used in process diagnosis. Gamma radiography, gamma column scanning and the radioisotope tracer technique are examples of gamma ray application in industries. In spite of many outdoor non-gamma ray tomographic equipment, the most of gamma ray tomographic systems still remained as indoor equipment. But, as the gamma tomography has developed, the demand on gamma tomography for real scale plants also increased. To develop the industrial scale system, we introduced the gamma-ray tomographic system with fixed detectors and rotating source. The general system configuration is similar to 4 th generation geometry. But the main effort has been made to actualize the instant installation of the system for real scale industrial plant. This work would be a first attempt to apply the 4th generation industrial gamma tomographic scanning by experimental method. The individual 0.5-inch NaI detector was used for gamma ray detection by configuring circular shape around industrial plant. This tomographic scan method can reduce mechanical complexity and require a much smaller space than a conventional CT. Those properties make it easy to get measurement data for a real scale plant

  19. Single-photon tomographic determination of regional cerebral blood flow in epilepsy

    International Nuclear Information System (INIS)

    Bonte, F.J.; Devous, M.D. Sr.; Stokely, E.M.; Homan, R.W.

    1983-01-01

    Using a single-photon emission computed tomographic scanner (SPECT) the authors determined regional cerebral blood flow (rCBF) with inhaled xenon-133, a noninvasive procedure. Studies were performed in 40 normal individuals, and these were compared with rCBF determinations in 51 patients with seizure disorders. Although positive results were obtained in 15 of 16 patients with mass lesions, the group of principal interest comprised 25 patients suffering from ''temporal lobe'' epilepsy. Only one of these had a positive x-ray computed tomogram, but 16 had positive findings on rCBF study. These findings included increased local blood flow in the ictal state and reduced flow interictally

  20. Text Coherence in Translation

    Science.gov (United States)

    Zheng, Yanping

    2009-01-01

    In the thesis a coherent text is defined as a continuity of senses of the outcome of combining concepts and relations into a network composed of knowledge space centered around main topics. And the author maintains that in order to obtain the coherence of a target language text from a source text during the process of translation, a translator can…

  1. Coherent Multistatic ISAR Imaging

    NARCIS (Netherlands)

    Dorp, Ph. van; Otten, M.P.G.; Verzeilberg, J.M.M.

    2012-01-01

    This paper presents methods for Coherent Multistatic Radar Imaging for Non Cooperative Target Recognition (NCTR) with a network of radar sensors. Coherent Multistatic Radar Imaging is based on an extension of existing monostatic ISAR algorithms to the multistatic environment. The paper describes the

  2. VCSEL Based Coherent PONs

    DEFF Research Database (Denmark)

    Jensen, Jesper Bevensee; Rodes, Roberto; Caballero Jambrina, Antonio

    2014-01-01

    We present a review of research performed in the area of coherent access technologies employing vertical cavity surface emitting lasers (VCSELs). Experimental demonstrations of optical transmission over a passive fiber link with coherent detection using VCSEL local oscillators and directly modula...

  3. Modeling coherent errors in quantum error correction

    Science.gov (United States)

    Greenbaum, Daniel; Dutton, Zachary

    2018-01-01

    Analysis of quantum error correcting codes is typically done using a stochastic, Pauli channel error model for describing the noise on physical qubits. However, it was recently found that coherent errors (systematic rotations) on physical data qubits result in both physical and logical error rates that differ significantly from those predicted by a Pauli model. Here we examine the accuracy of the Pauli approximation for noise containing coherent errors (characterized by a rotation angle ɛ) under the repetition code. We derive an analytic expression for the logical error channel as a function of arbitrary code distance d and concatenation level n, in the small error limit. We find that coherent physical errors result in logical errors that are partially coherent and therefore non-Pauli. However, the coherent part of the logical error is negligible at fewer than {ε }-({dn-1)} error correction cycles when the decoder is optimized for independent Pauli errors, thus providing a regime of validity for the Pauli approximation. Above this number of correction cycles, the persistent coherent logical error will cause logical failure more quickly than the Pauli model would predict, and this may need to be combated with coherent suppression methods at the physical level or larger codes.

  4. Long-lived coherence in carotenoids

    Energy Technology Data Exchange (ETDEWEB)

    Davis, J A; Cannon, E; Van Dao, L; Hannaford, P [ARC Centre of Excellence for Coherent X-ray Science, Centre for Atom Optics and Ultrafast Spectroscopy, Swinburne University of Technology, Victoria 3122 (Australia); Quiney, H M; Nugent, K A, E-mail: jdavis@swin.edu.a [ARC Centre of Excellence for Coherent X-ray Science, School of Physics, University of Melbourne, Victoria 3010 (Australia)

    2010-08-15

    We use two-colour vibronic coherence spectroscopy to observe long-lived vibrational coherences in the ground electronic state of carotenoid molecules, with decoherence times in excess of 1 ps. Lycopene and spheroidene were studied isolated in solution, and within the LH2 light-harvesting complex extracted from purple bacteria. The vibrational coherence time is shown to increase significantly for the carotenoid in the complex, providing further support to previous assertions that long-lived electronic coherences in light-harvesting complexes are facilitated by in-phase motion of the chromophores and surrounding proteins. Using this technique, we are also able to follow the evolution of excited state coherences and find that for carotenoids in the light-harvesting complex the (S{sub 2}|S{sub 0}) superposition remains coherent for more than 70 fs. In addition to the implications of this long electronic decoherence time, the extended coherence allows us to observe the evolution of the excited state wavepacket. These experiments reveal an enhancement of the vibronic coupling to the first vibrational level of the C-C stretching mode and/or methyl-rocking mode in the ground electronic state 70 fs after the initial excitation. These observations open the door to future experiments and modelling that may be able to resolve the relaxation dynamics of carotenoids in solution and in natural light-harvesting systems.

  5. Long-lived coherence in carotenoids

    International Nuclear Information System (INIS)

    Davis, J A; Cannon, E; Van Dao, L; Hannaford, P; Quiney, H M; Nugent, K A

    2010-01-01

    We use two-colour vibronic coherence spectroscopy to observe long-lived vibrational coherences in the ground electronic state of carotenoid molecules, with decoherence times in excess of 1 ps. Lycopene and spheroidene were studied isolated in solution, and within the LH2 light-harvesting complex extracted from purple bacteria. The vibrational coherence time is shown to increase significantly for the carotenoid in the complex, providing further support to previous assertions that long-lived electronic coherences in light-harvesting complexes are facilitated by in-phase motion of the chromophores and surrounding proteins. Using this technique, we are also able to follow the evolution of excited state coherences and find that for carotenoids in the light-harvesting complex the (S 2 |S 0 ) superposition remains coherent for more than 70 fs. In addition to the implications of this long electronic decoherence time, the extended coherence allows us to observe the evolution of the excited state wavepacket. These experiments reveal an enhancement of the vibronic coupling to the first vibrational level of the C-C stretching mode and/or methyl-rocking mode in the ground electronic state 70 fs after the initial excitation. These observations open the door to future experiments and modelling that may be able to resolve the relaxation dynamics of carotenoids in solution and in natural light-harvesting systems.

  6. Scalable coherent interface

    International Nuclear Information System (INIS)

    Alnaes, K.; Kristiansen, E.H.; Gustavson, D.B.; James, D.V.

    1990-01-01

    The Scalable Coherent Interface (IEEE P1596) is establishing an interface standard for very high performance multiprocessors, supporting a cache-coherent-memory model scalable to systems with up to 64K nodes. This Scalable Coherent Interface (SCI) will supply a peak bandwidth per node of 1 GigaByte/second. The SCI standard should facilitate assembly of processor, memory, I/O and bus bridge cards from multiple vendors into massively parallel systems with throughput far above what is possible today. The SCI standard encompasses two levels of interface, a physical level and a logical level. The physical level specifies electrical, mechanical and thermal characteristics of connectors and cards that meet the standard. The logical level describes the address space, data transfer protocols, cache coherence mechanisms, synchronization primitives and error recovery. In this paper we address logical level issues such as packet formats, packet transmission, transaction handshake, flow control, and cache coherence. 11 refs., 10 figs

  7. Measuring coherence with entanglement concurrence

    Science.gov (United States)

    Qi, Xianfei; Gao, Ting; Yan, Fengli

    2017-07-01

    Quantum coherence is a fundamental manifestation of the quantum superposition principle. Recently, Baumgratz et al (2014 Phys. Rev. Lett. 113 140401) presented a rigorous framework to quantify coherence from the view of theory of physical resource. Here we propose a new valid quantum coherence measure which is a convex roof measure, for a quantum system of arbitrary dimension, essentially using the generalized Gell-Mann matrices. Rigorous proof shows that the proposed coherence measure, coherence concurrence, fulfills all the requirements dictated by the resource theory of quantum coherence measures. Moreover, strong links between the resource frameworks of coherence concurrence and entanglement concurrence is derived, which shows that any degree of coherence with respect to some reference basis can be converted to entanglement via incoherent operations. Our work provides a clear quantitative and operational connection between coherence and entanglement based on two kinds of concurrence. This new coherence measure, coherence concurrence, may also be beneficial to the study of quantum coherence.

  8. A tomographic approach to intravenous coronary arteriography

    International Nuclear Information System (INIS)

    Ritman, E.L.; Bove, A.A.

    1986-01-01

    Coronary artery anatomy can be visualized using high speed, volume scanning X-ray CT. A single scan during a bolus injection of contrast medium provides image data for display of all angles of view of the opacified coronary arterial tree. Due to the tomographic nature of volume image data the superposition of contrast filled cardiac chambers, such as would occur in the levophase of an intravenous injection of contrast agent, can be eliminated. Data are presented which support these statements. The Dynamic Spatial Reconstructor (DSR) was used to scan a life-like radiologic phantom of an adult human thorax in which the left atrial and ventricular chambers and the major epicardial coronary arteries were opacified so as to simulate the levophase of an intravenous injection of contrast agent. A catheter filled with diluted contrast agent and with regions of luminal narrowing (i.e. 'stenoses') was advanced along a tract equivalent to a right ventricular catheterization. Ease of visualization of the catheter 'stenoses' and the accuracy with which they can be measured are presented. (Auth.)

  9. Comparison among tomographic reconstruction with limited data

    International Nuclear Information System (INIS)

    Oliveira, Eric F.; Dantas, Carlos C.; Vasconcelos, Daniel A.A.; Cadiz, Luis F.; Melo, Silvio B.

    2011-01-01

    Nowadays there is a continuing interest in applying computed tomography (CT) techniques in non-destructive testing and inspection of many industrial products. These applications of CT usually require a differentiated analysis when there are strong limitations in acquiring a sufficiently large amount of projection data. The use of a low number of tomographic data normally degrades the quality of the reconstructed image, highlighting the formation of artifacts and noise. This work investigates the reconstruction methods most commonly used (FBP, ART, SIRT, MART, SMART) and shows the performance of each one in this limited scenario. For this purpose, all methods were implemented and tested with a phantom of uniform density with well-known distribution, with measures of transmission of gamma radiation in a first generation CT scanner. The phantom is a concentric stainless steel tube coupled with a half - cylinder of aluminum. The measurements were made with an highest root mean square error, with the formation of visible artifacts. The artifacts are diminished but still visible in the ART and SIRT techniques, and the best performance was observed with the techniques MART and SMART. The technical superiority of these multiplicative methods is clearly seen in the reconstructed image quality, endorsing their application to situations of limited input data. (author)

  10. Cone Beam Computed Tomographic imaging in orthodontics.

    Science.gov (United States)

    Scarfe, W C; Azevedo, B; Toghyani, S; Farman, A G

    2017-03-01

    Over the last 15 years, cone beam computed tomographic (CBCT) imaging has emerged as an important supplemental radiographic technique for orthodontic diagnosis and treatment planning, especially in situations which require an understanding of the complex anatomic relationships and surrounding structures of the maxillofacial skeleton. CBCT imaging provides unique features and advantages to enhance orthodontic practice over conventional extraoral radiographic imaging. While it is the responsibility of each practitioner to make a decision, in tandem with the patient/family, consensus-derived, evidence-based clinical guidelines are available to assist the clinician in the decision-making process. Specific recommendations provide selection guidance based on variables such as phase of treatment, clinically-assessed treatment difficulty, the presence of dental and/or skeletal modifying conditions, and pathology. CBCT imaging in orthodontics should always be considered wisely as children have conservatively, on average, a three to five times greater radiation risk compared with adults for the same exposure. The purpose of this paper is to provide an understanding of the operation of CBCT equipment as it relates to image quality and dose, highlight the benefits of the technique in orthodontic practice, and provide guidance on appropriate clinical use with respect to radiation dose and relative risk, particularly for the paediatric patient. © 2017 Australian Dental Association.

  11. Distance weighting for improved tomographic reconstructions

    International Nuclear Information System (INIS)

    Koeppe, R.A.; Holden, J.E.

    1984-01-01

    An improved method for the reconstruction of emission computed axial tomography images has been developed. The method is a modification of filtered back-projection, where the back projected values are weighted to reflect the loss of formation, with distance from the camera, which is inherent in gamma camera imaging. This information loss is a result of: loss of spatial resolution with distance, attenuation, and scatter. The weighting scheme can best be described by considering the contributions of any two opposing views to the reconstruction image pixels. The weight applied to the projections of one view is set to equal the relative amount of the original activity that was initially received in that projection, assuming a uniform attenuating medium. This yields a weighting value which is a function of distance into the image with a value of one for pixels ''near the camera'', a value of .5 at the image center, and a value of zero on the opposite side. Tomographic reconstructions produced with this method show improved spatial resolution when compared to conventional 360 0 reconstructions. The improvement is in the tangential direction, where simulations have indicated a FWHM improvement of 1 to 1.5 millimeters. The resolution in the radial direction is essentially the same for both methods. Visual inspection of the reconstructed images show improved resolution and contrast

  12. Formation of tomographic images with neutrons

    International Nuclear Information System (INIS)

    Duarte, A.; Tenreiro, C; Valencia, J; Steinman, G.; Henriquez, C

    2000-01-01

    The possibility of having a non-destructive method of analysis for archaeological and paleontological samples is of interest. A special group of fossil samples has come to our attention, which because of their value should be preserved and, therefore, the availability of an indirect, non-destructive, non contaminating analytical technique is important. The strong absorption of usual kinds of radiation by a fossilized sample restricts the application of conventional methods of analysis. A type of radiation that is not completely attenuated by thick samples, in sizes that are typical in paleontology, is necessary. Neutrons may be considered as an ideal non-invasive probe with the possibility of developing a technique for the formation and analysis of images. A technique has been developed for the spatial reconstruction of the contents of a fossilized sample (tomography) with neutrons, without touching or altering the sample in any way. The neutron beam was extracted from the RECH-1 reactor belonging to the CCHEN, La Reina. The tomographic images of the contents of a fossilized egg are presented for the first time and represent views or cuts of the content as well as a set that permits the three dimensional reconstruction of the inside of the object and its subsequent animation in graphic format. This project developed a technique for taking neutron radiographs of this kind of sample including the numerical algorithms and the treatment and formation of the images (CW)

  13. Method and apparatus for producing tomographic images

    International Nuclear Information System (INIS)

    Annis, M.

    1989-01-01

    A device useful in producing a tomographic image of a selected slice of an object to be examined is described comprising: a source of penetrating radiation, sweep means for forming energy from the source into a pencil beam and repeatedly sweeping the pencil beam over a line in space to define a sweep plane, first means for supporting an object to be examined so that the pencil beam intersections the object along a path passing through the object and the selected slice, line collimating means for filtering radiation scattered by the object, the line collimating means having a field of view which intersects and sweep plane in a bounded line so that the line collimating means passes only radiation scattered by elementary volumes of the object lying along the bounded line, and line collimating means including a plurality of channels such substantially planar in form to collectively define the field of view, the channels oriented so that pencil beam sweeps along the bounded line as a function of time, and radiation detector means responsive to radiation passed by the line collimating means

  14. Collimator trans-axial tomographic scintillation camera

    International Nuclear Information System (INIS)

    Jaszczak, Ronald J.

    1979-01-01

    An improved collimator is provided for a scintillation camera system that employs a detector head for transaxial tomographic scanning. One object of this invention is to significantly reduce the time required to obtain statistically significant data in radioisotope scanning using a scintillation camera. Another is to increase the rate of acceptance of radioactive events to contribute to the positional information obtainable from a radiation source of known strength without sacrificing spatial resolution. A further object is to reduce the necessary scanning time without degrading the images obtained. The collimator described has apertures defined by septa of different radiation transparency. The septa are aligned to provide greater radiation shielding from gamma radiation travelling within planes perpendicular to the cranial-caudal axis and less radiation shielding from gamma radiation travelling within other planes. Septa may also define apertures such that the collimator provides high spatial resolution of gamma rays traveling within planes perpendicular to the cranial-caudal axis and directed at the detector and high radiation sensitivity to gamma radiation travelling other planes and indicated at the detector. (LL)

  15. The research of clinical application of computed tomographic virtual gastroscopy

    International Nuclear Information System (INIS)

    Zhang Lei; Pan Zhenyu; Zhai Xiaoli; Gu Hua; Wang Yajie; Ding Yi; Wang Li; Liang Ying; Zhai Renyou

    2000-01-01

    Objective: To investigate the values, methods and findings of computed tomographic virtual gastroscopy (CTVG). Methods: Sixty-nine patients underwent the examination of spiral CT after charged air into stomachs in different cubage. The CT scan conditions were collimating width 3 mm, pitch 1.2 - 2.5, scanning speed 0.8 s/360 degree, the raw data of CT volume scan was reconstructed in overlapping rate 33% - 67%. Then the images of CTVG were built using navigator software (GE AG, USA). Results: The accuracy, sensitivity, and specificity of CTVG were 92.8%, 96.4%, and 78.6%, respectively. CTVG corresponded well with fibrous gastroscopy and specimens in demonstrating the gastric lesions. CTVG was provided with the ability of revealing the tiny lesions of chronic atrophic gastritis, chronic erosive gastritis, chronic proliferative gastritis, and acute hemorrhagic gastritis in some degree. The high quality imaging of CTVG could be obtained in condition of collimating width 3 mm, pitch 1.2 - 1.5, overlapping 50% - 67%, well hold-breath, gastric cubage in full and feasible scan positions. Conclusion: CTVG is a rising means of gastric examination and has great value in clinic applications

  16. Computed tomographic mammography using a conventional body scanner.

    Science.gov (United States)

    Chang, C H; Nesbit, D E; Fisher, D R; Fritz, S L; Dwyer, S J; Templeton, A W; Lin, F; Jewell, W R

    1982-03-01

    The technique for computed tomographic (CT) examination of the breasts using a conventional body scanner is described, and experience with 67 patients is reported. In the diagnosis of both malignant and benign breast lesions, the results with a body scanner were equal to those of a dedicated CT/M mammographic unit. Although the CT study of the breast cannot replace conventional mammography in screening or in routine diagnostic workup, the unique capability of demonstrating both anatomic changes and increased iodide concentration in a cancer provides many advantages over conventional mammography. CT mammography appears to have the capability to detect breast cancers that are occult to other methods. Indications for a CT study of the breasts are: (1) clinically suspected breast cancer, especially with a mammographically occult lesion; (2) questionable mammographic findings, including microcalcifications, tumor shape, architectural distortion, and uncertain lesion location; and (3) evaluation of postbiopsy or postlumpectomy breast cancers when a primary irradiation therapy is contemplated. Breast CT also appears to be a valuable diagnostic tool in searching for a second primary breast cancer, follow-up study of postirradiation of breast cancer, followup study for postmastectomy patients, and screening procedure for genetically high-risk patients, especially those with dense breasts.

  17. Coherence properties of the radiation from FLASH

    International Nuclear Information System (INIS)

    Schneidmiller, E.A.; Yurkov, M.V.

    2015-02-01

    FLASH is the first free electron laser user facility operating in the vacuum ultraviolet and soft x-ray wavelength range. Many user experiments require knowledge of the spatial and temporal coherence properties of the radiation. In this paper we present an analysis of the coherence properties of the radiation for the fundamental and for the higher odd frequency harmonics. We show that temporal and spatial coherence reach maximum close to the FEL saturation but may degrade significantly in the post-saturation regime. We also find that the pointing stability of short FEL pulses is limited due to the fact that non-azimuthal FEL eigenmodes are not sufficiently suppressed. We discuss possible ways for improving the degree of transverse coherence and the pointing stability.

  18. Computed tomographic study of 50 patients with hypodense hepatic injuries in childhood; Estudo de 50 casos por tomografia computadorizada de lesoes hipodensas hepaticas fundamentais na infancia

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Ines Minniti Rodrigues; Alvares, Beatriz Regina; Baracat, Jamal; Martins, Daniel Lahan [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Ciencias Medicas. Dept. de Radiologia]. E-mail: iminniti@fcm.unicamp.br; Pereira, Ricardo Minniti Rodrigues [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Ciencias Medicas

    2006-03-15

    Objective: To describe the different tomographic findings in hypodense hepatic lesions in children and its differential diagnosis. Materials and methods: computed tomographic studies were obtained from 50 patients (age range: 0-16 years) with low-density liver lesions previously diagnosed by ultrasound. Images were made before and after administration of intravenous contrast medium. Image findings were analyzed and afterwards correlated with anatomopathological diagnosis. Results: forty-seven of 50 cases were confirmed, 30 by anatomopathological diagnosis. Most of then were benign lesions, hemangioma in 20%. Such lesions presented a homogeneous contrast absorption, mainly at the delayed phase, differing from malignant lesions. Metastasis was the most frequently found malignant lesion (18%). Conclusion: computed tomographic study is of great value in complementing the diagnosis of hypodense hepatic lesions in children, and must follow ultrasound diagnosis as a routine procedure. (author)

  19. Computed tomographic features of lymphangioleiomyomatosis: Evaluation in 138 patients

    Energy Technology Data Exchange (ETDEWEB)

    Tobino, Kazunori, E-mail: tobino@juntendo.ac.jp [Department of Respiratory Medicine, Iizuka Hospital, 3-83 Yoshiomachi, Iizuka, Fukuoka 820-0018 (Japan); Division of Respiratory Medicine, Juntendo University Faculty of Medicine & Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-Ku, Tokyo 113-8421 (Japan); The Study Group of Pneumothorax and Cystic Lung Diseases, 4-8-1 Seta, Setagaya-Ku, Tokyo 158-0095 (Japan); Johkoh, Takeshi [Department of Radiology, Kinki Central Hospital of Mutual Aid Association of Public School Teachers, Kurumazuka 3-1, Itami, Hyogo 664-0872 (Japan); Fujimoto, Kiminori [Department of Radiology, Kurume University School of Medicine and Center for Diagnostic Imaging, Kurume University Hospital, 67 Asahi-machi, Kurume, Fukuoka 830-0011 (Japan); Sakai, Fumikazu [Department of Diagnostic Radiology, Saitama International Medical Center, Saitama Medical University, 1397-1 Yamane, Hidaka, Saitama 350-1298 (Japan); Arakawa, Hiroaki [Department of Radiology, Dokkyo Medical University, 880 Kita-Kobayashi, Mibu, Tochigi 321-0293 (Japan); Kurihara, Masatoshi [The Study Group of Pneumothorax and Cystic Lung Diseases, 4-8-1 Seta, Setagaya-Ku, Tokyo 158-0095 (Japan); Pneumothorax Center, Nissan Tamagawa Hospital, 4-8-1 Seta, Setagaya-Ku, Tokyo 158-0095 (Japan); Kumasaka, Toshio [The Study Group of Pneumothorax and Cystic Lung Diseases, 4-8-1 Seta, Setagaya-Ku, Tokyo 158-0095 (Japan); Department of Pathology, Japanese Red Cross Medical Center, 4-1-22 Hiroo, Shibuya-Ku, Tokyo 150-0012 (Japan); Koike, Kengo; Takahashi, Kazuhisa [Division of Respiratory Medicine, Juntendo University Faculty of Medicine & Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-Ku, Tokyo 113-8421 (Japan); Seyama, Kuniaki [Division of Respiratory Medicine, Juntendo University Faculty of Medicine & Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-Ku, Tokyo 113-8421 (Japan); The Study Group of Pneumothorax and Cystic Lung Diseases, 4-8-1 Seta, Setagaya-Ku, Tokyo 158-0095 (Japan)

    2015-03-15

    Highlights: •In our series, the frequency of pulmonary nodules was higher than in the previous reports. •Our sporadic LAM patients had a lower frequency of renal AML than in that of previous reports. •LAM patients may have a high incidence of renal and hepatic cysts. •LAM cells may originate in the pelvis then spread via the axial lymphatic system. -- Abstract: Purpose: The aim was to characterize the computed tomographic (CT) findings from Japanese patients with lymphangioleiomyomatosis (LAM). Materials and methods: CT scans of the chest, abdomen, and pelvis from 124 patients with sporadic LAM (S-LAM, mean age, 37.4 years) and 14 patients with tuberous sclerosis complex (TSC)-LAM (mean age, 35.6 years) were analyzed. Results: Pulmonary nodules (18.8%) and hepatic angiomyolipoma (AML, 24.3%) were more common in our patients than those in previous reports. Compared with TSC-LAM, S-LAM group had a higher frequency of pulmonary nodules (28.6% vs 32.3%, P < 0.01) and lower frequencies of air-space consolidation (21.4% vs 2.4%, P < 0.01), pneumothorax (28.6% vs 8.1%, P = 0.02), pulmonary hilar lymphadenopathy (14.3% vs 0.8%, P < 0.01), renal AML (85.7% vs 17.4%, P < 0.01), hepatic AML (71.4% vs 17.4%, P < 0.01), and retrocrural lymphadenopathy (14.3% vs 1.4%, P = 0.04). Axial lymphatic abnormalities (i.e., thoracic duct dilatation, lymphadenopathy, and lymphangioleiomyoma) were most common in the pelvis and tended to decrease in incidence with increased distance from the pelvis. Conclusion: The incidence of some CT findings in Japanese patients differed from those in previous reports. Axial lymphatic abnormalities noted here suggest that the origin of LAM cells may be the pelvis.

  20. Intracoronary optical coherence tomography

    DEFF Research Database (Denmark)

    Tenekecioglu, Erhan; Albuquerque, Felipe N; Sotomi, Yohei

    2017-01-01

    By providing valuable information about the coronary artery wall and lumen, intravascular imaging may aid in optimizing interventional procedure results and thereby could improve clinical outcomes following percutaneous coronary intervention (PCI). Intravascular optical coherence tomography (OCT...

  1. Coherent imaging at FLASH

    International Nuclear Information System (INIS)

    Chapman, H N; Bajt, S; Duesterer, S; Treusch, R; Barty, A; Benner, W H; Bogan, M J; Frank, M; Hau-Riege, S P; Woods, B W; Boutet, S; Cavalleri, A; Hajdu, J; Iwan, B; Seibert, M M; Timneanu, N; Marchesini, S; Sakdinawat, A; Sokolowski-Tinten, K

    2009-01-01

    We have carried out high-resolution single-pulse coherent diffractive imaging at the FLASH free-electron laser. The intense focused FEL pulse gives a high-resolution low-noise coherent diffraction pattern of an object before that object turns into a plasma and explodes. In particular we are developing imaging of biological specimens beyond conventional radiation damage resolution limits, developing imaging of ultrafast processes, and testing methods to characterize and perform single-particle imaging.

  2. Thanatophoric dysplasia: case report of an autopsy complemented by postmortem computed tomographic study

    Directory of Open Access Journals (Sweden)

    Éber Emanuel Mayoral

    2014-06-01

    Full Text Available Thanatophoric dysplasia (TD is one of the most common lethal skeletal dysplasias, which was first designated as thanatophoric dwarfism and described in 1967. The authors report a case of a Caucasian girl with TD, born to a 31-year-old woman without comorbidities. The newborn presented respiratory distress immediately after delivery, progressing to death in less than 2 hours. An autopsy was carried out after postmortem tomographic examination. The autopsy findings depicted extensive malformations of the skeletal system and the brain. The aim of this report is to discuss the pathogenesis and correlate the morphologic features of TD that were disclosed at the tomography and the autopsy.

  3. A tomographic test of cosmological principle using the JLA compilation of type Ia supernovae

    Science.gov (United States)

    Chang, Zhe; Lin, Hai-Nan; Sang, Yu; Wang, Sai

    2018-05-01

    We test the cosmological principle by fitting a dipolar modulation of distance modulus and searching for an evolution of this modulation with respect to cosmological redshift. Based on a redshift tomographic method, we divide the Joint Light-curve Analysis compilation of supernovae of type Ia into different redshift bins, and employ a Markov-Chain Monte-Carlo method to infer the anisotropic amplitude and direction in each redshift bin. However, we do not find any significant deviations from the cosmological principle, and the anisotropic amplitude is stringently constrained to be less than a few thousandths at 95% confidence level.

  4. The computed tomographic appearance of cerebral cysticercosis in adults and children

    International Nuclear Information System (INIS)

    Byrd, S.E.; Locke, G.E.; Biggers, S.; Percy, A.K.

    1982-01-01

    The computed tomographic (CT) scans of 45 patients (30 adults, 15 children) with cerebral cysticercosis were reviewed. These patients had undergone complete diagnostic evaluations including skin tests, laboratory tests, plain skull radiography, radionuclide brain scanning, CT, and cerebral angiography. All of these tests were unrewarding except CT and the indirect hemagglutination tests on the serum. A classification of cerebral cysticercosis based on the location of the lesions in the brain and the CT appearance was developed. Cerebral cysticercosis can be diagnosed by CT findings when there is also a history of seizures and of the patient having lived in an area where the disease is endemic

  5. Painlevé IV coherent states

    International Nuclear Information System (INIS)

    Bermudez, David; Contreras-Astorga, Alonso; Fernández C, David J.

    2014-01-01

    A simple way to find solutions of the Painlevé IV equation is by identifying Hamiltonian systems with third-order differential ladder operators. Some of these systems can be obtained by applying supersymmetric quantum mechanics (SUSY QM) to the harmonic oscillator. In this work, we will construct families of coherent states for such subset of SUSY partner Hamiltonians which are connected with the Painlevé IV equation. First, these coherent states are built up as eigenstates of the annihilation operator, then as displaced versions of the extremal states, both involving the related third-order ladder operators, and finally as extremal states which are also displaced but now using the so called linearized ladder operators. To each SUSY partner Hamiltonian corresponds two families of coherent states: one inside the infinite subspace associated with the isospectral part of the spectrum and another one in the finite subspace generated by the states created through the SUSY technique. - Highlights: • We use SUSY QM to obtain Hamiltonians with third-order differential ladder operators. • We show that these systems are related with the Painlevé IV equation. • We apply different definitions of coherent states to these Hamiltonians using the third-order ladder operators and some linearized ones. • We construct families of coherent states for such systems, which we called Painlevé IV coherent states

  6. Painlevé IV coherent states

    Energy Technology Data Exchange (ETDEWEB)

    Bermudez, David, E-mail: david.bermudez@weizmann.ac.il [Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100 (Israel); Departamento de Física, Cinvestav, A.P. 14-740, 07000 México D.F. (Mexico); Contreras-Astorga, Alonso, E-mail: aloncont@iun.edu [Department of Mathematics and Actuarial Science, Indiana University Northwest, 3400 Broadway, Gary IN 46408 (United States); Departamento de Física, Cinvestav, A.P. 14-740, 07000 México D.F. (Mexico); Fernández C, David J., E-mail: david@fis.cinvestav.mx [Departamento de Física, Cinvestav, A.P. 14-740, 07000 México D.F. (Mexico)

    2014-11-15

    A simple way to find solutions of the Painlevé IV equation is by identifying Hamiltonian systems with third-order differential ladder operators. Some of these systems can be obtained by applying supersymmetric quantum mechanics (SUSY QM) to the harmonic oscillator. In this work, we will construct families of coherent states for such subset of SUSY partner Hamiltonians which are connected with the Painlevé IV equation. First, these coherent states are built up as eigenstates of the annihilation operator, then as displaced versions of the extremal states, both involving the related third-order ladder operators, and finally as extremal states which are also displaced but now using the so called linearized ladder operators. To each SUSY partner Hamiltonian corresponds two families of coherent states: one inside the infinite subspace associated with the isospectral part of the spectrum and another one in the finite subspace generated by the states created through the SUSY technique. - Highlights: • We use SUSY QM to obtain Hamiltonians with third-order differential ladder operators. • We show that these systems are related with the Painlevé IV equation. • We apply different definitions of coherent states to these Hamiltonians using the third-order ladder operators and some linearized ones. • We construct families of coherent states for such systems, which we called Painlevé IV coherent states.

  7. Polarization Sensitive Coherent Raman Measurements of DCVJ

    Science.gov (United States)

    Anderson, Josiah; Cooper, Nathan; Lawhead, Carlos; Shiver, Tegan; Ujj, Laszlo

    2014-03-01

    Coherent Raman spectroscopy which recently developed into coherent Raman microscopy has been used to produce label free imaging of thin layers of material and find the spatial distributions of certain chemicals within samples, e.g. cancer cells.(1) Not all aspects of coherent scattering have been used for imaging. Among those for example are special polarization sensitive measurements. Therefore we have investigated the properties of polarization sensitive CARS spectra of a highly fluorescent molecule, DCVJ.(2) Spectra has been recorded by using parallel polarized and perpendicular polarized excitations. A special polarization arrangement was developed to suppress the non-resonant background scattering from the sample. These results can be used to improve the imaging properties of a coherent Raman microscope in the future. This is the first time coherent Raman polarization sensitive measurements have been used to characterize the vibrational modes of DCVJ. 1: K. I. Gutkowski, et al., ``Fluorescence of dicyanovinyl julolidine in a room temperature ionic liquid '' Chemical Physics Letters 426 (2006) 329 - 333 2: Fouad El-Diasty, ``Coherent anti-Stokes Raman scattering: Spectroscopy and microscopy'' Vibrational Spectroscopy 55 (2011) 1-37

  8. Computed Tomographic Perfusion Improves Diagnostic Power of Coronary Computed Tomographic Angiography in Women

    DEFF Research Database (Denmark)

    Penagaluri, Ashritha; Higgins, Angela Y.; Vavere, Andrea L

    2016-01-01

    laboratories. Prevalence of flow-limiting CAD defined by invasive coronary angiography equal to 50% or greater with an associated single-photon emission computed tomography myocardial perfusion imaging defect was 45% (114/252) and 23% (30/129) in males and females, respectively. Patient-based diagnostic......Background-Coronary computed tomographic angiography (CTA) and myocardial perfusion imaging (CTP) is a validated approach for detection and exclusion of flow-limiting coronary artery disease (CAD), but little data are available on gender-specific performance of these modalities. In this study, we...... aimed to evaluate the diagnostic accuracy of combined coronary CTA and CTP in detecting flow-limiting CAD in women compared with men.  Methods and Results-Three hundred and eighty-one patients who underwent both CTA-CTP and single-photon emission computed tomography myocardial perfusion imaging...

  9. Correction of ring artifacts in X-ray tomographic images

    DEFF Research Database (Denmark)

    Lyckegaard, Allan; Johnson, G.; Tafforeau, P.

    2011-01-01

    Ring artifacts are systematic intensity distortions located on concentric circles in reconstructed tomographic X-ray images. When using X-ray tomography to study for instance low-contrast grain boundaries in metals it is crucial to correct for the ring artifacts in the images as they may have...... the same intensity level as the grain boundaries and thus make it impossible to perform grain segmentation. This paper describes an implementation of a method for correcting the ring artifacts in tomographic X-ray images of simple objects such as metal samples where the object and the background...... are separable. The method is implemented in Matlab, it works with very little user interaction and may run in parallel on a cluster if applied to a whole stack of images. The strength and robustness of the method implemented will be demonstrated on three tomographic X-ray data sets: a mono-phase β...

  10. A tomograph VMEbus parallel processing data acquisition system

    International Nuclear Information System (INIS)

    Wilkinson, N.A.; Rogers, J.G.; Atkins, M.S.

    1989-01-01

    This paper describes a VME based data acquisition system suitable for the development of Positron Volume Imaging tomographs which use 3-D data for improved image resolution over slice-oriented tomographs. the data acquisition must be flexible enough to accommodate several 3-D reconstruction algorithms; hence, a software-based system is most suitable. Furthermore, because of the increased dimensions and resolution of volume imaging tomographs, the raw data event rate is greater than that of slice-oriented machines. These dual requirements are met by our data acquisition system. Flexibility is achieved through an array of processors connected over a VMEbus, operating asynchronously and in parallel. High raw data throughput is achieved using a dedicated high speed data transfer device available for the VMEbus. The device can attain a raw data rate of 2.5 million coincidence events per second for raw events which are 64 bits wide

  11. Coherent structures in tokamak plasmas workshop: Proceedings

    International Nuclear Information System (INIS)

    Koniges, A.E.; Craddock, G.G.

    1992-08-01

    Coherent structures have the potential to impact a variety of theoretical and experimental aspects of tokamak plasma confinement. This includes the basic processes controlling plasma transport, propagation and efficiency of external mechanisms such as wave heating and the accuracy of plasma diagnostics. While the role of coherent structures in fluid dynamics is better understood, this is a new topic for consideration by plasma physicists. This informal workshop arose out of the need to identify the magnitude of structures in tokamaks and in doing so, to bring together for the first time the surprisingly large number of plasma researchers currently involved in work relating to coherent structures. The primary purpose of the workshop, in addition to the dissemination of information, was to develop formal and informal collaborations, set the stage for future formation of a coherent structures working group or focus area under the heading of the Tokamak Transport Task Force, and to evaluate the need for future workshops on coherent structures. The workshop was concentrated in four basic areas with a keynote talk in each area as well as 10 additional presentations. The issues of discussion in each of these areas was as follows: Theory - Develop a definition of structures and coherent as it applies to plasmas. Experiment - Review current experiments looking for structures in tokamaks, discuss experimental procedures for finding structures, discuss new experiments and techniques. Fluids - Determine how best to utilize the resource of information available from the fluids community both on the theoretical and experimental issues pertaining to coherent structures in plasmas. Computation - Discuss computational aspects of studying coherent structures in plasmas as they relate to both experimental detection and theoretical modeling

  12. Generalized Row-Action Methods for Tomographic Imaging

    DEFF Research Database (Denmark)

    Andersen, Martin Skovgaard; Hansen, Per Christian

    2014-01-01

    Row-action methods play an important role in tomographic image reconstruction. Many such methods can be viewed as incremental gradient methods for minimizing a sum of a large number of convex functions, and despite their relatively poor global rate of convergence, these methods often exhibit fast...... initial convergence which is desirable in applications where a low-accuracy solution is acceptable. In this paper, we propose relaxed variants of a class of incremental proximal gradient methods, and these variants generalize many existing row-action methods for tomographic imaging. Moreover, they allow...

  13. Stimulated coherent transition radiation

    International Nuclear Information System (INIS)

    Hung-chi Lihn.

    1996-03-01

    Coherent radiation emitted from a relativistic electron bunch consists of wavelengths longer than or comparable to the bunch length. The intensity of this radiation out-numbers that of its incoherent counterpart, which extends to wavelengths shorter than the bunch length, by a factor equal to the number of electrons in the bunch. In typical accelerators, this factor is about 8 to 11 orders of magnitude. The spectrum of the coherent radiation is determined by the Fourier transform of the electron bunch distribution and, therefore, contains information of the bunch distribution. Coherent transition radiation emitted from subpicosecond electron bunches at the Stanford SUNSHINE facility is observed in the far-infrared regime through a room-temperature pyroelectric bolometer and characterized through the electron bunch-length study. To measure the bunch length, a new frequency-resolved subpicosecond bunch-length measuring system is developed. This system uses a far-infrared Michelson interferometer to measure the spectrum of coherent transition radiation through optical autocorrelation with resolution far better than existing time-resolved methods. Hence, the radiation spectrum and the bunch length are deduced from the autocorrelation measurement. To study the stimulation of coherent transition radiation, a special cavity named BRAICER is invented. Far-infrared light pulses of coherent transition radiation emitted from electron bunches are delayed and circulated in the cavity to coincide with subsequent incoming electron bunches. This coincidence of light pulses with electron bunches enables the light to do work on electrons, and thus stimulates more radiated energy. The possibilities of extending the bunch-length measuring system to measure the three-dimensional bunch distribution and making the BRAICER cavity a broadband, high-intensity, coherent, far-infrared light source are also discussed

  14. KiDS-450: tomographic cross-correlation of galaxy shear with Planck lensing

    Science.gov (United States)

    Harnois-Déraps, Joachim; Tröster, Tilman; Chisari, Nora Elisa; Heymans, Catherine; van Waerbeke, Ludovic; Asgari, Marika; Bilicki, Maciej; Choi, Ami; Erben, Thomas; Hildebrandt, Hendrik; Hoekstra, Henk; Joudaki, Shahab; Kuijken, Konrad; Merten, Julian; Miller, Lance; Robertson, Naomi; Schneider, Peter; Viola, Massimo

    2017-10-01

    We present the tomographic cross-correlation between galaxy lensing measured in the Kilo Degree Survey (KiDS-450) with overlapping lensing measurements of the cosmic microwave background (CMB), as detected by Planck 2015. We compare our joint probe measurement to the theoretical expectation for a flat Λ cold dark matter cosmology, assuming the best-fitting cosmological parameters from the KiDS-450 cosmic shear and Planck CMB analyses. We find that our results are consistent within 1σ with the KiDS-450 cosmology, with an amplitude re-scaling parameter AKiDS = 0.86 ± 0.19. Adopting a Planck cosmology, we find our results are consistent within 2σ, with APlanck = 0.68 ± 0.15. We show that the agreement is improved in both cases when the contamination to the signal by intrinsic galaxy alignments is accounted for, increasing A by ∼0.1. This is the first tomographic analysis of the galaxy lensing - CMB lensing cross-correlation signal, and is based on five photometric redshift bins. We use this measurement as an independent validation of the multiplicative shear calibration and of the calibrated source redshift distribution at high redshifts. We find that constraints on these two quantities are strongly correlated when obtained from this technique, which should therefore not be considered as a stand-alone competitive calibration tool.

  15. Elastic energies of coherent germanium islands on silicon

    International Nuclear Information System (INIS)

    Vanderbilt, D.; Wickham, L.K.

    1991-01-01

    Motivated by recent observations of coherent Ge island formation during growth of Ge on Si (100), the authors of this paper have carried out a theoretical study of the elastic energies associated with the evolution of a uniform strained overlayer as it segregates into coherent islands. In the context of a two-dimensional model, the authors have explored the conditions under which coherent islands may be energetically favored over both uniform epitaxial films and dislocated islands. The authors find that if the interface energy (for dislocated islands) is more than about 15% of the surface energy, then there is a range of island sizes for which the coherent island structure is preferred

  16. Orthopedic applications of single photon emission computed Tomographic bone scanning

    International Nuclear Information System (INIS)

    Collier, B.D.

    1987-01-01

    When compared with planar bone scanning, single photon emission computed tomography (SPECT) has technical advantages of potential diagnostic significance. Planar imaging often superimposes substantial underlying or overlying activity on the bony structure of medical interest. SPECT, however, can be used to remove such unwanted activity. For example, in the hip the acetabulum extends downwards behind the femoral head. Therefore when using planar bone scanning techniques, the photon-deficient defect typical of avascular necrosis (AVN) of the femoral had may be obscured by activity originating in the underlying acetabulum. By using SPECT, underlying and overlying distributions of activity can be separated into sequential tomographic planes. For this reason SPECT facilitates the detection of AVN of the femoral head. When referring a patient without a history of malignancy for bone scanning, the orthopaedic surgeon usually has a specific clinical question involving a limited portion of the skeleton. Orthopaedic surgeons at their institution commonly use bone scanning to clarify the cause of back, hip or knee pain; to determine with a physiological test the significance of radiographic findings; and to establish the extent of disease at symptomatic skeletal sites such as the three compartments of the knee. In instances such as these, when clinical concern is limited to a specific anatomical region, a bone scan procedure that includes SPECT imaging of only a portion of the skeleton is appropriate. To date, SPECT of the skeletal system has most frequently been used to evaluate patients with pain the larger joints and bony structures such as the lumbar spine, hips, knees, or temporomandibular joints (TMJ)

  17. COMPUTED TOMOGRAPHIC EVALUATION OF POSTERIOR REVERSIBLE ENCEPHALOPATHY SYNDROME

    Directory of Open Access Journals (Sweden)

    Vishwaprem Raj

    2016-04-01

    Full Text Available BACKGROUND AND PURPOSE Posterior Reversible Encephalopathy Syndrome (PRES is a neurotoxic state that occurs secondary to the inability of posterior circulation to autoregulate. The clinical spectrum and the underlying pathophysiology are still poorly defined. No conclusive evidence has been put forward regarding the relationship between clinical conditions and specific imaging findings of severity or location of oedema. PURPOSE To assess the role of computed tomography in evaluation of Posterior Reversible Encephalopathy Syndrome. MATERIALS AND METHODS 55 patients referred to the Department of Radio-Diagnosis, with a history of neurological abnormalities, including altered mental function, visual loss, stupor with a predisposing history favouring PRES and followed up for a period of 10 – 30 days. RESULTS 21 patients (38.2% were females. 32 patients (58.1% were in the age group between 21 to 30 years. Predisposing condition; 16 (29.1% presented with pre-eclampsia, 12 (21.8% with post-partum status in altered sensorium, 9 (16.4% with seizures, 7 (12.7% with hypertension, 6 (10.9% with visual disturbances, 4 (7.3% with eclampsia and 1 (1.8% with uraemia. 20 cases (36.4% showed findings suggestive of posterior reversible encephalopathy syndrome on initial computed tomography examination. 35 cases showed no initial radiological evidence suggestive of posterior reversible encephalopathy syndrome. Of the 20 cases which showed computed tomographic evidence of posterior reversible encephalopathy syndrome, recovery was noted in 5 cases (9.1%. Persistence of findings detected on first CT was noted in 13 patients (23.6%. Regional predominance of the lesions was as follows. Frontal lobe (39%, Parietal lobe (32%, Temporal lobe (15% and occipital lobe (15%. CONCLUSION Varied clinical manifestations are associated with anatomical findings recognisable by neuro-imaging as PRES. Prompt imaging is necessary for the recognition of the condition and appropriate

  18. SAR image effects on coherence and coherence estimation.

    Energy Technology Data Exchange (ETDEWEB)

    Bickel, Douglas Lloyd

    2014-01-01

    Radar coherence is an important concept for imaging radar systems such as synthetic aperture radar (SAR). This document quantifies some of the effects in SAR which modify the coherence. Although these effects can disrupt the coherence within a single SAR image, this report will focus on the coherence between separate images, such as for coherent change detection (CCD) processing. There have been other presentations on aspects of this material in the past. The intent of this report is to bring various issues that affect the coherence together in a single report to support radar engineers in making decisions about these matters.

  19. COHERENT Experiment: current status

    International Nuclear Information System (INIS)

    Akimov, D; Belov, V; Bolozdynya, A; Burenkov, A; Albert, J B; Del Valle Coello, M; D’Onofrio, M; Awe, C; Barbeau, P S; Cervantes, M; Becker, B; Cabrera-Palmer, B; Collar, J I; Cooper, R J; Cooper, R L; Cuesta, C; Detwiler, J; Eberhardt, A; Dean, D; Dolgolenko, A G

    2017-01-01

    The COHERENT Collaboration is realizing a long term neutrino physics research program. The main goals of the program are to detect and study elastic neutrino-nucleus scattering (CEνNS). This process is predicted by Standard Model but it has never been observed experimentally because of the very low energy of the recoil nucleus. COHERENT is using different detector technologies: CsI[Na] and NaI scintillator crystals, a single-phase liquid Ar and a Ge detectors. The placement of all the detector setups is in the basement of the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). The current status of the COHERENT experimental program is presented. (paper)

  20. Radiological findings of Currarino's triad - a case report and review of the literature

    International Nuclear Information System (INIS)

    Machado Junior, Marcos Alberto; Barbosa, Veronica Aline de Oliveira; Rocha, Josilton Antonio; Ferreira, Eliane Fiuza; Maximo, Marcia Andrade; Castro, Luiz Eduardo; Vieira, Lauro Conceicao

    1998-01-01

    The authors report a child case with congenital malformation Currarino triad characterized by a rare complex of a congenital sacral bony abnormality, anorectal malformation and a presacral mass. A bibliographic review was done, focusing the radiological and tomographic findings. (author)

  1. Temporal Coherence Strategies for Augmented Reality Labeling

    DEFF Research Database (Denmark)

    Madsen, Jacob Boesen; Tatzgern, Markus; Madsen, Claus B.

    2016-01-01

    Temporal coherence of annotations is an important factor in augmented reality user interfaces and for information visualization. In this paper, we empirically evaluate four different techniques for annotation. Based on these findings, we follow up with subjective evaluations in a second experiment...

  2. Tomographic spectral imaging: microanalysis in 3D

    International Nuclear Information System (INIS)

    Kotula, P.G.; Keenan, M.R.; Michael, J.R.

    2003-01-01

    Full text: Spectral imaging, where a series of complete x-ray spectra are typically collected from a 2D area, holds great promise for comprehensive near-surface microanalysis. There are however numerous microanalysis problems where 3D chemical information is needed as well. In the SEM, some sort of sectioning (either mechanical or with a focused ion beam (FIB) tool) followed by x-ray mapping has, in the past, been utilized in an attempt to perform 3D microanalysis. Reliance on simple mapping has the potential to miss important chemical features as well as misidentify others. In this paper we will describe the acquisition of serial-section tomographic spectral images (TSI) with a dual-beam FIB/SEM equipped with an EDS system. We will also describe the application of a modified version of our multivariate statistical analysis algorithms to TSIs. Serial sectioning was performed with a FEI DB-235 FIB/SEM. Firstly, the specimen normal was tilted to the optic axis of the FIB column and a trench was milled into the surface of the specimen. A second trench was then milled perpendicular to the first to provide visibility of the entire analysis surface to the x-ray detector. In addition, several fiducial markers were milled into the surface to allow for alignment from slice to slice. The electron column is at an angle of 52 deg to the ion column so the electron beam can 'see' the analysis surface milled by the FIB with no additional specimen tilting or rotation. Likewise the x-ray detector is at a radial angle of 45 deg to the plane of the electron and ion columns (about the electron column) and a take-off-angle of 35 deg with respect to an untilted specimen so it can 'see' the analysis surface as well with no additional sample tilting or rotation. Spectral images were acquired from regions 40 μm wide and 20μm deep for each slice. Approximately 1μm/slice was milled and 10-12 total slices were cut. Spectral images were acquired with a Thermo NORAN Vantage (Digital imaging

  3. Maintaining Web Cache Coherency

    Directory of Open Access Journals (Sweden)

    2000-01-01

    Full Text Available Document coherency is a challenging problem for Web caching. Once the documents are cached throughout the Internet, it is often difficult to keep them coherent with the origin document without generating a new traffic that could increase the traffic on the international backbone and overload the popular servers. Several solutions have been proposed to solve this problem, among them two categories have been widely discussed: the strong document coherency and the weak document coherency. The cost and the efficiency of the two categories are still a controversial issue, while in some studies the strong coherency is far too expensive to be used in the Web context, in other studies it could be maintained at a low cost. The accuracy of these analysis is depending very much on how the document updating process is approximated. In this study, we compare some of the coherence methods proposed for Web caching. Among other points, we study the side effects of these methods on the Internet traffic. The ultimate goal is to study the cache behavior under several conditions, which will cover some of the factors that play an important role in the Web cache performance evaluation and quantify their impact on the simulation accuracy. The results presented in this study show indeed some differences in the outcome of the simulation of a Web cache depending on the workload being used, and the probability distribution used to approximate updates on the cached documents. Each experiment shows two case studies that outline the impact of the considered parameter on the performance of the cache.

  4. Design and applications of Computed Industrial Tomographic Imaging System (CITIS)

    Energy Technology Data Exchange (ETDEWEB)

    Ramakrishna, G S; Kumar, Umesh; Datta, S S [Bhabha Atomic Research Centre, Bombay (India). Isotope Div.

    1994-12-31

    This paper highlights the design and development of a prototype Computed Tomographic (CT) imaging system and its software for image reconstruction, simulation and display. It also describes results obtained with several test specimens including Dhruva reactor uranium fuel assembly and possibility of using neutrons as well as high energy x-rays in computed tomography. 5 refs., 4 figs.

  5. Computer tomographic detection of an intraspinal arachnoidal cyst

    Energy Technology Data Exchange (ETDEWEB)

    Kuckein, D; Walter, K; Paal, G

    1981-03-01

    A 46 year old female patient who after 3-4 weeks of influenza suffered from strong headaches, vomiting and rotatory vertigo was subjected to a myelograph and then to a computerized tomographic investigation due to suspect cerebrospinal fluid. The computerized tomography is better than the myelography in diagnosing intraspinal arachnoidal cysts, however this should be preceded by most accurate possible segment location.

  6. Comparison of the practical diagnostic value of different tomographic movements

    International Nuclear Information System (INIS)

    Laehde, S.; Vuoria, P.

    1977-01-01

    The practical results of linear and circular tomography with angles of 6, 20, 30 and 45 degrees and spiral tomography were compared. The spiral proved to be suitable as a tomographic movement for different purposes. In zonography, circular movement with 6 degrees of deviation proved suitable. The linear movement presented no advantages when compared with the multidirectional movements. ( orig.) [de

  7. Tomographic Particle Image Velocimetry using Smartphones and Colored Shadows

    KAUST Repository

    Aguirre-Pablo, Andres A.; Alarfaj, Meshal K.; Li, Erqiang; Hernandez Sanchez, Jose Federico; Thoroddsen, Sigurdur T

    2017-01-01

    We demonstrate the viability of using four low-cost smartphone cameras to perform Tomographic PIV. We use colored shadows to imprint two or three different time-steps on the same image. The back-lighting is accomplished with three sets

  8. Expediting model-based optoacoustic reconstructions with tomographic symmetries

    International Nuclear Information System (INIS)

    Lutzweiler, Christian; Deán-Ben, Xosé Luís; Razansky, Daniel

    2014-01-01

    Purpose: Image quantification in optoacoustic tomography implies the use of accurate forward models of excitation, propagation, and detection of optoacoustic signals while inversions with high spatial resolution usually involve very large matrices, leading to unreasonably long computation times. The development of fast and memory efficient model-based approaches represents then an important challenge to advance on the quantitative and dynamic imaging capabilities of tomographic optoacoustic imaging. Methods: Herein, a method for simplification and acceleration of model-based inversions, relying on inherent symmetries present in common tomographic acquisition geometries, has been introduced. The method is showcased for the case of cylindrical symmetries by using polar image discretization of the time-domain optoacoustic forward model combined with efficient storage and inversion strategies. Results: The suggested methodology is shown to render fast and accurate model-based inversions in both numerical simulations andpost mortem small animal experiments. In case of a full-view detection scheme, the memory requirements are reduced by one order of magnitude while high-resolution reconstructions are achieved at video rate. Conclusions: By considering the rotational symmetry present in many tomographic optoacoustic imaging systems, the proposed methodology allows exploiting the advantages of model-based algorithms with feasible computational requirements and fast reconstruction times, so that its convenience and general applicability in optoacoustic imaging systems with tomographic symmetries is anticipated

  9. Optical Coherence Tomography

    DEFF Research Database (Denmark)

    Mogensen, Mette; Themstrup, Lotte; Banzhaf, Christina

    2014-01-01

    Optical coherence tomography (OCT) has developed rapidly since its first realisation in medicine and is currently an emerging technology in the diagnosis of skin disease. OCT is an interferometric technique that detects reflected and backscattered light from tissue and is often described as the o......Optical coherence tomography (OCT) has developed rapidly since its first realisation in medicine and is currently an emerging technology in the diagnosis of skin disease. OCT is an interferometric technique that detects reflected and backscattered light from tissue and is often described...

  10. Coherent light microscopy

    CERN Document Server

    Ferraro, Pietro; Zalevsky, Zeev

    2011-01-01

    This book deals with the latest achievements in the field of optical coherent microscopy. While many other books exist on microscopy and imaging, this book provides a unique resource dedicated solely to this subject. Similarly, many books describe applications of holography, interferometry and speckle to metrology but do not focus on their use for microscopy. The coherent light microscopy reference provided here does not focus on the experimental mechanics of such techniques but instead is meant to provide a users manual to illustrate the strengths and capabilities of developing techniques. Th

  11. Transient ischemic attacks with and without a relevant infarct on computed tomographic scans cannot be distinguished clinically. Dutch Transient Ischemic Attack Study Group

    NARCIS (Netherlands)

    Koudstaal, P. J.; van Gijn, J.; Lodder, J.; Frenken, W. G.; Vermeulen, M.; Franke, C. L.; Hijdra, A.; Bulens, C.

    1991-01-01

    We prospectively studied clinical and computed tomographic (CT) scan findings in 79 patients with a transient ischemic attack (TIA) and a relevant cerebral infarction on CT, also known as cerebral infarction with transient signs (CITS). We compared the results with those of 527 concurrent patients

  12. Automatic method detection of artifacts for control of tomographic uniformity on SPECT; Metodo automatico de dteccion de artefactos para el control de la uniformidad tomografica en SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Reynes Llompart, G.; Puchal, R.

    2013-07-01

    The objective of this work is the find an automatic method for the detection and classification of artifacts produced in tomographic uniformity, extracting the characteristics necessary to apply a classification algorithm using pattern recognition techniques. The method has been trained and validated with synthetic images and tested with real images. (Author)

  13. Enhancement of the resolution of full-field optical coherence tomography by using a colour image sensor

    Energy Technology Data Exchange (ETDEWEB)

    Kalyanov, A L; Lychagov, V V; Smirnov, I V; Ryabukho, V P [N.G. Chernyshevsky Saratov State University, Saratov (Russian Federation)

    2013-08-31

    The influence of white balance in a colour image detector on the resolution of a full-field optical coherence tomograph (FFOCT) is studied. The change in the interference pulse width depending on the white balance tuning is estimated in the cases of a thermal radiation source (incandescent lamp) and a white light emitting diode. It is shown that by tuning white balance of the detector in a certain range, the FFOCT resolution can be increased by 20 % as compared to the resolution, attained with the use of a monochrome detector. (optical coherence tomography)

  14. Enhancement of the resolution of full-field optical coherence tomography by using a colour image sensor

    International Nuclear Information System (INIS)

    Kalyanov, A L; Lychagov, V V; Smirnov, I V; Ryabukho, V P

    2013-01-01

    The influence of white balance in a colour image detector on the resolution of a full-field optical coherence tomograph (FFOCT) is studied. The change in the interference pulse width depending on the white balance tuning is estimated in the cases of a thermal radiation source (incandescent lamp) and a white light emitting diode. It is shown that by tuning white balance of the detector in a certain range, the FFOCT resolution can be increased by 20 % as compared to the resolution, attained with the use of a monochrome detector. (optical coherence tomography)

  15. An evolutionary algorithm for tomographic reconstructions in limited data sets problems

    International Nuclear Information System (INIS)

    Turcanu, Catrinel; Craciunescu, Teddy

    2000-01-01

    The paper proposes a new method for tomographic reconstructions. Unlike nuclear medicine applications, in physical science problems we are often confronted with limited data sets: constraints in the number of projections or limited angle views. The problem of image reconstruction from projections may be considered as a problem of finding an image (solution) having projections that match the experimental ones. In our approach, we choose a statistical correlation coefficient to evaluate the fitness of any potential solution. The optimization process is carried out by an evolutionary algorithm. Our algorithm has some problem-oriented characteristics. One of them is that a chromosome, representing a potential solution, is not linear but coded as a matrix of pixels corresponding to a two-dimensional image. This kind of internal representation reflects the genuine manifestation and slight differences between two points situated in the original problem space give rise to similar differences once they become coded. Another particular feature is a newly built crossover operator: the grid-based crossover, suitable for high dimension two-dimensional chromosomes. Except for the population size and the dimension of the cutting grid for the grid-based crossover, all the other parameters of the algorithm are independent of the geometry of the tomographic reconstruction. The performances of the method are evaluated in comparison with a traditional tomographic method, based on the maximization of the entropy of the image, that proved to work well with limited data sets. The test phantom is typical for an application with limited data sets: the determination of the neutron energy spectra with time resolution in case of short-pulsed neutron emission. The qualitative judgement and also the quantitative one, based on some figures of merit, point out that the proposed method ensures an improved reconstruction of shapes, sizes and resolution in the image, even in the presence of noise

  16. Coherence protection in coupled quantum systems

    Science.gov (United States)

    Cammack, H. M.; Kirton, P.; Stace, T. M.; Eastham, P. R.; Keeling, J.; Lovett, B. W.

    2018-02-01

    The interaction of a quantum system with its environment causes decoherence, setting a fundamental limit on its suitability for quantum information processing. However, we show that if the system consists of coupled parts with different internal energy scales then the interaction of one part with a thermal bath need not lead to loss of coherence from the other. Remarkably, we find that the protected part can remain coherent for longer when the coupling to the bath becomes stronger or the temperature is raised. Our theory will enable the design of decoherence-resistant hybrid quantum computers.

  17. Connecting coherent structures and strange attractors

    Science.gov (United States)

    Keefe, Laurence R.

    1990-01-01

    A concept of turbulence derived from nonlinear dynamical systems theory suggests that turbulent solutions to the Navier-Stokes equations are restricted to strange attractors, and, by implication, that turbulent phenomenology must find some expression or source in the structure of these mathematical objects. Examples and discussions are presented to link coherent structures to some of the commonly known characteristics of strange attractors. Basic to this link is a geometric interpretation of conditional sampling techniques employed to educe coherent structures that offers an explanation for their appearance in measurements as well as their size.

  18. Pipelining Computational Stages of the Tomographic Reconstructor for Multi-Object Adaptive Optics on a Multi-GPU System

    KAUST Repository

    Charara, Ali

    2014-11-01

    The European Extremely Large Telescope project (E-ELT) is one of Europe\\'s highest priorities in ground-based astronomy. ELTs are built on top of a variety of highly sensitive and critical astronomical instruments. In particular, a new instrument called MOSAIC has been proposed to perform multi-object spectroscopy using the Multi-Object Adaptive Optics (MOAO) technique. The core implementation of the simulation lies in the intensive computation of a tomographic reconstruct or (TR), which is used to drive the deformable mirror in real time from the measurements. A new numerical algorithm is proposed (1) to capture the actual experimental noise and (2) to substantially speed up previous implementations by exposing more concurrency, while reducing the number of floating-point operations. Based on the Matrices Over Runtime System at Exascale numerical library (MORSE), a dynamic scheduler drives all computational stages of the tomographic reconstruct or simulation and allows to pipeline and to run tasks out-of order across different stages on heterogeneous systems, while ensuring data coherency and dependencies. The proposed TR simulation outperforms asymptotically previous state-of-the-art implementations up to 13-fold speedup. At more than 50000 unknowns, this appears to be the largest-scale AO problem submitted to computation, to date, and opens new research directions for extreme scale AO simulations. © 2014 IEEE.

  19. Propagation of partially coherent vector anomalous vortex beam in turbulent atmosphere

    Science.gov (United States)

    Zhang, Xu; Wang, Haiyan; Tang, Lei

    2018-01-01

    A theoretical model is proposed to describe a partially coherent vector anomalous vortex(AV) beam. Based on the extended Huygens-Fresnel principle, analytical propagation formula for the proposed beams in turbulent atmosphere is derived. The spectral properties of the partially coherent vector AV beam are explored by using the unified theory of coherence and polarization in detail. It is interesting to find that the turbulence of atmosphere and the source parameter of the partially coherent vector AV beam( order, topological charge, coherence length, beam waist size etc) have significantly impacted the propagation properties of the partially coherent vector AV beam in turbulent atmosphere.

  20. Estimation of spatial uncertainties of tomographic velocity models

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, M.; Du, Z.; Querendez, E. [SINTEF Petroleum Research, Trondheim (Norway)

    2012-12-15

    This research project aims to evaluate the possibility of assessing the spatial uncertainties in tomographic velocity model building in a quantitative way. The project is intended to serve as a test of whether accurate and specific uncertainty estimates (e.g., in meters) can be obtained. The project is based on Monte Carlo-type perturbations of the velocity model as obtained from the tomographic inversion guided by diagonal and off-diagonal elements of the resolution and the covariance matrices. The implementation and testing of this method was based on the SINTEF in-house stereotomography code, using small synthetic 2D data sets. To test the method the calculation and output of the covariance and resolution matrices was implemented, and software to perform the error estimation was created. The work included the creation of 2D synthetic data sets, the implementation and testing of the software to conduct the tests (output of the covariance and resolution matrices which are not implicitly provided by stereotomography), application to synthetic data sets, analysis of the test results, and creating the final report. The results show that this method can be used to estimate the spatial errors in tomographic images quantitatively. The results agree with' the known errors for our synthetic models. However, the method can only be applied to structures in the model, where the change of seismic velocity is larger than the predicted error of the velocity parameter amplitudes. In addition, the analysis is dependent on the tomographic method, e.g., regularization and parameterization. The conducted tests were very successful and we believe that this method could be developed further to be applied to third party tomographic images.

  1. Phase coherence induced by correlated disorder.

    Science.gov (United States)

    Hong, Hyunsuk; O'Keeffe, Kevin P; Strogatz, Steven H

    2016-02-01

    We consider a mean-field model of coupled phase oscillators with quenched disorder in the coupling strengths and natural frequencies. When these two kinds of disorder are uncorrelated (and when the positive and negative couplings are equal in number and strength), it is known that phase coherence cannot occur and synchronization is absent. Here we explore the effects of correlating the disorder. Specifically, we assume that any given oscillator either attracts or repels all the others, and that the sign of the interaction is deterministically correlated with the given oscillator's natural frequency. For symmetrically correlated disorder with zero mean, we find that the system spontaneously synchronizes, once the width of the frequency distribution falls below a critical value. For asymmetrically correlated disorder, the model displays coherent traveling waves: the complex order parameter becomes nonzero and rotates with constant frequency different from the system's mean natural frequency. Thus, in both cases, correlated disorder can trigger phase coherence.

  2. Coherence in the Danish Healthcare System

    DEFF Research Database (Denmark)

    Frederiksen, Jesper; Olivares Bøgeskov, Benjamin Miguel

    2017-01-01

    In this article, we investigate ‘coherence in healthcare’ as a strategy of welfare policy. We conduct our investigation within the theoretical and methodological framework of Scandinavian praxeology, and we construct our empirical data from Danish administrative documents. The tools and terms...... of this tradition are used to generate data from discourse as representations of institutional logics. The aim is to uncover how coherence in healthcare emerges as different strategies in healthcare governance in relation to different institutions seen as positions. Hence, our findings suggest that, although...... the stated aim in policy is to improve coherence in healthcare for the benefit of the patients, various ambiguities within the institutions producing policy tend to maintain a certain order rather than introducing changes. Furthermore, we discuss how this section of the welfare state, examined in relation...

  3. The Puzzle of Coherence

    DEFF Research Database (Denmark)

    Andersen, Anne Bendix; Frederiksen, Kirsten; Beedholm, Kirsten

    2016-01-01

    Background During the past decade, politicians and healthcare providers have strived to create a coherent healthcare system across primary and secondary healthcare sectors in Denmark. Nevertheless, elderly patients with chronic diseases (EPCD) continue to report experiences of poor-quality care a...

  4. Coherence in quantum estimation

    Science.gov (United States)

    Giorda, Paolo; Allegra, Michele

    2018-01-01

    The geometry of quantum states provides a unifying framework for estimation processes based on quantum probes, and it establishes the ultimate bounds of the achievable precision. We show a relation between the statistical distance between infinitesimally close quantum states and the second order variation of the coherence of the optimal measurement basis with respect to the state of the probe. In quantum phase estimation protocols, this leads to propose coherence as the relevant resource that one has to engineer and control to optimize the estimation precision. Furthermore, the main object of the theory i.e. the symmetric logarithmic derivative, in many cases allows one to identify a proper factorization of the whole Hilbert space in two subsystems. The factorization allows one to discuss the role of coherence versus correlations in estimation protocols; to show how certain estimation processes can be completely or effectively described within a single-qubit subsystem; and to derive lower bounds for the scaling of the estimation precision with the number of probes used. We illustrate how the framework works for both noiseless and noisy estimation procedures, in particular those based on multi-qubit GHZ-states. Finally we succinctly analyze estimation protocols based on zero-temperature critical behavior. We identify the coherence that is at the heart of their efficiency, and we show how it exhibits the non-analyticities and scaling behavior proper of a large class of quantum phase transitions.

  5. Coherence Multiplex System Topologies

    NARCIS (Netherlands)

    Meijerink, Arjan; Taniman, R.O.; Heideman, G.H.L.M.; van Etten, Wim

    2007-01-01

    Coherence multiplexing is a potentially inexpensive form of optical code-division multiple access, which is particularly suitable for short-range applications with moderate bandwidth requirements, such as access networks, LANs, or interconnects. Various topologies are known for constructing an

  6. Coherent synchrotron radiation

    International Nuclear Information System (INIS)

    Agoh, Tomonori

    2006-01-01

    This article presents basic properties of coherent synchrotron radiation (CSR) with numerical examples and introduces the reader to important aspects of CSR in future accelerators with short bunches. We show interesting features of the single bunch instability due to CSR in storage rings and discuss the longitudinal CSR field via the impedance representation. (author)

  7. Interference due to coherence swapping

    Indian Academy of Sciences (India)

    particle is, its interaction with the beam splitter does not reveal this information .... If one shines a strong linearly polarised monochromatic laser beam, or a quasi .... to be a hindrance to coherence, can be suitably designed to create coherence.

  8. Effects of Coupling Distance on Synchronization and Coherence in Chaotic Neural Networks

    International Nuclear Information System (INIS)

    Wang Maosheng

    2009-01-01

    Effects of coupling distance on synchronization and coherence of chaotic neurons in complex networks are numerically investigated. We find that it is not beneficial to neurons synchronization if confining the coupling distance of random edges to a limit d max , but help to improve their coherence. Moreover, there is an optimal value of d max at which the coherence is maximum.

  9. Impaired coherence of life narratives of patients with schizophrenia.

    Science.gov (United States)

    Allé, Mélissa C; Potheegadoo, Jevita; Köber, Christin; Schneider, Priscille; Coutelle, Romain; Habermas, Tilmann; Danion, Jean-Marie; Berna, Fabrice

    2015-08-10

    Self-narratives of patients have received increasing interest in schizophrenia since they offer unique material to study patients' subjective experience related to their illness, in particular the alteration of self that accompanies schizophrenia. In this study, we investigated the life narratives and the ability to integrate and bind memories of personal events into a coherent narrative in 27 patients with schizophrenia and 26 controls. Four aspects of life narratives were analyzed: coherence with cultural concept of biography, temporal coherence, causal-motivational coherence and thematic coherence. Results showed that in patients cultural biographical knowledge is preserved, whereas temporal coherence is partially impaired. Furthermore, causal-motivational and thematic coherence are significantly impaired: patients have difficulties explaining how events have modeled their identity, and integrating different events along thematic lines. Impairment of global causal-motivational and thematic coherence was significantly correlated with patients' executive dysfunction, suggesting that cognitive impairment observed in patients could affect their ability to construct a coherent narrative of their life by binding important events to their self. This study provides new understanding of the cognitive deficits underlying self-disorders in patients with schizophrenia. Our findings suggest the potential usefulness of developing new therapeutic interventions to improve autobiographical reasoning skills.

  10. Ultrasound findings in biliary system

    International Nuclear Information System (INIS)

    Park, Won Sik; Lee, Yong Woo; Cheung, Hwan

    1986-01-01

    In the liver and biliary system ultrasound has emerged as one of the most useful imaging techniques. It is usually the first radiological procedure selected and is often sufficient alone to enable a clinical decision to be made. Good result with ultrasound depend critically on expert scanning technique coupled with an understanding of tomographic anatomy and, of course, an appreciation of the clinical significance of any findings. In addition to we'd like to stress on the ultrasonical anatomy and for the technologist and also discuss about pathological part

  11. Coherent states in quantum mechanics

    International Nuclear Information System (INIS)

    Rodrigues, R. de Lima; Fernandes Junior, Damasio; Batista, Sheyla Marques

    2001-12-01

    We present a review work on the coherent states is non-relativistic quantum mechanics analysing the quantum oscillators in the coherent states. The coherent states obtained via a displacement operator that act on the wave function of ground state of the oscillator and the connection with Quantum Optics which were implemented by Glauber have also been considered. A possible generalization to the construction of new coherent states it is point out. (author)

  12. Coherent states in quantum mechanics

    CERN Document Server

    Rodrigues, R D L; Fernandes, D

    2001-01-01

    We present a review work on the coherent states is non-relativistic quantum mechanics analysing the quantum oscillators in the coherent states. The coherent states obtained via a displacement operator that act on the wave function of ground state of the oscillator and the connection with Quantum Optics which were implemented by Glauber have also been considered. A possible generalization to the construction of new coherent states it is point out.

  13. Thoracic textilomas: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Dianne Melo; Zanetti, Glaucia; Araujo Neto, Cesar Augusto; Nobre, Luiz Felipe; Meirelles, Gustavo de Souza Portes; Silva, Jorge Luiz Pereira e; Guimaraes, Marcos Duarte; Escuissato, Dante Luiz; Souza Junior, Arthur Soares; Hochhegger, Bruno; Marchiori, Edson, E-mail: edmarchiori@gmail.com [Hospital Universitario Antonio Pedro (HUAP/UFF), Niteroi, RJ (Brazil)

    2014-09-15

    Objective: the aim of this study was to analyze chest CT scans of patients with thoracic textiloma. Methods: this was a retrospective study of 16 patients (11 men and 5 women) with surgically confirmed thoracic textiloma. The chest CT scans of those patients were evaluated by two independent observers, and discordant results were resolved by consensus. Results: the majority (62.5%) of the textilomas were caused by previous heart surgery. The most common symptoms were chest pain (in 68.75%) and cough (in 56.25%). In all cases, the main tomographic finding was a mass with regular contours and borders that were well-defined or partially defined. Half of the textilomas occurred in the right hemithorax and half occurred in the left. The majority (56.25%) were located in the lower third of the lung. The diameter of the mass was ≤ 10 cm in 10 cases (62.5%) and > 10 cm in the remaining 6 cases (37.5%). Most (81.25%) of the textilomas were heterogeneous in density, with signs of calcification, gas, radiopaque marker, or sponge-like material. Peripheral expansion of the mass was observed in 12 (92.3%) of the 13 patients in whom a contrast agent was used. Intraoperatively, pleural involvement was observed in 14 cases (87.5%) and pericardial involvement was observed in 2 (12.5%). Conclusions: it is important to recognize the main tomographic aspects of thoracic textilomas in order to include this possibility in the differential diagnosis of chest pain and cough in patients with a history of heart or thoracic surgery, thus promoting the early identification and treatment of this postoperative complication. (author)

  14. Coherent hybrid electromagnetic field imaging

    Science.gov (United States)

    Cooke, Bradly J [Jemez Springs, NM; Guenther, David C [Los Alamos, NM

    2008-08-26

    An apparatus and corresponding method for coherent hybrid electromagnetic field imaging of a target, where an energy source is used to generate a propagating electromagnetic beam, an electromagnetic beam splitting means to split the beam into two or more coherently matched beams of about equal amplitude, and where the spatial and temporal self-coherence between each two or more coherently matched beams is preserved. Two or more differential modulation means are employed to modulate each two or more coherently matched beams with a time-varying polarization, frequency, phase, and amplitude signal. An electromagnetic beam combining means is used to coherently combine said two or more coherently matched beams into a coherent electromagnetic beam. One or more electromagnetic beam controlling means are used for collimating, guiding, or focusing the coherent electromagnetic beam. One or more apertures are used for transmitting and receiving the coherent electromagnetic beam to and from the target. A receiver is used that is capable of square-law detection of the coherent electromagnetic beam. A waveform generator is used that is capable of generation and control of time-varying polarization, frequency, phase, or amplitude modulation waveforms and sequences. A means of synchronizing time varying waveform is used between the energy source and the receiver. Finally, a means of displaying the images created by the interaction of the coherent electromagnetic beam with target is employed.

  15. Methodology for tomographic imaging ahead of mining using the shearer as a seismic source

    Energy Technology Data Exchange (ETDEWEB)

    King, A.; Luo, X. [CSIRO Exploration and Mining, Kenmore, Qld. (Australia)

    2009-03-15

    Poor rock conditions in a coal long wall panel can result in roof collapse when a problematic zone is mined, significantly interrupting mine production. The ability to image rock conditions (stress and degree of fracturing) ahead of the face gives the miners the ability to respond proactively to such problems. This method uses the energy from mining machinery, in this case a coal shearer, to produce an image of the rock velocity ahead of the mining face without interrupting mining. Data from an experiment illustrates the concept. Geophones installed in gate-road roofs record the noise generated by the shearer after it has traversed the panel ahead of the mining face. A generalized crosscorrelation of the signals from pairs of sensors determines relative arrival times from the continuous seismic noise produced by the shearer. These relative times can then be inverted for a velocity structure. The crosscorrelations, performed in the frequency domain, are weighted by a confidence value derived from the spectral coherence between the traces. This produces stable crosscorrelation lags in the presence of noise. The errors in the time-domain data are propagated through to the relative traveltimes and then to the final tomographic velocity image, yielding an estimate of the uncertainty in velocity at each point. This velocity image can then be used to infer information about the stress and fracture state of the rock, providing advance warning of potentially hazardous zones.

  16. Tomographic Structural Changes of Retinal Layers after Internal Limiting Membrane Peeling for Macular Hole Surgery.

    Science.gov (United States)

    Faria, Mun Yueh; Ferreira, Nuno P; Cristóvao, Diana M; Mano, Sofia; Sousa, David Cordeiro; Monteiro-Grillo, Manuel

    2018-01-01

    To highlight tomographic structural changes of retinal layers after internal limiting membrane (ILM) peeling in macular hole surgery. Nonrandomized prospective, interventional study in 38 eyes (34 patients) subjected to pars plana vitrectomy and ILM peeling for idiopathic macular hole. Retinal layers were assessed in nasal and temporal regions before and 6 months after surgery using spectral domain optical coherence tomography. Total retinal thickness increased in the nasal region and decreased in the temporal region. The retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), and inner plexiform layer (IPL) showed thinning on both nasal and temporal sides of the fovea. The thickness of the outer plexiform layer (OPL) increased. The outer nuclear layer (ONL) and outer retinal layers (ORL) increased in thickness after surgery in both nasal and temporal regions. ILM peeling is associated with important alterations in the inner retinal layer architecture, with thinning of the RNFL-GCL-IPL complex and thickening of OPL, ONL, and ORL. These structural alterations can help explain functional outcome and could give indications regarding the extent of ILM peeling, even though peeling seems important for higher rate of hole closure. © 2017 S. Karger AG, Basel.

  17. Diferencias tomográficas y funcionales entre la EPOC severa relacionada con humo de leña y con cigarrillo Tomographic and functional findings in severe COPD: comparison between the wood smoke-related and smoking-related disease

    Directory of Open Access Journals (Sweden)

    Mauricio González-García

    2013-04-01

    Full Text Available OBJETIVO: La exposición a humo de leña es factor de riesgo para EPOC. A diferencia de la EPOC por cigarrillo (EPOC-C, para un mismo nivel de obstrucción, en la EPOC por leña (EPOC-L, la DLCO está menos disminuida, sugiriendo menos enfisema. Por tanto, el objetivo de este estudio fue comparar los hallazgos en la TCAR en mujeres con EPOC-L y con EPOC- C. MÉTODOS: Veintidós mujeres con EPOC severa (VEF1/CVF OBJECTIVE: Wood smoke exposure is a risk factor for COPD. For a given degree of airway obstruction, the reduction in DLCO is smaller in individuals with wood smoke-related COPD than in those with smoking-related COPD, suggesting that there is less emphysema in the former. The objective of this study was to compare HRCT findings between women with wood smoke-related COPD and women with smoking-related COPD. METHODS: Twenty-two women with severe COPD (FEV1/FVC ratio < 70% and FEV1 < 50% were divided into two groups: those with wood smoke-related COPD (n = 12 and those with smoking-related COPD (n = 10. The two groups were compared regarding emphysema scores and airway involvement (as determined by HRCT; and functional abnormalities-spirometry results, DLCO, alveolar volume (VA, the DLCO/VA ratio, lung volumes, and specific airway resistance (sRaw. Results: There were no significant differences between the two groups in terms of FEV1, sRaw, or lung hyperinflation. Decreases in DLCO and in the DLCO/VA ratio were greater in the smoking-related COPD group subjects, who also had higher emphysema scores, in comparison with the wood smoke-related COPD group subjects. In the wood smoke-related COPD group, HRCT scans howed no significant emphysema, the main findings being peribronchial thickening, bronchial dilation, and subsegmental atelectasis. CONCLUSIONS: Female patients with severe wood smoke-related COPD do not appear to develop emphysema, although they do show severe airway involvement. The reduction in DLCO and VA, with a normal DLCO

  18. A computed tomographic study on epilepsy

    International Nuclear Information System (INIS)

    Bae, Hoon Sik

    1980-01-01

    140 patients with epileptic seizure were studied by computed tomography during the period from Feb. 1979 to Aug. 1979 in the Department or Radiology, College of Medicine, Hangyang University. Those findings on CT and clinical records including EEG findings were reviewed. The results were as follows: 1. Age distribution of the total 140 patients was broad ranging from 1 month to 63 years. 73.5% of patients was below the age of 30. The patient population was comprised of 93 males and 47 females, and its male to female ratio was 2 : 1. 2. The type of epileptic seizure were classified according to the International League against Epilepsy. 42.9% of patients had primary generalized seizure, 47.1% with partial seizure, and 10% with non classifiable seizure. 3. As additional symptoms and signs except seizure, headache was most common, and the next was nausea and vomiting. Uncommonly, there were also insomnia, personality change, and memory disturbance. 4. 37.1% of patients had less than 1 month of seizure history, 19.3% between 1 year and 5 years. 5. EEG findings were available in 41 patients, and normal in 15 cases. 26 patients revealed abnormal findings. Among those abnormal findings focal slowing was appeared in 19.5% and generalized slowing in 17.1%. 6. 52% of patients showed abnormal findings on CT. The most common abnormal findings was focal low density (30%), and the next was diffuse hydrocephalus (7.1%). After contrast infusion, contrast enhancement was occurred in cases with focal low density, focal high or isodense mass density. In patients with focal low density, ring or nodular enhancement were common, and diffuse or serpentime enhancement in focal high or isodence mass density. 7. The frequency of structural abnormalities on CT was more common in patients below the age of 10 and over 30 than other age groups. The epilepsy starting below 10 and over 30 years of age showed structural abnormalities in 63.6-100%. 8. The patients who had less than 6 months of

  19. A computed tomographic study on epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Hoon Sik [Hanyang University College of Medicine, Seoul (Korea, Republic of)

    1980-06-15

    140 patients with epileptic seizure were studied by computed tomography during the period from Feb. 1979 to Aug. 1979 in the Department or Radiology, College of Medicine, Hangyang University. Those findings on CT and clinical records including EEG findings were reviewed. The results were as follows: 1. Age distribution of the total 140 patients was broad ranging from 1 month to 63 years. 73.5% of patients was below the age of 30. The patient population was comprised of 93 males and 47 females, and its male to female ratio was 2 : 1. 2. The type of epileptic seizure were classified according to the International League against Epilepsy. 42.9% of patients had primary generalized seizure, 47.1% with partial seizure, and 10% with non classifiable seizure. 3. As additional symptoms and signs except seizure, headache was most common, and the next was nausea and vomiting. Uncommonly, there were also insomnia, personality change, and memory disturbance. 4. 37.1% of patients had less than 1 month of seizure history, 19.3% between 1 year and 5 years. 5. EEG findings were available in 41 patients, and normal in 15 cases. 26 patients revealed abnormal findings. Among those abnormal findings focal slowing was appeared in 19.5% and generalized slowing in 17.1%. 6. 52% of patients showed abnormal findings on CT. The most common abnormal findings was focal low density (30%), and the next was diffuse hydrocephalus (7.1%). After contrast infusion, contrast enhancement was occurred in cases with focal low density, focal high or isodense mass density. In patients with focal low density, ring or nodular enhancement were common, and diffuse or serpentime enhancement in focal high or isodence mass density. 7. The frequency of structural abnormalities on CT was more common in patients below the age of 10 and over 30 than other age groups. The epilepsy starting below 10 and over 30 years of age showed structural abnormalities in 63.6-100%. 8. The patients who had less than 6 months of

  20. Optical Coherence and Quantum Optics

    CERN Document Server

    Mandel, Leonard

    1995-01-01

    This book presents a systematic account of optical coherence theory within the framework of classical optics, as applied to such topics as radiation from sources of different states of coherence, foundations of radiometry, effects of source coherence on the spectra of radiated fields, coherence theory of laser modes, and scattering of partially coherent light by random media. The book starts with a full mathematical introduction to the subject area and each chapter concludes with a set of exercises. The authors are renowned scientists and have made substantial contributions to many of the topi

  1. Meningoencefalites toxoplásmica e chagásica em pacientes com infecção pelo vírus da imunodeficiência humana: diagnóstico diferencial anatomopatológico e tomográfico Meningoencephalitis due to Toxoplasma gondii and Trypanosoma cruzi in patients with HIV infection. Diferencial diagnosis of pathologic and tomographic findings

    Directory of Open Access Journals (Sweden)

    Javier E. Lazo

    1998-04-01

    Full Text Available Em 22 pacientes com sorologia positiva para o vírus da imunodeficiência humana, com ou sem síndrome da imunodeficiência adquirida, dos quais 7 com meningoencefalite toxoplásmica e 15 com meningoencefalite chagásica associadas, procuraram-se dados diferenciais, entre as duas encefalopatias, tanto à anatomia patológica quanto à tomografia computadorizada do crânio. Os resultados observados e os dados da literatura nos permitiram concluir que enquanto na meningoencefalite necrosante focal por Toxoplasma gondii o acometimento dos núcleos da base é freqüente, na meningoencefalite necrosante focal causada pelo Trypanosoma cruzi, lesões dessas estruturas parecem não ocorrer ou ser excepcionais. De outro lado, o acometimento da substância branca parece nitidamente maior na meningoencefalite chagásica que na meningoencefalite toxoplásmica, ao passo que o parasitismo e a hemorragia do tecido nervoso, bem como as lesões das bainhas de mielina são mais freqüentes e intensos na meningoencefalite causada pelo Trypanosoma cruzi que naquela por Toxoplasma.Twenty-two HIV+ patients with encephalitis were studied. Of these, 7 had meningoencephalitis due to Toxoplasma gondii (MT and 15 due to Trypanosoma cruzi (MC. Pathologic and computerized axial tomography (CAT changes were compared. We found that focal necrotizing encephalitis due to Toxoplasma involved the cerebral cortex and the basal ganglia, whereas lesions due to Trypanosoma cruzi were centered in the white matter, sometimes extending into the cortex. Hemorrhages, myelin lesions and organisms were more pronounced in chagasic than in toxoplasmic encephalitis. These findings are consistent with the literature reviewed.

  2. Coherent imaging using SACLA

    International Nuclear Information System (INIS)

    Nishino, Yoshinori; Kimura, Takashi; Suzuki, Akihiro; Joti, Yasumasa; Bessho, Yoshitaka

    2017-01-01

    X-ray free-electron lasers (XFELs) with femtosecond pulse duration offer an innovative solution to transcend the spatial resolution limitation in conventional X-ray imaging for biological samples and soft matters by clearing up the radiation damage problem using the “diffraction-before-destruction” strategy. Building on this strategy, the authors are developing a method to image solution sample under controlled environment, pulsed coherent X-ray solution scattering (PCXSS), using XFELs and phase retrieval algorithms in coherent diffractive imaging (CDI). This article describes the basics of PCXSS and examples of PCXSS measurement, for a living cell and self-assemblies of gold nanoparticles, performed by the authors using SACLA. An attempt toward the industrial application of PCXSS is also described. (author)

  3. Coherent dynamics in semiconductors

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher

    1998-01-01

    enhanced in quantum confined lower-dimensional systems, where exciton and biexciton effects dominate the spectra even at room temperature. The coherent dynamics of excitons are at modest densities well described by the optical Bloch equations and a number of the dynamical effects known from atomic......Ultrafast nonlinear optical spectroscopy is used to study the coherent dynamics of optically excited electron-hole pairs in semiconductors. Coulomb interaction implies that the optical inter-band transitions are dominated, at least at low temperatures, by excitonic effects. They are further...... and molecular systems are found and studied in the exciton-biexciton system of semiconductors. At densities where strong exciton interactions, or many-body effects, become dominant, the semiconductor Bloch equations present a more rigorous treatment of the phenomena Ultrafast degenerate four-wave mixing is used...

  4. Generalized hypergeometric coherent states

    International Nuclear Information System (INIS)

    Appl, Thomas; Schiller, Diethard H

    2004-01-01

    We introduce a large class of holomorphic quantum states by choosing their normalization functions to be given by generalized hypergeometric functions. We call them generalized hypergeometric states in general, and generalized hypergeometric coherent states in particular, if they allow a resolution of unity. Depending on the domain of convergence of the generalized hypergeometric functions, we distinguish generalized hypergeometric states on the plane, the open unit disc and the unit circle. All states are eigenstates of suitably defined lowering operators. We then study their photon number statistics and phase properties as revealed by the Husimi and Pegg-Barnett phase distributions. On the basis of the generalized hypergeometric coherent states we introduce new analytic representations of arbitrary quantum states in Bargmann and Hardy spaces as well as generalized hypergeometric Husimi distributions and corresponding phase distributions

  5. On coherent states

    International Nuclear Information System (INIS)

    Polubarinov, I.V.

    1975-01-01

    A definition of the coherent state representation is given in this paper. In the representation quantum theory equations take the form of classical field theory equations (with causality inherent to the latter) not only in simple cases (free field and interactions with an external current or field), but also in the general case of closed systems of interacting fields. And, conversely, a classical field theory can be transformed into a form of a quantum one

  6. The Puzzle of Coherence

    DEFF Research Database (Denmark)

    Andersen, Anne Bendix; Frederiksen, Kirsten; Beedholm, Kirsten

    2016-01-01

    During the past decade, politicians and health care providers have strived to create a coherent health care system across primary and secondary health care systems in Denmark. Nevertheless, elderly patients with chronic diseases (EPCD) continue to report experiences of poor-quality care and lack ...... both nationally and internationally in preparation of health agreements, implementation of new collaboration forms among health care providers, and in improvement of delegation and transfer of information and assignments across sectors in health care....

  7. Spectral coherence in windturbine wakes

    Energy Technology Data Exchange (ETDEWEB)

    Hojstrup, J. [Riso National Lab., Roskilde (Denmark)

    1996-12-31

    This paper describes an experiment at a Danish wind farm to investigate the lateral and vertical coherences in the nonequilibrium turbulence of a wind turbine wake. Two meteorological masts were instrumented for measuring profiles of mean speed, turbulence, and temperature. Results are provided graphically for turbulence intensities, velocity spectra, lateral coherence, and vertical coherence. The turbulence was somewhat influenced by the wake, or possibly from aggregated wakes further upstream, even at 14.5 diameters. Lateral coherence (separation 5m) seemed to be unaffected by the wake at 7.5 diameters, but the flow was less coherent in the near wake. The wake appeared to have little influence on vertical coherence (separation 13m). Simple, conventional models for coherence appeared to be adequate descriptions for wake turbulence except for the near wake situation. 3 refs., 7 figs., 1 tab.

  8. Computed-tomographic determination of mineral content of bones

    International Nuclear Information System (INIS)

    Delov, I.; Tabakov, S.

    1988-01-01

    The problem of precise computed-tomographic densitometry of the mineral content of bones is pointed out. A method is proposed including the use of standard density and observance of definite radiation, scanning and image estimation parameters. A good correlation of the results obtained for the mineral content of the lumbar vertebrae with literature data are reported. A method is also described for determining the mineral content of tubular bones based on densiprofile check-up of the computed-tomographic density. The procedure takes 10-15 minutes and includes 1 or 2 scans. It might therefore gain wide acceptance for the diagnosis and tracing of osteoporosis and other osteopathies associated with distrorted calcium metabolism

  9. Design and applications of Computed Industrial Tomographic Imaging System (CITIS)

    International Nuclear Information System (INIS)

    Ramakrishna, G.S.; Umesh Kumar; Datta, S.S.; Rao, S.M.

    1996-01-01

    Computed tomographic imaging is an advanced technique for nondestructive testing (NDT) and examination. For the first time in India a computed aided tomography system has been indigenously developed in BARC for testing industrial components and was successfully demonstrated. The system in addition to Computed Tomography (CT) can also perform Digital Radiography (DR) to serve as a powerful tool for NDT applications. It has wider applications in the fields of nuclear, space and allied fields. The authors have developed a computed industrial tomographic imaging system with Cesium 137 gamma radiation source for nondestructive examination of engineering and industrial specimens. This presentation highlights the design and development of a prototype system and its software for image reconstruction, simulation and display. The paper also describes results obtained with several tests specimens, current development and possibility of using neutrons as well as high energy x-rays in computed tomography. (author)

  10. Time-resolved tomographic images of a relativistic electron beam

    International Nuclear Information System (INIS)

    Koehler, H.A.; Jacoby, B.A.; Nelson, M.

    1984-07-01

    We obtained a sequential series of time-resolved tomographic two-dimensional images of a 4.5-MeV, 6-kA, 30-ns electron beam. Three linear fiber-optic arrays of 30 or 60 fibers each were positioned around the beam axis at 0 0 , 61 0 , and 117 0 . The beam interacting with nitrogen at 20 Torr emitted light that was focused onto the fiber arrays and transmitted to a streak camera where the data were recorded on film. The film was digitized, and two-dimensional images were reconstructed using the maximum-entropy tomographic technique. These images were then combined to produce an ultra-high-speed movie of the electron-beam pulse

  11. The CDD system in computed tomographic diagnosis of diverticular disease

    International Nuclear Information System (INIS)

    Pustelnik, Daniel; Elsholtz, Fabian Henry Juergen; Hamm, Bernd; Niehues, Stefan Markus; Bojarski, Christian

    2017-01-01

    Purpose cation in computed tomographic diagnosis and briefly recapitulates its targeted advantages over preliminary systems. Primarily, application of the CDD in computed tomography diagnostics is described. Differences with respect to the categories of the older systems are pointed out on the level of each CDD type using imaging examples. The presented images are derived from our institute according to the S2k criteria. Literature was researched on PubMed. Results The CDD constitutes an improvement compared to older systems for categorizing the stages of diverticular disease. It provides more discriminatory power on the descriptive-morphological level and defines as well as differentiates more courses of the disease. Furthermore, the categories translate more directly into state-of-the-art decision-making concerning hospitalization and therapy. The CDD should be applied routinely in the computed tomographic diagnosis of diverticular disease. Typical imaging patterns are presented.

  12. Terahertz Imaging for Biomedical Applications Pattern Recognition and Tomographic Reconstruction

    CERN Document Server

    Yin, Xiaoxia; Abbott, Derek

    2012-01-01

    Terahertz Imaging for Biomedical Applications: Pattern Recognition and Tomographic Reconstruction presents the necessary algorithms needed to assist screening, diagnosis, and treatment, and these algorithms will play a critical role in the accurate detection of abnormalities present in biomedical imaging. Terahertz biomedical imaging has become an area of interest due to its ability to simultaneously acquire both image and spectral information. Terahertz imaging systems are being commercialized with an increasing number of trials performed in a biomedical setting. Terahertz tomographic imaging and detection technology contributes to the ability to identify opaque objects with clear boundaries,and would be useful to both in vivo and ex vivo environments. This book also: Introduces terahertz radiation techniques and provides a number of topical examples of signal and image processing, as well as machine learning Presents the most recent developments in an emerging field, terahertz radiation Utilizes new methods...

  13. Geometry of generalized coherent states

    International Nuclear Information System (INIS)

    Bacry, H.; Centre National de la Recherche Scientifique, 13 - Marseille; Grossmann, A.; Zak, J.

    1975-09-01

    Various attempts have been made to generalize the concept of coherent states (c.s.). One of them, due to Perelomov, seems to be very promising but no restrictive enough. The Perelomov c.s. are briefly reviewed. One shows how his definition gives rise to Radcliffe's c.s. Relationship between the usual and Radcliffe's c.s. can be investigated either from group contraction point of view (Arecchi et al.) or from a physical point of view (with the aid of the Poincare sphere of elliptic polarizations of electromagnetic plane waves). The question of finding complete subsets of c.s. is revisited and an attempt is made to restrict the Perelomov definition [fr

  14. Coherent laser vision system

    International Nuclear Information System (INIS)

    Sebastion, R.L.

    1995-01-01

    The Coherent Laser Vision System (CLVS) is being developed to provide precision real-time 3D world views to support site characterization and robotic operations and during facilities Decontamination and Decommissioning. Autonomous or semiautonomous robotic operations requires an accurate, up-to-date 3D world view. Existing technologies for real-time 3D imaging, such as AM laser radar, have limited accuracy at significant ranges and have variability in range estimates caused by lighting or surface shading. Recent advances in fiber optic component technology and digital processing components have enabled the development of a new 3D vision system based upon a fiber optic FMCW coherent laser radar. The approach includes a compact scanner with no-moving parts capable of randomly addressing all pixels. The system maintains the immunity to lighting and surface shading conditions which is characteristic to coherent laser radar. The random pixel addressability allows concentration of scanning and processing on the active areas of a scene, as is done by the human eye-brain system

  15. Collision-induced coherence

    International Nuclear Information System (INIS)

    Bloembergen, N.

    1985-01-01

    Collision-induced coherence is based on the elimination of phase correlations between coherent Feynman-type pathways which happen to interfere destructively in the absence of damping for certain nonlinear processes. One consequence is the appearance of the extra resonances in four-wave light mixing experiments, for which the intensity increases with increasing buffer gas pressure. These resonances may occur between a pair of initially unpopulated excited states, or between a pair of initially equally populated ground states. The pair of levels may be Zeeman substrates which became degenerate in zero magnetic field. The resulting collision-enhanced Hanle resonances can lead to very sharp variations in the four-wave light mixing signal as the external magnetic field passes through zero. The theoretical description in terms of a coherence grating between Zeeman substrates is equivalent to a description in terms of a spin polarization grating obtained by collision-enhanced transverse optical pumping. The axis of quantization in the former case is taken perpendicular to the direction of the light beams; in the latter case is taken parallel to this direction

  16. Coherent laser vision system

    Energy Technology Data Exchange (ETDEWEB)

    Sebastion, R.L. [Coleman Research Corp., Springfield, VA (United States)

    1995-10-01

    The Coherent Laser Vision System (CLVS) is being developed to provide precision real-time 3D world views to support site characterization and robotic operations and during facilities Decontamination and Decommissioning. Autonomous or semiautonomous robotic operations requires an accurate, up-to-date 3D world view. Existing technologies for real-time 3D imaging, such as AM laser radar, have limited accuracy at significant ranges and have variability in range estimates caused by lighting or surface shading. Recent advances in fiber optic component technology and digital processing components have enabled the development of a new 3D vision system based upon a fiber optic FMCW coherent laser radar. The approach includes a compact scanner with no-moving parts capable of randomly addressing all pixels. The system maintains the immunity to lighting and surface shading conditions which is characteristic to coherent laser radar. The random pixel addressability allows concentration of scanning and processing on the active areas of a scene, as is done by the human eye-brain system.

  17. Coherent electron cooling

    Energy Technology Data Exchange (ETDEWEB)

    Litvinenko,V.

    2009-05-04

    Cooling intense high-energy hadron beams remains a major challenge in modern accelerator physics. Synchrotron radiation is still too feeble, while the efficiency of two other cooling methods, stochastic and electron, falls rapidly either at high bunch intensities (i.e. stochastic of protons) or at high energies (e-cooling). In this talk a specific scheme of a unique cooling technique, Coherent Electron Cooling, will be discussed. The idea of coherent electron cooling using electron beam instabilities was suggested by Derbenev in the early 1980s, but the scheme presented in this talk, with cooling times under an hour for 7 TeV protons in the LHC, would be possible only with present-day accelerator technology. This talk will discuss the principles and the main limitations of the Coherent Electron Cooling process. The talk will describe the main system components, based on a high-gain free electron laser driven by an energy recovery linac, and will present some numerical examples for ions and protons in RHIC and the LHC and for electron-hadron options for these colliders. BNL plans a demonstration of the idea in the near future.

  18. Coherent radiation from pulsars

    International Nuclear Information System (INIS)

    Cox, J.L. Jr.

    1979-01-01

    Interaction between a relativistic electrom stream and a plasma under conditions believed to exist in pulsar magnetospheres is shown to result in the simultaneous emission of coherent curvature radiation at radio wavelengths and incoherent curvature radiation at X-ray wavelengths from the same spatial volume. It is found that such a stream can propagate through a plasma parallel to a very strong magnetic field only if its length is less than a critical length L/sub asterisk/ic. Charge induced in the plasma by the stream co-moves with the stream and has the same limitation in longitudinal extent. The resultant charge bunching is sufficient to cause the relatively low energy plasma particles to radiate at radio wavelengths coherently while the relatively high energy stream particles radiate at X-ray wavelengths incoherently as the stream-plasma system moves along curved magnetic field lines. The effective number of coherently radiating particles per bunch is estimated to be approx.10 14 --10 15 for a tupical pulsar

  19. Heidelberg Retina Tomograph for the Detection of Glaucoma

    Directory of Open Access Journals (Sweden)

    Barbara Cvenkel

    2012-06-01

    Full Text Available Heidelberg Retina Tomograph (HRT is a confocal scanning laser ophthalmoscope which acquires and analyzes 3-dimensional images of the optic nerve head. The latest instrument HRT3 includes software with larger ethinic-specific normative database. This review summarizes relevant published literature on HRT in diagnosing glaucoma, detecting glaucoma progression, the diagnostic accuracy of HRT among other imaging devices and its role in clinical practice.

  20. Computed tomographic diagnosis of abdominal abscess in childhood

    International Nuclear Information System (INIS)

    Kuhn, J.P.; Berger, P.E.

    1980-01-01

    Twenty-eight children suspected clinically of having an abdominal abscess were examined by CT. Eighteen had gallium 67 citrate scans and 22 had ultrasound studies. Computed tomography was found to be the most accurate test for diagnosis and evaluation of an abscess and the computed tomographic appearance of abscess is illustrated. However, because of cost factors, radiation dose, and clinical considerations, computed tomography is not always the first modality of choice in evaluating a suspected abdominal abscess [fr

  1. A general purpose tomographic program with combined inversions

    International Nuclear Information System (INIS)

    Xu Wenbin; Dong Jiafu; Li Fanzhu

    1996-01-01

    A general tomographic program has been developed by combining the Bessel expansion with the Zernicke expansion. It is useful for studying of the magnetic island structure of the tearing mode and in reconstructing the density profiles of impurities in tokamak plasmas. This combined method have the advantages of both expansions, i.e. there will be no spurious images in the edge and it will be of high inverse precision in the center of plasma

  2. Computer tomographic detection of an intraspinal arachnoidal cyst

    International Nuclear Information System (INIS)

    Kuckein, D.; Walter, K.; Paal, G.; Staedtisches Krankenhaus Harlaching, Muenchen

    1981-01-01

    A 46 year old female patient who after 3-4 weeks of influenza suffered from strong headaches, vomiting and rotatory vertigo was subjected to a myelograph and then to a computerized tomographic investigation due to suspect cerebrospinal fluid. The computerized tomography is better than the myelography in diagnosing intraspinal arachnoidal cysts, however this should be preceded by most accurate possible segment location. (MG) [de

  3. Initial results from the Donner 600-crystal positron tomograph

    International Nuclear Information System (INIS)

    Derenzo, S.E.; Huesman, R.H.; Cahoon, J.L.; Geyer, A.B.; Uber, D.C.; Vuletich, T.; Budinger, T.F.

    1987-01-01

    These results show the 3-mm BGO crystals can improve the resolution in positron tomography by a substantial factor. This measured crystal-pair resolution of 2.4 mm FWHM and the reconstructed image resolution of 2.9 mm FWHM at the center of the tomograph are in good agreement with expected values. The most serious limitation of the detector design is that only a single section can be imaged. 4 refs., 4 figs

  4. Computer tomographic evaluation of digestive tract non-Hodgkin lymphomas.

    Science.gov (United States)

    Lupescu, Ioana G; Grasu, Mugur; Goldis, Gheorghe; Popa, Gelu; Gheorghe, Cristian; Vasilescu, Catalin; Moicean, Andreea; Herlea, Vlad; Georgescu, Serban A

    2007-09-01

    Computer Tomographic (CT) study is crucial for defining distribution, characteristics and staging of primary gastrointestinal lymphomas. The presence of multifocal sites, the wall thickening with diffuse infiltration of the affected gastrointestinal (GI) segment in association with regional adenopathies, permit the orientation of the CT diagnosis for primary GI lymphomas. The gold standard for diagnosis remains, in all cases of digestive tract non-Hodgkin lymphomas (NHL), the histological examination, which allows a tissue diagnosis, performed preferably by transmural biopsy.

  5. Tomographic diagnosis and relevant aspects of otosclerosis

    International Nuclear Information System (INIS)

    Gaiotti, Juliana Oggioni; Gomes, Natalia Delage; Costa, Ana Maria Doffemond; Villela, Caroline Laurita Batista Couto; Moreira, Wanderval; Diniz, Renata Lopes Furletti Caldeira

    2013-01-01

    A literature review and pictorial essay were developed to discuss the importance of knowing the main findings and locations of otosclerosis at multidetector computed tomography (MDCT). The authors performed a retrospective review of cases of otosclerosis diagnosed in their institution by means of high resolution multidetector computed tomography. Otosclerosis corresponds to otic capsule dysplasia characterized by metabolic derangement of its endochondral layer. Such condition constitutes a relevant cause of sensorineural hearing loss, affecting about 7% to 10% of the general population. The diagnosis is usually clinical, but imaging methods play a significant role in the anatomical detailing, differential diagnosis, surgical planning and evaluation of postoperative complications. Among such methods, the relevance of MDCT is highlighted. Radiologists should be familiar with the MDCT findings of otosclerosis, as well as with the temporal bone anatomy to assist in the appropriate clinical management of this disease. (author)

  6. Computer tomographic examination of the thymus

    International Nuclear Information System (INIS)

    Weiss, C.; Dinkel, E.; Wimmer, B.; Grosser, G.; Schildge, J.

    1987-01-01

    The diagnostic value of CT in follicular thymic hyperplasia and in thymomas in 8 patients with myasthenia gravis and in 12 patients without myasthenia gravis suffering from thymic tumors was evaluated by correlating CT-findings to surgical results and pathological-histological findings. Thymic size of the six patients with histologically proven follicular hyperplasia were scattered within the normal range, but half of them were at the upper limit. Thymic tumors were differentiated between invasive and non invasive tumors by CT staging. Solid tumors with different histology could not be further classified; the attenuation values ranging from 15-55 HU were the same in tumors, follicular hyperplasia and normal thymus. (orig.) [de

  7. Tomographic diagnosis and relevant aspects of otosclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Gaiotti, Juliana Oggioni; Gomes, Natalia Delage; Costa, Ana Maria Doffemond; Villela, Caroline Laurita Batista Couto; Moreira, Wanderval; Diniz, Renata Lopes Furletti Caldeira, E-mail: jugaiotti@gmail.com [Hospital Mater Dei-Mater Imagem, Belo Horizonte, MG (Brazil)

    2013-09-15

    A literature review and pictorial essay were developed to discuss the importance of knowing the main findings and locations of otosclerosis at multidetector computed tomography (MDCT). The authors performed a retrospective review of cases of otosclerosis diagnosed in their institution by means of high resolution multidetector computed tomography. Otosclerosis corresponds to otic capsule dysplasia characterized by metabolic derangement of its endochondral layer. Such condition constitutes a relevant cause of sensorineural hearing loss, affecting about 7% to 10% of the general population. The diagnosis is usually clinical, but imaging methods play a significant role in the anatomical detailing, differential diagnosis, surgical planning and evaluation of postoperative complications. Among such methods, the relevance of MDCT is highlighted. Radiologists should be familiar with the MDCT findings of otosclerosis, as well as with the temporal bone anatomy to assist in the appropriate clinical management of this disease. (author)

  8. Intrauterine Devices Penetrated and Migrated: CT Findings

    International Nuclear Information System (INIS)

    Mejia Restrepo, Jorge; Lopez, Juan Esteban; Aldana Sepulveda, Natalia; Ruiz Zabaleta, Tania; Mazzaro Mauricio

    2011-01-01

    Intrauterine devices have been used for over 40 years, and they constitute the most widely accepted method of contraception among women because of the low rates of complications and low cost. Although uncommon, with the growing use of multidetector CT penetrated and migrated intrauterine devices have become a more common incidental finding. In some cases, intrauterine devices migrate to adjacent viscera, in particular the bladder and bowel and may give rise to symptoms. Consequently tomographic localization and characterization are essential for treatment planning.

  9. Computed tomographic feature of tuberculous arthritis

    International Nuclear Information System (INIS)

    Kim, Hak Hee; Lee, Hae Giu; Cha, Eun Suk; Kang, Kyung Jin; Jeon, Jeong Su; Park, Young Ha; Yim, Jung Ik; Bahk, Yong Whee

    1992-01-01

    The sparsity of publication concerning CT findings of tuberculous arthritis prompted authors to retrospectively evaluate 12 patients with tuberculous arthritis for characteristic CT findings. In each patients, the diagnosis of tuberculous arthritis was confirmed by surgery or biopsy. The CT examinations were evaluated by two radiologists retrospectively. Involved joints were the hip joint in seven patients, the sacroiliac joint in three patients, and the shoulder and ankle joint in one patient each. CT features included subchondral bony erosion(12 patients), soft tissue mass in the joint space(nine), widening of the joint space(eight), ipsilateral music atrophy(eight), thickening of the joint capsule(seven), intra-articular effusion(six), soft tissue abscess(five), and bony sclerosis(four). In seven patients with the duration of symptoms less than 1 year, thickening of joint capsule and intra-articular effusion were the predominant findings, while bony sclerosis, gross bone destruction, and soft tissue mass in joint space were seen in five patients with the duration of symptoms longer than 1 year. Our results indicate that CT is useful in the diagnosis of tuberculous arthritis by demonstrating characteristic pathologic changes of the joint space, soft tissue abnormality and bony involvement

  10. An introduction to the tomographic picture of quantum mechanics

    International Nuclear Information System (INIS)

    Ibort, A; Man'ko, V I; Marmo, G; Simoni, A; Ventriglia, F

    2009-01-01

    Starting from the famous Pauli problem on the possibility of associating quantum states with probabilities, the formulation of quantum mechanics in which quantum states are described by fair probability distributions (tomograms, i.e. tomographic probabilities) is reviewed in a pedagogical style. The relation between the quantum state description and the classical state description is elucidated. The difference between those sets of tomograms is described by inequalities equivalent to a complete set of uncertainty relations for the quantum domain and to non-negativity of probability density on phase space in the classical domain. The intersection of such sets is studied. The mathematical mechanism that allows us to construct different kinds of tomographic probabilities like symplectic tomograms, spin tomograms, photon number tomograms, etc is clarified and a connection with abstract Hilbert space properties is established. The superposition rule and uncertainty relations in terms of probabilities as well as quantum basic equations like quantum evolution and energy spectra equations are given in an explicit form. A method to check experimentally the uncertainty relations is suggested using optical tomograms. Entanglement phenomena and the connection with semigroups acting on simplexes are studied in detail for spin states in the case of two-qubits. The star-product formalism is associated with the tomographic probability formulation of quantum mechanics.

  11. A tomograph VMEbus parallel processing data acquisition system

    International Nuclear Information System (INIS)

    Atkins, M.S.; Wilkinson, N.A.; Rogers, J.G.

    1988-11-01

    This paper describes a VME based data acquisition system suitable for the development of Positron Volume Imaging tomographs which use 3-D data for improved image resolution over slice-oriented tomographs. The data acquisition must be flexible enough to accommodate several 3-D reconstruction algorithms; hence, a software-based system is most suitable. Furthermore, because of the increased dimensions and resolution of volume imaging tomographs, the raw data event rate is greater than that of slice-oriented machines. These dual requirements are met by our data acquisition systems. Flexibility is achieved through an array of processors connected over a VMEbus, operating asynchronously and in parallel. High raw data throughput is achieved using a dedicated high speed data transfer device available for the VMEbus. The device can attain a raw data rate of 2.5 million coincidence events per second for raw events per second for raw events which are 64 bits wide. Real-time data acquisition and pre-processing requirements can be met by about forty 20 MHz Motorola 68020/68881 processors

  12. Tomographic Particle Image Velocimetry Using Colored Shadow Imaging

    KAUST Repository

    Alarfaj, Meshal K.

    2016-02-01

    Tomographic Particle Image Velocimetry Using Colored Shadow Imaging by Meshal K Alarfaj, Master of Science King Abdullah University of Science & Technology, 2015 Tomographic Particle image velocimetry (PIV) is a recent PIV method capable of reconstructing the full 3D velocity field of complex flows, within a 3-D volume. For nearly the last decade, it has become the most powerful tool for study of turbulent velocity fields and promises great advancements in the study of fluid mechanics. Among the early published studies, a good number of researches have suggested enhancements and optimizations of different aspects of this technique to improve the effectiveness. One major aspect, which is the core of the present work, is related to reducing the cost of the Tomographic PIV setup. In this thesis, we attempt to reduce this cost by using an experimental setup exploiting 4 commercial digital still cameras in combination with low-cost Light emitting diodes (LEDs). We use two different colors to distinguish the two light pulses. By using colored shadows with red and green LEDs, we can identify the particle locations within the measurement volume, at the two different times, thereby allowing calculation of the velocities. The present work tests this technique on the flows patterns of a jet ejected from a tube in a water tank. Results from the images processing are presented and challenges discussed.

  13. Field experience with a mobile tomographic nondestructive assay system

    International Nuclear Information System (INIS)

    Prettyman, T.H.; Betts, S.E.; Taggart, D.P.; Estep, R.J.; Nicholas, N.J.; Lucas, M.C.; Harlan, R.A.

    1995-01-01

    A mobile tomographic gamma-ray scanner (TGS) developed by Los Alamos National Laboratory was recently demonstrated at the Rocky Flats Environmental Technology Site and is currently in use at Los Alamos waste storage areas. The scanner was developed to assay radionuclides in low-level, transuranic, and mixed waste in containers ranging in size from 2 ft 3 boxes to 83-gallon overpacks. The tomographic imaging capability provides a complete correction for source distribution and matrix attenuation effects, enabling accurate assays of Pu-239 and other gamma-ray emitting isotopes. In addition, the system can reliably detect self-absorbing material such as plutonium metal shot, and can correct for bias caused by self-absorption. The system can be quickly configured to execute far-field scans, segmented gamma-ray scans, and a host of intermediate scanning protocols, enabling higher throughput (up to 20 drums per 8-hour shift). In this paper, we will report on the results of field trials of the mobile system at Rocky Flats and Los Alamos. Assay accuracy is confirmed for cases in which TGS assays can be compared with assays (e.g. with calorimetry) of individual packages within the drums. The mobile tomographic technology is expected to considerably reduce characterization costs at DOE production and environmental technology sites

  14. Coherent Raman scattering: Applications in imaging and sensing

    Science.gov (United States)

    Cui, Meng

    In this thesis, I discuss the theory, implementation and applications of coherent Raman scattering to imaging and sensing. A time domain interferometric method has been developed to collect high resolution shot-noise-limited Raman spectra over the Raman fingerprint regime and completely remove the electronic background signal in coherent Raman scattering. Compared with other existing coherent Raman microscopy methods, this time domain approach is proved to be simpler and more robust in rejecting background signal. We apply this method to image polymers and biological samples and demonstrate that the same setup can be used to collect two photon fluorescence and self phase modulation signals. A signal to noise ratio analysis is performed to show that this time domain method has a comparable signal to noise ratio to spectral domain methods, which we confirm experimentally. The coherent Raman method is also compared with spontaneous Raman scattering. The conditions under which coherent methods provide signal enhancement are discussed and experiments are performed to compare coherent Raman scattering with spontaneous Raman scattering under typical biological imaging conditions. A critical power, above which coherent Raman scattering is more sensitive than spontaneous Raman scattering, is experimentally determined to be ˜1mW in samples of high molecule concentration with a 75MHz laser system. This finding is contrary to claims that coherent methods provide many orders of magnitude enhancement under comparable conditions. In addition to the far field applications, I also discuss the combination of our time domain coherent Raman method with near field enhancement to explore the possibility of sensing and near field imaging. We report the first direct time-resolved coherent Raman measurement performed on a nanostructured substrate for molecule sensing. The preliminary results demonstrate that sub 20 fs pulses can be used to obtain coherent Raman spectra from a small number

  15. EDITORIAL: Coherent Control

    Science.gov (United States)

    Fielding, Helen; Shapiro, Moshe; Baumert, Thomas

    2008-04-01

    Quantum mechanics, though a probabilistic theory, gives a 'deterministic' answer to the question of how the present determines the future. In essence, in order to predict future probabilities, we need to (numerically) propagate the time-dependent Schrödinger equation from the present to the future. It is interesting to note that classical mechanics of macroscopic bodies, though reputed to be a deterministic theory, does not allow, due to chaos (which unfortunately is more prevalent than integrability), such clear insights into the future. In contrast, small (e.g., atomic, molecular and photonic) systems which are best understood using the tools of quantum mechanics, do not suffer from chaos, rendering the prediction of the probability-distributions of future events possible. The field of quantum control deals with an important modification of this task, namely, it asks: given a wave function in the present, what dynamics, i.e. what Hamiltonian, guarantees a desired outcome or 'objective' in the future? In practice one may achieve this goal of modifying and finding the desired Hamiltonian by introducing external fields, e.g. laser light. It is then possible to reach the objective in a 'trial-and-error' fashion, performed either numerically or in the laboratory. We can guess or build a Hamiltonian, do an experiment, or propagate the initial wave function to the future, compare the result with the desirable objective, and correct the guess for the Hamiltonian until satisfactory agreement with the objective is reached. A systematic way of executing this procedure is the sub-field called 'optimal control'. The trial-and-error method is often very time consuming and rarely provides mechanistic insight. There are situations where analytical solutions exist, rendering the control strategies more transparent. This is especially so when one can identify quantum interferences as the heart of quantum control, the essence of the field called 'coherent control'. The experience

  16. Subgingival calculus imaging based on swept-source optical coherence tomography

    Science.gov (United States)

    Hsieh, Yao-Sheng; Ho, Yi-Ching; Lee, Shyh-Yuan; Lu, Chih-Wei; Jiang, Cho-Pei; Chuang, Ching-Cheng; Wang, Chun-Yang; Sun, Chia-Wei

    2011-07-01

    We characterized and imaged dental calculus using swept-source optical coherence tomography (SS-OCT). The refractive indices of enamel, dentin, cementum, and calculus were measured as 1.625 +/- 0.024, 1.534 +/- 0.029, 1.570 +/- 0.021, and 2.097 +/- 0.094, respectively. Dental calculus leads strong scattering properties, and thus, the region can be identified from enamel with SS-OCT imaging. An extracted human tooth with calculus is covered with gingiva tissue as an in vitro sample for tomographic imaging.

  17. Three-dimensional ophthalmic optical coherence tomography with a refraction correction algorithm

    Science.gov (United States)

    Zawadzki, Robert J.; Leisser, Christoph; Leitgeb, Rainer; Pircher, Michael; Fercher, Adolf F.

    2003-10-01

    We built an optical coherence tomography (OCT) system with a rapid scanning optical delay (RSOD) line, which allows probing full axial eye length. The system produces Three-dimensional (3D) data sets that are used to generate 3D tomograms of the model eye. The raw tomographic data were processed by an algorithm, which is based on Snell"s law to correct the interface positions. The Zernike polynomials representation of the interfaces allows quantitative wave aberration measurements. 3D images of our results are presented to illustrate the capabilities of the system and the algorithm performance. The system allows us to measure intra-ocular distances.

  18. Full-field optical coherence tomography using immersion Mirau interference microscope.

    Science.gov (United States)

    Lu, Sheng-Hua; Chang, Chia-Jung; Kao, Ching-Fen

    2013-06-20

    In this study, an immersion Mirau interference microscope was developed for full-field optical coherence tomography (FFOCT). Both the reference and measuring arms of the Mirau interferometer were filled with water to prevent the problems associated with imaging a sample in air with conventional FFOCT systems. The almost-common path interferometer makes the tomographic system less sensitive to environmental disturbances. En face OCT images at various depths were obtained with phase-shifting interferometry and Hariharan algorithm. This immersion interferometric method improves depth and quality in three-dimensional OCT imaging of scattering tissue.

  19. Industrial dynamic tomographic reconstruction; Reconstrucao tomografica dinamica industrial

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Eric Ferreira de

    2016-07-01

    The state of the art methods applied to industrial processes is currently based on the principles of classical tomographic reconstructions developed for tomographic patterns of static distributions, or is limited to cases of low variability of the density distribution function of the tomographed object. Noise and motion artifacts are the main problems caused by a mismatch in the data from views acquired in different instants. All of these add to the known fact that using a limited amount of data can result in the presence of noise, artifacts and some inconsistencies with the distribution under study. One of the objectives of the present work is to discuss the difficulties that arise from implementing reconstruction algorithms in dynamic tomography that were originally developed for static distributions. Another objective is to propose solutions that aim at reducing a temporal type of information loss caused by employing regular acquisition systems to dynamic processes. With respect to dynamic image reconstruction it was conducted a comparison between different static reconstruction methods, like MART and FBP, when used for dynamic scenarios. This comparison was based on a MCNPx simulation as well as an analytical setup of an aluminum cylinder that moves along the section of a riser during the process of acquisition, and also based on cross section images from CFD techniques. As for the adaptation of current tomographic acquisition systems for dynamic processes, this work established a sequence of tomographic views in a just-in-time fashion for visualization purposes, a form of visually disposing density information as soon as it becomes amenable to image reconstruction. A third contribution was to take advantage of the triple color channel necessary to display colored images in most displays, so that, by appropriately scaling the acquired values of each view in the linear system of the reconstruction, it was possible to imprint a temporal trace into the regularly

  20. Computed tomographic study of aged schizophrenic patients

    International Nuclear Information System (INIS)

    Seno, Haruo; Fujimoto, Akihiko; Ishino, Hiroshi; Shibata, Masahiro; Kuroda, Hiroyuki; Kanno, Hiroshi.

    1997-01-01

    The width of interhemispheric fissure, lateral ventricles and third ventricle were measured using cranial computed tomography (CT; linear method) in 45 elderly inpatients with chronic schizophrenia and in 28 age-matched control subjects. Twenty-three patients were men and 22 were women. In addition, Mini-Mental State Examination, Brief Psychiatric Rating Scale (BPRS) and a subclass of BPRS were undertaken in all patients. There is a significant enlargement of the maximum width of the interhemispheric fissure (in both male and female) and a significant enlargement of ventricular system (more severe in men than in women) in aged schizophrenics, as seen with CT, compared with normal controls. These findings are consistent with previous studies of non-aged schizophrenic patients. Based upon the relation between psychiatric symptoms and CT findings, the most striking is a significant negative correlation between the third ventricle enlargement and the positive and depressive symptoms in all patients. This result suggests that the advanced third ventricle enlargement may decrease these symptoms in aged schizophrenics. (author)

  1. Computed tomographic study on Mycoplasma pneumoniae pneumonia

    International Nuclear Information System (INIS)

    Tanaka, Hiroshi; Koba, Hiroyuki; Mori, Takuji; Mori, Masaki; Tsunematsu, Kazunori; Natori, Hiroshi; Asakawa, Mitsuo; Suzuki, Akira; Doi, Mikio.

    1985-01-01

    Serologically proven 21 patients with Mycoplasma pneumoniae pneumonia that showed infiltrative shadows on chest radiograms were studied by computed tomography (CT). Localization of the lesion and the fashion of its progression through the lung were analyzed. Following 3 loci were defined on the basis of the investigations of critical analysis of the chest radiograms, and of radiopathological analysis of the experimental animal model of mycoplasmal pneumonia with soft X-ray image. I: Peribronchial and periarterial interstitium. II: Bronchiole and its surroundings. III: Lung parenchyma, on hilar area as IIIh, on marginal area as IIIm. Even in the early phase of this disease, radiopathological findings on CT have been distributed in all loci mentioned above. The Shadow disappeared from locus III approximately 14th day from the onset. The shadow have remained, however, loci I, II for a long period. Those findings suggest that locus I and II are one of the major focus of Mycoplasma neumoniae pneumonia. Volume loss in the locus III was observed 78 % of the cases at 28th day from the onset. The shadow on locus IIIh was more prominent than locus IIIm. Reported analytical method with CT could be widely applied to disclose a radiopathological details in other infectious diseases of the lung. (author)

  2. A study of the decoding of multiple pinhole coded aperture RI tomographic images

    International Nuclear Information System (INIS)

    Hasegawa, Takeo; Kobayashi, Akitoshi; Nishiyama, Yutaka

    1980-01-01

    The authors constructed a Multiple Pinhole Coded Aperture (MPCA) and developed related decoding software. When simple coordinate transformation was performed, omission of points and shifting of counts occurred. By selecting various tomographic planes and collecting count for each tomographic depth from the shadowgram, a solution to these problems was found. The counts from the central portion of the tomographic image from the MPCA were incorrectly high, this was rectified by a correction function to improve the uniformity correction program of the γ-camera. Depth resolution of the tomographic image improved in proportion to the area encompassed by the pinhole configuration. An MPCA with a uniform arrangement of pinholes (e, g, pinholes in an arrangement parallel to the X-axis or the Y-axis) yielded decoded tomographic images of inferior quality. Optimum results were obtained with a ring-shaped arrangement yielding clinically applicable tomographic images even for large objects. (author)

  3. Implementation of 3D tomographic visualisation through planar ICT data from experimental gamma-ray tomographic system

    International Nuclear Information System (INIS)

    Umesh Kumar; Singh, Gursharan; Ravindran, V.R.

    2001-01-01

    Industrial Computed Tomography (ICT) is one of the latest methods of non-destructive testing and examination. Different prototypes of Computed Industrial Tomographic Imaging System (CITIS) have been developed and experimental data have been generated in Isotope Applications Division. The experimental gamma-rays based tomographic imaging system comprises of beam generator containing approx. 220 GBq (6 Curies) of 137 Cs, a single NaI(Tl) -PMT integral assembly in a thick shielding and associated electronics, stepper motor controlled mechanical manipulator, collimators and required software. CITIS data is normally acquired in one orientation of the sample. It may be sometimes required to view a tomographic plane in a different orientation. Also, 3D visualization may be required with the available 2D data set. All these can be achieved by processing the available data. We have customized some of the routines for this purpose provided IDL (Integrated Data Language) package to suit our requirements. The present paper discusses methodology adopted for this purpose with an illustrative example. (author)

  4. Lymphadenopathy in celiac disease: computed tomographic observations

    International Nuclear Information System (INIS)

    Jones, B.; Bayless, T.M.; Fishman, E.K.; Siegelman, S.S.

    1984-01-01

    Lymphadenopathy in patients with celiac disease is generally viewed with alarm due to the association between celiac disease and intestinal lymphoma. Four patients with celiac disease are described in whom significant mesenteric and paraaortic adenopathy was demonstrated by computed tomogrophy (CT). The subsequent clinical course of these patients revealed no evidence of lymphoma. In two patients with longstanding celiac disease and recent relapse, exploratory laparotomy revealed reactive hyperplasia in the enlarged glands; in one patient this was associated with intestinal ulceration, and in the other no underlying pathology was found. Follow-up CT scans in both these patients demonstrated regression of the findings with clinical improvement. In the other two patients, CT was performed as part of the initial evaluation

  5. Computed tomographical evaluation of diabetic nephropathy

    International Nuclear Information System (INIS)

    Ubara, Yoshifumi; Hara, Shigeko; Arizono, Kenji; Katori, Hideyuki; Yamada, Akira; Mimura, Nobuhide; Hagura, Ryoko.

    1996-01-01

    Diabetic nephropathy can be regarded mainly as a type of microangiopathy, but is a disease that may also include aspects of macroangiopathy. This is especially true of renal disease in non-insulin dependent diabetes mellitus (NIDDM), which is characterized not only by diabetic glomerulosclerosis, but also by atherosclerosis. We performed morphological studies on the kidney, using computed tomography (CT), focusing on such points as: abdominal aortic calcifications at the level of kidney, calcifications in the renal artery, and wedge-shaped defects on the renal surface. We noted that these findings became more prominent in NIDDM patients during end-stage renal failure than during normal renal function, and were significantly more common in those two NIDDM groups than in age-matched nondiabetic patients without hypertension, hyperlipidemia or gout. NIDDM patients exhibited these features more frequently than IDDM patients. (author)

  6. Lymphadenopathy in celiac disease: computed tomographic observations

    Energy Technology Data Exchange (ETDEWEB)

    Jones, B.; Bayless, T.M.; Fishman, E.K.; Siegelman, S.S.

    1984-06-01

    Lymphadenopathy in patients with celiac disease is generally viewed with alarm due to the association between celiac disease and intestinal lymphoma. Four patients with celiac disease are described in whom significant mesenteric and paraaortic adenopathy was demonstrated by computed tomogrophy (CT). The subsequent clinical course of these patients revealed no evidence of lymphoma. In two patients with longstanding celiac disease and recent relapse, exploratory laparotomy revealed reactive hyperplasia in the enlarged glands; in one patient this was associated with intestinal ulceration, and in the other no underlying pathology was found. Follow-up CT scans in both these patients demonstrated regression of the findings with clinical improvement. In the other two patients, CT was performed as part of the initial evaluation.

  7. Sense of Coherence and Gambling: Exploring the Relationship Between Sense of Coherence, Gambling Behaviour and Gambling-Related Harm.

    Science.gov (United States)

    Langham, Erika; Russell, Alex M T; Hing, Nerilee; Gainsbury, Sally M

    2017-06-01

    Understanding why some people experience problems with gambling whilst others are able to restrict gambling to recreational levels is still largely unexplained. One potential explanation is through salutogenesis, which is a health promotion approach of understanding factors which move people towards health rather than disease. An important aspect of salutogenesis is sense of coherence. Individuals with stronger sense of coherence perceive their environment as comprehensible, manageable and meaningful. The present study examined the relationship of individuals' sense of coherence on their gambling behaviour and experience of gambling related harm. This exploratory study utilised an archival dataset (n = 1236) from an online, cross sectional survey of people who had experienced negative consequences from gambling. In general, a stronger sense of coherence was related to lower problem gambling severity. When gambling behaviour was controlled for, sense of coherence was significantly related to the experience of individual gambling harms. A strong sense of coherence can be seen as a protective factor against problematic gambling behaviour, and subsequent gambling related harms. These findings support the value of both primary and tertiary prevention strategies that strengthen sense of coherence as a harm minimisation strategy. The present study demonstrates the potential value of, and provides clear direction for, considering sense of coherence in order to understand gambling-related issues.

  8. Correlation between computed tomographic and magnetic resonance imaging findings of parenchymal lung diseases

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, Miriam Menna; Rafful, Patricia Piazza [Department of Radiology, Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); Rodrigues, Rosana Souza [Department of Radiology, Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); D’Or Institute for Research and Education, Rio de Janeiro, RJ (Brazil); Zanetti, Gláucia [Department of Radiology, Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); Hochhegger, Bruno [Complexo Hospitalar Santa Casa de Misericórdia de Porto Alegre, Porto Alegre, RS (Brazil); Souza, Arthur Soares [Department of Radiology, Medical School of Rio Preto (FAMERP) and Ultra X, São José do Rio Preto, SP (Brazil); Guimarães, Marcos Duarte [Department of Imaging, Hospital AC Camargo, São Paulo, SP (Brazil); Marchiori, Edson, E-mail: edmarchiori@gmail.com [Department of Radiology, Federal University of Rio de Janeiro, Rio de Janeiro (Brazil)

    2013-09-15

    Computed tomography (CT) is considered to be the gold standard method for the assessment of morphological changes in the pulmonary parenchyma. Although its spatial resolution is lower than that of CT, MRI offers the advantage of characterizing different aspects of tissue based on the degree of contrast on T1-weighted image (WI) and T2-WI. In this article, we describe and correlate the MRI and CT features of several common patterns of parenchymal lung disease (air trapping, atelectasis, bronchiectasis, cavitation, consolidation, emphysema, ground-glass opacities, halo sign, interlobular septal thickening, masses, mycetoma, nodules, progressive massive fibrosis, reverse halo sign and tree-in-bud pattern). MRI may be an alternative modality for the collection of morphological and functional information useful for the management of parenchymal lung disease, which would help reduce the number of chest CT scans and radiation exposure required in patients with a variety of conditions.

  9. Computer tomographic findings in portal hypertension due to cirrhosis of the liver. Pt. 2

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, P; Koester, O; Lackner, K; Kunz, R; Koischwitz, D

    1983-07-01

    The results of a discriminant analysis for the objective diagnosis of cirrhosis of the liver are reported. Eight quantitative parameters seen on CT which, by themselves, are not diagnostic, were studied, and three relationships found to be of discriminatory significance; they are the diameter of the superior mesenteric vein, the ratio of the diameter of the caudate lobe and the right lobe of the liver and a quotient derived from the splenic and hepatic index. Cirrhosis of the liver with portal hypertension could be distinguished with a specificity of 100%, an accuracy of 96% and a sensitivity of 94%.

  10. Computer tomographic findings in portal hypertension due to cirrhosis of the liver. Pt. 3

    International Nuclear Information System (INIS)

    Koester, O.; Fischer, P.; Lindecken, K.D.; Lackner, K.; Bonn Univ.

    1984-01-01

    Contract injection for angio-CT shows kinetic changes in patients with portal hypertension due to cirrhosis of the liver when compared with normals. Contrast-duration diagrams show a higher aortic peak, low contrast and delayed contrast maximum in the liver and protal vein in patients with liver cirrhosis and portal hypertension. On these criteria it is possible to distinguish patients with cirrhosis (n = 18) from normals (n = 16). (orig.) [de

  11. Computer tomographic findings in portal hypertension due to cirrhosis of the liver. Pt. 3

    Energy Technology Data Exchange (ETDEWEB)

    Koester, O; Fischer, P; Lindecken, K D; Lackner, K

    1984-03-01

    Contract injection for angio-CT shows kinetic changes in patients with portal hypertension due to cirrhosis of the liver when compared with normals. Contrast-duration diagrams show a higher aortic peak, low contrast and delayed contrast maximum in the liver and protal vein in patients with liver cirrhosis and portal hypertension. On these criteria it is possible to distinguish patients with cirrhosis (n = 18) from normals (n = 16). 5 figs.

  12. Computer tomographic findings in portal hypertension due to cirrhosis of the liver. Pt. 2

    International Nuclear Information System (INIS)

    Fischer, P.; Koester, O.; Lackner, K.; Kunz, R.; Koischwitz, D.

    1983-01-01

    The results of a discriminant analysis for the objective diagnosis of cirrhosis of the liver are reported. Eight quantitative parameters seen on CT which, by themselves, are not diagnostic, were studied, and three relationships found to be of discriminatory significance; they are the diameter of the superior mesenteric vein, the ratio of the diameter of the caudate lobe and the right lobe of the liver and a quotient derived from the splenic and hepatic index. Cirrhosis of the liver with portal hypertension could be distinguished with a specificity of 100%, an accuracy of 96% and a sensitivity of 94%. (orig.) [de

  13. Computed tomographic findings of abdominal complications of Crohn's disease - pictorial essay

    Energy Technology Data Exchange (ETDEWEB)

    Zissin, R. [Tel-Aviv Univ., Dept. of Diagnostic Imaging, Sapir Medical Center, Kfar Saba, Sackler Faculty of Medicine, Tel Aviv (Israel)]. E-mail: zisinrivka@clalit.org.il; Hertz, M. [Tel-Aviv Univ., Dept. of Diagnostic Imaging, Chaim Sheba Medical Center, Tel Hashomer, Sackler Faculty of Medicine, Tel Aviv (Israel); Osadchy, A. [Tel-Aviv Univ., Dept. of Diagnostic Imaging, Sapir Medical Center, Kfar Saba, Sackler Faculty of Medicine, Tel Aviv (Israel); Novis, B. [Tel-Aviv Univ., Dept. of Gastroenterology, Sapir Medical Center, Kfar Saba, Sackler Faculty of Medicine, Tel Aviv (Israel); Gayer, G. [Tel-Aviv Univ., Department of Diagnostic Imaging, Assaf Harode Medical Center, Zrifin, Sackler Faculty of Medicine, Tel Aviv (Israel)

    2005-02-15

    Crohn's disease (CD) is a chronic, transmural, inflammatory disease of the gastrointestinal tract (CIT) most often affecting the terminal ileum and colon. Diarrhea, abdominal pain, anorexia, nausea, and weight loss are the most common clinical symptoms. Abdominal complications of CD, both intestinal and extraintestinal, are frequent and variable. The most common intestinal complications include ileocolitis with external or internal fistulas and abscess formation, strictures, and bowel obstruction. Less common are free perforation, intussusception, and malignancy. The extraintestinal complications include nephrolithiasis, cholelithiasis, fatty liver, portal vein gas, and thromboembolic events. Nowadays, computed tomography (CT) provides superb anatomic detail and diagnostic accuracy of various intra-abdominal pathological processes, and it thus has become an essential diagnostic tool in the evaluation and management of patients wit known CD for the assessment of bowel wall involvement, the mesenteric extent of the disease, and inn-abdominal complications. In addition, as CT is frequently performed to evaluate patients with acute abdomen, it may encounter clinically unsuspected complications in patients with CD. This article reviews the CT features of various intra-abdominal complications of CD. (author)

  14. Computed tomographic findings of abdominal complications of Crohn's disease - pictorial essay

    International Nuclear Information System (INIS)

    Zissin, R.; Hertz, M.; Osadchy, A.; Novis, B.; Gayer, G.

    2005-01-01

    Crohn's disease (CD) is a chronic, transmural, inflammatory disease of the gastrointestinal tract (CIT) most often affecting the terminal ileum and colon. Diarrhea, abdominal pain, anorexia, nausea, and weight loss are the most common clinical symptoms. Abdominal complications of CD, both intestinal and extraintestinal, are frequent and variable. The most common intestinal complications include ileocolitis with external or internal fistulas and abscess formation, strictures, and bowel obstruction. Less common are free perforation, intussusception, and malignancy. The extraintestinal complications include nephrolithiasis, cholelithiasis, fatty liver, portal vein gas, and thromboembolic events. Nowadays, computed tomography (CT) provides superb anatomic detail and diagnostic accuracy of various intra-abdominal pathological processes, and it thus has become an essential diagnostic tool in the evaluation and management of patients wit known CD for the assessment of bowel wall involvement, the mesenteric extent of the disease, and inn-abdominal complications. In addition, as CT is frequently performed to evaluate patients with acute abdomen, it may encounter clinically unsuspected complications in patients with CD. This article reviews the CT features of various intra-abdominal complications of CD. (author)

  15. Computed tomographic findings of leg muscles in the hemiplegics due to cerebrovascular accidents

    International Nuclear Information System (INIS)

    Odajima, Natsu; Ishiai, Sumio; Kotera, Minoru; Furukawa, Tetsuo; Tsukagoshi, Hiroshi.

    1986-01-01

    The computed tomography (CT) scan was performed in 52 hemiplegics due to cerebrovascular accidents and 12 normal controls on the mid-portion of the thigh and the largest-diameter section of the calf. Muscle size and average CT density of the muscle were measured. The salient feature was hypertrophic gracilis muscle of the hemiplegic side. Other muscles were more atrophied with lower CT density compared with those of the contralateral side. The size of the quadriceps muscle was especially small. The ratio of the quadriceps to all the thigh muscles in cross section was significantly smaller in affected side of hemiplegics than that of normal controls. This was observed even in normal side of the hemiplegics but the ratios of adductor and flexor muscles of the thigh showed no difference. Hypertrophy of gracilis muscle with high CT density was observed only on hemiplegic side. Muscle atrophies were marked in non-ambulatory patients. The ratios of quadriceps and saltorius muscles of thigh in non-ambulatory patients were significantly smaller than those of ambulatory patients. It could not be detected that there is relationship of the sevirity of the muscle atrophy and parietal lobe dysfunction. This atrophy considered to be the result of disuse of the paralyzed leg and pyramidal tract dysfunction. (author)

  16. Single-photon emission computed tomographic findings and motor neuron signs in amyotrophic lateral sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Terao, Shin-ichi; Sobue, Gen; Higashi, Naoki; Takahashi, Masahiko; Suga, Hidemichi; Mitsuma, Terunori [Aichi Medical Univ., Nagakute (Japan)

    1995-03-01

    {sup 123}I-amphetamine-single photon emission computed tomography (SPECT) was performed on 16 patients with amyotrophic lateral sclerosis (ALS) to investigate the correlation between regional cerebral blood flow (rCBF) and upper motor neuron signs. Significant decreased blood flow less than 2 SDs below the mean of controls was observed in the frontal lobe in 4 patients (25%) and in the frontoparietal lobe including the cortical motor area in 4 patients, respectively. The severity of extermity muscular weakness was significantly correlate with decrease in blood flow through the frontal lobe (p<0.05) and through the frontoparietal lobe (p<0.001). A significant correlation was also noted to exist between the severity of bulbar paralysis and decrease in blood flow through the frontoparietal lobe. No correlation, however, was observed between rCBF and severity of spasticity, presence or absence of Babinski`s sign and the duration of illness. Although muscular weakness in the limbs and bulbar paralysis are not pure upper motor neuron signs, the observed reduction in blood flow through the frontal or frontoparietal lobes appears to reflect extensive progression of functional or organic lesions of cortical neurons including the motor area. (author).

  17. Single-photon emission computed tomographic findings and motor neuron signs in amyotrophic lateral sclerosis

    International Nuclear Information System (INIS)

    Terao, Shin-ichi; Sobue, Gen; Higashi, Naoki; Takahashi, Masahiko; Suga, Hidemichi; Mitsuma, Terunori

    1995-01-01

    123 I-amphetamine-single photon emission computed tomography (SPECT) was performed on 16 patients with amyotrophic lateral sclerosis (ALS) to investigate the correlation between regional cerebral blood flow (rCBF) and upper motor neuron signs. Significant decreased blood flow less than 2 SDs below the mean of controls was observed in the frontal lobe in 4 patients (25%) and in the frontoparietal lobe including the cortical motor area in 4 patients, respectively. The severity of extermity muscular weakness was significantly correlate with decrease in blood flow through the frontal lobe (p<0.05) and through the frontoparietal lobe (p<0.001). A significant correlation was also noted to exist between the severity of bulbar paralysis and decrease in blood flow through the frontoparietal lobe. No correlation, however, was observed between rCBF and severity of spasticity, presence or absence of Babinski's sign and the duration of illness. Although muscular weakness in the limbs and bulbar paralysis are not pure upper motor neuron signs, the observed reduction in blood flow through the frontal or frontoparietal lobes appears to reflect extensive progression of functional or organic lesions of cortical neurons including the motor area. (author)

  18. Electromyographic and computed tomographic findings in five patients with monomelic spinal muscular atrophy

    NARCIS (Netherlands)

    de Visser, M.; Ongerboer de Visser, B. W.; Verbeeten, B.

    1988-01-01

    Five patients with monomelic spinal muscular atrophy are described. Clinical features included insidious onset of wasting and weakness of one limb, lack of involvement of the cranial nerves, brain stem, pyramidal tracts and sensory system, and a stable condition over a period of 4-20 years. Clinical

  19. Computed tomographic findings in a calf with actinomycosis: a case report

    International Nuclear Information System (INIS)

    Mohamed, T.; Al-Sobayil, F.; Kurwasawa, T.; Nakade, T.; Floeck, M.

    2011-01-01

    In this report a case of actinomycosis in a five-month-old Holstein calf is described. The patient displayed a hard and immobile swelling in the mandible and fever. Computed tomography (CT) imaging of the skull was performed under deep sedation and revealed an asymmetrical appearance of the mandible with the presence of intra-mandibular hypodense lesions. Haematologic and serum biochemical profiles revealed leukocytosis, neutrophilia, hypoalbuminaemia and hypergammaglobulinaemia. Treatment consisted of flushing the lesion and administration of antibiotics and non-steroidal anti-inflammatory drugs. The calf responded to therapy and had recovered almost completely four months later. The present case indicates that CT is an effective non-invasive means of identifying mandibular lesions in cattle

  20. Partially coherent isodiffracting pulsed beams

    Science.gov (United States)

    Koivurova, Matias; Ding, Chaoliang; Turunen, Jari; Pan, Liuzhan

    2018-02-01

    We investigate a class of isodiffracting pulsed beams, which are superpositions of transverse modes supported by spherical-mirror laser resonators. By employing modal weights that, for stationary light, produce a Gaussian Schell-model beam, we extend this standard model to pulsed beams. We first construct the two-frequency cross-spectral density function that characterizes the spatial coherence in the space-frequency domain. By assuming a power-exponential spectral profile, we then employ the generalized Wiener-Khintchine theorem for nonstationary light to derive the two-time mutual coherence function that describes the space-time coherence of the ensuing beams. The isodiffracting nature of the laser resonator modes permits all (paraxial-domain) calculations at any propagation distance to be performed analytically. Significant spatiotemporal coupling is revealed in subcycle, single-cycle, and few-cycle domains, where the partial spatial coherence also leads to reduced temporal coherence even though full spectral coherence is assumed.

  1. Coherent quantum logic

    International Nuclear Information System (INIS)

    Finkelstein, D.

    1987-01-01

    The von Neumann quantum logic lacks two basic symmetries of classical logic, that between sets and classes, and that between lower and higher order predicates. Similarly, the structural parallel between the set algebra and linear algebra of Grassmann and Peano was left incomplete by them in two respects. In this work a linear algebra is constructed that completes this correspondence and is interpreted as a new quantum logic that restores these invariances, and as a quantum set theory. It applies to experiments with coherent quantum phase relations between the quantum and the apparatus. The quantum set theory is applied to model a Lorentz-invariant quantum time-space complex

  2. Diffraction coherence in optics

    CERN Document Server

    Françon, M; Green, L L

    2013-01-01

    Diffraction: Coherence in Optics presents a detailed account of the course on Fraunhofer diffraction phenomena, studied at the Faculty of Science in Paris. The publication first elaborates on Huygens' principle and diffraction phenomena for a monochromatic point source and diffraction by an aperture of simple form. Discussions focus on diffraction at infinity and at a finite distance, simplified expressions for the field, calculation of the path difference, diffraction by a rectangular aperture, narrow slit, and circular aperture, and distribution of luminous flux in the airy spot. The book th

  3. Hadron coherent production

    International Nuclear Information System (INIS)

    Dremin, I.M.

    1981-01-01

    The process of the coherent production of hadrons analogous to Cherenkov radiation of photons is considered. Its appearence and qualitative treatment are possible now because it is known from experiment that the real part of the πp (and pp) forward elastic scattering amplitude is positive at high energies. The threshold behaviour of the process as well as very typical angular and psub(T)-distributions where psub(t)-transverse momentum corresponding to the ring structure of the target diagram at rather large angles and to high-psub(T) jet production are emphasized [ru

  4. Optical coherence refractometry.

    Science.gov (United States)

    Tomlins, Peter H; Woolliams, Peter; Hart, Christian; Beaumont, Andrew; Tedaldi, Matthew

    2008-10-01

    We introduce a novel approach to refractometry using a low coherence interferometer at multiple angles of incidence. We show that for plane parallel samples it is possible to measure their phase refractive index rather than the group index that is usually measured by interferometric methods. This is a significant development because it enables bulk refractive index measurement of scattering and soft samples, not relying on surface measurements that can be prone to error. Our technique is also noncontact and compatible with in situ refractive index measurements. Here, we demonstrate this new technique on a pure silica test piece and a highly scattering resin slab, comparing the results with standard critical angle refractometry.

  5. Coherent laser beam combining

    CERN Document Server

    Brignon, Arnaud

    2013-01-01

    Recently, the improvement of diode pumping in solid state lasers and the development of double clad fiber lasers have allowed to maintain excellent laser beam quality with single mode fibers. However, the fiber output power if often limited below a power damage threshold. Coherent laser beam combining (CLBC) brings a solution to these limitations by identifying the most efficient architectures and allowing for excellent spectral and spatial quality. This knowledge will become critical for the design of the next generation high-power lasers and is of major interest to many industrial, environme

  6. Coherent beam combination via microparticle plasma modes

    International Nuclear Information System (INIS)

    Rogovin, D.; Shen, T.P.

    1988-01-01

    Recently, there have been interesting observations and calculations on phase conjugation via degenerate four-wave mixing in gold colloids. The generation of phase conjugate radiation in these media arises from and reflects the creation of static index grating imposed on the electronic wave functions within the microparticles. These encouraging findings motivate us to consider the possibility of generating moving index gratings in these media with possible applications to coherent beam combination

  7. Consistency of ocular coherence tomography fast macular thickness mapping in diabetic diffuse macular edema

    International Nuclear Information System (INIS)

    Saraiva, Fabio Petersen; Costa, Patricia Grativol; Inomata, Daniela Lumi; Melo, Carlos Sergio Nascimento; Helal Junior, John; Nakashima, Yoshitaka

    2007-01-01

    Objectives: To investigate optical coherence tomography consistency on foveal thickness, foveal volume, and macular volume measurements in patients with and without diffuse diabetic macular edema. Introduction: Optical coherence tomography represents an objective technique that provides cross-sectional tomographs of retinal structure in vivo. However, it is expected that poor fixation ability, as seen in diabetic macular edema, could alter its results. Several authors have discussed the reproducibility of optical coherence tomography, but only a few have addressed the topic with respect to diabetic maculopathy. Methods: The study recruited diabetic patients without clinically evident retinopathy (control group) and with diffuse macular edema (case group). Only one eye of each patient was evaluated. Five consecutive fast macular scans were taken using Ocular Coherence Tomography 3; the 6 mm macular map was chosen. The consistency in measurements of foveal thickness, foveal volume, and total macular volume for both groups was evaluated using the Pearson's coefficient of variation. The T-test for independent samples was used in order to compare measurements of both groups. Results: Each group consisted of 20 patients. All measurements had a coefficient of variation less than 10%. The most consistent parameter for both groups was the total macular volume. Discussion: Consistency in measurement is a mainstay of any test. A test is unreliable if its measurements can not be correctly repeated. We found a good index of consistency, even considering patients with an unstable gaze. Conclusions: Optical coherence tomography is a consistent method for diabetic subjects with diffuse macular edema. (author)

  8. Consistency of ocular coherence tomography fast macular thickness mapping in diabetic diffuse macular edema

    Energy Technology Data Exchange (ETDEWEB)

    Saraiva, Fabio Petersen; Costa, Patricia Grativol; Inomata, Daniela Lumi; Melo, Carlos Sergio Nascimento; Helal Junior, John; Nakashima, Yoshitaka [Universidade de Sao Paulo (USP), SP (Brazil). Hospital das Clinicas. Dept. de Oftalmologia]. E-mail: fabiopetersen@yahoo.com.br

    2007-07-01

    Objectives: To investigate optical coherence tomography consistency on foveal thickness, foveal volume, and macular volume measurements in patients with and without diffuse diabetic macular edema. Introduction: Optical coherence tomography represents an objective technique that provides cross-sectional tomographs of retinal structure in vivo. However, it is expected that poor fixation ability, as seen in diabetic macular edema, could alter its results. Several authors have discussed the reproducibility of optical coherence tomography, but only a few have addressed the topic with respect to diabetic maculopathy. Methods: The study recruited diabetic patients without clinically evident retinopathy (control group) and with diffuse macular edema (case group). Only one eye of each patient was evaluated. Five consecutive fast macular scans were taken using Ocular Coherence Tomography 3; the 6 mm macular map was chosen. The consistency in measurements of foveal thickness, foveal volume, and total macular volume for both groups was evaluated using the Pearson's coefficient of variation. The T-test for independent samples was used in order to compare measurements of both groups. Results: Each group consisted of 20 patients. All measurements had a coefficient of variation less than 10%. The most consistent parameter for both groups was the total macular volume. Discussion: Consistency in measurement is a mainstay of any test. A test is unreliable if its measurements can not be correctly repeated. We found a good index of consistency, even considering patients with an unstable gaze. Conclusions: Optical coherence tomography is a consistent method for diabetic subjects with diffuse macular edema. (author)

  9. Thermodynamic limit for coherence-limited solar power conversion

    Science.gov (United States)

    Mashaal, Heylal; Gordon, Jeffrey M.

    2014-09-01

    The spatial coherence of solar beam radiation is a key constraint in solar rectenna conversion. Here, we present a derivation of the thermodynamic limit for coherence-limited solar power conversion - an expansion of Landsberg's elegant basic bound, originally limited to incoherent converters at maximum flux concentration. First, we generalize Landsberg's work to arbitrary concentration and angular confinement. Then we derive how the values are further lowered for coherence-limited converters. The results do not depend on a particular conversion strategy. As such, they pertain to systems that span geometric to physical optics, as well as classical to quantum physics. Our findings indicate promising potential for solar rectenna conversion.

  10. Preparation of freezing quantum state for quantum coherence

    Science.gov (United States)

    Yang, Lian-Wu; Man, Zhong-Xiao; Zhang, Ying-Jie; Han, Feng; Du, Shao-jiang; Xia, Yun-Jie

    2018-06-01

    We provide a method to prepare the freezing quantum state for quantum coherence via unitary operations. The initial product state consists of the control qubit and target qubit; when it satisfies certain conditions, the initial product state converts into the particular Bell diagonal state under the unitary operations, which have the property of freezing of quantum coherence under quantum channels. We calculate the frozen quantum coherence and corresponding quantum correlations, and find that the quantities are determined by the control qubit only when the freezing phenomena occur.

  11. Memory coherence of a sympathetically cooled trapped-ion qubit

    International Nuclear Information System (INIS)

    Home, J. P.; McDonnell, M. J.; Szwer, D. J.; Keitch, B. C.; Lucas, D. M.; Stacey, D. N.; Steane, A. M.

    2009-01-01

    We demonstrate sympathetic cooling of a 43 Ca + trapped-ion 'memory' qubit by a 40 Ca + 'coolant' ion sufficiently near the ground state of motion for fault-tolerant quantum logic, while maintaining coherence of the qubit. This is an essential ingredient in trapped-ion quantum computers. The isotope shifts are sufficient to suppress decoherence and phase shifts of the memory qubit due to the cooling light which illuminates both ions. We measure the qubit coherence during ten cycles of sideband cooling, finding a coherence loss of 3.3% per cooling cycle. The natural limit of the method is O(10 -4 ) infidelity per cooling cycle.

  12. A fast tomographic method for searching the minimum free energy path

    International Nuclear Information System (INIS)

    Chen, Changjun; Huang, Yanzhao; Xiao, Yi; Jiang, Xuewei

    2014-01-01

    Minimum Free Energy Path (MFEP) provides a lot of important information about the chemical reactions, like the free energy barrier, the location of the transition state, and the relative stability between reactant and product. With MFEP, one can study the mechanisms of the reaction in an efficient way. Due to a large number of degrees of freedom, searching the MFEP is a very time-consuming process. Here, we present a fast tomographic method to perform the search. Our approach first calculates the free energy surfaces in a sequence of hyperplanes perpendicular to a transition path. Based on an objective function and the free energy gradient, the transition path is optimized in the collective variable space iteratively. Applications of the present method to model systems show that our method is practical. It can be an alternative approach for finding the state-to-state MFEP

  13. Radiological findings of congenital lipoid adrenal hyperplasia: a case report

    International Nuclear Information System (INIS)

    Kim, Mi Jeong; Shin, Joo Yong; Lee, Hee Jung; Lee, Jin Hee; Sohn, Cheol Ho; Lee, Sung Moon; Kim, Hong; Woo, Seong Ku; Suh, Soo Ji

    2001-01-01

    Congenital lipoid adrenal hyperplasia (CLAH) is a rare autosomal recessive disorder characterized by the marked accumulation of lipids and cholesterol in the adrenal cortex, and the failure of adrenal steroids to synthesise. We report the ultrasound (US), computed tomographic (CT), and magnetic resonance (MR) imaging findings in a four-day-old female neonate with CLAH

  14. Coherent states and rational surfaces

    International Nuclear Information System (INIS)

    Brody, Dorje C; Graefe, Eva-Maria

    2010-01-01

    The state spaces of generalized coherent states associated with special unitary groups are shown to form rational curves and surfaces in the space of pure states. These curves and surfaces are generated by the various Veronese embeddings of the underlying state space into higher dimensional state spaces. This construction is applied to the parameterization of generalized coherent states, which is useful for practical calculations, and provides an elementary combinatorial approach to the geometry of the coherent state space. The results are extended to Hilbert spaces with indefinite inner products, leading to the introduction of a new kind of generalized coherent states.

  15. Array-Enhanced Coherence Resonance: Nontrivial Effects of Heterogeneity and Spatial Independence of Noise

    International Nuclear Information System (INIS)

    Zhou, Changsong; Kurths, Juergen; Hu, Bambi

    2001-01-01

    We demonstrate the effect of coherence resonance in a heterogeneous array of coupled Fitz Hugh--Nagumo neurons. It is shown that coupling of such elements leads to a significantly stronger coherence compared to that of a single element. We report nontrivial effects of parameter heterogeneity and spatial independence of noise on array-enhanced coherence resonance; especially, we find that (i) the coherence increases as spatial correlation of the noise decreases, and (ii) inhomogeneity in the parameters of the array enhances the coherence. Our results have the implication that generic heterogeneity and background noise can play a constructive role to enhance the time precision of firing in neural systems

  16. Thoracic pathologies on scout views and bolus tracking slices for computed tomographic cerebral angiography

    Energy Technology Data Exchange (ETDEWEB)

    Groth, M.; Fiehler, J.; Buhk, J.H. [University Medical Center Hamburg-Eppendorf (Germany). Dept. of Diagnostic and Interventional Neuroradiology; Henes, F.O. [University Medical Center Hamburg-Eppendorf (Germany). Dept. of Diagnostic and Interventional Radiology

    2015-08-15

    To evaluate the incidence of additional thoracic pathologic findings (TPF) detected on scout views and corresponding bolus tracking slices (SVBT) for computed tomographic cerebral angiography (CTCA) and to test the reliability and accuracy of these findings. The study collective included 505 consecutive patients who underwent multidetector CTCA. Appendant SVBT of all patients were reviewed for any pathologic findings and patient medical reports were analyzed, if any medical treatment was initiated for the detected pathologic findings. In 18 patients thoracic CT scans were performed in the same session. These were additionally reviewed by two blinded observers to test for intra- and interobserver reliability as well as for accuracy of detecting thoracic pathologies on SVBT. TPF were detected in 165 (33 %) SVBT. The five most common pathologic findings were: pleural effusion, 12 %; pneumonia, 8 %; atelectasis/dystelecatsis, 6 %; pericardial effusion, 2 % and elevated diaphragm, 1 %. For 48 % of these findings medical treatment was initiated. SVBT showed a sensitivity of 53 %, a specificity of 99 %, a positive predictive value of 89 %, a negative predictive value of 94 % and accuracy of 94 % for the detection of TPF. The intraobserver reliability was very good and the interobserver reliability showed moderate agreement. SVBT for CTCA should be reviewed with care by radiologists, since additional TPF can affect patient management. Nevertheless, despite a high specificity of SVBT for detecting TPF, an only moderate sensitivity has to be taken into account.

  17. Computerized tomographic evaluation of primary brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin Ok; Lee, Jong Soon; Jeon, Doo Sung; Kim, Hong Soo; Rhee, Hak Song [Presbyterian Mediacal center, Cheonju (Korea, Republic of); Kim, Jong Deok [Inje Medical College, Paik Hospital, Pusan (Korea, Republic of)

    1985-10-15

    In a study of primary brain tumors 104 cases having satisfactory clinical, operative and histological proofs were analyzed by computerized tomography at Presbyterian Medical Center from May, 1982 to April 1985. The results were as follows: 1. The male to female ratio of primary brain tumor was 54 : 46. 2. The 2nd decade group (26%) was the most prevalent age group, followed by the 5th decade (16.3%), 1st decade (14.4%) , 3rd decade (12.5%), 4th decade (11.5%), 6th decade (10.6%), 7th decade (8.7%) in that order. 3. The incidence of primary brain tumors was found to be: glioma 64 cases (61.6%) among the GM, the most frequent 17 cases (16.3%), followed by meningioma 12 cases (11.5%), pituitary adenoma 10 cases (9.6%), craniopharyngioma 6 cases (5.8%), pinealoma and germinoma 3 cases (2.9%) respectively, and dermoid cyst 2 cases (1.9%) in that order. 4. The location of the primary brain tumors were as follows: cb. hemisphere (49%) of these 24.5% in parietal region, 11.9% in temporal region, 9.7% in frontal region, 3.0% in occipital region: juxtasella area (16.3%), cerebellar hemisphere (8.7%), parapineal and intraventricle (7.7%) respectively, cerebello-pontine angle area (5.8%), vermis and 4th ventricular region (4.8%). 5. There were no remarkable differences in the findings of pre- and post-contrast CT scanning of primary brain tumors computed with others.

  18. Computed tomographic pelvimetry in English bulldogs.

    Science.gov (United States)

    Dobak, Tetyda P; Voorhout, George; Vernooij, Johannes C M; Boroffka, Susanne A E B

    2018-05-31

    English bulldogs have been reported to have a high incidence of dystocia and caesarean section is often performed electively in this breed. A narrow pelvic canal is the major maternal factor contributing to obstructive dystocia. The objective of this cross-sectional study was to assess the pelvic dimensions of 40 clinically healthy English bulldogs using computed tomography pelvimetry. A control group consisting of 30 non-brachycephalic dogs that underwent pelvic computed tomography was retrospectively collected from the patient archive system. Univariate analysis of variance was used to compare computed tomography pelvimetry of both groups and the effects of weight and gender on the measurements. In addition, ratios were obtained to address pelvic shape differences. A significantly (P = 0.00) smaller pelvic size was found in English bulldogs compared to the control group for all computed tomography measurements: width and length of the pelvis, pelvic inlet and caudal pelvic aperture. The pelvic conformation was significantly different between the groups, English bulldogs had an overall shorter pelvis and pelvic canal and a narrower pelvic outlet. Weight had a significant effect on all measurements whereas gender that only had a significant effect on some (4/11) pelvic dimensions. Our findings prove that English bulldogs have a generally reduced pelvic size as well as a shorter pelvis and narrower pelvic outlet when compared to non-brachycephalic breeds. We suggest that some of our measurements may serve as a baseline for pelvic dimensions in English bulldogs and may be useful for future studies on dystocia in this breed. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Regulatory risk coherence

    International Nuclear Information System (INIS)

    Remick, F.J.

    1992-01-01

    As one of the most progressive users of risk assessment in decision making, the US Nuclear Regulatory Commission (NRC) is in a position to play an important role in influencing the development of standard government wide policies for the application of risk assessment in decision making. The NRC, with the support of the nuclear industry, should use the opportunity provided by its experience with risk assessment to actively encourage the adoption of standard national and international health-based safety goals and at the same time accelerate its own efforts to implement the safety goals it has already developed for itself. There are signs of increased recognition of the need for consistency and coherence in the application of risk assessment in government decision making. The NRC and the nuclear industry have recently taken a great step toward establishing a consistant and coherent risk assessment-based culture in the US nuclear industry. As a result of Generic Letter 88-20, which asks each commercial nuclear power plant licensee to perform an individual plant examination by September 1992, for the first time a risk assessment characterizing initiating events in each plant will exist

  20. Implementation of Japanese male and female tomographic phantoms to multi-particle Monte Carlo code for ionizing radiation dosimetry

    International Nuclear Information System (INIS)

    Lee, Choonsik; Nagaoka, Tomoaki; Lee, Jai-Ki

    2006-01-01

    phantoms for other irradiation geometries should be carried by employing additional tomographic phantoms to find out the dosimetric difference of Asian human phantoms from Caucasian-based phantoms. (author)

  1. Ordering states with various coherence measures

    Science.gov (United States)

    Yang, Long-Mei; Chen, Bin; Fei, Shao-Ming; Wang, Zhi-Xi

    2018-04-01

    Quantum coherence is one of the most significant theories in quantum physics. Ordering states with various coherence measures is an intriguing task in quantification theory of coherence. In this paper, we study this problem by use of four important coherence measures—the l_1 norm of coherence, the relative entropy of coherence, the geometric measure of coherence and the modified trace distance measure of coherence. We show that each pair of these measures give a different ordering of qudit states when d≥3. However, for single-qubit states, the l_1 norm of coherence and the geometric coherence provide the same ordering. We also show that the relative entropy of coherence and the geometric coherence give a different ordering for single-qubit states. Then we partially answer the open question proposed in Liu et al. (Quantum Inf Process 15:4189, 2016) whether all the coherence measures give a different ordering of states.

  2. NONINVASIVE DIAGNOSIS OF URINARY BLADDER CANCER BY CROSS-POLARIZATION OPTICAL COHERENCE TOMOGRAPHY: CLINICAL RESULTS

    Directory of Open Access Journals (Sweden)

    O. S. Streltsova

    2014-07-01

    Full Text Available The investigation examined the feasibility of cross-polarization optical cohe-rence tomography (CP OCT to detect early urinary bladder cancer (UBC. Studies were performed in 376 patients; 5290 images were obtained using an OCT 133-U optical coherence tomograph. To acquire and compare intrared-light scattering images in baseline and orthogonal polarizations is the basis of CP OCT; their analysis makes it possible to judge from the state of the epithelium/connective tissue system and to obtain information on changes in tissue depolarizing components, collagen in particular. The authors elaborated criteria as determinants of the nature of CP OCT changes in direct and orthogonal polarizations in health, inflammatory changes, and UBC at its early stage - urothelial dysplasia and carcinoma in situ in flat suspected areas.

  3. DG TOMO: A new method for tomographic reconstruction

    International Nuclear Information System (INIS)

    Freitas, D. de; Feschet, F.; Cachin, F.; Geissler, B.; Bapt, A.; Karidioula, I.; Martin, C.; Kelly, A.; Mestas, D.; Gerard, Y.; Reveilles, J.P.; Maublant, J.

    2006-01-01

    Aim: FBP and OSEM are the most popular tomographic reconstruction methods in scintigraphy. FBP is a simple method but artifacts of reconstruction are generated which corrections induce degradation of the spatial resolution. OSEM takes account of statistical fluctuations but noise strongly increases after a certain number of iterations. We compare a new method of tomographic reconstruction based on discrete geometry (DG TOMO) to FBP and OSEM. Materials and methods: Acquisitions were performed on a three-head gamma-camera (Philips) with a NEMA Phantom containing six spheres of sizes from 10 to 37 mm inner diameter, filled with around 325 MBq/l of technetium-99 m. The spheres were positioned in water containing 3 MBq/l of technetium-99 m. Acquisitions were realized during a 180 o -rotation around the phantom by 25-s steps. DG TOMO has been developed in our laboratory in order to minimize the number of projections at acquisition. Two tomographic reconstructions utilizing 32 and 16 projections with FBP, OSEM and DG TOMO were performed and transverse slices were compared. Results: FBP with 32 projections detects only the activity in the three largest spheres (diameter ≥22 mm). With 16 projections, the star effect is predominant and the contrast of the third sphere is very low. OSEM with 32 projections provides a better image but the three smallest spheres (diameter ≤17 mm) are difficult to distinguish. With 16 projections, the three smaller spheres are not detectable. The results of DG TOMO are similar to OSEM. Conclusion: Since the parameters of DG TOMO can be further optimized, this method appears as a promising alternative for tomoscintigraphy reconstruction

  4. Imaging MOSS tomographic system for H-1NF

    International Nuclear Information System (INIS)

    Glass, F.; Howard, J.

    1999-01-01

    A tomographic diagnostic utilising the Modulated Optical Solid-State spectrometer (MOSS) is planned for the H-1NF stellarator at the ANU. It is designed to create two-dimensional temperature or velocity maps of a poloidal cross-section of the high temperature plasma of H-1NF. The introduction of the MOSS spectrometers has enabled the development of several diagnostics to be used on the H-1NF stellerator. The MOSS spectrometer allows calculations of the plasma temperature and bulk velocity based on a line-integrated measurement of light emitted from electronic transitions within the plasma. A tomographic system utilising a rotatable multi-view ring apparatus and spatial multiplexing through a MOSS spectrometer is currently being developed. The ring apparatus is placed inside the H-1NF vessel and encircles the plasma. Multiple line-of-sight views collect light through a poloidal cross-section of the plasma and the emitted light is coupled into large core optical fibres. The transmitted light, via the optical fibre bundle, is then imaged through a large aperture MOSS spectrometer and onto another optical fibre array. Each fibre is then fed into a photomultiplier tube for signal detection. Characterisation of the properties of the lithium niobate (LiNbO 3 ) crystal used for modulation in the MOSS spectrometer is being undertaken to account for ray divergence in the imaging system. Tomographic techniques enable the construction of a temperature or velocity map of the poloidal cross-section. Rotating the ring apparatus to a new viewing position for the next pulse of plasma should allow an accurate picture to be built up based on the reproducibility of the plasma pulses. It is expected that initial testing of the system will begin in May when H-1NF begins operations at 0.5 Telsa field strength

  5. ULTRASOUND AND COMPUTED TOMOGRAPHIC DIAGNOSIS OF OPTIC NERVE TUMORS

    Directory of Open Access Journals (Sweden)

    S. V. Saakyan

    2012-01-01

    Full Text Available A comprehensive examination was made in 93 patients, including 18 children, with tumors of the optic nerve (ON. Duplex ultrasound scanning was performed in 39 patients, of them there were 11 patients with ON gliomas and 28 with ON meningiomas. The specific computed tomographic and echographic signs of ON glioma and meningiomas were detected. The studies have shown that duplex ultrasound scanning and structural computed tomography of orbital sockets are highly informative complementary imaging procedures for ON tumors, which permits one to make their correct diagnosis, to specify surgical volume, and to plan adequate treatment.

  6. Tomographic elastography of contracting skeletal muscles from their natural vibrations

    Science.gov (United States)

    Sabra, Karim G.; Archer, Akibi

    2009-11-01

    Conventional elastography techniques require an external mechanical or radiation excitation to measure noninvasively the viscoelastic properties of skeletal muscles and thus monitor human motor functions. We developed instead a passive elastography technique using only an array of skin-mounted accelerometers to record the low-frequency vibrations of the biceps brachii muscle naturally generated during voluntary contractions and to determine their two-dimensional directionality. Cross-correlating these recordings provided travel-times measurements of these muscle vibrations between multiple sensor pairs. Travel-time tomographic inversions yielded spatial variations of their propagation velocity during isometric elbow flexions which indicated a nonuniform longitudinal stiffening of the biceps.

  7. Gas microstrip detectors for X-ray tomographic flow imaging

    CERN Document Server

    Key, M J; Luggar, R D; Kundu, A

    2003-01-01

    A investigation into the suitability of gas microstrip detector technology for a high-speed industrial X-ray tomography system is reported. X-ray energies in the region 20-30 keV are well suited to the application, which involves imaging two-dimensional slices through gas/liquid multiphase pipeline flows for quantitative component fraction measurement. Stable operation over a period representing several hundred individual tomographic scans at gas gains of 500 is demonstrated using a Penning gas mixture of krypton/propylene.

  8. Development of the Shimadzu computed tomographic scanner SCT-200N

    International Nuclear Information System (INIS)

    Ishihara, Hiroshi; Yamaoka, Nobuyuki; Saito, Masahiro

    1982-01-01

    The Shimadzu Computed Tomographic Scanner SCT-200N has been developed as an ideal CT scanner for diagnosing the head and spine. Due to the large aperture, moderate scan time and the Zoom Scan Mode, any part of the body can be scanned. High quality image can be obtained by adopting the precisely stabilized X-ray unit and densely packed array of 64-detectors. As for its operation, capability of computed radiography (CR) prior to patient positioning and real time reconstruction ensure efficient patient through-put. Details of the SCT-200N are described in this paper. (author)

  9. Design of a volume-imaging positron emission tomograph

    International Nuclear Information System (INIS)

    Harrop, R.; Rogers, J.G.; Coombes, G.H.; Wilkinson, N.A.; Pate, B.D.; Morrison, K.S.; Stazyk, M.; Dykstra, C.J.; Barney, J.S.; Atkins, M.S.; Doherty, P.W.; Saylor, D.P.

    1988-11-01

    Progress is reported in several areas of design of a positron volume imaging tomograph. As a means of increasing the volume imaged and the detector packing fraction, a lens system of detector light coupling is considered. A prototype layered scintillator detector demonstrates improved spatial resolution due to a unique Compton rejection capability. The conceptual design of a new mechanism for measuring scattered radiation during emission scans has been tested by Monte Carlo simulation. The problem of how to use effectively the resulting sampled scattered radiation projections is presented and discussed

  10. Computed tomographic spectrum of intracranial mycosis: correlation with histopathology

    International Nuclear Information System (INIS)

    Whelan, M.A.; Stern, J.; deNapoli, R.A.

    1981-01-01

    Four cases of intracerebral fungal infection are reviewed. The clinical course is outlined, and the computed tomographic (CT) characteristics are analyzed in light of known pathological data. The CT appearance of intracranial mycosis is dependent on the type of fungus as well as the dominant infecting form, i.e., yeast or hyphae. The hyphal form leads predominantly to a CT pattern consistent with vascular occlusion and secondary abscess formation; the yeast form generally results in noncaseating granulomas, which appear on CT scan as nodular enhancing lesions. If the patient survives the acute infective process, these fungal lesions undergo a prolonged subacute phase, and may eventually calcify

  11. Direct computation of harmonic moments for tomographic reconstruction

    International Nuclear Information System (INIS)

    Nara, Takaaki; Ito, Nobutaka; Takamatsu, Tomonori; Sakurai, Tetsuya

    2007-01-01

    A novel algorithm to compute harmonic moments of a density function from its projections is presented for tomographic reconstruction. For projection p(r, θ), we define harmonic moments of projection by ∫ π 0 ∫ ∞ -∞ p(r,θ)(re iθ ) n drd θ and show that it coincides with the harmonic moments of the density function except a constant. Furthermore, we show that the harmonic moment of projection of order n can be exactly computed by using n+ 1 projection directions, which leads to an efficient algorithm to reconstruct the vertices of a polygon from projections.

  12. 4-D tomographic monitoring of enhanced oil recovery

    International Nuclear Information System (INIS)

    Brzostowski, M.A.; McMechan, G.A.

    1991-01-01

    One application of tomography that has recently received considerable attention is reservoir monitoring for Enhanced Oil Recovery (EOR). Tomographic monitoring of a moving steam front uses the significant decrease in compressional wave velocity that occurs as hydrocarbon temperature increases. The purposes of this paper are to present a working algorithm for 3-D tomography, to demonstrate the feasibility of 3-D imaging of a simulated reservoir in which the position of a steam front changes with time, and to illustrate the relations between survey geometry and the resolution of the target

  13. Non tumoral intracranial expansive processes: clinical tomographic correlation

    International Nuclear Information System (INIS)

    Campos, P.; Herrera, G.; Valneica, F.

    1991-01-01

    Presentation of clinical-tomographic correlation in 111 cases of non tumoral intracranial expansive processes seen between 1984-1988 in the Hospital Cayetano Heredia (Lima, Peru). Emphasis is given fundamentally to: the importance of establishing the organicity of partial and late epilepsy; the high incidence rate of inflammatory infectious processes with CNS compromise in under developing countries; the necessity of making public the importance of two parasitic diseases in the differential diagnosis of non tumoral intracranial expansive processes: free living amebiasis, and toxoplasmosis (especially in association with AIDS). (author)

  14. 3D Tomographic Image Reconstruction using CUDA C

    International Nuclear Information System (INIS)

    Dominguez, J. S.; Assis, J. T.; Oliveira, L. F. de

    2011-01-01

    This paper presents the study and implementation of a software for three dimensional reconstruction of images obtained with a tomographic system using the capabilities of Graphic Processing Units(GPU). The reconstruction by filtered back-projection method was developed using the CUDA C, for maximum utilization of the processing capabilities of GPUs to solve computational problems with large computational cost and highly parallelizable. It was discussed the potential of GPUs and shown its advantages to solving this kind of problems. The results in terms of runtime will be compared with non-parallelized implementations and must show a great reduction of processing time. (Author)

  15. Deformable 3D–2D registration for CT and its application to low dose tomographic fluoroscopy

    International Nuclear Information System (INIS)

    Flach, Barbara; Brehm, Marcus; Sawall, Stefan; Kachelrieß, Marc

    2014-01-01

    Many applications in medical imaging include image registration for matching of images from the same or different modalities. In the case of full data sampling, the respective reconstructed images are usually of such a good image quality that standard deformable volume-to-volume (3D–3D) registration approaches can be applied. But research in temporal-correlated image reconstruction and dose reductions increases the number of cases where rawdata are available from only few projection angles. Here, deteriorated image quality leads to non-acceptable deformable volume-to-volume registration results. Therefore a registration approach is required that is robust against a decreasing number of projections defining the target position. We propose a deformable volume-to-rawdata (3D–2D) registration method that aims at finding a displacement vector field maximizing the alignment of a CT volume and the acquired rawdata based on the sum of squared differences in rawdata domain. The registration is constrained by a regularization term in accordance with a fluid-based diffusion. Both cost function components, the rawdata fidelity and the regularization term, are optimized in an alternating manner. The matching criterion is optimized by a conjugate gradient descent for nonlinear functions, while the regularization is realized by convolution of the vector fields with Gaussian kernels. We validate the proposed method and compare it to the demons algorithm, a well-known 3D–3D registration method. The comparison is done for a range of 4–60 target projections using datasets from low dose tomographic fluoroscopy as an application example. The results show a high correlation to the ground truth target position without introducing artifacts even in the case of very few projections. In particular the matching in the rawdata domain is improved compared to the 3D–3D registration for the investigated range. The proposed volume-to-rawdata registration increases the robustness

  16. Geometry of spin coherent states

    Science.gov (United States)

    Chryssomalakos, C.; Guzmán-González, E.; Serrano-Ensástiga, E.

    2018-04-01

    Spin states of maximal projection along some direction in space are called (spin) coherent, and are, in many respects, the ‘most classical’ available. For any spin s, the spin coherent states form a 2-sphere in the projective Hilbert space \

  17. Damping of Coherent oscillations

    CERN Document Server

    Vos, L

    1996-01-01

    Damping of coherent oscillations by feedback is straightforward in principle. It has been a vital ingredient for the safe operation of accelerators since a long time. The increasing dimensions and beam intensities of the new generation of hadron colliders impose unprecedented demands on the performance of future systems. The arguments leading to the specification of a transverse feedback system for the CERN SPS in its role as LHC injector and the LHC collider itself are developped to illustrate this. The preservation of the transverse emittance is the guiding principle during this exercise keeping in mind the hostile environment which comprises: transverse impedance bent on developping coupled bunch instabilities, injection errors, unwanted transverse excitation, unavoidable tune spreads and noise in the damping loop.

  18. Quantum information and coherence

    CERN Document Server

    Öhberg, Patrik

    2014-01-01

    This book offers an introduction to ten key topics in quantum information science and quantum coherent phenomena, aimed at graduate-student level. The chapters cover some of the most recent developments in this dynamic research field where theoretical and experimental physics, combined with computer science, provide a fascinating arena for groundbreaking new concepts in information processing. The book addresses both the theoretical and experimental aspects of the subject, and clearly demonstrates how progress in experimental techniques has stimulated a great deal of theoretical effort and vice versa. Experiments are shifting from simply preparing and measuring quantum states to controlling and manipulating them, and the book outlines how the first real applications, notably quantum key distribution for secure communication, are starting to emerge. The chapters cover quantum retrodiction, ultracold quantum gases in optical lattices, optomechanics, quantum algorithms, quantum key distribution, quantum cont...

  19. Development of a laser-based heating system for in situ synchrotron-based X-ray tomographic microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fife, Julie L., E-mail: julie.fife@psi.ch [Laboratory for Synchrotron Radiation, Swiss Light Source, Paul Scherrer Institut, Villigen (Switzerland); Computational Materials Laboratory, Ecole Polytechnique Federale de Lausanne, Lausanne (Switzerland); Rappaz, Michel [Computational Materials Laboratory, Ecole Polytechnique Federale de Lausanne, Lausanne (Switzerland); Pistone, Mattia [Institute for Geochemistry and Petrology, Swiss Federal Institute of Technology of Zurich, Zurich (Switzerland); Celcer, Tine [Laboratory for Synchrotron Radiation, Swiss Light Source, Paul Scherrer Institut, Villigen (Switzerland); The Centre of Excellence for Biosensors, Instrumentation and Process Control, Solkan (Slovenia); Mikuljan, Gordan [Laboratory for Synchrotron Radiation, Swiss Light Source, Paul Scherrer Institut, Villigen (Switzerland); Stampanoni, Marco [Laboratory for Synchrotron Radiation, Swiss Light Source, Paul Scherrer Institut, Villigen (Switzerland); Institute for Biomedical Engineering, Swiss Federal Institute of Technology and University of Zurich, Zurich (Switzerland)

    2012-05-01

    A laser-based heating system has been developed at the TOMCAT beamline of the Swiss Light Source for in situ observations of moderate-to-high-temperature applications of materials. Understanding the formation of materials at elevated temperatures is critical for determining their final properties. Synchrotron-based X-ray tomographic microscopy is an ideal technique for studying such processes because high spatial and temporal resolutions are easily achieved and the technique is non-destructive, meaning additional analyses can take place after data collection. To exploit the state-of-the-art capabilities at the tomographic microscopy and coherent radiology experiments (TOMCAT) beamline of the Swiss Light Source, a general-use moderate-to-high-temperature furnace has been developed. Powered by two diode lasers, it provides controlled localized heating, from 673 to 1973 K, to examine many materials systems and their dynamics in real time. The system can also be operated in various thermal modalities. For example, near-isothermal conditions at a given sample location can be achieved with a prescribed time-dependent temperature. This mode is typically used to study isothermal phase transformations; for example, the formation of equiaxed grains in metallic systems or to nucleate and grow bubble foams in silicate melts under conditions that simulate volcanic processes. In another mode, the power of the laser can be fixed and the specimen moved at a constant speed in a user-defined thermal gradient. This is similar to Bridgman solidification, where the thermal gradient and cooling rate control the microstructure formation. This paper details the experimental set-up and provides multiple proofs-of-concept that illustrate the versatility of using this laser-based heating system to explore, in situ, many elevated-temperature phenomena in a variety of materials.

  20. Integrated coherent matter wave circuits

    International Nuclear Information System (INIS)

    Ryu, C.; Boshier, M. G.

    2015-01-01

    An integrated coherent matter wave circuit is a single device, analogous to an integrated optical circuit, in which coherent de Broglie waves are created and then launched into waveguides where they can be switched, divided, recombined, and detected as they propagate. Applications of such circuits include guided atom interferometers, atomtronic circuits, and precisely controlled delivery of atoms. We report experiments demonstrating integrated circuits for guided coherent matter waves. The circuit elements are created with the painted potential technique, a form of time-averaged optical dipole potential in which a rapidly moving, tightly focused laser beam exerts forces on atoms through their electric polarizability. Moreover, the source of coherent matter waves is a Bose-Einstein condensate (BEC). Finally, we launch BECs into painted waveguides that guide them around bends and form switches, phase coherent beamsplitters, and closed circuits. These are the basic elements that are needed to engineer arbitrarily complex matter wave circuitry