Computerized tomography in atypical Pott's disease

International Nuclear Information System (INIS)

Cabrera, M.N.B.; Wang, E.H.M.

1993-01-01

Classical Pott's disease is described as a two-vertebrae disease with the destruction of the intervening invertebral disc. Computerized tomography has been used in the differential diagnosis of spine infections and neoplasms. We reviewed CT scans of patients seen at the Philippine General Hospital over a two-year period with atypical presentations of atypical tuberculous spondylitis. We used the computerized tomography findings described as characteristic of classical Pott's disease as criteria in evaluating the CT scans of patients diagnosed to have Atypical Pott's Disease. Although the number of patients prevented sensitivity and specificity studies to be done, our results strongly suggest that the same CT criteria used to diagnose Classical Pott's Disease may also be used to diagnose Pott's disease in its atypical form. (Author.). 13 refs

Staging of bronchogenic carcinoma by computerized tomography

International Nuclear Information System (INIS)

Sommer, B.; Bauer, W.M.; Rath, M.; Fenzl, G.; Stelter, W.J.; Lissner, J.

1981-01-01

It was possible to check the information obtained by CT scanning in 36 patients out of 49 who had been subjected to computerized tomography, in respect of the extension of the primary tumour (T stage), and in 25 patients in respect of the degree of mediastinal lymphatic node involvement (N stage). In all 49 patients, the presence of bronchogenic carcinoma had been safely established. In 97% of the cases, assessment of the extension of the primary tumour was found to be correct. Assessment of the N stage, however, is more problematic, since detection of mediastinal lymphatic nodes by computerized tomography does not necessarily tell us something about their metastatic involvement. If all recognizable lymphatic nodes are interpreted as potential metastases, we have no false negative but 61% false positive results because of the frequency of postinflammatory or anthracotic lymphatic nodes. In case of exclusive assessment of lymphatic node enlargement above 1 cm diameter, the rate of metastatic nodes increases considerably (83%). Computerized tomography is definitely superior to all roentgenological methods in assessing the stage of a bronchogenic carcinoma; hence, it could occupy a key position in determining the diagnostic and therapeutic approach in patients with this disease. (orig.) [de

Comparison of computerized tomography to sonography, applied in diseases of the pancreas

International Nuclear Information System (INIS)

Kluge, K.

1982-01-01

The examination results of 418 patients whose epigastria had been examined both by computerized tomography and sonography over 1 week in the time from beginning January 1978 until and of July 1979 were compared with regard to the imaging of the pancreas, reliability, and the specificity and sensitivity in establishing the diagnosis. For the sonographic examination, a compound and a real-time unit were used; the computerized tomography was carried out by means of an equipment of the 3rd generation with a scan time of 4 sec. The screening of the pancreas was significantly better using computerized tomography (99.3% US. 84% with US). As for accuracy, computerized tomography had 92.5% exact diagnoses versus 79.9% obtained by sonography. If, however, we look at the cases in which the pancreas could be screened with both methods the accuracy was almost the same (93.7 CT and 93.3% US). Specificity was almost of the same quality, however, the method of computerized tomography with 0.963 was slightly better than ultrasound with 0.943. As for sensitivity, sonography with 0.838 was better than CT with 0.721. The reason for that is the fact that a big part of the chronic pancreatites (30.3%) were not recognized by means of computerized tomography. (orig.) [de

Role of computerized tomography in diagnosis of atypical gall bladder and common bile duct stones

International Nuclear Information System (INIS)

El-Husseni, Tareq K.; Al-Shebrein, Ibrahim A.

2001-01-01

Objective was to assess the value of computerized tomography as an adjuvant to ultrasound in the diagnosis of atypical gallbladder and common duct stone disease. Real time ultrasound scanning for the gallbladder and common duct was performed in the routine manner. High resolution computerized tomography images were subsequently obtained for the region of interest. Computerized tomography resolved undetermined results as follows: 1. Non shadowing gallbladder debris (6 points), 2. Focal gallbladder wall thickening (2 points), 3. Stone obscured by calcified gallbladder wall (3 points), 4. Non visualized gallbladder double arc shadow (4 points), 5 and 6. Impacted gallbladder neck and common duct stones (18 points), computerized tomography gave false positive diagnosis in (2 points). Computerized tomography provided an effective and reliable means for the diagnosis of atypical gallbladder calculi when ultrasound was imprecise or the findings contradicted the clinical presentation. Finally if gallbladder neck or common duct stones are suspected, in addition to computerized tomography other imaging techniques such as magnetic resonance cholangio pancreatography or endoscopic retrograde cholangiopancreatography in addition to computerized tomography may be needed to avoid false positive diagnosis prior to surgery. (author)

Computerized tomography of kidneys in long-term dialysis patients

International Nuclear Information System (INIS)

Srp, A.; Merta, M.; Sulkova, S.

1990-01-01

A cohort is presented of 21 patients with irreversible kidney failure who were examined by computerized tomography in 1986-1987. The mean period of dialysis programme was 5.7 years, chronic glomerulonephritis and interstitial nephritis were the basic conditions. According to the results of computerized tomography, the patients were divided into four groups: 1. the presence of cysts or tumors was not established, 2. multiplecysts were found in bilateral location, 3. less than 3 cysts were found, 4. kidney tumor was diagnosed. The factor causing the development of the cysts was not identified. It is presumed that the disease is caused by a biologically active substance which is not efficiently dialyzed. The examination of the kidneys is recommended in patients in the stage of chronic kidney insufficiency and particularly in patients on dialysis for a long period of time. The recommended examination uses computerized tomography, and attention should be given to the possible occurence of acquired cystic disease or kidney tumors. (author). 6 figs., 8 refs

Morphological analysis of the vestibular aqueduct by computerized tomography images

International Nuclear Information System (INIS)

Marques, Sergio Ricardo; Smith, Ricardo Luiz; Isotani, Sadao; Alonso, Luis Garcia; Anadao, Carlos Augusto; Prates, Jose Carlos; Lederman, Henrique Manoel

2007-01-01

Objective: In the last two decades, advances in the computerized tomography (CT) field revise the internal and medium ear evaluation. Therefore, the aim of this study is to analyze the morphology and morphometric aspects of the vestibular aqueduct on the basis of computerized tomography images (CTI). Material and method: Computerized tomography images of vestibular aqueducts were acquired from patients (n = 110) with an age range of 1-92 years. Thereafter, from the vestibular aqueducts images a morphometric analysis was performed. Through a computerized image processing system, the vestibular aqueduct measurements comprised of its area, external opening, length and the distance from the vestibular aqueduct to the internal acoustic meatus. Results: The morphology of the vestibular aqueduct may be funnel-shaped, filiform or tubular and the respective proportions were found to be at 44%, 33% and 22% in children and 21.7%, 53.3% and 25% in adults. The morphometric data showed to be of 4.86 mm 2 of area, 2.24 mm of the external opening, 4.73 mm of length and 11.88 mm of the distance from the vestibular aqueduct to the internal acoustic meatus, in children, and in adults it was of 4.93 mm 2 , 2.09 mm, 4.44 mm, and 11.35 mm, respectively. Conclusions: Computerized tomography showed that the vestibular aqueduct presents high morphological variability. The morphometric analysis showed that the differences found between groups of children and adults or between groups of both genders were not statistically significant

Case of neurosarcoidosis monitored by computerized tomography

Energy Technology Data Exchange (ETDEWEB)

Kubota, T; Kimura, M; Komai, T; Yamamoto, S; Yamamura, I [Kanazawa Univ. (Japan). School of Medicine

1979-12-01

A 21-year-old man complaining of impaired visual acuity was admitted to the hospital. Physical examinations showed asymptomatic bilateral hilar lymphadenopathy and cardiomyopathy. Neurological findings disclosed left blindness and right temporal hemianopsia. Computerized tomography, pneumoencephalography and carotid angiography revealed a suprasellar mass. After the admission, the following symptoms deteriorated rapidly: diabetes insipidus, anterior pituitary dysfunction, visual loss of the right eye and hepatomegaly, subsequently consciousness disorder developed during a month though he was given steroids. The more deteriorated the clinical course, the larger the suprasellar mass with expanding hydrocephalus in repeated computerized tomographies. After the ventriculo-peritoneal shunt operation, consciousness improved. Diabetes insipidus also improved after Diabenese administration. On the operation, adhesive arachnoiditis over all the frontotemporal cortex and swollen purplishly red optic chiasm were exposed. Microscopically the specimen from the optic chiasm evidenced a sarcoid granuloma which composed of epitheroid cells, lymphocytes and multi-nucleated giant cells with numerous hemosiderin droplets. The specimen from the surface of the left frontal lobe showed thick fibrosis in the subarachnoid space. By steroids therapy, diabetes insipidus and hepatomegaly disappeared five months after the admission, whereas blindness never recovered. He died of developed status epilepticus eleven months after the admission. The authors reviewed neuroradiological findings of neurocarcoidosis based on pathological findings in the literature, and emphasized that computerized tomography was the most useful for diagnosis and treatment of neurosarcoidosis.

Recurrent lymph node metastases after craniocervical tumours: Computerized tomography

International Nuclear Information System (INIS)

Helmberger, H.; Lenz, M.; Kersting-Sommerhoff, B.; Bautz, W.; Kretz, S.

1992-01-01

A total of 544 CT examinations of the craniocervical region carried out in 231 patients were analyzed on a retrospective basis in order to assess the clinical value of contrast-enhanced computerized tomography, being carried out either for comparison with or in combination with clinical control examinations, in the post-therapeutic surveillance of patients treated for craniocervical tumours. The diagnostic accuracy attained with computerized tomography in the detection of recurrent lymph node metastases was 95% and thus superior to that determined for clinical control examinations (80%). (orig./GDG) [de

Density evaluation by computerized tomography in plain soils over different manipulation systems

International Nuclear Information System (INIS)

Pedrotti, Alceu

1996-08-01

The objective of this paper is the evaluation of a plain soil density in different culture systems determined by X ray computerized tomography.It was observed a larger variation in densities in soils profiles analysed. The identification of layers is better utilising computerized tomography than others technic

Materials testing by computerized tomography with neutrons and gamma-rays

Energy Technology Data Exchange (ETDEWEB)

El-Ghobary, A M; Bakkoush, F A; Megahid, R M [Reactor and Neutron Physics Department, Nuclear Research Center, A.E.A., Cairo (Egypt)

1997-12-31

The method of computerized tomography by fast neutrons and gamma-rays are used for inspecting and testing of materials by non-destructive technique. The transmission technique was applied using narrow collimated beams of reactor neutrons and gamma-ray. The neutron and gamma-rays transmitted through the object inspection were measured by means of a neutron gamma detector with Ne - 213 liquid organic scintillator. The undesired pulses of neutrons or gamma-rays are rejected from the transmitted beam by a discrimination technique based on the difference in the decay part of light pulse produced by recoil electrons or recoil protons. The transmitted neutrons or gamma-rays for different projections used to get the image of the section through the object investigated using the method of filtered back projection (FBP) algorithm. 8 figs.

Radiographic analysis of body composition by computerized axial tomography

International Nuclear Information System (INIS)

Heymsfield, S.B.

1986-01-01

Radiographic methods of evaluating body composition have been applied for over five decades. A marked improvement in this approach occurred in the mid-nineteen-seventies with the introduction of computerized axial tomography. High image contrast, cross-sectional imaging and rapid computerized data processing make this technique a sophisticated clinically applicable tool. (author)

Diffuse nesidioblastosis diagnosed on a Ga-68 DOTATATE positron emission tomography/computerized tomography

International Nuclear Information System (INIS)

Arun, Sasikumar; Mittal, Bhagwant Rai; Shukla, Jaya; Bhattacharya, Anish; Kumar, Praveen

2013-01-01

The authors describe a 50 days old pre-term infant with persistent hyperinsulinemic hypoglycemia of infancy in whom 68 Ga DOTATATE positron emission tomography/computerized tomography scan showed diffusely increased tracer uptake in the entire pancreas with no abnormal tracer uptake anywhere else in the body, suggestive of a diffuse variant of nesidioblastosis. (author)

Patient surface doses in computerized tomography examinations

International Nuclear Information System (INIS)

Vekic, B; Kovacevic, S.; Ranogajec-Komor, M.; Duvnjak, N.; Marusic, P.; Anic, P.; Dolencic, P.

1996-01-01

The diagnostic value of computerized tomography has increased due to very rapid technical advances in both equipment and techniques. When the CT scanners were introduced, a significant problem for the specification of the radiation dose imparted to the patient undergoing CT examination has been created. In CT, the conditions of exposure are quite different from those in conventional X-ray imaging. CT procedure involves the continuous tomography of thin layers. Some of these layers touch each other while others overlap. The radiation doses received by patients can vary considerably. In addition to the radiation from the collimated primary beam, patients are exposed to significant scattered doses in unpredictable amounts. Every effort should be made to keep these doses to a reasonable minimum, without sacrificing the image quality. The aims of this work were to determine the surface doses delivered to various organs of patients during various computerized tomography examinations (head, thorax, kidney, abdomen and pelvis). Particular attention was directed to the precise determination of doses received by the eyes (during CT of head) and gonads (during CT of pelvis and lower abdomen) since these organs can be near or even in the primary X-ray beam

A case of neurosarcoidosis monitored by computerized tomography

International Nuclear Information System (INIS)

Kubota, Toshihiko; Kimura, Makoto; Komai, Toshio; Yamamoto, Shinjiro; Yamamura, Itaru

1979-01-01

A 21-year-old man complaining of impaired visual acuity was admitted to the hospital. Physical examinations showed asymptomatic bilateral hilar lymphadenopathy and cardiomyopathy. Neurological findings disclosed left blindness and right temporal hemianopsia. Computerized tomography, pneumoencephalography and carotid angiography revealed a suprasellar mass. After the admission, the following symptoms deteriorated rapidly: diabetes insipidus, anterior pituitary dysfunction, visual loss of the right eye and hepatomegaly, subsequently consciousness disorder developed during a month though he was given steroids. The more deteriorated the clinical course, the larger the suprasellar mass with expanding hydrocephalus in repeated computerized tomographies. After the ventriculo-peritoneal shunt operation, consciousness improved. Diabetes insipidus also improved after Diabenese administration. On the operation, adhesive arachnoiditis over all the frontotemporal cortex and swollen purplishly red optic chiasm were exposed. Microscopically the specimen from the optic chiasm evidenced a sarcoid granuloma which composed of epitheroid cells, lymphocytes and multi-nucleated giant cells with numerous hemosiderin droplets. The specimen from the surface of the left frontal lobe showed thick fibrosis in the subarachnoid space. By steroids therapy, diabetes insipidus and hepatomegaly disappeared five months after the admission, whereas blindness never recovered. He died of developed status epilepticus eleven months after the admission. The authors reviewed neuroradiological findings of neurocarcoidosis based on pathological findings in the literature, and emphasized that computerized tomography was the most useful for diagnosis and treatment of neurosarcoidosis. (author)

Computerized tomography in radiodiagnosis of pneumonia

International Nuclear Information System (INIS)

Degtyareva, I.A.; Mamaev, V.V.; Savchenko, A.P.

1989-01-01

Experience in the use of computerized tomography (CT) in combined radiodiagnosis of pneumonia was analysed. It has been concluded that CT objectively reflects morphological inflammatory changes and permits their all-round assessment over time. The diagnosis of pneumonia in CT is based on classical x-ray symptoms. As compared to survery radiography CT reveals symptoms of pneumonia to the full at earlier stages. CT is an important additional method of investigation of inflammatory pulmonary diseases but it should not be used separately without survey radiography. In a majority of cases when CT is performed there is no need in x-ray tomography

Evaluation of the absorbed dose in odontological computerized tomography

International Nuclear Information System (INIS)

Legnani, Adriano; Schelin, Hugo R.; Rocha, Anna Silvia P.S. da; Khoury, Helen J.

2011-01-01

This paper evaluated the absorbed dose at the surface entry known as 'cone beam computed tomography' (CBCT) in odontological computerized tomography. Examination were simulated with CBCT for measurements of dose. A phantom were filled with water, becoming scatter object of radiation. Thermoluminescent dosemeters were positioned on points correspondent to eyes and salivary glands

Impact of Multidetector Computerized Tomography (MDCT) On The General Population

Energy Technology Data Exchange (ETDEWEB)

Leite, B.B.; Ribeiro, N.C. [Servico de Radiologia, Hospital de Curry Cabral, Rua da Beneficencia, 8, 1069-166 Lisboa (Portugal)

2009-05-15

Multidetector computerized tomography (MDCT) appeared in the early 1990s, as a technological evolution of computerized tomography. As one would expect, the evolution continues and, each year, more powerful equipments appear, with new medical applications. However, the general use of this technique has lead to the dramatic increase on the general population irradiation. Special concern is required regarding the most vulnerable groups, like the pediatric population, the pregnant and the young female. Due to a larger awareness of this irradiation risks, some initiatives have been developed, coming from different areas, aiming to maximize the benefit to risk ratio of MDCT. (author)

Efficiency of computerized tomography in comparison with other neuroradiological investigation methods

International Nuclear Information System (INIS)

Kretzschmar, H.

1979-01-01

Computerized tomography is considered to be a decisive and the most reliable investigation method for the diagnosis of cerebral tumors. The rate of detection of intracranial blastomas is over 90%. Supratentorial growths are more easy to prove than tumors at the posterior cranial fossa. In the group of patients examined, 97.3% of the cerebral tumors were confirmed by computerized tomography: 98.7% of these were located above the tentorium and 89.3% under the tentorium. But the diagnostic value of computerized tomography is not only due to the high growth detection rate but also to its informative power as regards the position of growths in relation to vital centres, the type of the blastomas and their space-occupying effect. Thus this investigation method permits to evaluate the complex ''space occupation'' at one glance. By the angiographic method cerebral growths are confirmed in 86% of the cases; 88.6% of these are located above the tentorium. (orig.) [de

Computerized Tomography and its Applications : a Guided Tour

NARCIS (Netherlands)

Roerdink, J.B.T.M.

1992-01-01

We present a review of the mathematical principles of computerized tomography. Topics treated include the role of the Radon transform and related transforms, inversion formulas, uniqueness, ill-posedness and stability, practical reconstruction algorithms, and various generalizations such as

10 years of computerized tomography reviewed

International Nuclear Information System (INIS)

Duemmling, K.

1984-01-01

The history and some highlights of computerized tomography are reviewed. The various technologies employed in the course of CT development are described along with the limitations that led to their disappearance. The problems still to be solved in medicine, the increasing influence of nuclear magnetic resonance, and some scientific aspects have opened up new lines of development which are briefly mentioned. (orig./WU) [de

Quantitative inspection by computerized tomography

International Nuclear Information System (INIS)

Lopes, R.T.; Assis, J.T. de; Jesus, E.F.O. de

1989-01-01

The computerized Tomography (CT) is a method of nondestructive testing, that furnish quantitative information, that permit the detection and accurate localization of defects, internal dimension measurement, and, measurement and chart of the density distribution. The CT technology is much versatile, not presenting restriction in relation to form, size or composition of the object. A tomographic system, projected and constructed in our laboratory is presented. The applications and limitation of this system, illustrated by tomographyc images, are shown. (V.R.B.)

Sonography and computerized tomography in a comparison in renal mass diseases

International Nuclear Information System (INIS)

Brommer, M.

1981-01-01

One hundred and thirteen patients with renal mass processes were examined sonographically and by computized tomography. The diagnosis was assured in 32 cases histologically, in 40 cases angiographically clinically and by the course and in 41 cases only clinically and by the course resp. by sonographic and computerized tomography control studies. The accuracy of a hit in sonography is smaller compared with computerized tomography with fast image formation. However, due to its relative safety, it is judged as the most useful technique for a first diagnossis of renal masses after ureographic diagnostic of excreta. A diagnostic procedure is proposed in which the number of necessary angiographies and diagnostic sampling surgery can be considerably reduced. (orig.) [de

Two cases of posterior scleritis and findings of computerized tomography and ultrasonography

International Nuclear Information System (INIS)

Ohara, Takakazu; Uji, Yukitaka; Fujioka, Chieko; Mori, Kazuma

1982-01-01

Two cases of unilateral posterior scleritis, seen in 56-year-old and 68-year-old females, are reported. Computerized tomography showed characteristic findings, as follows: 1) Thickening of the posterior sclera and surrounding tissue. 2) Irregularity of the posterior wall of the eyeball. 3) Increased radiographic density in the posterior wall of the eyeball. Ultrasonography also suggested thickening of the posterior sclera. Computerized tomography and ultrasonography are considered useful in the diagnosis of posterior scleritis. (author)

Radio astronomical interferometry and x-ray's computerized tomography

Energy Technology Data Exchange (ETDEWEB)

Rodriguez, L F [Universidad Nacional Autonoma de Mexico, Mexico City. Inst. de Astronomia

1982-01-01

Radio astronomical interferometry and computerized tomography are techniques of great importance for astronomy and medicine, respectively. In this paper we emphasize that both techniques are based on the same mathematical principles, and present them as an example of interaction between basic and applied science.

Proton computed tomography

International Nuclear Information System (INIS)

Hanson, K.M.

1978-01-01

The use of protons or other heavy charged particles instead of x rays in computed tomography (CT) is explored. The results of an experimental implementation of proton CT are presented. High quality CT reconstructions are obtained at an average dose reduction factor compared with an EMI 5005 x-ray scanner of 10:1 for a 30-cm-diameter phantom and 3.5:1 for a 20-cm diameter. The spatial resolution is limited by multiple Coulomb scattering to about 3.7 mm FWHM. Further studies are planned in which proton and x-ray images of fresh human specimens will be compared. Design considerations indicate that a clinically useful proton CT scanner is eminently feasible

Single photon emission computerized tomography (SPECT)

International Nuclear Information System (INIS)

Ganatra, R.D.

1992-01-01

Tomography in nuclear medicine did not originate after the introduction of X-ray computerized tomography (CT). Even in the days of rectilinear scanner, tomography was attempted with multiple detector heads rotating around the patient, but the counts at each plane were never very high to obtain a satisfactory image. A high resolution focusing collimator can look at different depths but taking several slices in one projection was a time consuming process. Rectilinear scanners lose lot of counts in the collimator to look at one point, at on time, in one plane. It is true that attempts to do tomography with gamma camera really got a boost after the success of CT. By that time, algorithms for doing reconstruction of images also were highly refined and for advanced. Clinical application of SPECT has become widespread now, because of the development of suitable radiopharmaceuticals and improvement in instrumentation. The SPECT provides a direct measure of regional organ function and is performed with nuclides such as 123 I and 99 Tc m that emit a mono-image photon during their decay. SPECT is far less expensive than positron emission tomography

Single photon emission computerized tomography (SPECT)

Energy Technology Data Exchange (ETDEWEB)

Ganatra, R D

1993-12-31

Tomography in nuclear medicine did not originate after the introduction of X-ray computerized tomography (CT). Even in the days of rectilinear scanner, tomography was attempted with multiple detector heads rotating around the patient, but the counts at each plane were never very high to obtain a satisfactory image. A high resolution focusing collimator can look at different depths but taking several slices in one projection was a time consuming process. Rectilinear scanners lose lot of counts in the collimator to look at one point, at on time, in one plane. It is true that attempts to do tomography with gamma camera really got a boost after the success of CT. By that time, algorithms for doing reconstruction of images also were highly refined and for advanced. Clinical application of SPECT has become widespread now, because of the development of suitable radiopharmaceuticals and improvement in instrumentation. The SPECT provides a direct measure of regional organ function and is performed with nuclides such as {sup 123}I and {sup 99}Tc{sup m} that emit a mono-image photon during their decay. SPECT is far less expensive than positron emission tomography

Cranial Computerized Tomography In The Evaluation Of Stroke ...

African Journals Online (AJOL)

206 patients clinically diagnosed as stroke / cerebrovascular accidents (CVA) were investigated using computerized tomography (CT) scan. 19 patients (9%) had normal scan. While 20(9.7%) had other lesions including atrophy and tumours. Of the 167 (18. %) patients proven to have suffered a cerebro- vascular accident ...

Computerized tomography in the examination of the orbit

International Nuclear Information System (INIS)

Ammerich, H.; Wackenheim, A.; Golabek, R.

1980-01-01

The importance of computerized tomography in the ophtalmological diagnosis is discussed. A great value of the information obtained by this not cumbersome method is stressed. The findings achieved this method in the most frequent diseases of the eyeball, orbit and neighbouring anatomical structures are described. (author)

Computerized tomography of adrenal glands in the investigation of Cushing's syn

International Nuclear Information System (INIS)

Abucham Filho, J.; Albertotti, C.; Kater, C.E.; Vieira, J.G.H.; Chacra, A.R.

1983-01-01

Computerized tomography of the adrenal glands was performed in 10 patients with Cushing's syndrome using a G.E. 8800 CT/T Body Scanner. The tomographic findings of unilateral adrenal masses in 4 patients were confirmed by surgery. In the remaining 6 patients, computerized tomography did not identify any masses, and both glands were well visualized and showed normal shape. In these patients, measurement of the adrenal glands revealed both normal (n=1) and enlarged glands (n=5). The findings of adrenalectomy (n=4) or transphenoidal surgery and follow-up (n=2) established the diagnosis of adrenal phyperplasia in all patients. (Author) [pt

The limited angle problem in computerized tomography

International Nuclear Information System (INIS)

Louis, A.K.

1984-01-01

Fast reconstruction formulae in X-ray computerized tomography demand the directions, in which the measurements are taken, to be equally distributed over the whole circle. In many applications data can only be provided in a restricted range. Here the intrinsic difficulties are studied by giving a singular value decomposition of the Radon transform in a restricted range. Practical limitations are deduced. (orig.)

Patient radiation exposure in computerized tomography

Energy Technology Data Exchange (ETDEWEB)

Pavlov, V [Meditsinska Akademiya, Sofia (Bulgaria)

1980-01-01

Radiation exposure to patients undergoing axial computerized tomography as a tool of neurological X-ray diagnostics was studied. Doses thereby delivered were compared with those from routine head films at X-ray tube parameters 200 W, 70 kV, and 70 cm target-to-patient distance. Radiation exposures were analyzed with a view to improving shielding and procedural techniques. Comparisons were made using LiF TLD measurements with an Alderson phantom (standard for axial computer tomography). Skin and intracranial space doses were compared using two computers, Siretom I and Siretom 2000, for various positionings: frontal, fronto-lateral, temporal, temporo-occipital, and occipital. In addition, patient body doses with or without shielding and doses to subjects attending sick children or restless adults were examined. Achievable protection was estimated for lead shields of 0.5 mm lead equivalent. It was concluded that radiation doses delivered to neurologic patients undergoing axial computer tomography are smaller than those resulting from conventional X-ray examinations.

Emission computerized-tomography and determination of local brain function

International Nuclear Information System (INIS)

Kuhl, D.E.; Alavi, A.; Reivich, M.; Edwards, R.Q.; Fenton, C.A.; Zimmerman, R.A.

1975-01-01

Methods for the three dimensional reconstruction of /sup 99m/Tc brain scans are described. The diagnostic advantages of computerized tomography in the localization of brain tumors and in measurements of local cerebral blood flow are discussed. (U.S.)

Quality criteria in computerized tomography of the chest

International Nuclear Information System (INIS)

Doehring, W.

1985-01-01

The quality of thoracical computerized tomography (CT) - like any other CT examination - depends from the quality of the equipment used, from the skill of the examinor and the properties of the patient. Concerning computerized chest tomograms, rapid scan equipment should be used only and slow translation - rotation systems should not be used any more. Whereas the quality of computerized tomograms may be influenced by the patient in the scanning process only, the examining physician will decisively influence the possible informative value of the examination also in the reconstruction of the CT value matrix, in single demonstration of CT values and, possibly, in additional measurement value processing as well as in the interpretation of findings. Use of equipment should always consider the technical potential provided by the equipment to be oriented to the clinical issue, and the conditions preset by the patient. (orig.) [de

Use of computerized tomography and magnetic resonance imaging

International Nuclear Information System (INIS)

Tjoerstad, K.

1992-01-01

This is a neurologist's opinion on how computerized tomography and magnetic resonance imaging have improved the doctor's diagnostic possibilities, changed patient/doctor relationship and increased the patients' expectations from diagnostic tests. How should the often conflicting interests of patients, society and doctors be handled? 15 refs., 1 fig., 1 tab

Coupling two iteratives algorithms for density measurements by computerized tomography

International Nuclear Information System (INIS)

Silva, L.E.M.C.; Santos, C.A.C.; Borges, J.C.; Frenkel, A.D.B.; Rocha, G.M.

1986-01-01

This work develops a study for coupling two iteratives algotithms for density measurements by computerized tomography. Tomographies have been obtained with an automatized prototype, controled by a microcomputer, projected and assembled in the Nuclear Instrumentation Laboratory, at COPPE/UFRJ. Results show a good performance of the tomographic system, and demonstrate the validity of the method of calculus adopted. (Author) [pt

Computerized tomography of gall bladder cancer

International Nuclear Information System (INIS)

Todua, F.I.; Karmazanovskij, G.G.

1989-01-01

The authors have summed up the experience in the use of computerized tomography (CT) in diagnosis of gall bladder cancer. The investigation of 17 patients with cancer of this site showed a high informative value of the method. A retrospective comparative study of the results of CT and surgical interventions was carried out. It has been concluded that CT makes it possible not only to diagnose malignant lesions of the bile ducts but also to assess a possible scope of a forthcoming operation

Significance of computerized tomography and nasal cytology in the ...

African Journals Online (AJOL)

Ehab

assessment of sinus disease in asthmatic children. Rhinosinusitis is a common asthma comorbidity. Nasal eosinophil or neutrophil score >0.5 provides a better predictive value for rhinosinusitis compared to total serum IgE. Keywords: computerized tomography, nasal sinus, asthma, sinusitis, allergic rhinitis, children.

Computerized axial tomography : the tool in osseointegrated dental implants

International Nuclear Information System (INIS)

Fernandez-Lopez, Otton

2002-01-01

Failure rates in rehabilitations with osseointegrated implants are handled through appropriate radiographic preoperative planning. The appropriate length of the implant without running the risk of a perforation of vital structures, has been determined by a radiographic diagnosis. Computerized and conventional axial tomography have proved to be invaluable elements for pre-surgical evaluation. A radiologic guidance is elaborated to perform a computerized axial tomography (CT) of maxillary bones in totally edentulous patients. Surgical guides are constructed from a wax-up emanated from the information of the CT. The CT has proven to be an radiographic indispensable element to achieve the surgical-prosthetic success in osseointegrated dental implants. The CT has allowed the realization of a precise wax-up for making of surgical guide and a precise temporary prostheses in positioning of osseointegrated implants, with the consequent saving time and money for the rehabilitator and patient [es

GEANT4 simulations for low energy proton computerized tomography

International Nuclear Information System (INIS)

Milhoretto, Edney; Schelin, Hugo R.; Setti, Joao A.P.; Denyak, Valery; Paschuk, Sergei A.; Evseev, Ivan G.; Assis, Joaquim T. de; Yevseyeva, O.; Lopes, Ricardo T.; Vinagre Filho, Ubirajara M.

2010-01-01

This work presents the recent results of computer simulations for the low energy proton beam tomographic scanner installed at the cyclotron CV-28 of IEN/CNEN. New computer simulations were performed in order to adjust the parameters of previous simulation within the first experimental results and to understand some specific effects that affected the form of the final proton energy spectra. To do this, the energy and angular spread of the initial proton beam were added, and the virtual phantom geometry was specified more accurately in relation to the real one. As a result, a more realistic view on the measurements was achieved.

GEANT4 simulations for low energy proton computerized tomography

Energy Technology Data Exchange (ETDEWEB)

Milhoretto, Edney [Federal University of Technology-Parana, UTFPR, Av. Sete de Setembro 3165, Curitiba-PR (Brazil); Schelin, Hugo R. [Federal University of Technology-Parana, UTFPR, Av. Sete de Setembro 3165, Curitiba-PR (Brazil)], E-mail: schelin@utfpr.edu.br; Setti, Joao A.P.; Denyak, Valery; Paschuk, Sergei A. [Federal University of Technology-Parana, UTFPR, Av. Sete de Setembro 3165, Curitiba-PR (Brazil); Evseev, Ivan G.; Assis, Joaquim T. de; Yevseyeva, O. [Polytechnic Institute/UERJ, Rua Alberto Rangel s/n, N. Friburgo, RJ, Brazil 28630-050 (Brazil); Lopes, Ricardo T. [Nuclear Instr. Lab./COPPE/UFRJ, Av. Horacio Macedo 2030, Rio de Janeiro-RJ (Brazil); Vinagre Filho, Ubirajara M. [Institute of Nuclear Engineering-IEN/CNEN, Rua Helio de Almeida 75, Rio de Janeiro-RJ (Brazil)

2010-04-15

This work presents the recent results of computer simulations for the low energy proton beam tomographic scanner installed at the cyclotron CV-28 of IEN/CNEN. New computer simulations were performed in order to adjust the parameters of previous simulation within the first experimental results and to understand some specific effects that affected the form of the final proton energy spectra. To do this, the energy and angular spread of the initial proton beam were added, and the virtual phantom geometry was specified more accurately in relation to the real one. As a result, a more realistic view on the measurements was achieved.

The industrial computerized tomography applied to the rock analysis

International Nuclear Information System (INIS)

Tetzner, Guaraciaba de Campos

2008-01-01

This work is a study of the possibilities of the technical applications of Computerized Tomography (CT) by using a device developed in the Radiation Technology Center (CTR), Institute for Energy and Nuclear Research (IPEN-CNEN/SP). The equipment consists of a gamma radiation source ( 60 Co), a scintillation detector of sodium iodide doped with thallium (NaI (Tl)), a mechanical system to move the object (rotation and translation) and a computer system. This operating system has been designed and developed by the CTR-IPEN-CNEN/SP team using national resources and technology. The first validation test of the equipment was carried out using a cylindrical sample of polypropylene (phantom) with two cylindrical cavities (holes) of 5 x 25 cm (diameter and length). In these tests, the holes were filled with materials of different density (air, oil and metal), whose attenuation coefficients are well known. The goal of this first test was to assess the response quality of the equipment. The present report is a study comparing computerized tomography equipment CTR-IPEN-CNEN/SP which uses a source of gamma radiation ( 60 Co) and other equipment provided by the Department of Geosciences in the University of Texas (CTUT), which uses an X-ray source (450 kV and 3.2 mA). As a result, the images obtained and the comprehensive study of the usefulness of the equipment developed here strengthened the proposition that the development of industrial computerized tomography is an important step toward consolidating the national technology. (author)

Computerized tomography in diffuse diseases of the liver. Pt. 2

International Nuclear Information System (INIS)

Helmberger, H.; Vogel, U.; Bautz, W.

1993-01-01

Computerized tomography is a first-line method of imaging to confirm diffuse disorders of the liver suggested by preliminary clinical and biochemical findings. If the disease is caused by an obstructed vessel, this is reliably detected. For most types of thesaurismosis as well as hepatic steatosis and cirrhosis of the liver approaches to quantitative determinations of the spread of disease have been described in theory but so far failed to show great merits in practice. The transition from hepatic fibrosis to cirrhosis as the final developmental stage common to all those disorders has typical features on computerized tomography. This explains why the use of this method in diffuse hepatic disease offers particular advantages as regards the detection of complications occurring at an advanced stage ot the diagnosis of changes developing into malignancies. (orig.) [de

Increased intracranial pressure: evaluation by computerized tomography

International Nuclear Information System (INIS)

Lightfoote, W.E.; Pressman, B.D.

1975-01-01

Computerized tomography is clearly very useful in the evaluation of patients with increased intracranial pressure and suspected pseudotumor cerebri. It provides an index of ventricular size and configuration and has the capability of demonstrating intracranial lesions. Moreover, this new technique is rapid and non-invasive, and is without attendant risks. Examinations may be performed serially as the clinical process evolves, thereby giving roentgenographic correlation to the clinical features. (U.S.)

Contribution of computerized tomography to orbit fracture diagnosis

International Nuclear Information System (INIS)

Nemeth, T.; Sobota, J.

1984-01-01

Suitability and specificity of examinations using computerized tomography are discussed for diagnoses fractures of the orbit including accurate anatomical localization of traumatic changes. The possibility of accurate assessment of the drop of the floor of the orbit which is essential for determination of the thickness of the bone or cartilaginous graft under the eyeball is also important

Diagnostic Yield of Transbronchial Biopsy in Comparison to High Resolution Computerized Tomography in Sarcoidosis Cases

Science.gov (United States)

Akten, H Serpil; Kilic, Hatice; Celik, Bulent; Erbas, Gonca; Isikdogan, Zeynep; Turktas, Haluk; Kokturk, Nurdan

2018-04-25

This study aimed to evaluate the diagnostic yield of fiberoptic bronchoscopic (FOB) transbronchial biopsy and its relation with quantitative findings of high resolution computerized tomography (HRCT). A total of 83 patients, 19 males and 64 females with a mean age of 45.1 years diagnosed with sarcoidosis with complete records of high resolution computerized tomography were retrospectively recruited during the time period from Feb 2005 to Jan 2015. High resolution computerized tomography scans were retrospectively assessed in random order by an experienced observer without knowledge of the bronchoscopic results or lung function tests. According to the radiological staging with HRCT, 2.4% of the patients (n=2) were stage 0, 19.3% (n=16) were stage 1, 72.3% (n=60) were stage 2 and 6.0% (n=5) were stage 3. This study showed that transbronchial lung biopsy showed positive results in 39.7% of the stage I or II sarcoidosis patients who were diagnosed by bronchoscopy. Different high resolution computerized tomography patterns and different scores of involvement did make a difference in the diagnostic accuracy of transbronchial biopsy (p=0.007). Creative Commons Attribution License

Computerized tomography of orbital lesions

International Nuclear Information System (INIS)

Kuroiwa, Mayumi

1981-01-01

Two different types of computerized tomography scanners (CT scanner), i.e. a whole-body CT scanner (GE-CT/T8800) and a cerebral CT scanner (EMI-1010), were compared in the assessment and diagnosis of various orbital lesions. The whole-body CT scanner was found to be advantageous over the cerebral CT scanner for the following reasons: (1) CT images were more informative due to thinner slices associated with smaller-sized and larger-numbered matrices; (2) less artifacts derived from motion of the head or eyeball were produced because of the shorter scanning time; (3) with a devised gantry, coronal dissections were available whenever demanded. (author)

Acute renal failure following contrast injection for head computerized tomography in two patients with diabetic nephropathy

International Nuclear Information System (INIS)

Matsunaga, Hiroshi; Sando, Hiroyuki; Nunokawa, Tomoo; Murakami, Tooru; Miyakawa, Yuzo

1981-01-01

Two cases of diabetes mellitus with renal and retinal involvement developed acute renal failure after undergoing head computerized tomography. The first case was a 62-year-old male who had been diagnosed as having diabetes 25 years before. He had diabetic retinopathy of Scott IIIb. Before head computerized tomography, the serum BUN was 37 mg/dl, and creatinine was 4.1 mg/dl. Oliguria began immediately after the scanning and confinued for 48 hr. The serum levels of BUN and creatinine rose to 106 and 7.7 mg/dl, respectively. Case 2 was a 49-year-old male who had been diagnosed as having diabetes 15 years before. He showed Scott IIb and IV retinopathy. The BUN and creatinine levels in the serum were 32 and 2.3 mg/dl, respectively. After receiving head computerized tomography, he developed oliguria and remained oliguric for 48 hr. During that period, the serum levels of BUN and creatinin were elevated to 112 and 7.5 mg/dl, respectively. Fortunately, both of these patients recovered from the oliguria without resorting to hemodialysis. The iodine contrast medium routinely used for contrast enhancement in the head computerized tomography was implicated in the acute renal failure of these patients. Only elevn cases have so far been reported in the literature who developed acute renal failure following computerized tomography. In view of the three or four times greater dosis of iodine contrast medium employed in computerized tomography compared to intravenous pyelography, the acute incidence of such complications might be much higher. Among the thirteen cases including the two reported here, as many as eight were diabetic. It is well recongnized that the incidence of acute renal failure after intravenous pyelography is particularly high in cases of diabetic nephropathy. (author)

Computerized abdominal tomography in Wilson's disease

Energy Technology Data Exchange (ETDEWEB)

Tsuchikura, Keiko; Ogawa, Teruyuki; Nakajima, Akihisa; Ono, Yasuhiko

1986-05-01

Cranial and abdominal computerized tomography (CT) was performed in a 10-year-old boy with Wilson's disease complicated by liver cirrhosis. Abdominal CT showed diffuse high density areas over the whole part of the liver propably due to copper sediments, although there was no abnormal cranial CT findings. Decreased high density area of the liver was seen 60 days after the administration of D-penicillamine, suggesting the excretion of copper from the liver. Abdominal CT, as well as cranial CT, may be of help to diagnose Wilson's disease and evaluate therapeutic effects. (Namekawa, K.).

Computerized tomography and its diagnostic value in the imaging of limbs

International Nuclear Information System (INIS)

Myllylae, V.; Tervonen, O.; Paeivaensalo, M.; Jalovaara, P.; Merikanto, J.; Maekaeraeinen, H.; Oulu Univ.

1987-01-01

The application of computerized tomography in skeletal diagnostics has many advantages over plain film radiography. Its use as a supplementary technique in traumatology and oncology is strongly advised. (orig.) [de

A case of multiple intracranial tuberculoma followed by serial computerized tomography

International Nuclear Information System (INIS)

Kummer, R. von; Storch, B.; Krause, K.H.; Rauch, H.

1981-01-01

This is the case report of an Indian living in Europe who suffered from multiple cerebral tuberculomes in connexion with extrapulmonal tuberculosis. The retrogression of the inflammatory granulomes and the surrounding cerebral edema by treatment with tuberculostatics and Dexamethasone was observed by means of computerized tomography (CT) over a period of 8 months. The value of CT in the diagnosis and treatment of cerebral tuberculomes is discussed. The diagnosis of cerebral tuberculomes is difficult as neither the clinical picture nor additional neuroradiological tests ensure safe delimitation against other intracranial growths. In how far this situation has changed by the introduction of CT into diagnostics is discussed by the example of serial computerized tomography on a patient with multiple cerebral tuberculomes. (orig.) [de

Status of routine post-mortem computerized tomography in Odense, Denmark

DEFF Research Database (Denmark)

Leth, Peter Mygind

2008-01-01

rarely is a substitute for autopsy, but may contribute with important new information in many cases such as identifications (including mass-disasters), battered child, gunshot wounds, traffic accidents and air embolism. Computerized tomography provides documentation in digital form - easily stored...

Computerized tomography of the mandibular joints and masticatory muscles

International Nuclear Information System (INIS)

Huels, A.B.

1981-01-01

A methodology for computerized tomography of the mandibular joints was developed and applied in 80 test persons. Imaging of the mandibular joints is possible with a tomographic technique with 5 mm-overlap, full utilisation of the enlargement capacity of the imaging device, and combined use of transversal and coronary tomography. The method yields full latero-medial, cranio-caudal and anterior-posterior views of the condyle and fossa contours, free of interferences and of distortions caused by the projection. Positional diagnoses are thus possible as well as diagnoses of pathological structural changes. (orig./MG) [de

Prognosis of the computerized tomography in the severe head injury

International Nuclear Information System (INIS)

Garcia-Nieto, J.J.; Lorenzo Dominguez, M.T.; Martin Sanchez, M.J.; Sanchez Gonzalez, E.

1991-01-01

A prospective study is made with sixty five people affected of severe head injury, that is to say, with eight or less points in the Glasgow Coma Scale (GCS), when they get to the hospital. They are studied by computerized tomography at the income, but also, three and seven days after arriving. In this way, we appraise the type of the lesion the intensity and the possible effect-wass, considering in the last case, three features: a) ventricular collapse; b) the mean line structure s shift; c) perimesencefalic cisterns affectation. The findings of this study, are parametized and we were able to introduce them into a computer, getting. The relations between these findings ands the end-results. These last ones appraised throungh the Glasgow Outcome Scale (GOS). We could confirm, that certain findings in the computerized tomography have and unavoidable prognosis, where as others have a better prognosis. (Author)

Dosimetry of computerized tomography in the evaluation of hip dysplasia

Energy Technology Data Exchange (ETDEWEB)

Guyer, B.; Bassano, D.A.; Levinsohn, E.M.; Smith, D.S.; Cady, R.B.

1984-07-01

The usefulness of computerized tomography (CT) in the assessment of hip dysplasia has recently been given attention in the literature and concern regarding radiation dose has been raised. This study was undertaken to measure the radiation dose, both in and out of plaster, for plain films, arthrography, tomography, and CT. A method is suggested to reduce dosage by 80% without compromising diagnostic information. Our experience with 25 scans of patients aged 4 months to 39 years is presented.

Computerized tomography of the vertebral column following traumatic lesion

International Nuclear Information System (INIS)

Taenzer, B.; Gmelin, E.; Burmester, E.; Babaian, E.; Weiss, H.D.; Hohlbach, G.

1984-01-01

In 58 patients with lesions of the vertebral column in the thoracal and lumbar section established by conventional X-ray, the informative power of computerized tomography was tested. Axial projection with the superimposition-free presentation of bone and soft-tissue structures in the motional segment clears up the diagnostically decisive question of the extent of the lesion and form of fracture, and thus provides information on the stability or instability of the fracture relevant for the therapeutic action taken. All patients had compression fractures of vertebrae, with a fragment of the front edge broken away in 50 cases and one of the back edge broken away in 17 cases. In 30 cases the intervertebral disks were damaged. 43 fractures were stable, 25 were unstable. The instability of 13 fractures was only recognized by CT. In essence, the diagnostic action to be taken begins with a grand-survey X-ray in two planes as a screening, with computerized tomography following in the positive case. Conventional tomograms are not necessary. (BWU) [de

Proton computed tomography images with algebraic reconstruction

Energy Technology Data Exchange (ETDEWEB)

Bruzzi, M. [Physics and Astronomy Department, University of Florence, Florence (Italy); Civinini, C.; Scaringella, M. [INFN - Florence Division, Florence (Italy); Bonanno, D. [INFN - Catania Division, Catania (Italy); Brianzi, M. [INFN - Florence Division, Florence (Italy); Carpinelli, M. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Chemistry and Pharmacy Department, University of Sassari, Sassari (Italy); Cirrone, G.A.P.; Cuttone, G. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Presti, D. Lo [INFN - Catania Division, Catania (Italy); Physics and Astronomy Department, University of Catania, Catania (Italy); Maccioni, G. [INFN – Cagliari Division, Cagliari (Italy); Pallotta, S. [INFN - Florence Division, Florence (Italy); Department of Biomedical, Experimental and Clinical Sciences, University of Florence, Florence (Italy); SOD Fisica Medica, Azienda Ospedaliero-Universitaria Careggi, Firenze (Italy); Randazzo, N. [INFN - Catania Division, Catania (Italy); Romano, F. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Sipala, V. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Chemistry and Pharmacy Department, University of Sassari, Sassari (Italy); Talamonti, C. [INFN - Florence Division, Florence (Italy); Department of Biomedical, Experimental and Clinical Sciences, University of Florence, Florence (Italy); SOD Fisica Medica, Azienda Ospedaliero-Universitaria Careggi, Firenze (Italy); Vanzi, E. [Fisica Sanitaria, Azienda Ospedaliero-Universitaria Senese, Siena (Italy)

2017-02-11

A prototype of proton Computed Tomography (pCT) system for hadron-therapy has been manufactured and tested in a 175 MeV proton beam with a non-homogeneous phantom designed to simulate high-contrast material. BI-SART reconstruction algorithms have been implemented with GPU parallelism, taking into account of most likely paths of protons in matter. Reconstructed tomography images with density resolutions r.m.s. down to ~1% and spatial resolutions <1 mm, achieved within processing times of ~15′ for a 512×512 pixels image prove that this technique will be beneficial if used instead of X-CT in hadron-therapy.

Method of evaluation of diagnostics reference levels in computerized tomography

International Nuclear Information System (INIS)

Vega, Walter Flores

1999-04-01

Computerized tomography is a complex technique with several selectable exposition parameters delivering high doses to the patient. In this work it was developed a simple methodology to evaluate diagnostic reference levels in computerized tomography, using the concept of Multiple Scan Average Dose (MSAD), recently adopted by the Health Ministry. For evaluation of the MSAD, a dose distribution was obtained through a measured dose profile on the axial axis of a water phantom with thermoluminescence dosemeters, TLD-100, for different exam technique. The MSAD was evaluated hrough two distinct methods. First, it was evaluated by the integration of the dose profile of a single slice and, second, obtained by the integration on central slice of the profile of several slices. The latter is in of accordance with the ionization chamber method, suggesting to be the most practical method of dose evaluation to be applied in the diagnostic reference level assessment routine for CT, using TLDs. (author)

Anatomic radiological study of transverse diameter of abdominal aorta by computerized tomography

International Nuclear Information System (INIS)

Ures, S.

1984-01-01

The transverse diameter of abdominal aorta by computerized tomography is studied. The purpose is establish the frequent standard diameters and then diagnose early pathologies, mainly aneurisms. (M.A.C.) [pt

Detection of lymph node metastasis in patients with nodal prostate cancer relapse using (18)F/(11)C-choline positron emission tomography/computerized tomography.

Science.gov (United States)

Jilg, Cordula A; Schultze-Seemann, Wolfgang; Drendel, Vanessa; Vach, Werner; Wieser, Gesche; Krauss, Tobias; Jandausch, Anett; Hölz, Stefanie; Henne, Karl; Reske, Sven N; Grosu, Anca-L; Weber, Wolfgang A; Rischke, H Christian

2014-07-01

We evaluated the diagnostic accuracy of choline positron emission tomography/computerized tomography for nodal relapse of prostate cancer according to topographical site and tumor infiltration size in lymph nodes. A total of 72 patients with nodal prostate cancer relapse after primary therapy underwent pelvic and/or retroperitoneal salvage lymph node dissection. Salvage was done after whole body positron emission tomography/computerized tomography with (11)C-choline or (18)F-fluoroethylcholine showed positron emission tomography positive lymph nodes but no other detectable metastasis. Diagnostic accuracy was evaluated in 160 dissected lymph node regions (pelvic left/right and retroperitoneal), 498 subregions (common, external and internal iliac, obturator, presacral, aortic bifurcation, aortal, vena caval and interaortocaval) and 2,122 lymph nodes. Lymph node metastasis was present in 32% of resected lymph nodes (681 of 2,122), resulting in 238 positive subregions and 111 positive regions. Positron emission tomography/computerized tomography was positive for 110 regions and 209 subregions. Sensitivity, specificity, positive and negative predictive values, and accuracy were 91.9%, 83.7%, 92.7%, 82.0% and 89.4% (region based), 80.7%, 93.5%, 91.9%, 84.1% and 87.3% (subregion based), and 57.0%, 98.4%, 94.5%, 82.6% and 84.9% (lesion based), respectively. Of 393 positive lymph node metastases detected by this method 278 (70.7%) were in lymph nodes with a less than 10 mm short axis diameter. Imaging sensitivity was 13.3%, 57.4% and 82.8% for a tumor infiltration depth of 2 or greater to less than 3 mm, 5 or greater to less than 6 mm and 10 or greater to less than 11 mm, respectively. Lymph node metastasis site and the radiotracer ((11)C-choline/(18)F-fluoroethylcholine) had no substantial impact on diagnostic accuracy. Choline positron emission tomography/computerized tomography detects affected lymph node regions (pelvic left/right and retroperitoneal) in patients with

Preoperative localization of parathyroid tumor by computerized tomography

International Nuclear Information System (INIS)

Kan, Seiji; Hiraishi, Koji; Nakamura, Shoichiro; Yamamoto, Schuzo; Odachi, Motoaki; Yamashita, Toshiyuki.

1984-01-01

Five patients of primary hyperparathyroidism with urolithiasis underwent CT-scanning for the preoperative localization of parathyroid tumor. The tumor was identified in all patients but one, who had a multiple adenomatous goiter. In this case, postoperative observation of the CT-scan revealed the parathyroid tumor. It appears that if the size of the parathyroid tumor is about 1cm in diameter, there is a high possibility of preoperative localization by computerized tomography. (author)

Scanning transmission proton microscopy tomography of reconstruction cells from simulated data

International Nuclear Information System (INIS)

Zhang Conghua; Li Min; Hou Qing

2011-01-01

For scanning transmission proton microscopy tomography, to compare cell images of the proton stopping power and relative electron density, two cell phantoms are designed and simulated by code FLUKA. The cell images are reconstructed by the filtered back projection algorithm, and compared with their tomography imaging. The images of stopping power and relative electron density slightly vary with proton energies, but the internal images are of clear with high resolution. The organic glass image of relative electron density reveals the resolution power of proton tomography. Also, the simulation results reflect effects of the boundary enhancement, the weak artifacts, and the internal structure border extension by multiple scattering. So using proton tomography to analyze internal structure of a cell is a superior. (authors)

Single-Photon Emission Computerized Tomography (SPECT in Neuropsychiatry: A Review

Directory of Open Access Journals (Sweden)

B. K. Puri

1992-01-01

Full Text Available Cranial single-photon emission computerized tomography (SPECT or SPET can now give regional cerebral blood flow images with a resolution approaching that of positron emission tomography (PET. In this paper, the use of high resolution SPECT neuroimaging in neuropsychiatric disorders, including Alzheimer's disease, multi-infarct dementia, Pick's disease, progressive supranuclear palsy, Korsakoff's psychosis, Creutzfeld-Jakob disease, Parkinson's disease, Huntington's disease, schizophrenia, mood disorders, obsessive–compulsive disorder, HIV infection and AIDS is reviewed. Finally, further potential research and clinical uses, based on ligand studies, are outlined.

Radiation exposure of the gonads in infant brain computerized tomography

International Nuclear Information System (INIS)

Berndt, L.; Rosenkranz, G.; Tellkamp, H.

1988-01-01

In 61 babies and infants the gonadal dose due to brain computerized tomography was determined over the symphysis by thermoluminescent dosimetry. The average radiation dose was 43 mGy corresponding with data reported. Shielding of the testes in infants is an additional burden and worth discussing because of the low absolute gonadal dose

Radiation conditions for computerized tomography: determination and comparison

International Nuclear Information System (INIS)

Andrade, Lucio das Chagas de

2016-01-01

Radiology is the practice in which radiation beams, usually radiation X are used to produce an image of the human body in order to obtain a diagnosis, for example, to evaluate a pathological condition by computerized tomography (CT). Although the computerized tomography diagnostic potential is unquestionable, caution must be taken because the doses are almost always higher than the observed in conventional radiology procedures. The ionization chamber used for dosimetry in CT is a unsealed cylindrical chamber with 10 cm and 15 cm of sensitive length. A typical characteristics of this camera is its uniform response to radiation incident at all angles around its axis. The revised edition of IEC 61267 (2005) brought as an innovation the radiation conditions for computed tomography, RQT, that simulate non-attenuated beam and are used in special CT applications. This study aims to establish the necessary conditions to obtain radiation pattern beam computed tomography, RQT, and a calibration laboratory implementation for pencil ionization chambers used in the beam dosimetry produced by these scanners in the Metrology National Laboratory of Ionizing Radiation (LNMRI). In the implementation of RQT conditions we were found that the ratio of kerma rates in the air, with or without additional filtration equivalent to the first HVL (half-value layer), are in accordance with IEC 61267 (2005), which provides a range between 48.5% and 51.5% for each quality. The LNMRI characterized the radiation conditions of RQT series (IEC, 2005), obtaining a percentage of 49.6% for the RQT 8, 50% for the RQT 9 and 50,4% for the RQT 10. With the substitution of the total additional filtration RQT qualities, composed by Al + Cu and by a total filtration composed by copper (Cu) only, it can be seen the emergence of a similar RQT quality named Quality Copper Tomography - QCT. The results of the calibration, the RQT and QCT qualities, had expanded uncertainties with a confidence level 95.45%, less

Positron emission computerized tomography: a potential tool for in vivo quantitation of the distribution of radiopharmaceuticals

International Nuclear Information System (INIS)

Huebner, K.F.; King, P.; Gibbs, W.D.; Washburn, L.C.; Hayes, R.L.

1981-01-01

The principles and some of the difficulties in quantitative positron emission computerized tomography have been discussed. We have shown that randoms and scattered events are a major cause of noise and counting errors in positron emission computerized tomography. The noise has been identified as a convoluting process and a mathematical solution has been presented. Examples of phantom studies and in vivo measurements have demonstrated that the distribution of positron emitting radiopharmaceuticals can be quantitated with much improved accuracy using the deconvolution equation to remove undesired noise

Application of protons to computer tomography

International Nuclear Information System (INIS)

Hanson, K.M.; Bradbury, J.N.; Cannon, T.M.; Hutson, R.L.; Laubacher, D.B.; Macek, R.; Paciotti, M.A.; Taylor, C.A.

1977-01-01

It was demonstrated that the application of protons to computed tomography can result in a significant dose advantage relative to x rays. Thus, at the same dose as is delivered by contemporary commercial x-ray scanners, a proton scanner could produce reconstructions with a factor of 2 or more improvement in density resolution. Whether such an improvement can result in significantly better diagnoses of human disease is an open question which can only be answered by the implementation of a proton scanner in a clinical situation

Computerized tomography-guided neurolytic splanchnic nerve block

International Nuclear Information System (INIS)

Henriquet, Franco; De Martini, Giuseppe; Roy, Maria Teresa; Pretrolesi, Fabio; Martinoli, Carlo; Cariati, Maurizio; Fiorentini, Franco.

1997-01-01

Computerized tomography-guided neurolytic splanchnic nerve block is a technique for relieving abdominal cancer pain; the goal is the alcoholic neurolytic interruption of the sensitive structures in retroperitoneal space. Computerized tomography yields accurate anatomical detailing and the course for needle placement and alcohol spread. January, 1993, to July, 1996, twenty-one bilateral splanchnic nerve blocks were performed through the posterior access. Forty-eight hours after alcoholism. 14 patients (66%) had complete pain regression; 52% of the patients needed no analgesics for 6 to 54 days and only 9 patients (42%) needed another low opioid therapy. Complications included hypotension and diarrhea in all cases. One had a cardiac arrest and diet 8 days after the procedure. There were no other complications. The whole procedure usually lasted 60 min (range: 45 to 90 min). Splanchnic nerve neurolysis is a useful treatment in the patients with severe chronic abdominal pain. It is used as a second line treatment when large lesions change celia anatomy and complicate the percutaneous block of the celiac plexus. Endosulfan, Malathion and Methyl parathion, on the metabolic rate of the estuarine clam, Villorita cyprinoides var. cochinensis, have been investigated. The animals exposed to the lower sublethal concentrations of Endosulfan, Malthion and Methyl parathion consumed oxygen at the rate of 1.60, 1.98 and 2.09 ml. 0 2 g - 1 h -1 respectively, while at the higher concentrations of the pesticides, consumption of oxygen by the animal dropped to nearly half the control value. When compared to Malathion and Methyl parathion. Endosulfan induced animals recorded a greater reduction in her percentage deviation (from control) of oxygen consumption, possibly due to hypoxia induced by the pollutants

Computerized tomography with X-rays: an instrument in the analysis physico-chemical between formations and drilling fluids interactions

International Nuclear Information System (INIS)

Coelho, Marcus Vinicius Cavalcante

1998-01-01

In this study it is demonstrated the applicability of the Computerized Tomography technique with x-rays to evaluate the reactivity degree between various drilling fluids and argillaceous sediments (Shales and Sandstones). The research has been conducted in the Rock-Fluid Interaction Pressure Simulator (RFIPS), where the possible physico-chemical alterations can be observed through successive tomography images, which are obtained during the flow of the fluid through the samples. In addition, it was noticed the formation of mud cake in Berea Sandstones samples in the RFIPS, though the Computerized Tomography with X-rays, when utilizing drilling fluids weighted with the baryte. (author)

Development of a proton Computed Tomography Detector System

Energy Technology Data Exchange (ETDEWEB)

Naimuddin, Md. [Delhi U.; Coutrakon, G. [Northern Illinois U.; Blazey, G. [Northern Illinois U.; Boi, S. [Northern Illinois U.; Dyshkant, A. [Northern Illinois U.; Erdelyi, B. [Northern Illinois U.; Hedin, D. [Northern Illinois U.; Johnson, E. [Northern Illinois U.; Krider, J. [Northern Illinois U.; Rukalin, V. [Northern Illinois U.; Uzunyan, S. A. [Northern Illinois U.; Zutshi, V. [Northern Illinois U.; Fordt, R. [Fermilab; Sellberg, G. [Fermilab; Rauch, J. E. [Fermilab; Roman, M. [Fermilab; Rubinov, P. [Fermilab; Wilson, P. [Fermilab

2016-02-04

Computer tomography is one of the most promising new methods to image abnormal tissues inside the human body. Tomography is also used to position the patient accurately before radiation therapy. Hadron therapy for treating cancer has become one of the most advantegeous and safe options. In order to fully utilize the advantages of hadron therapy, there is a necessity of performing radiography with hadrons as well. In this paper we present the development of a proton computed tomography system. Our second-generation proton tomography system consists of two upstream and two downstream trackers made up of fibers as active material and a range detector consisting of plastic scintillators. We present details of the detector system, readout electronics, and data acquisition system as well as the commissioning of the entire system. We also present preliminary results from the test beam of the range detector.

Dose profile measurement in computerized axial tomography equipment using thermoluminescent dosemeters

International Nuclear Information System (INIS)

Azorin V, J.C.; Falcony, C.; Azorin N, J.

2000-01-01

In this work are presented the results about measuring the radiation dose profile in two equipment of computerized axial tomography (Tac). Thermoluminescent dosemeters (Dtl) of LiF, Mg, Cu, P + Ptfe in form of disks were used which were developed and made in Mexico. The results showed that Dtl are appropriated for these type of studies. (Author)

'High resolution' computerized tomography in spinal narrow and spinal column diagnosis

International Nuclear Information System (INIS)

Koester, O.

1985-01-01

Bearing in mind that direct comparison is lacking, high resolution computerized tomography in spinal column diagnosis can be said to supply considerably increased information when dealing with the issues of a cervical prolapse and bony changes of any origin. Its advantages appear to be reduced when assessing lumbar prolapse, intraspinal masses and paravertebral soft-tissue processes. (orig.) [de

Computerized tomography findings in nasolacrimal dysfunction

International Nuclear Information System (INIS)

Ishida, Toshio; Nakamura, Yasuhisa; Kumagai, Michiasa

1985-01-01

We examined 17 cases (22 lesions) with stenosis or obstruction in the lacrimal drainage system with the use of computerized tomography (CT). In idio pathic cases, the site of obstruction was located either in the upper nasolacrimal duct or at the junction of the lacrimal sac and the nasolacrimal duct. In post-traumatic cases, it was located in the lower nasolacrimal duct. The obstructed areas appeared as homogenous in CT image with CT values ranging between +60 and +80. These findings were suggestive of granulation tissue. The stenosed areas appeared, on the other hand, as areas of unequal density. Lacrimal passage appeared to be maintained through the low-density portion. The CT values of the lacrimal sac was around +40 in dacryocystitis and around +20 to +30 other cases. (author)

Development and prospects of X-ray computerized tomography. I

International Nuclear Information System (INIS)

Dobes, V.

1985-01-01

The history and developmental trends are described of X-ray computerized tomography (CT) as are its applications in clinical practise. Suitable criteria and economic aspects are proposed for the choice of CT systems. The types are listed and described of X-ray CT systems, including brain, whole-body, mobile and special systems. A table is given showing available specifications (types of detectors, X-ray source, resolution, configuration, scan angles, scan fields, image reconstruction, etc.) for machines by different companies. (M.D.)

Computerized axial tomography in traumatic cervical lesions

International Nuclear Information System (INIS)

Koyama, Tsunemaro

1982-01-01

Although plain computerized axial tomography cannot routinely demonstrate the spinal cord, it does provide excellent visualization of the bony outline of the spinal canal and vertebral column. So it should be reasonable to use this technique in cases of cervical traumatic disorders. In this paper we presented 10 cases of cervical traumatic lesions; 3 atlanto-axial dislocation, 2 cervical canal stenosis, 3 OPLL, 1 intramedullary hematoma and 1 C 2 -neurinoma. In some patients neurologic deficits were induced by cervical trauma. Bony lesions appeared more adequately deliniated than intraspinal lesions, however, in some cases intramedullary changes could also be demonstrated. The use of metrizamide with high resolution CT-scanner could improve the usefullness of this technique. (author)

Computerized transverse tomography of vascular lesions of the brain. II. Aneurysms

International Nuclear Information System (INIS)

Pressman, B.D.; Gilbert, G.E.; Davis, D.O.

1975-01-01

Computerized transverse tomography (CTT) is an excellent screening examination for intracerebral disease. Unfortunately, the detection rate of small aneurysms by this procedure is not high. Nevertheless, CTT may be useful in aneurysm cases since it may indicate the need for further evaluation in patients with associated hematomas, encephalomalacia, or ventricular dilatation, even if the aneurysm itself is not delineated. (U.S.)

Organ doses from computerized tomography examinations

Energy Technology Data Exchange (ETDEWEB)

Janeczek, J.

1995-12-31

Estimates of mean organs doses from five typical computerized tomography (CT) examinations were obtained. Measurements were done using Rando-Alderson anthropomorphic phantom and thermoluminescent dosemeters (TLD). Radiation dose distributions within a phantom has been measured for each examination and results were used for organ dose calculation. Doses to organs specified by ICPR 60 Recommendations were measured for five CT scanners (CT/T8800, CT 9800, CT MAX - made by General Electric; CT 1200 SX - made by Picker; SOMATOM 2 - made by Siemens). Dose distributions from scattered radiation were measured and indicate that scattered radiation dose to thyroid and eye lens can be reduced by proper examination limits setting. The lowest mean organ doses were obtained from CT/T8800 scanner. More advanced scanners using high intensity continuous radiation were giving higher organ doses. (author). 23 refs, 6 figs, 13 tabs.

Organ doses from computerized tomography examinations

International Nuclear Information System (INIS)

Janeczek, J.

1995-01-01

Estimates of mean organs doses from five typical computerized tomography (CT) examinations were obtained. Measurements were done using Rando-Alderson anthropomorphic phantom and thermoluminescent dosemeters (TLD). Radiation dose distributions within a phantom has been measured for each examination and results were used for organ dose calculation. Doses to organs specified by ICPR 60 Recommendations were measured for five CT scanners (CT/T8800, CT 9800, CT MAX - made by General Electric; CT 1200 SX - made by Picker; SOMATOM 2 - made by Siemens). Dose distributions from scattered radiation were measured and indicate that scattered radiation dose to thyroid and eye lens can be reduced by proper examination limits setting. The lowest mean organ doses were obtained from CT/T8800 scanner. More advanced scanners using high intensity continuous radiation were giving higher organ doses. (author). 23 refs, 6 figs, 13 tabs

Computerized tomography and conventional radiography: A comparison from the standpoint of X-ray physics and technology

Energy Technology Data Exchange (ETDEWEB)

Pfeiler, M; Linke, G [Siemens A.G., Erlangen (Germany, F.R.). Unternehmensbereich Medizinische Technik

1979-08-01

After a short explantation of the technical foundations of computerized tomography (CT) from terms used in conventional X-ray technique and CT the differences (dose distribution, image character) and similarities (quantum noise, beam quality) of both methods are discussed. Finally possible methods of quantitative evaluation of CT images and computation of longitudinal layers from a series of computerized tomograms are described. (author).

Findings of psychopathology and computerized tomography in neuropsychiatric diseases

International Nuclear Information System (INIS)

Gross, G.; Huber, G.; Schuettler, R.

1982-01-01

1978-1980 we examined 451 patients of the Psychiatric University Clinic of Bonn by computerized tomography. From 260 patients with characterized diseases of the brain and brain damages 78 patients had neuropsychiatric diseases of old age, i.e. cerebro-vascular processes (average age of 63.7 years) and 9 patients had primary degenerative processes of the brain (average age of 62.1 years). Patients with diseases of the cerebral vessels showed irreversible psychopathological syndromes in 87%. The rate of pathological findings in CT increases in relation to degree of severity of the chronic (irreversible) organic psychosyndromes from 76% in pseudoneurasthenics syndromes to 93% in patients with organic changes of personality and to 100% in patients with dementia. The ambiguity of the conception of the multi-infarct-dementia is discussed. Only 19% of the sample with irreversible psychopathological changes showed localized neurological deficits and infarctions in CT, but none of them more than one. In all patients with dementia a cortical atrophy was found. There is a significant positive correlation between cerebral atrophy in CT and irreversible organic psychosyndrome. These findings with computerized tomography demonstrate in accordance with earlier pneumoencephalographic findings that distinct types of irreversible psychosyndromes can be correlated to distinct types of cerebral atrophy. But these statistical correlations between the degree of the severity of the loss of psychic functions and the reduction of cerebral tissue are not necessarily valid for any single case. (orig.) [de

Accurately Diagnosing Uric Acid Stones from Conventional Computerized Tomography Imaging: Development and Preliminary Assessment of a Pixel Mapping Software.

Science.gov (United States)

Ganesan, Vishnu; De, Shubha; Shkumat, Nicholas; Marchini, Giovanni; Monga, Manoj

2018-02-01

Preoperative determination of uric acid stones from computerized tomography imaging would be of tremendous clinical use. We sought to design a software algorithm that could apply data from noncontrast computerized tomography to predict the presence of uric acid stones. Patients with pure uric acid and calcium oxalate stones were identified from our stone registry. Only stones greater than 4 mm which were clearly traceable from initial computerized tomography to final composition were included in analysis. A semiautomated computer algorithm was used to process image data. Average and maximum HU, eccentricity (deviation from a circle) and kurtosis (peakedness vs flatness) were automatically generated. These parameters were examined in several mathematical models to predict the presence of uric acid stones. A total of 100 patients, of whom 52 had calcium oxalate and 48 had uric acid stones, were included in the final analysis. Uric acid stones were significantly larger (12.2 vs 9.0 mm, p = 0.03) but calcium oxalate stones had higher mean attenuation (457 vs 315 HU, p = 0.001) and maximum attenuation (918 vs 553 HU, p uric acid stones. A combination of stone size, attenuation intensity and attenuation pattern from conventional computerized tomography can distinguish uric acid stones from calcium oxalate stones with high sensitivity and specificity. Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Contribution of computerized tomography to diagnosis of primary hyperaldosteronism

International Nuclear Information System (INIS)

Hrabaneova, J.; Stribrna, J.; Bultasova, H.; Karasova, L.; Placer, Z.; Pinsker, P.

1987-01-01

Two cases are reported of computerized tomography (CT) examination for proof of suspect primary hyperaldosteronism caused by adenoma of the adrenals. The findings were then confirmed surgically and histologically. CT was again found to be an invaluable tool for differential diagnosis of this condition, which spared the patients demanding invasive examinations and clearly differentiated primary hyperaldosteronism from adrenal cortex hyperplasia. This is mainly important for the fact that adenoma or more rarely carcinoma causing primary hyperaldosteronism can surgically be removed. (L.O.). 2 figs., 2 tabs., 6 refs

Diagnostic perspectives of mobile x-ray computerized tomography

International Nuclear Information System (INIS)

Portnoj, L.M.; Dibirov, M.P.; Denisova, L.B.

1992-01-01

Mobile x-ray computerized tomography (CT) and an organization and methodological scheme of its application were assessed. CT is realized in special hospitals of large regions, where the patients with the optimal indications for CT are assembled. Over 15000 examinations were carried out with the use of the suggested CT program over 4 years, that resulted in detection of 1295 brain tumors, 804 cases with neoplastic involvement of the abdominal cavity and the retroperitoneal space. Wide application of mobile CT devices according to the program will help to decide the problem of unavailability of such examinations. One mobile device may replace 3 permanent CT devices

Contribution to differential diagnosis of lumbar spine disc hernia by computerized tomography

International Nuclear Information System (INIS)

Dolansky, J.

1989-01-01

The significance is discussed of computerized tomography in differential diagnosis of disc hernias of the lumbar spine. A simple technique is described that allows to differentiate disc hernias from epidural vein varices. It mostly includes repeat imaging of the same body section and/or the application of a contrast medium. (L.O.). 2 figs., 4 refs

Computerized detection of acute ischemic stroke in brain computed tomography images

International Nuclear Information System (INIS)

Nagashima, Hiroyuki; Shiraishi, Akihisa; Harakawa, Tetsumi; Shiraishi, Junji; Doi, Kunio; Sunaga, Shinichi

2009-01-01

The interpretation of acute ischemic stroke (AIS) in computed tomography (CT) images is a very difficult challenge for radiologists. To assist radiologists in CT image interpretation, we have developed a computerized method for the detection of AIS using 100 training cases and 60 testing cases. In our computerized method, the inclination of the isotropic brain CT volume data is corrected by rotation and shifting. The subtraction data for the contralateral volume is then derived by subtraction from the mirrored (right-left reversed) volume data. Initial candidates suspected to have experienced AIS were identified using multiple-thresholding and filtering techniques. Twenty-one image features of these candidates were extracted and applied to a rule-based test to identify final candidates for AIS. The detection sensitivity values for the training cases and for the testing cases were 95.0% with 3.1 false positives per case and 85.7% with 3.4 false positives per case, respectively. Our computerized method showed good performance in the detection of AIS by CT and is expected to be useful in decision-making by radiologists. (author)

Contrast Dose and Radiation Dose Reduction in Abdominal Enhanced Computerized Tomography Scans with Single-phase Dual-energy Spectral Computerized Tomography Mode for Children with Solid Tumors

OpenAIRE

Tong Yu; Jun Gao; Zhi-Min Liu; Qi-Feng Zhang; Yong Liu; Ling Jiang; Yun Peng

2017-01-01

Background: Contrast dose and radiation dose reduction in computerized tomography (CT) scan for adult has been explored successfully, but there have been few studies on the application of low-concentration contrast in pediatric abdominal CT examinations. This was a feasibility study on the use of dual-energy spectral imaging and adaptive statistical iterative reconstruction (ASiR) for the reduction of radiation dose and iodine contrast dose in pediatric abdominal CT patients with solid tumors...

Prediction of traumatic avascular necrosis of the femoral head by single photon emission computerized tomography and computerized tomography: an experimental study in dogs

Directory of Open Access Journals (Sweden)

SHEN Feng

2012-02-01

Full Text Available 【Abstract】 Objective: To evaluate the femoral head perfusion and to predict the traumatic avascular necrosis (AVN of the femoral head by single photon emission computerized tomography and computerized tomography (SPECT/CT. Methods: Totally 18 adult beagle dogs were divided randomly into three equal-sized (n=6 groups. Subsequently different degrees of ischemia model were developed by destroying blood vessels of the femoral head. The left hip received sham operation as normal control and the right hip underwent blood interruption. In Group A, the ligamentum teres was cut off. In Group B, the marrow cavity of the right femoral neck was destroyed while in Group C, the soft tissues at the base of the femoral neck were stripped in addition to the resection of the ligamentum teres and destruction of the marrow cavity. Three hours after surgery, SPECT/CT was performed. Laser Doppler Flowmetry (LDF measurements were also obtained at three different time points (before operation, immediately and three hours after operation in order to assess the change process of blood supply to the femoral head. Results: SPECT/CT showed no significant difference in the radionuclide uptake between the right and left femoral heads in Group A (t=-0.09, P=0.94 and Group B (t= 0.52, P=0.62. However, in Group C, it was 261±62 for the right femoral head, only 12% of that in the left femoral head. LDF measurements indicated that the femoral head perfusion was decreased from (45.0±3.3 PU to (39.1±3.7 PU in Group A, from (44.0±2.7 PU to (34.3±2.6 PU in Group B, and from (47.3±2.1 PU to (4.96±0.6 PU in Group C immediately after operation. However, the perfusion was restored and returned to normal values three hours after operation except in Group C. Conclusion: SPECT/CT could assess the perfusion of the femoral head semiquantitatively, which might be useful in predicting the development of traumatic AVN. Key words: Femur head necrosis; Femoral head; Tomography, emission

GEANT4 simulations for Proton computed tomography applications

International Nuclear Information System (INIS)

Yevseyeva, Olga; Assis, Joaquim T. de; Evseev, Ivan; Schelin, Hugo R.; Shtejer Diaz, Katherin; Lopes, Ricardo T.

2011-01-01

Proton radiation therapy is a highly precise form of cancer treatment. In existing proton treatment centers, dose calculations are performed based on X-ray computed tomography (CT). Alternatively, one could image the tumor directly with proton CT (pCT). Proton beams in medical applications deal with relatively thick targets like the human head or trunk. Thus, the fidelity of proton computed tomography (pCT) simulations as a tool for proton therapy planning depends in the general case on the accuracy of results obtained for the proton interaction with thick absorbers. GEANT4 simulations of proton energy spectra after passing thick absorbers do not agree well with existing experimental data, as showed previously. The spectra simulated for the Bethe-Bloch domain showed an unexpected sensitivity to the choice of low-energy electromagnetic models during the code execution. These observations were done with the GEANT4 version 8.2 during our simulations for pCT. This work describes in more details the simulations of the proton passage through gold absorbers with varied thickness. The simulations were done by modifying only the geometry in the Hadron therapy Example, and for all available choices of the Electromagnetic Physics Models. As the most probable reasons for these effects is some specific feature in the code or some specific implicit parameters in the GEANT4 manual, we continued our study with version 9.2 of the code. Some improvements in comparison with our previous results were obtained. The simulations were performed considering further applications for pCT development. The authors want to thank CNPq, CAPES and 'Fundacao Araucaria' for financial support of this work. (Author)

Can duplex Doppler ultrasound replace computerized tomography in staging patients with renal cell carcinoma?

NARCIS (Netherlands)

Bos, SD; Mensink, HJA

The purpose of this study was to evaluate the accuracy and reliability of duplex Doppler ultrasound (US) and computerized tomography (CT) in staging patients with renal cell carcinoma (RCC). Sixty-six patients were evaluated pre-operatively with duplex Doppler ultrasound and CT. The results were

Computerized tomography anatomy of the kidneys and retroperitoneal space

International Nuclear Information System (INIS)

Savchenko, A.P.; Mamaev, V.V.; Pkhakadze, Eh.G.

1989-01-01

The authors described the anatomy of the kidneys and retroperitoneal space in health on the basis of computerized tomography (CT) of 90 patients. Five typical levels in CT (ensuring all necessary data on roentgenomorphological trains of the kidneys and retroperitoneal space in the kidney area) were singled out. Some roentgenometric data on kidney cross-sections as well as the quantitative densitometric characterization of the parenchyma of the kidneys, renal sinus and adjacent tissues were presented. X-ray anatomy of the renal fiscia, pararenal space and perirenal fatty space of the kidney with different parts of the tetroperitoneal space was described

Evaluation of the absorbed dose in odontological computerized tomography; Avaliacao da dose absorvida em tomografia computadorizada odontologica

Energy Technology Data Exchange (ETDEWEB)

Legnani, Adriano; Schelin, Hugo R; Rocha, Anna Silvia P.S. da, E-mail: schelin@utfpr.edu.b, E-mail: anna@utfpr.edu.b [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Khoury, Helen J., E-mail: khoury@ufpe.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

2011-10-26

This paper evaluated the absorbed dose at the surface entry known as 'cone beam computed tomography' (CBCT) in odontological computerized tomography. Examination were simulated with CBCT for measurements of dose. A phantom were filled with water, becoming scatter object of radiation. Thermoluminescent dosemeters were positioned on points correspondent to eyes and salivary glands

Spontaneous intracerebral haematomas - the influence of computerized tomography on the results of surgery

International Nuclear Information System (INIS)

Kolodziejczyk, D.

1981-01-01

The report covers 30 patients of 10 to 74 years of age who has hard spontaneous intracerebral haematomas in the time from 1975 to 1980 and had been operated on after diagnosing by means of computerized tomography. The total mortality rate was 40% and was not significantly different from the total operative result obtained by other authors in the CT-period, but it compares poor to the pre-CT-aera. This deterioration despite improved diagnoses might be an effect of computerized tomography on the operating surgeon. Out of 18 survivors, 8 were completely healed. 4 patients kept some neurological symptoms, but could manage everyday life on their own. 6 patients kept serious neurological defects needing care. The influence of neurological-clinical parameters on the final operation result hasn't lost its importance in the CT-aera. The value of CT for the therapy of intracerebral haematomas lies in course control which often justifies a conservative proceeding with good absorption tendency taking into consideration the clinical-neurological picture, despite the persistence of growing and displacing processes. (orig./MG) [de

Evaluation of the absorbed dose in odontological computerized tomography; Avaliacao da dose absorvida em tomografia computadorizada odontologica

Energy Technology Data Exchange (ETDEWEB)

Legnani, Adriano; Schelin, Hugo R.; Rocha, Anna Silvia P.S. da, E-mail: schelin@utfpr.edu.b, E-mail: anna@utfpr.edu.b [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Khoury, Helen J., E-mail: khoury@ufpe.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

2011-10-26

This paper evaluated the absorbed dose at the surface entry known as 'cone beam computed tomography' (CBCT) in odontological computerized tomography. Examination were simulated with CBCT for measurements of dose. A phantom were filled with water, becoming scatter object of radiation. Thermoluminescent dosemeters were positioned on points correspondent to eyes and salivary glands

Computerized transverse tomography of vascular lesions of the brain. I. Arteriovenous malformations

International Nuclear Information System (INIS)

Pressman, B.D.; Kirkwood, J.R.; Davis, D.O.

1975-01-01

Computerized transverse tomography (CTT) of the brain is a recently developed method which allows non-invasive roentgenologic evaluation of intracranial disease. Since its inception, major attention has been given to the diagnosis and evaluation of tumors, clots, infarcts, venticular size, and orbital lesions. The purpose of this report is to discuss the application of CTT to the diagnosis and evaluation of intracerebral arteriovenous malformations. (U.S.)

The diagnostic value of cranial computerized tomography in exogenous psychoses and mental disorders associated with organic diseases

International Nuclear Information System (INIS)

Strobl, G.; Reisner, Th.; Zeiler, K.; Vienna Univ.

1980-01-01

205 patients hospitalized in a psychiatric department were subjected to cranial computerized tomography. The diagnosis on discharge according to the ICD key in each case was ''psychoses or mental disorders associated with physical conditions''. Pathological findings were obtained in 67.8% of the patients. In the case of space-occupying lesions the connection between psychiatric symptoms and syndromes and the underlying organic disease is obvious. Moreover, with inflammatory, vascular or traumatic diseases, a relationship to focal lesions found on the computer tomography appears likely if backed by appropriate neurological indications in the history or an clinical examinations. However, when alterations signifying diffuse brain atrophy are obtained on computer tomography any connections with psychiatric features should be very critically evaluated and, in individual cases, such connections had better not be looked for at all. Especially in cases of psychoses or mental disorders associated with physical conditions cranial computerized tomography is of high diagnostic value and the indications for its implementation in these cases should be judged very leniently. (author)

Normal anatomical measurements in cervical computerized tomography

International Nuclear Information System (INIS)

Zaunbauer, W.; Daepp, S.; Haertel, M.

1985-01-01

Radiodiagnostically relevant normal values and variations for measurements of the cervical region, the arithmetical average and the standard deviation were determined from adequate computer tomograms on 60 healthy women and men, aged 20 to 83 years. The sagittal diameter of the prevertebral soft tissue and the lumina of the upper respiratory tract were evaluated at exactly defined levels between the hyoid bone and the incisura jugularis sterni. - The thickness of the aryepiglottic folds, the maximal sagittal and transverse diameters of the thyroid gland and the calibre of the great cervical vessels were defined. - To assess information about laryngeal function in computerized tomography, measurements of distances between the cervical spine and anatomical fixed points of the larynx and hypopharynx were made as well as of the degree of vocal cord movement during normal respiration and phonation. (orig.) [de

Computerized industrial tomography

International Nuclear Information System (INIS)

Ashraf, M.M.

1999-01-01

Computerized Tomographic (CT) has been used for a number of applications in the field of medicine and industry. For the last couple of years, the technique has been applied for the material characterization and detection of defects and flaws inside the industrial components of nuclear, aerospace and missile industries. A CT scanner of first generation was developed at the institute. The scanner has been used to demonstrate couple of applications of CT in the field of non destructive testing of materials. The data acquired by placing the test objects at various angles and scanning the object through a source detector assembly has been processed on a Pentium computer for image reconstruction using a filtered back projection method. The technique has been developed which can be modified and improved to study various other applications in materials science and a modern computerized tomographic facility can be established. (author)

Dose evaluation in diagnostic for computerized tomography

International Nuclear Information System (INIS)

Flores, W.; Borges, J.C.; Mota, H.

1998-01-01

The patients which are subjected to computerized tomography tests are exposed to relatively high doses given as result doses on organs that are not matter to test. It was realized a dose levels raising in patients subjected to tests by T C, utilizing to measure this magnitude, TLD-100 thermoluminescent dosemeters which were put directly on the patient, in eye regions, thyroid, breast and navel; founding doses fluctuating between 29.10-49.39 mGy in organs examined and dose values between 0.21-29.10 mGy for organs that no matter to test. The applications of ionizing radiations in medicine do not have dose limits, but paying attention to the radiological protection optimization principle, it is recommended the use of clothes to anti-rays protection for zones not examined, getting with this to reduce the level doses as low as possible, without this to diminish the test quality. (Author)

Quality criteria for abdominal computerized tomography

International Nuclear Information System (INIS)

Huebener, K.H.; Kurtz, B.; Metzger, H.O.F.

1985-01-01

Quality, not only in obdominal computerized tomography, is determined by the measurable technical parameters and, to an important extent, also bei individual factors, among which the diagnostic skill and experience of the examiner is one of the most decisive. These individual factors and the part they play with regard to the quality of CT-assisted diagnosis may well equal the technical parameters, as they significantly influence the course of examinations, resulting indications for contrast medium application, and the sensitivity of the diagnosis. The authors are convinced that especially for abdominal CT, standardized examination techniques inevitably would bring down the diagnostic quality. The technical parameters are of equal significance to achieving the diagnostic optimum, and to these parameters one has to count equipment characteristics as well as the data given by the examiner. Exposure time, spatial resolution and density differentiation are given by the equipment specifications but have to be adapted to and optimised to the clinical problems involved in every case. Another important task is that of routine imaging of given anatomic structures, for adequate evaluation of individual conditions. (orig./MG) [de

Some aspects of evaluation of image quality in computerized tomography

International Nuclear Information System (INIS)

Travassos, Paulo Cesar Baptista; Peixoto, Jose Guilherme; Almeida, Carlos Eduardo Veloso de; Campos, Luciana Tourinho; Magalhaes, Luis Alexandre

2016-01-01

The evaluation of CT scanners image quality includes measuring the Hounsfield values, HU, using a table with the limit values. This table does not consider that different devices have different effective energies, which may cause some false results. The evaluation of 90 computerized tomography, by the American College Radiology methodology, showed that some failed devices in the evaluation showed excellent linear fit between the values of the linear attenuation coefficients calculated for the actual energy used, according to the HU values. The analysis of the coefficient of determination suggests that 10 of these devices could have been approved. (author)

Computerized tomography in the diagnosis of early and late complications after lung surgery

International Nuclear Information System (INIS)

Jeschke, W.; Linder, M.; Weiss, A.; Kihm, W.D.; Kempmann, G.

1980-01-01

The advantages of computerized tomography over conventional radiography for correctly interpreting doubtful findings after lung surgery are illustrated by 4 cases histories. In the immediate post-operative period the technique generally succeeds in identifying the nature of the abnormal findings and in differentiating between effusion, infiltration, abscess and empyema. Leakage from the bronchial stump can be clearly demonstrated without inconveniencing the patient. (orig.) [de

Cone beam computerized tomography of face. Technological assessment report

International Nuclear Information System (INIS)

Saint-Pierre, Francoise; Fanelli, Gaelle; Mosnegutu, Lavinia; Devaux, Frederique

2009-12-01

Cone beam computerized tomography is an imagery technique notably used for the maxillofacial complex or a complete or limited exploration of maxillo-mandibular and dento-alveolar structures. Typically, this technique is implemented with devices which are different from scanners in various respects (performance of several linear cuts, use of an open cone beam). Based on a literature survey, this document reports an assessment which aimed at determining technical and dosimetric performances of the device, potential benefits in terms of diagnosis and therapy with respect to existing imagery techniques, specifications and role of this technique in odonto-stomatology, maxillofacial surgery, and even in ENT, and operation conditions and training to perform this act

Computerized axial tomography in the detection of brain damage

International Nuclear Information System (INIS)

Cala, L.A.; Mastaglia, F.L.

1980-01-01

The cranial computerized axial tomography (CAT) findings in groups of patients with epilepsy, migraine, hypertension, and other general medical disorders have been reviewed to assess the frequency and patterns of focal and diffuse brain damage. In addition to demonstrating focal lesions in a proportion of patients with seizures and in patients presenting with a stroke, the CAT scan showed a premature degree of cerebral atrophy in an appreciable proportion of patients with long-standing epilepsy, hypertension and diabetes, and in some patients with migraine, valvular and ischaemic heart disease, chronic obstructive airways disease, and chronic renal failure. The value of CAT as a means of screening for brain damage in groups of individuals at risk is discussed

The application of computerized tomography in the diagnosis of renal diseases

International Nuclear Information System (INIS)

Rzymski, K.

1980-01-01

The purpose of the report is presentation of the experiences collected in the diagnosis of renal changes obtained by means of computerized tomography after application of this method in 800 examinations of the abdominal cavity. In 88 cases the examination was performed because of diagnosed or supposed renal disease. The examination was done using an EMI Medical CT 5005/2 whole-body scanner. In the group of 88 cases in 22 unilateral or bilateral hydronephros was diagnosed, in 16 cases single cysts were demonstrated in the kidneys, in 5 polycystic renal disease, in 9 malignant neoplasms and in 11 nephrosclerosis were found. Besides that, atrophic kidneys were recognized and patients were examined after nepherctomy carried out for neoplasm. The final diagnosis was based on surgical, autopsy, angiographic and clinical findings. Computerized tomography of the kidneys is important mainly as a method supplementing traditional methods of examination of the kidneys. The main indication to the use of this method as the first radiological examination of the kidneys is in search for the cause of morphological renal failure, so called ''dumb kidney'' in urography, and in search for retroperitoneal metastases and recurrences after operations of renal neoplasms. In all other circumstances it should be accepted as a rule to begin renal examination with plain-film taking and intravenous urography, which methods together with other classic radiological methods make possible recognition of the causes of renal diseases in most cases. (author)

The measurement of proton stopping power using proton-cone-beam computed tomography

International Nuclear Information System (INIS)

Zygmanski, P.; Rabin, M.S.Z.; Gall, K.P.; Rosenthal, S.J.

2000-01-01

A cone-beam computed tomography (CT) system utilizing a proton beam has been developed and tested. The cone beam is produced by scattering a 160 MeV proton beam with a modifier that results in a signal in the detector system, which decreases monotonically with depth in the medium. The detector system consists of a Gd 2 O 2 S:Tb intensifying screen viewed by a cooled CCD camera. The Feldkamp-Davis-Kress cone-beam reconstruction algorithm is applied to the projection data to obtain the CT voxel data representing proton stopping power. The system described is capable of reconstructing data over a 16x16x16cm 3 volume into 512x512x512 voxels. A spatial and contrast resolution phantom was scanned to determine the performance of the system. Spatial resolution is significantly degraded by multiple Coulomb scattering effects. Comparison of the reconstructed proton CT values with x-ray CT derived proton stopping powers shows that there may be some advantage to obtaining stopping powers directly with proton CT. The system described suggests a possible practical method of obtaining this measurement in vivo. (author)

Advanced proton imaging in computed tomography

CERN Document Server

Mattiazzo, S; Giubilato, P; Pantano, D; Pozzobon, N; Snoeys, W; Wyss, J

2015-01-01

In recent years the use of hadrons for cancer radiation treatment has grown in importance, and many facilities are currently operational or under construction worldwide. To fully exploit the therapeutic advantages offered by hadron therapy, precise body imaging for accurate beam delivery is decisive. Proton computed tomography (pCT) scanners, currently in their R&D phase, provide the ultimate 3D imaging for hadrons treatment guidance. A key component of a pCT scanner is the detector used to track the protons, which has great impact on the scanner performances and ultimately limits its maximum speed. In this article, a novel proton-tracking detector was presented that would have higher scanning speed, better spatial resolution and lower material budget with respect to present state-of-the-art detectors, leading to enhanced performances. This advancement in performances is achieved by employing the very latest development in monolithic active pixel detectors (to build high granularity, low material budget, ...

Intoxication for methyl alcohol: computerized tomography and finding in the necrosis

International Nuclear Information System (INIS)

Abaitua Ibanez, J.M.; Garcia Monco, J.C.; Gallardo Rebollan, S.; Hernando Aguado, G.; Alcaraz, R.; Lopez-Ruiz, J.A.

1994-01-01

We present a case of voluntary intake of methyl alcohol studied by means of computerized tomography (CT) in a previously healthy patient. The classical findings of bilateral putaminal necrosis are corroborated and cerebral white matter lesions are detected in frontal and occipital zones, signs that are unusual in this disorder. CT can be of diagnostic interest in certain comas of metabolic origin such as methanol intoxication, revealing antemortem lesions of both putamens and white matter. Finally, a correlation between the CT and necropsy findings is established. (Author) 11 refs

Computerized tomography in diagnosis of parasitic hepatic lesions

International Nuclear Information System (INIS)

Filimonov, G.P.; Garibashvili, R.N.; Tumol'skaya, N.I.

1984-01-01

An attempt has been made to estimate the diagnostic importance of computerized tomography (CT) in cases of hepatic echinococcosis and alveococcosis to outline the semiotics of these lesions and to establish an order of using CT in a general diagnostic complex. 73 patients at the age of 15-70 (49 with echinococcosis, 24-alveococcosis) have been supervised. The analysis of the results of clinical CT application in cases of parasitic hepatic lesions has shown that CT permits not only to reveal parasitic nodes up to 2 cm size in the liver and other organs but give also their topographoanatomic characteristic. By means of CT one can determine interrelations of parasitic formation with vessels and hepatic bileducts, vena cava inferior, other organs. One can judge at the same time on their compression and germination, remote echinococcosis residues, other complications

Density evaluation by computerized tomography in plain soils over different manipulation systems; Avaliacao da densidade pelo metodo da tomografia computadorizada de um planossolo sob diferentes sistemas de manejo

Energy Technology Data Exchange (ETDEWEB)

Pedrotti, Alceu [Lavras Univ., MG (Brazil). Dept. de Ciencia do Solo; Pauletto, Eloy Antonio [Pelotas Univ., RS (Brazil). Dept. de Solos; Crestana, Silvio [Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Sao Carlos, SP (Brazil). Centro Nacional de Pesquisa e Desenvolvimento de Instrumentacao Agropecuaria (CNPDIA)

1996-08-01

The objective of this paper is the evaluation of a plain soil density in different culture systems determined by X ray computerized tomography.It was observed a larger variation in densities in soils profiles analysed. The identification of layers is better utilising computerized tomography than others technic 1 fig.

Dose profile study on computerized tomography scanning of skull with simulator object

International Nuclear Information System (INIS)

Mourao, A.P.

2011-01-01

This work presents a comparison among the dose profiles in scanning of computerized tomography of a simulator object of PMMA in its periphery region. To obtain the deposited dose at the PMMA thermoluminescent dosemeters were used positioned at the interior of PMMA simulated object longitudinal to periphery and at the center of cylinder (positions denominated North, South, East, West and Center). Eight scanning were performed of simulator object using the routine protocol for skull in eight different services of radiodiagnostic by TC

Computerized tomography

International Nuclear Information System (INIS)

1980-01-01

Improvements in the design of computerized tomographic X-ray equipment are described which lead to improvements in the mechanical properties, speed and size of scanning areas. The method envisages the body being scanned as a two-dimensional matrix of elements arising from a plurality of concentric rings. The concentric centre need not coincide with the axis of rotation. The procedures for rotation of the X-ray beam and detectors around the patient and for translating the measured information into attenuation coefficients for each matrix element of the body are described in detail. Explicit derivations are given for the mathematical formulae used. (U.K.)

Contribution of computerized tomography to diagnosis of congenital toxoplasmosis

International Nuclear Information System (INIS)

Kouba, K.; Kalvach, P.; Nevarilova, A.; Stankova, M.

1986-01-01

Computerized tomography (CT) of the brain in 20 patients (age 6 to 20 years) with the ocular form of toxoplasmosis and various damage of the CNS revealed that in 8 patients intracranial calcifications were present while no calcifications were found on the X-ray of the skull. On the CT also other pathological findings were detected in the brain apart from calcifications. (Similarly as in 25% of the AIDS syndrome where affections of the CNS are not yet known.) Based on the authors'experience and data from abroad, CT examination of the brain can be recommended as very useful for the confirmation of the diagnosis of congenital toxoplasmosis also with regard to the prognosis of further psychomotoric development of the child. (author). 2 tabs., 7 refs

Motion Estimation and Compensation Strategies in Dynamic Computerized Tomography

Science.gov (United States)

Hahn, Bernadette N.

2017-12-01

A main challenge in computerized tomography consists in imaging moving objects. Temporal changes during the measuring process lead to inconsistent data sets, and applying standard reconstruction techniques causes motion artefacts which can severely impose a reliable diagnostics. Therefore, novel reconstruction techniques are required which compensate for the dynamic behavior. This article builds on recent results from a microlocal analysis of the dynamic setting, which enable us to formulate efficient analytic motion compensation algorithms for contour extraction. Since these methods require information about the dynamic behavior, we further introduce a motion estimation approach which determines parameters of affine and certain non-affine deformations directly from measured motion-corrupted Radon-data. Our methods are illustrated with numerical examples for both types of motion.

Regional aspects of cerebral cysticercosis. Incidence and evaluation by computerized tomography in 1000 consecutive studies

Energy Technology Data Exchange (ETDEWEB)

Jozzolino, D.A. (Instituto de Tomografia Axial Computadorizada de Londrina (Brazil))

One thousand consecutive studies of the entire brain were performed and 122 patients with tomographic diagnosis of cysticercosis were found. The high incidence of this disease is discussed and its endemic characteristics as well. Various forms and types are described, the most frequent being the presence of calcifications; other tests performed at the time of computerized tomography are mentioned.

Extension of the Gladstone-Dale equation for flame flow field diagnosis by optical computerized tomography

International Nuclear Information System (INIS)

Chen Yunyun; Li Zhenhua; Song Yang; He Anzhi

2009-01-01

An extended model of the original Gladstone-Dale (G-D) equation is proposed for optical computerized tomography (OCT) diagnosis of flame flow fields. For the purpose of verifying the newly established model, propane combustion is used as a practical example for experiment, and moire deflection tomography is introduced with the probe wavelength 808 nm. The results indicate that the temperature based on the extended model is more accurate than that based on the original G-D equation. In a word, the extended model can be suitable for all kinds of flame flow fields whatever the components, temperature, and ionization are.

Assessment of computerized tomography devices in Minas Gerais state, Brazil

International Nuclear Information System (INIS)

Oliveira, Paulo Marcio C.; Horta, Mara Alice Avelar Saraiva; Santana, Priscila do Carmo; Magalhaes, Marcos Juliano

2011-01-01

Computed Tomography (CT) is the diagnostic imaging method most commonly performed today. It is a device that is undergoing a technological evolution and their quality control is sorely needed. The image quality evaluation process allow a better diagnosis and control of the patient dose received during image acquisition. The CT doses are higher than other X-ray examination techniques, like a conventional X-ray. Performance evaluation of computed tomography in Minas Gerais is not significant. Therefore, this work aims to analyze 20 CT equipment in Minas Gerais, with parameters according to the national regulatory agency (ANVISA - Agencia Nacional de Vigilancia Sanitaria) in twelve quality control tests. Sixty five percent (65%) of CT equipment evaluated showed excellent results and were not disapproved in any of the tests performed and 30% had failed in only one of the twelve tests performed. The worst result was found in the CT scanners in the test that evaluates the low contrast resolution, where 20% of CT showed non-compliance, followed by the test that evaluates the x-rays collimation beam, where 15% had failed. The tests allowed us to observe that the twenty computerized tomography equipment achieved a great pass rate. Considering that the evaluated CTs performed the quality control tests for the first time, it is concluded that the equipment used in clinics and hospitals are of good quality image and low radiation doses. (author)

VARIABILITY OF MANUAL AND COMPUTERIZED METHODS FOR MEASURING CORONAL VERTEBRAL INCLINATION IN COMPUTED TOMOGRAPHY IMAGES

Directory of Open Access Journals (Sweden)

Tomaž Vrtovec

2015-06-01

Full Text Available Objective measurement of coronal vertebral inclination (CVI is of significant importance for evaluating spinal deformities in the coronal plane. The purpose of this study is to systematically analyze and compare manual and computerized measurements of CVI in cross-sectional and volumetric computed tomography (CT images. Three observers independently measured CVI in 14 CT images of normal and 14 CT images of scoliotic vertebrae by using six manual and two computerized measurements. Manual measurements were obtained in coronal cross-sections by manually identifying the vertebral body corners, which served to measure CVI according to the superior and inferior tangents, left and right tangents, and mid-endplate and mid-wall lines. Computerized measurements were obtained in two dimensions (2D and in three dimensions (3D by manually initializing an automated method in vertebral centroids and then searching for the planes of maximal symmetry of vertebral anatomical structures. The mid-endplate lines were the most reproducible and reliable manual measurements (intra- and inter-observer variability of 0.7° and 1.2° standard deviation, SD, respectively. The computerized measurements in 3D were more reproducible and reliable (intra- and inter-observer variability of 0.5° and 0.7° SD, respectively, but were most consistent with the mid-wall lines (2.0° SD and 1.4° mean absolute difference. The manual CVI measurements based on mid-endplate lines and the computerized CVI measurements in 3D resulted in the lowest intra-observer and inter-observer variability, however, computerized CVI measurements reduce observer interaction.

Analysis of risk in computerized tomography and other diagnostic radiology procedures

International Nuclear Information System (INIS)

Mossman, K.L.

1982-01-01

Medical practice entails continuous risks to the patient taken in good faith by the physician for the benefit of the patient. Risk of radiation induced cancer death approximates 10(-4) per cGy (rad). Assuming an average whole body dose of 0.1 cGy for many diagnostic X-ray procedures, the probability of radiation-induced cancer death is about 10(-5). The purpose of this paper is to compare the risks of common diagnostic X-ray procedures including computerized tomography (CT) with risks of smoking or automobile travel. Such comparisons should be constructive in putting radiation in perspective and facilitating explanation of risk/benefit to patients

Non-Conventional Applications of Computerized Tomography: Analysis of Solid Dosage Forms Produced by Pharmaceutical Industry

International Nuclear Information System (INIS)

Martins de Oliveira, Jose Jr.; Germano Martins, Antonio Cesar

2010-01-01

X-ray computed tomography (CT) refers to the cross-sectional imaging of an object measuring the transmitted radiation at different directions. In this work, we describe a non-conventional application of computerized tomography: visualization and improvements in the understanding of some internal structural features of solid dosage forms. A micro-CT X-ray scanner, with a minimum resolution of 30 μm was used to characterize some pharmaceutical tablets, granules, controlled-release osmotic tablet and liquid-filled soft-gelatin capsules. The analysis presented in this work are essentially qualitative, but quantitative parameters, such as porosity, density distribution, tablets dimensions, etc. could also be obtained using the related CT techniques.

A numerical solution of the equation of the computerized tomography and its application in astrophysics

International Nuclear Information System (INIS)

Krastev, A.; Nedialkov, J.

1983-01-01

A method for numerical solving the equation of the computerized tomography is proposed. The method, is based on the Cormack's formulae and is applied for studying media with central symmetry. The generalization for the nonsymmetric case does not lead to complications. The method is applied for the investigation of the density distribution of the Earth, the other planets and the Sun by means of neutrino experiments

Radiation protection in computerized tomography diagnostics; Strahlenschutz in der Computertomografie

Energy Technology Data Exchange (ETDEWEB)

Grust, Andreas [Radiologie am Hauptbahnhof, Duesseldorf (Germany)

2012-11-01

The essential advantage of computerized tomography (CT) compared to projecting radiographic techniques is the display of organs free of superposition using a 3D data set and additional enhanced contrast resolution. CT is a mostly objective and examination-independent technique that has developed towards an indispensable tool for tumor diagnostics and traumatology. With respect to the total amount of X-ray diagnostic examinations CT is a rather seldom used technique, nevertheless causing a disproportionately high amount of the collective effective dose of the German population. This disadvantage triggers the necessity to work on a radiation dose reduction. The author discusses the issues X-ray tube current reduction, layer thickness, pitch factor, scan length, dose modulation, adaptive collimation, and iterative reconstruction.

Importance of computerized tomography for surgical treatment of intracranial hematomas

International Nuclear Information System (INIS)

Diemath, H.E.

1982-01-01

The improved treatment by using computerized tomography (CT) located operating theater and intensive care unit is reported in comparison of 3,382 patients with severe head injuries. By preoperative use of CT the frequency of diagnosed hermatomas was about the same (29.5% before CT; 27.0% with CT) but the preoperative diagnosed multiple hematomas were much more frequent (14.0% resp. 27.0%). The most important advantage however is the saving of time by CT in this localisation by which the chance of survival has increased from 54% to 69%. Without any doubt everywhere in neurotraumatology the CT should be situated as near as possible to the intensive care unit and to the operating theater and should be available 24 hours a day. (Author) [de

Sparse-view proton computed tomography using modulated proton beams

Energy Technology Data Exchange (ETDEWEB)

Lee, Jiseoc; Kim, Changhwan; Cho, Seungryong, E-mail: scho@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejon 305-701 (Korea, Republic of); Min, Byungjun [Department of Radiation Oncology, Kangbuk Samsung Hospital, 110–746 (Korea, Republic of); Kwak, Jungwon [Department of Radiation Oncology, Asan Medical Center, 138–736 (Korea, Republic of); Park, Seyjoon; Lee, Se Byeong [Proton Therapy Center, National Cancer Center, 410–769 (Korea, Republic of); Park, Sungyong [Proton Therapy Center, McLaren Cancer Institute, Flint, Michigan 48532 (United States)

2015-02-15

Purpose: Proton imaging that uses a modulated proton beam and an intensity detector allows a relatively fast image acquisition compared to the imaging approach based on a trajectory tracking detector. In addition, it requires a relatively simple implementation in a conventional proton therapy equipment. The model of geometric straight ray assumed in conventional computed tomography (CT) image reconstruction is however challenged by multiple-Coulomb scattering and energy straggling in the proton imaging. Radiation dose to the patient is another important issue that has to be taken care of for practical applications. In this work, the authors have investigated iterative image reconstructions after a deconvolution of the sparsely view-sampled data to address these issues in proton CT. Methods: Proton projection images were acquired using the modulated proton beams and the EBT2 film as an intensity detector. Four electron-density cylinders representing normal soft tissues and bone were used as imaged object and scanned at 40 views that are equally separated over 360°. Digitized film images were converted to water-equivalent thickness by use of an empirically derived conversion curve. For improving the image quality, a deconvolution-based image deblurring with an empirically acquired point spread function was employed. They have implemented iterative image reconstruction algorithms such as adaptive steepest descent-projection onto convex sets (ASD-POCS), superiorization method–projection onto convex sets (SM-POCS), superiorization method–expectation maximization (SM-EM), and expectation maximization-total variation minimization (EM-TV). Performance of the four image reconstruction algorithms was analyzed and compared quantitatively via contrast-to-noise ratio (CNR) and root-mean-square-error (RMSE). Results: Objects of higher electron density have been reconstructed more accurately than those of lower density objects. The bone, for example, has been reconstructed

Detection of drugs and explosives using neutron computerized tomography and artificial intelligence techniques

Energy Technology Data Exchange (ETDEWEB)

Ferreira, F.J.O. [Instituto de Engenharia Nuclear, Cidade Universitaria, Rio de Janeiro, CEP 21945-970, Caixa Postal 68550 (Brazil)], E-mail: fferreira@ien.gov.br; Crispim, V.R.; Silva, A.X. [DNC/Poli, PEN COPPE CT, UFRJ Universidade Federal do Rio de Janeiro, CEP 21941-972, Caixa Postal 68509, Rio de Janeiro (Brazil)

2010-06-15

In this study the development of a methodology to detect illicit drugs and plastic explosives is described with the objective of being applied in the realm of public security. For this end, non-destructive assay with neutrons was used and the technique applied was the real time neutron radiography together with computerized tomography. The system is endowed with automatic responses based upon the application of an artificial intelligence technique. In previous tests using real samples, the system proved capable of identifying 97% of the inspected materials.

Detection of drugs and explosives using neutron computerized tomography and artificial intelligence techniques

International Nuclear Information System (INIS)

Ferreira, F.J.O.; Crispim, V.R.; Silva, A.X.

2010-01-01

In this study the development of a methodology to detect illicit drugs and plastic explosives is described with the objective of being applied in the realm of public security. For this end, non-destructive assay with neutrons was used and the technique applied was the real time neutron radiography together with computerized tomography. The system is endowed with automatic responses based upon the application of an artificial intelligence technique. In previous tests using real samples, the system proved capable of identifying 97% of the inspected materials.

Effect of quantization and interpolation of projections on the sensitivity of computerized tomography

International Nuclear Information System (INIS)

Vajnberg, Eh.I.; Fajngojz, M.L.

1984-01-01

The sources and forms of manifestation of errors in quantization and interpolation of projections in case of X-ray computerized tomography are considered and quantitative criteria of their evaluation are formulated. The dominating role of the interaction of two successive quantizations of projections - one-dimensional and two-dimensional ones is revealed. The necessity of joint optimization of the two-dimensional quantization range, expansion and form of interpolation function, quantized convolution nucleus is substantiated. The experimental results at aspect ratio of tomograms 256x256 and 480 projections are presented

Study on forefoot by computerized tomography

Energy Technology Data Exchange (ETDEWEB)

Machida, Eiichi (Nihon Univ., Tokyo. School of Medicine)

1983-10-01

Computerized tomography (CT) was used to study coronary sections of the forefoot in both normal and abnormal human feet. CT images of the transverse arches at the metatarsal head, middle and base of the shaft were classified into five patterns. In the pattern most commonly found in normal feet, the second metatarsus appeared elevated above the other metatarsal bones at all points, and there was a gradual and even reduction in elevation from the second to the fifth metatarsal. In cases of hallux valgus, however, a variety of deformities were noted in the arc of the second to fifth metatarsals, particularly at the head. The rotation of the first metatarsus and shift of the sesamoids were measured from CT images at the head of the first metatarsus. In hallux valgus, both the rotation and the sesamoid shift appeared to have a wider angle than in the case of normal feet. In normal feet, the differences between the rotation of the first metatarsus and shift of the sesamoids were relatively small, whereas in hallux valgus there was a much greater degree of variation. Furthermore, while normal feet the variation in rotation of the first metatarsus and sesamoid shift both tended to be either great or small, in hallux valgus a large degree of sesamoid shift was sometimes found in combination with a small degree of rotation of the first metatarsus.

Study on forefoot by computerized tomography

International Nuclear Information System (INIS)

Machida, Eiichi

1983-01-01

Computerized tomography (CT) was used to study coronary sections of the forefoot in both normal and abnormal human feet. CT images of the transverse arches at the metatarsal head, middle and base of the shaft were classified into five patterns. In the pattern most commonly found in normal feet, the second metatarsus appeared elevated above the other metatarsal bones at all points, and there was a gradual and even reduction in elevation from the second to the fifth metatarsal. In cases of hallux valgus, however, a variety of deformities were noted in the arc of the second to fifth metatarsals, particularly at the head. The rotation of the first metatarsus and shift of the sesamoids were measured from CT images at the head of the first metatarsus. In hallux valgus, both the rotation and the sesamoid shift appeared to have a wider angle than in the case of normal feet. In normal feet, the differences between the rotation of the first metatarsus and shift of the sesamoids were relatively small, whereas in hallux valgus there was a much greater degree of variation. Furthermore, while normal feet the variation in rotation of the first metatarsus and sesamoid shift both tended to be either great or small, in hallux valgus a large degree of sesamoid shift was sometimes found in combination with a small degree of rotatin of the first metatarsus. (author)

Computerized tomography magnified bone windows are superior to standard soft tissue windows for accurate measurement of stone size: an in vitro and clinical study.

Science.gov (United States)

Eisner, Brian H; Kambadakone, Avinash; Monga, Manoj; Anderson, James K; Thoreson, Andrew A; Lee, Hang; Dretler, Stephen P; Sahani, Dushyant V

2009-04-01

We determined the most accurate method of measuring urinary stones on computerized tomography. For the in vitro portion of the study 24 calculi, including 12 calcium oxalate monohydrate and 12 uric acid stones, that had been previously collected at our clinic were measured manually with hand calipers as the gold standard measurement. The calculi were then embedded into human kidney-sized potatoes and scanned using 64-slice multidetector computerized tomography. Computerized tomography measurements were performed at 4 window settings, including standard soft tissue windows (window width-320 and window length-50), standard bone windows (window width-1120 and window length-300), 5.13x magnified soft tissue windows and 5.13x magnified bone windows. Maximum stone dimensions were recorded. For the in vivo portion of the study 41 patients with distal ureteral stones who underwent noncontrast computerized tomography and subsequently spontaneously passed the stones were analyzed. All analyzed stones were 100% calcium oxalate monohydrate or mixed, calcium based stones. Stones were prospectively collected at the clinic and the largest diameter was measured with digital calipers as the gold standard. This was compared to computerized tomography measurements using 4.0x magnified soft tissue windows and 4.0x magnified bone windows. Statistical comparisons were performed using Pearson's correlation and paired t test. In the in vitro portion of the study the most accurate measurements were obtained using 5.13x magnified bone windows with a mean 0.13 mm difference from caliper measurement (p = 0.6). Measurements performed in the soft tissue window with and without magnification, and in the bone window without magnification were significantly different from hand caliper measurements (mean difference 1.2, 1.9 and 1.4 mm, p = 0.003, window settings with magnification. For uric acid calculi the measurement error was observed only in standard soft tissue window settings. In vivo 4.0x

Can carotid stenosis be operated without arteriography? Contribution of magnetic resonance and helical computerized tomography angiography

International Nuclear Information System (INIS)

Auffrau-Calvier, E.; Kersaint-Gilly, A. de; Desal, H.A.; Viarouge, M.P.; Havet, T.

1996-01-01

The aim of this work is to ascertain the role of the magnetic resonance angiography (MRA) and to compare it with the Doppler effect, the X-ray angiography and the new method of helical computerized tomography. Seventy one carotid bifurcations in 37 patients with suspected cerebral vascular events has been evaluated with the MRA and digitalized angiography, the reference method. The obtained data corroborate the good results proposed by other authors reporting in the literature and allow to propose this examination as a new means of investigating carotid bifurcations. Work with the helical computerized tomography appears to be promising too but there are few reported series. Therefore, there appears to be two interesting points: the reliability of distinguishing between very severe stenosis and occlusion, and the fine-tuned analysis of the plaque with detection of ulcerations. When a consistent approach is used to the evaluation of the carotid bifurcation, the Willis circle and the cerebral parenchyma, the MRA can complete the Doppler echo data and the preoperative arteriography can only be used in patients when the MRA and the Doppler echo results disagree. (authors)

Renal calyceal anatomy characterization with 3-dimensional in vivo computerized tomography imaging.

Science.gov (United States)

Miller, Joe; Durack, Jeremy C; Sorensen, Mathew D; Wang, James H; Stoller, Marshall L

2013-02-01

Calyceal selection for percutaneous renal access is critical for safe, effective performance of percutaneous nephrolithotomy. Available anatomical evidence is contradictory and incomplete. We present detailed renal calyceal anatomy obtained from in vivo 3-dimentional computerized tomography renderings. A total of 60 computerized tomography urograms were randomly selected. The renal collecting system was isolated and 3-dimensional renderings were constructed. The primary plane of each calyceal group of 100 kidneys was determined. A coronal maximum intensity projection was used for simulated percutaneous access. The most inferior calyx was designated calyx 1. Moving superiorly, the subsequent calyces were designated calyx 2 and, when present, calyx 3. The surface rendering was rotated to assess the primary plane of the calyceal group and the orientation of the select calyx. The primary plane of the upper pole calyceal group was mediolateral in 95% of kidneys and the primary plane of the lower pole calyceal group was anteroposterior in 95%. Calyx 2 was chosen in 90 of 97 simulations and it was appropriate in 92%. Calyx 3 was chosen in 7 simulations but it was appropriate in only 57%. Calyx 1 was not selected in any simulation and it was anteriorly oriented in 75% of kidneys. Appropriate lower pole calyceal access can be reliably accomplished with an understanding of the anatomical relationship between individual calyceal orientation and the primary plane of the calyceal group. Calyx 2 is most often appropriate for accessing the anteroposterior primary plane of the lower pole. Calyx 1 is most commonly oriented anterior. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Evaluation of the normal thoracic and abdominal aorta diameters by computerized tomography

International Nuclear Information System (INIS)

Lucarelli, Claudio Luiz

1995-01-01

The study was undertaken to evaluate, through computerized tomography, the diameters of the normal thoracic and abdominal aorta, as well as they are connected to gender, age and body surface area; and the ratio between measurements obtained at the ascending and descending limbs of the thoracic aorta, and between the abdominal aortic diameters. For that reason, we measured the widest anteroposterior diameters of the thoracic aortas at the levels of the arch, the root, the pulmonary artery, and the thoracic-abdominal transition, as well as the level of the emergence of the superior mesenteric artery, of the renal hila and just cephalad to the bifurcation of the abdominal aortas of 350 patients without cardiovascular diseases who had undergone computerized tomography of the thorax and/or abdomen for any other reasons. Observation and statistic analyses led us to conclude that: 1) both the thoracic and abdominal aortic diameters are reduced from their proximal to their distal portions; 2) the body surface influences the size of the aorta, although only extreme variations alter the vessel's caliber; 3) vessel diameter was observed to gradually increase with age; 4) men were found to have larger diameters than age matched women; 5) the ratio between the ascending and descending aortic diameters varies according to gender and age; 6) the relations between abdominal aortic diameters measured at the level of renal hila and cephalad to the bifurcation are independent from gender and age. But the relation between those measured at the level of the superior mesenteric artery and cephalad to the bifurcation are linked to gender, but not to age. (author)

Emission computerized axial tomography from multiple gamma-camera views using frequency filtering.

Science.gov (United States)

Pelletier, J L; Milan, C; Touzery, C; Coitoux, P; Gailliard, P; Budinger, T F

1980-01-01

Emission computerized axial tomography is achievable in any nuclear medicine department from multiple gamma camera views. Data are collected by rotating the patient in front of the camera. A simple fast algorithm is implemented, known as the convolution technique: first the projection data are Fourier transformed and then an original filter designed for optimizing resolution and noise suppression is applied; finally the inverse transform of the latter operation is back-projected. This program, which can also take into account the attenuation for single photon events, was executed with good results on phantoms and patients. We think that it can be easily implemented for specific diagnostic problems.

Computerized tomography of the lumbar vertebral column after intervertebral disk operation. Pt. 1

International Nuclear Information System (INIS)

Schindler, G.; Klott, K.

1984-01-01

Problems after intervertebral disk operations are to be expected in about 25-40% of the patients operated. Progressive degnerative alterations at the disks, the vertebrae and the intervertebral joints entail chronic mechanical pain resulting from the sensitive innervation of the structures mentioned, or lead in severe cases to the alteration of the epidural space respectively the spinal nerves with corresponding peripheral neurological symptoms. As post-surgical complications spondylodiscitis, spondylitis, haematomae, liquor fistulae, and split-off bone fragments can be the cause of complaints, for which computerized tomography is a better diagnostical method than myelography. (BWU) [de

Study of the human encephalon morphology by computerized axial tomography in neurological diseases

International Nuclear Information System (INIS)

Loynaz Fernandez, Clara Silvia; Milan Companioni, Daile; Gomez Padron, Ivo; Alvarez Leon, Oladys; Espinosa Quiros, Desiderio

2001-01-01

Since the middle of the last century, the study of the human encephalon morphology has been of great interest for the researchers. With the introduction of the computerized axial tomography in 1974, it was possible to expand the knowledge about this area and at the same time provide information on the structural lesions that are pathologies of great psychosocial repercussion like epilepsy and Parkinsonism. This paper used 90 tomographic studies on people aged 20-80 years. A series of linear measurements were made and statistically processed. The results showed variations in linear measurements among control, epileptic and Parkinsonian subjects

Use of computerized tomography in the Multibrauch Research and Technology Complex ''Eye microsurgery''

International Nuclear Information System (INIS)

Fedorov, S.N.; Ivashina, A.I.; Anisimov, S.I.; Prokopenko, L.N.; Moskvichev, A.L.

1989-01-01

The paper is devoted to analysis of the results of computerized tomography (CT) in 1000 patients examined in te Multibranch Research and Technology Complex ''Eye Microsurgery''. The specific feature of CT in this institution is that 52% of all investigations of ophthalmological patients fall to the share of eyeball abnormality and 40% - to a study of the other parts of the organ of vision. CT indications are extended for low tension glaucoma, complicated high myopia, and for monitoring the position of microsurgical implants. The use of CT is such a highly specialized medical institution as the MRTC ''Eye Microsurgery'' is considered indispensable

Review of medical radiography and tomography with proton beams

Science.gov (United States)

Johnson, Robert P.

2018-01-01

The use of hadron beams, especially proton beams, in cancer radiotherapy has expanded rapidly in the past two decades. To fully realize the advantages of hadron therapy over traditional x-ray and gamma-ray therapy requires accurate positioning of the Bragg peak throughout the tumor being treated. A half century ago, suggestions had already been made to use protons themselves to develop images of tumors and surrounding tissue, to be used for treatment planning. The recent global expansion of hadron therapy, coupled with modern advances in computation and particle detection, has led several collaborations around the world to develop prototype detector systems and associated reconstruction codes for proton computed tomography (pCT), as well as more simple proton radiography, with the ultimate intent to use such systems in clinical treatment planning and verification. Recent imaging results of phantoms in hospital proton beams are encouraging, but many technical and programmatic challenges remain to be overcome before pCT scanners will be introduced into clinics. This review introduces hadron therapy and the perceived advantages of pCT and proton radiography for treatment planning, reviews its historical development, and discusses the physics related to proton imaging, the associated experimental and computation issues, the technologies used to attack the problem, contemporary efforts in detector and computational development, and the current status and outlook.

Design and Construction of Detector and Data Acquisition Elements for Proton Computed Tomography

International Nuclear Information System (INIS)

Fermi Research Alliance; Northern Illinois University

2015-01-01

Proton computed tomography (pCT) offers an alternative to x-ray imaging with potential for three-dimensional imaging, reduced radiation exposure, and in-situ imaging. Northern Illinois University (NIU) is developing a second-generation proton computed tomography system with a goal of demonstrating the feasibility of three-dimensional imaging within clinically realistic imaging times. The second-generation pCT system is comprised of a tracking system, a calorimeter, data acquisition, a computing farm, and software algorithms. The proton beam encounters the upstream tracking detectors, the patient or phantom, the downstream tracking detectors, and a calorimeter. The schematic layout of the PCT system is shown. The data acquisition sends the proton scattering information to an offline computing farm. Major innovations of the second generation pCT project involve an increased data acquisition rate ( MHz range) and development of three-dimensional imaging algorithms. The Fermilab Particle Physics Division and Northern Illinois Center for Accelerator and Detector Development at Northern Illinois University worked together to design and construct the tracking detectors, calorimeter, readout electronics and detector mounting system.

Qualitative comparison of bremsstrahlung X-rays and 800 MeV protons for tomography of urania fuel pellets

Energy Technology Data Exchange (ETDEWEB)

Morris, C. L.; Bourke, M.; Byler, D. D.; Chen, C. F.; Hogan, G.; Hunter, J. F.; Kwiatkowski, K.; Mariam, F. G.; McClellan, K. J.; Merrill, F.; Morley, D. J.; Saunders, A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2013-02-15

We present an assessment of x-rays and proton tomography as tools for studying the time dependence of the development of damage in fuel rods. We also show data taken with existing facilities at Los Alamos National Laboratory that support this assessment. Data on surrogate fuel rods have been taken using the 800 MeV proton radiography (pRad) facility at the Los Alamos Neutron Science Center (LANSCE), and with a 450 keV bremsstrahlung X-ray tomography facility. The proton radiography pRad facility at LANSCE can provide good position resolution (<70 {mu}m has been demonstrate, 20 {mu}m seems feasible with minor changes) for tomography on activated fuel rods. Bremsstrahlung x-rays may be able to provide better than 100 {mu}m resolution but further development of sources, collimation, and detectors is necessary for x-rays to deal with the background radiation for tomography of activated fuel rods.

Qualitative comparison of bremsstrahlung X-rays and 800 MeV protons for tomography of urania fuel pellets

International Nuclear Information System (INIS)

Morris, C. L.; Bourke, M.; Byler, D. D.; Chen, C. F.; Hogan, G.; Hunter, J. F.; Kwiatkowski, K.; Mariam, F. G.; McClellan, K. J.; Merrill, F.; Morley, D. J.; Saunders, A.

2013-01-01

We present an assessment of x-rays and proton tomography as tools for studying the time dependence of the development of damage in fuel rods. We also show data taken with existing facilities at Los Alamos National Laboratory that support this assessment. Data on surrogate fuel rods have been taken using the 800 MeV proton radiography (pRad) facility at the Los Alamos Neutron Science Center (LANSCE), and with a 450 keV bremsstrahlung X-ray tomography facility. The proton radiography pRad facility at LANSCE can provide good position resolution (<70 μm has been demonstrate, 20 μm seems feasible with minor changes) for tomography on activated fuel rods. Bremsstrahlung x-rays may be able to provide better than 100 μm resolution but further development of sources, collimation, and detectors is necessary for x-rays to deal with the background radiation for tomography of activated fuel rods.

Diagnostic radiology for head and neck neoplasms with emphasis on computerized tomography

International Nuclear Information System (INIS)

Weber, A.L.; Manzione, J.V.

1986-01-01

The radiologic evaluation of head and neck neoplasms constitutes an important part in their diagnosis and treatment. The introduction of computerized tomography (CT) and the further development of this modality since 1972 have contributed significantly to the staging of these neoplasms. CT not only demonstrates soft tissue densities, but also bony structures, muscles, fascial planes, opacified vascular structures, and enlarged lymph nodes. CT, however, fails to differentiate the various histologic types of lesions in the majority of cases. Features such as size of the lesion, marginal definition, lytic bone destruction, sclerotic bony reaction, bony expansion, calcific densities, fat content, and obliteration of fascial planes are utilized to delimit the spectrum of diagnostic possibilities. Conventional films including tomography are also indicated as preliminary examinations in the investigation of head and neck neoplasms. They provide a survey of the abnormality in question and form the basis for special studies such as CT and angiography. They are often the first examination to demonstrate a lesion that may be suspected from the history and clinical examination. 13 refs.; 11 figs

Analysis of concrete material through gamma ray computerized tomography

International Nuclear Information System (INIS)

Oliveira Junior, J.M. de

2004-01-01

Computerized Tomography (CT) refers to the cross sectional imaging of an object from both transmission or reflection data collected by illuminating the object from many different directions. The most important contribution of CT is to greatly improve abilities to distinguish regions with different gamma ray transmittance and to separate over-lying structures. The mathematical problem of the CT imaging is that of estimating an image from its projections. These projections can represent, for example, the linear attenuation coefficient of γ-rays along the path of the ray. In this work we will present some new results obtained by using tomographic techniques to analyze column samples of concrete to check the distribution of various materials and structural problems. These concrete samples were made using different proportions of stone, sand and cement. Another set of samples with different proportions of sand and cement were also used to verify the outcome from the CT analysis and the differences between them. Those samples were prepared at the Material Laboratory of Faculdade de Engenharia de Sorocaba, following the same procedures used in real case of concrete tests. The projections used in this work was obtained by Mini Computerized Tomograph of Uniso (MTCU), located at the Experimental Nuclear Physics Laboratory at University of Sorocaba. This tomograph operates with a gamma ray source of 241 Am (photons of 60 keV and 100 mCi of intensity) and a NaI(Tl) solid state detector. The system features translation and rotation scanning modes, a 100 mm effective field of view, and 1 mm spatial resolution. The image reconstruction problem is solved using Discrete Filtered Backprojection (FBP). (author)

Computerized tomography of the brain and associated risk factors in 240 patients iwth reversible cerebral ischemic attacks (RIAs)

International Nuclear Information System (INIS)

Bozzao, L.; Fantozzi, L.M.; Carolei, A.; Pappata, S.; Vesentini, G.; Allori, L.; Rasura, M.; Fieschi, C.

1985-01-01

The frequency and distribution of focal low density cerebral ischemic lesions in RIA patients with regard to factors as age at onset, number and temporal profile of the reversible cerebral ischemic events on admission, presence of associated medical conditions such as hypertension and diabetes mellitus, have been investigated with computerized tomography of the brain. (author). 7 refs.; 1 tab

Effect of The Measuring Parameters on The Reconstructed Images by Computerized Tomography

International Nuclear Information System (INIS)

Ali, A.M.; Ali, A.M.; Megahid, R.M.

2011-01-01

In this paper, the potential of computerized tomography by neutrons and gamma rays as a main precise technique for nondestructive assay of materials and components of prime importance in nuclear and general industries are given and discussed. Both Fast Fourier Transform (FFT) and convolution techniques are introduced. Shepp and Logan human head phantom is used for theoretical testing and studying the effect of translation value for both techniques. Moreover, the effect of the projection number discussed. Comparison between the two reconstruction techniques wasper formed for the examined object. In addition, some of the experimentally scanned images using slit beam of gamma rays emitt ed from the ETRR- 1 reactor are presented and discussed.

Computerized tomography

International Nuclear Information System (INIS)

Caille, J.M.; Salamon, G.

1980-01-01

As X-ray Ct becomes more commonplace, other techniques of investigation using roughly comparable hardware and software have appeared. Positron-Emission Tomography already provides indispensable physiological and physio-pathological information. Similarly, in the histo-chemical field, Nuclear Magnetic Resonance seems very promising. Some of these new techniques will no doubt shortly be considered as essential as CT in establishing accurate diagnoses non-invasively. (orig./VJ) [de

Patient study of in vivo verification of beam delivery and range, using positron emission tomography and computed tomography imaging after proton therapy

NARCIS (Netherlands)

Parodi, Katia; Paganetti, Harald; Shih, Helen A; Michaud, Susan; Loeffler, Jay S; DeLaney, Thomas F; Liebsch, Norbert J; Munzenrider, John E; Fischman, Alan J; Knopf, Antje; Bortfeld, Thomas

2007-01-01

PURPOSE: To investigate the feasibility and value of positron emission tomography and computed tomography (PET/CT) for treatment verification after proton radiotherapy. METHODS AND MATERIALS: This study included 9 patients with tumors in the cranial base, spine, orbit, and eye. Total doses of 1.8-3

Testing objects in Computerized Axial Tomography. Contributions to the Spanish Protocol on quality control in radiodiagnostics

International Nuclear Information System (INIS)

Villaescusa, J.I.; Campayo, J.M.

1995-01-01

In the provisional version of the Spanish Protocol about the technical aspects of Quality Control in Radiodiagnostic,SEFM-SEPR 1993, it is dedicated a section to Computerized Axial tomography, establishing a total of eleven technical parameters of the equipment for examination. The present work describes the practical use of the Protocol using various types of Test Object. The authors also propose new tests that should be considered in the final version of the Spanish Protocol. (Author)

Positron emission tomography with Positome, 2

International Nuclear Information System (INIS)

Nukui, Hideaki; Yamamoto, Y.L.; Thompson, C.J.; Feindel, W.

1979-01-01

Positron emission tomography with Positome II using 68 Ga-EDTA was performed in cases with brain tumor and cerebral arteriovenous malformation. A significant focal uptake in static study and hemodynamic changes in dynamic study were noted in all cases except one case with intracranial lipoma. Comparing this method with sup(99m) Tc-pertechnetate cerebral image study and computerized axial tomography, the diagnostic rate for detecting brain tumor was almost equal in all of these three methods. However, detecting and localizing was easier and clearer in static positron emission tomography with 68 Ga-EDTA than in sup(99m) Tc-pertechnetate cerebral image and computerized axial tomography without infusion of contrast medium. Furthermore, static positron emission tomography with 68 Ga-EDTA was superior to computerized axial tomography without infusion of contrast medium for detecting cerebral arteriovenous malformation. Concerning dynamic positron emission tomography with 68 Ga-EDTA, semiquantitative values obtained by this method correlated well with findings of computerized axial tomography and was thought to be more precise and in detail than the findings of sup(99m) Tc-pertechnetate cerebral image study. Summation of the previous studies about dynamic positron emission tomography with 77 Kr in occlusive cerebrovascular disease is also reported. In conclusion, static positron emission tomography with 68 Ga-EDTA is a very useful diagnostic method for detecting and localizing brain tumor and cerebral arteriovenous malformation without any attendant complications. Furthermore, a good combination of static and dynamic positron emission tomography and computerized axial tomography appear to be outstandingly effective for not only detecting the lesion but also understanding the pathophysiological aspect in cases with various intracranial lesions. (author)

Application of fluence field modulation to proton computed tomography for proton therapy imaging.

Science.gov (United States)

Dedes, G; De Angelis, L; Rit, S; Hansen, D; Belka, C; Bashkirov, V; Johnson, R P; Coutrakon, G; Schubert, K E; Schulte, R W; Parodi, K; Landry, G

2017-07-12

This simulation study presents the application of fluence field modulated computed tomography, initially developed for x-ray CT, to proton computed tomography (pCT). By using pencil beam (PB) scanning, fluence modulated pCT (FMpCT) may achieve variable image quality in a pCT image and imaging dose reduction. Three virtual phantoms, a uniform cylinder and two patients, were studied using Monte Carlo simulations of an ideal list-mode pCT scanner. Regions of interest (ROI) were selected for high image quality and only PBs intercepting them preserved full fluence (FF). Image quality was investigated in terms of accuracy (mean) and noise (standard deviation) of the reconstructed proton relative stopping power compared to reference values. Dose calculation accuracy on FMpCT images was evaluated in terms of dose volume histograms (DVH), range difference (RD) for beam-eye-view (BEV) dose profiles and gamma evaluation. Pseudo FMpCT scans were created from broad beam experimental data acquired with a list-mode pCT prototype. FMpCT noise in ROIs was equivalent to FF images and accuracy better than  -1.3%(-0.7%) by using 1% of FF for the cylinder (patients). Integral imaging dose reduction of 37% and 56% was achieved for the two patients for that level of modulation. Corresponding DVHs from proton dose calculation on FMpCT images agreed to those from reference images and 96% of BEV profiles had RD below 2 mm, compared to only 1% for uniform 1% of FF. Gamma pass rates (2%, 2 mm) were 98% for FMpCT while for uniform 1% of FF they were as low as 59%. Applying FMpCT to preliminary experimental data showed that low noise levels and accuracy could be preserved in a ROI, down to 30% modulation. We have shown, using both virtual and experimental pCT scans, that FMpCT is potentially feasible and may allow a means of imaging dose reduction for a pCT scanner operating in PB scanning mode. This may be of particular importance to proton therapy given the low integral dose found

Computerized tomography in evaluation of decreased acetabular and femoral anteversion

International Nuclear Information System (INIS)

Toennis, D.; Skamel, H.J.

2003-01-01

Computerized tomography has received a new importance. It has been shown that decreased anteversion of femur and acetabulum, when both have decreased angles, are causing pain and osteoarthritis of the hip joint. Operative treatment should be performed before osteoarthritis develops. Exact measurements therefore are necessary. The investigation should be performed in prone position to have the pelvis lying in a defined and normal position. Femoral torsion is measured between the transverse axis of the knee and the femoral neck. The transverse axis for measurement of the femoral anteversion is defined by a rectangular line to the sagittal plane. For evaluation of the femoral anteversion in total the angle of the condyles has to be added to the femoral neck angle when the knee is found in internal rotation. Acetabular anteversion should be measured at the level where the femoral head is still in full contact and congruence with the anterior margin of the acetabulum. (orig.) [de

Computerized tomography using water to render the gastrointestinal tract opaque

International Nuclear Information System (INIS)

Gaa, J.; Deininger, H.K.; Georgi, M.

1993-01-01

An account is given of the technical procedure and results of computerized tomography in the examination of various gastrointestinal disorders using water as an oral and rectal contrast medium. The experience gained so far points to the fact that water as a contrast medium is mainly suitable in the preoperative staging of malignant gastric and colorectal tumours. The rectal injection of water further appears to be favourable in investigations for recidivation following deep anterior resection without impairment of the excretory functions. Our own results were contrary to the findings of other authors in that we had no difficulty in visualizing distal sections of the small intestine in patients suffering from Crohn's disease. The use of water as a contrast medium can, however, not be recommended in the presence of intra-abdominal abscesses, ascites or cystic tumours, as such changes cannot clearly be differentiated from intestinal loops filled with water. (orig./MG) [de

Analysis of the percentage voids of test and field specimens using computerized tomography

International Nuclear Information System (INIS)

Braz, D.; Lopes, R.T.; Motta, L.M.G. da

1999-01-01

Computerized tomography has been an excellent tool of analysis of asphaltics mixtures, because it allows comparison of the quality and integrity of test and field specimens. It was required to detect and follow the evolution of cracks, when these mixtures were submitted to fatigue tests, and also helping to interpret the distribution of tensions and deformations which occur in the several types of solicitations imposed to the mixtures. Comparing the medium values of percentage voids obtained from tomographic images with the project's values, it can be observed that the values of test and field specimens for the wearing course are closer to the ones of the project than the ones of the binder. It can be verified that the wearing course specimens always present a distribution of the aggregate, and voids quite homogeneously in the whole profile of the sample, while the binder specimens show an accentuated differentiation of the same factors in the several heights of the sample. Therefore, when choosing a slice for tomography, these considerations should be taken into account

Computerized tomography using high resolution X-ray imaging system with a microfocus source

International Nuclear Information System (INIS)

Zaprazny, Z.; Korytar, D.; Konopka, P.; Ac, V.; Bielecki, J.

2011-01-01

In recent years there is an effort to image an internal structure of an object by using not only conventional 2D X-ray radiography but also using high resolution 3D tomography which is based on reconstruction of multiple 2D projections at various angular positions of the object. We have previously reported [1] the development and basic parameters of a high resolution x-ray imaging system with a microfocus source. We report the recent progress using this high resolution X-ray laboratory system in this work. These first findings show that our system is particularly suitable for light weight and nonmetallic objects such as biological objects, plastics, wood, paper, etc. where phase contrast helps to increase the visibility of the finest structures of the object. Phase-contrast X-ray Computerized Tomography is of our special interest because it is an emerging imaging technique that can be implemented at third generation synchrotron radiation sources and also in laboratory conditions using a microfocus X-ray tube or beam conditioning optics. (authors)

Transformations and algorithms in a computerized brain atlas

International Nuclear Information System (INIS)

Thurfjell, L.; Bohm, C.; Eriksson, L.; Karolinska Institute/Hospital, Stockholm

1993-01-01

The computerized brain atlas constructed at the Karolinska Hospital, Stockholm, Sweden, has been further developed. This atlas was designed to be employed in different fields of neuro imaging such as positron emission tomography (PET), single photon emission tomography (SPECT), computerized tomography (CT) and magnetic resonance imaging (MR). The main objectives with the atlas is to aid the interpretation of functional images by introducing anatomical information, to serve as a tool in the merging of data from different imaging modalities and to facilitate the comparisons of data from different individuals by allowing for anatomical standardization of individual data. The purpose of this paper is to describe the algorithms and transformations used in the implementation of the atlas software

Value of the computerized axial tomography for early diagnosis of cranio cerebral trauma

International Nuclear Information System (INIS)

Rodriguez Cheong, Maricel; Dosouto Infante, Vivian; Rosales Fargie, Yamile

2010-01-01

A descriptive and cross-sectional study was conducted in 62 patients with cranio cerebral trauma admitted to 'Saturnino Lora' Provincial Teaching Hospital of Santiago de Cuba, from January 2005 to May 2006, in whom computerized axial tomography indicated at the emergency room was performed with the purpose of evaluating the effectiveness of this radiographic technique for early diagnosis of the injury. In the case material there was neither association between the source and imaging results, nor between the age and sex. The main clinical manifestations were vomiting, headache and motor deficit as well as frontal location, intraparenchymatous hematoma (the latter as the most common image finding) and the hyperdense area as tomographic pattern. The survival was of 91,9%

Study of Pelvicaliceal Anatomy by Helical Computerized Tomography

International Nuclear Information System (INIS)

Al-Qahtani, Fahd N.; Ali, Gaber A.; Kamal, Baher A.; Taha, Saud A.

2003-01-01

To evaluate the role of 3-dimensional images produced by computerized tomography (CT), using intravenous contrast, to study pelvicaliceal anatomy.This might be of help in endourological procedure. The study was conducted in the King Fahd Hospital of the University, King Faisal University. Dammam,Kingdom of Saudi Arabia. The study took place from July 2002 through to October 2002 .Helical CT was carried for patients who were investigated using excretory urography for any reason. A CT was carried out to the kidneys only within 10 minutes ( between 5 and 15 minute films of excretory urography).Images were reprocessed by 3-dimension construction after subtracting all structures except for the palvicaliceal system. Thity-six normal kidneys were studied. The upper pole was drained by a single caliceal infundibulum in all 36(100%) kidneys.the middle segement of the kidney was drained by 2 infundibula in 32 (89%) kidneys. Four (11%) kidneys have no middle caliceal infudibula. The lower pole was drained by 2 caliceal infundibula in 23 (64%) and a single infundibulum in 13 (36%) kidneys. The minor calices draining each renal segment were seen clearly. Three-dimensional images derived by helical CT are feasible for evaluating the anatomy of palvicaliceal system,and, can be of help in endourological procedures. (author)/

Computerized tomography and prognosis in paediatric head injury

International Nuclear Information System (INIS)

Tomberg, T.; Rink, U.; Pikkoja, E.; Tikk, A.

1996-01-01

The authors have analysed the computerized tomography (CT) findings and their correlation with the clinical state, early and late outcome in children and adolescents with head injuries (HI). This study represents clinical and CT data of 82 consecutive HI patients under 18 years of age. Among them 51 (62%) were boys and 31 (38 %) girls. The application of CT to the evaluation of the morphologic manifestations of HI in children has shown some differences in forms and mechanisms of injury and in outcome compared to adults. In the paediatric HI the most frequent finding was diffuse brain swelling with CT evidence of ventricular and cisternal compression or obliteration. Prognostically the most unfavourable findings were shearing injury, intracerebral and subdural haematomas combined with brain swelling and parenchymal damage. According to the Lidcombe impairment scale, outcome from severe paediatric HI was determined in the 3rd and 6th months, one year and 2 years after the injury. The outcome two years after severe HI varied to a great extent and was better in children than in adults. Although there was long-term disruption of the patient's quality of life, our data show that as there are no predictors of individual outcomes in child HI, no child should be excluded from early and long-term rehabilitation. (author)

Computerized axial tomography of the chest for visualization of ''absent'' pulmonary arteries

International Nuclear Information System (INIS)

Sondheimer, H.M.; Oliphant, M.; Schneider, B.; Kavey, R.E.W.; Blackman, M.S.; Parker, F.B. Jr.

1982-01-01

To expand the search for central pulmonary arteries in six patients with absence of cardiac-pulmonary continuity, computerized axial tomography (CAT) of the chest was performed. The CAT scans were compared with previous arteriograms and pulmonary vein wedge angiograms. Three patients with type IV truncus arteriosus were studied, and none had a central, right or left pulmonary artery on CAT scan. However, two patients with tetralogy of Fallot with pulmonary atresia and a patent ductus arteriosus to the right lung demonstrated the presence of a left pulmonary artery. In addition, one child with truncus arteriosus with ''absent'' left pulmonary artery demonstrated a left pulmonary artery on the CAT scan. The CAT scan may therefore enhance our ability to search for disconnected pulmonary arteries in children with complex cyanotic congenital heart disease

Computerized tomography. Fundamentals, equipment, image quality, applications. 2. rev. and enl. ed.

International Nuclear Information System (INIS)

Kalender, W.A.

2006-01-01

The book provides a clear and user-oriented outline of the theoretical and technical fundamentals of computerized tomography for a wide range of readers, from conventional CT to volume CT with conical beams. Image quality, its relevant influencing parameters and the performance factors to be observed for clinical application are discussed in detail, as are dose requirements, dose metering and dose reduction measures in CT. The second, revised edition contains updated information and also presents new technologies. A CD-ROM with attractive exemplary appications, animations and interactive exercises in image interpretation and manipulation is included. The book addresses everyone concerned with CT, either in their daily routine or even only every now and then, i.e. physicians, medical assistants, engineers, technicians and physicists. The book also contains a glossary of technical terms. (orig.)

Improved proton computed tomography by dual modality image reconstruction

Energy Technology Data Exchange (ETDEWEB)

Hansen, David C., E-mail: dch@ki.au.dk; Bassler, Niels [Experimental Clinical Oncology, Aarhus University, 8000 Aarhus C (Denmark); Petersen, Jørgen Breede Baltzer [Medical Physics, Aarhus University Hospital, 8000 Aarhus C (Denmark); Sørensen, Thomas Sangild [Computer Science, Aarhus University, 8000 Aarhus C, Denmark and Clinical Medicine, Aarhus University, 8200 Aarhus N (Denmark)

2014-03-15

Purpose: Proton computed tomography (CT) is a promising image modality for improving the stopping power estimates and dose calculations for particle therapy. However, the finite range of about 33 cm of water of most commercial proton therapy systems limits the sites that can be scanned from a full 360° rotation. In this paper the authors propose a method to overcome the problem using a dual modality reconstruction (DMR) combining the proton data with a cone-beam x-ray prior. Methods: A Catphan 600 phantom was scanned using a cone beam x-ray CT scanner. A digital replica of the phantom was created in the Monte Carlo code Geant4 and a 360° proton CT scan was simulated, storing the entrance and exit position and momentum vector of every proton. Proton CT images were reconstructed using a varying number of angles from the scan. The proton CT images were reconstructed using a constrained nonlinear conjugate gradient algorithm, minimizing total variation and the x-ray CT prior while remaining consistent with the proton projection data. The proton histories were reconstructed along curved cubic-spline paths. Results: The spatial resolution of the cone beam CT prior was retained for the fully sampled case and the 90° interval case, with the MTF = 0.5 (modulation transfer function) ranging from 5.22 to 5.65 linepairs/cm. In the 45° interval case, the MTF = 0.5 dropped to 3.91 linepairs/cm For the fully sampled DMR, the maximal root mean square (RMS) error was 0.006 in units of relative stopping power. For the limited angle cases the maximal RMS error was 0.18, an almost five-fold improvement over the cone beam CT estimate. Conclusions: Dual modality reconstruction yields the high spatial resolution of cone beam x-ray CT while maintaining the improved stopping power estimation of proton CT. In the case of limited angles, the use of prior image proton CT greatly improves the resolution and stopping power estimate, but does not fully achieve the quality of a 360�

Improved proton computed tomography by dual modality image reconstruction

International Nuclear Information System (INIS)

Hansen, David C.; Bassler, Niels; Petersen, Jørgen Breede Baltzer; Sørensen, Thomas Sangild

2014-01-01

Purpose: Proton computed tomography (CT) is a promising image modality for improving the stopping power estimates and dose calculations for particle therapy. However, the finite range of about 33 cm of water of most commercial proton therapy systems limits the sites that can be scanned from a full 360° rotation. In this paper the authors propose a method to overcome the problem using a dual modality reconstruction (DMR) combining the proton data with a cone-beam x-ray prior. Methods: A Catphan 600 phantom was scanned using a cone beam x-ray CT scanner. A digital replica of the phantom was created in the Monte Carlo code Geant4 and a 360° proton CT scan was simulated, storing the entrance and exit position and momentum vector of every proton. Proton CT images were reconstructed using a varying number of angles from the scan. The proton CT images were reconstructed using a constrained nonlinear conjugate gradient algorithm, minimizing total variation and the x-ray CT prior while remaining consistent with the proton projection data. The proton histories were reconstructed along curved cubic-spline paths. Results: The spatial resolution of the cone beam CT prior was retained for the fully sampled case and the 90° interval case, with the MTF = 0.5 (modulation transfer function) ranging from 5.22 to 5.65 linepairs/cm. In the 45° interval case, the MTF = 0.5 dropped to 3.91 linepairs/cm For the fully sampled DMR, the maximal root mean square (RMS) error was 0.006 in units of relative stopping power. For the limited angle cases the maximal RMS error was 0.18, an almost five-fold improvement over the cone beam CT estimate. Conclusions: Dual modality reconstruction yields the high spatial resolution of cone beam x-ray CT while maintaining the improved stopping power estimation of proton CT. In the case of limited angles, the use of prior image proton CT greatly improves the resolution and stopping power estimate, but does not fully achieve the quality of a 360�

Computerized tomography diagnosis of cartilage destruction in carcinoma of the larynx

International Nuclear Information System (INIS)

Kawashima, Osamu; Tomizawa, Yoshio; Yasuoka, Yoshihito; Kamei, Tamio

1991-01-01

In 20 cases of laryngeal carcinoma, the pre-operative computerized tomography (CT) films were correlated with the macroscopic appearance of specimens obtained at the time of surgery. A correct diagnosis of cartilage destruction was made by pre-operative CT in 75% of cases in which the thyroid cartilage was involved and in about 79% of those with either arytenoid or cricoid cartilage involvement. A comparison between the pathological findings and the pre-operative CT findings in 9 cases of laryngeal carcinoma with destruction of the thyroid cartilage revealed several pathological changes which may lead to an incorrect CT diagnosis. These changes include microscopic infiltration; destruction of cartilage at the anterior commisure; tumor advance to sites of ossification, especially infiltration into ossifying cartilage located between two areas of non-ossifying cartilage; and infiltration of the tumor within the cartilage with preservation of the perichondrium. (author)

Method of evaluation of diagnostics reference levels in computerized tomography; Metodo de avaliacao de niveis de referencia de radiodiagnostico em tomografia computadorizada

Energy Technology Data Exchange (ETDEWEB)

Vega, Walter Flores

1999-04-01

Computerized tomography is a complex technique with several selectable exposition parameters delivering high doses to the patient. In this work it was developed a simple methodology to evaluate diagnostic reference levels in computerized tomography, using the concept of Multiple Scan Average Dose (MSAD), recently adopted by the Health Ministry. For evaluation of the MSAD, a dose distribution was obtained through a measured dose profile on the axial axis of a water phantom with thermoluminescence dosemeters, TLD-100, for different exam technique. The MSAD was evaluated hrough two distinct methods. First, it was evaluated by the integration of the dose profile of a single slice and, second, obtained by the integration on central slice of the profile of several slices. The latter is in of accordance with the ionization chamber method, suggesting to be the most practical method of dose evaluation to be applied in the diagnostic reference level assessment routine for CT, using TLDs. (author)

Prognosis of the computerized tomography in the severe head injury. Valor pronostico de la tomografia axial computada (TC) en los traumatismos craneoencefalicos severos

Energy Technology Data Exchange (ETDEWEB)

Garcia-Nieto, J.J.; Lorenzo Dominguez, M.T.; Martin Sanchez, M.J.; Sanchez Gonzalez, E.

1991-01-01

A prospective study is made with sixty five people affected of severe head injury, that is to say, with eight or less points in the Glasgow Coma Scale (GCS), when they get to the hospital. They are studied by computerized tomography at admission, and three and seven days after arrival. In this way, we appraise the type of the lesion, its intensity and the possible prognosis, considering in the last case three features: a) ventricular collapse; b) the mean line structure s shift; and c) effects on perimesencephalic cistern. The findings were parametized and we were able to introduce into the computer program relationships between these findings and the end results. These last ones were appraised through the Glasgow Outcome Scale (GOS). We could show that certain findings in computerized tomography scans have an unavoidable prognosis while as others have a more favorable prognosis. (Author)

Study on beam geometry and image reconstruction algorithm in fast neutron computerized tomography at NECTAR facility

Science.gov (United States)

Guo, J.; Bücherl, T.; Zou, Y.; Guo, Z.

2011-09-01

Investigations on the fast neutron beam geometry for the NECTAR facility are presented. The results of MCNP simulations and experimental measurements of the beam distributions at NECTAR are compared. Boltzmann functions are used to describe the beam profile in the detection plane assuming the area source to be set up of large number of single neutron point sources. An iterative algebraic reconstruction algorithm is developed, realized and verified by both simulated and measured projection data. The feasibility for improved reconstruction in fast neutron computerized tomography at the NECTAR facility is demonstrated.

Study on beam geometry and image reconstruction algorithm in fast neutron computerized tomography at NECTAR facility

International Nuclear Information System (INIS)

Guo, J.; Buecherl, T.; Zou, Y.; Guo, Z.

2011-01-01

Investigations on the fast neutron beam geometry for the NECTAR facility are presented. The results of MCNP simulations and experimental measurements of the beam distributions at NECTAR are compared. Boltzmann functions are used to describe the beam profile in the detection plane assuming the area source to be set up of large number of single neutron point sources. An iterative algebraic reconstruction algorithm is developed, realized and verified by both simulated and measured projection data. The feasibility for improved reconstruction in fast neutron computerized tomography at the NECTAR facility is demonstrated.

Study on beam geometry and image reconstruction algorithm in fast neutron computerized tomography at NECTAR facility

Energy Technology Data Exchange (ETDEWEB)

Guo, J. [State Key Laboratory of Nuclear Physics and Technology and School of Physics, Peking University, 5 Yiheyuan Lu, Beijing 100871 (China); Lehrstuhl fuer Radiochemie, Technische Universitaet Muenchen, Garching 80748 (Germany); Buecherl, T. [Lehrstuhl fuer Radiochemie, Technische Universitaet Muenchen, Garching 80748 (Germany); Zou, Y., E-mail: zouyubin@pku.edu.cn [State Key Laboratory of Nuclear Physics and Technology and School of Physics, Peking University, 5 Yiheyuan Lu, Beijing 100871 (China); Guo, Z. [State Key Laboratory of Nuclear Physics and Technology and School of Physics, Peking University, 5 Yiheyuan Lu, Beijing 100871 (China)

2011-09-21

Investigations on the fast neutron beam geometry for the NECTAR facility are presented. The results of MCNP simulations and experimental measurements of the beam distributions at NECTAR are compared. Boltzmann functions are used to describe the beam profile in the detection plane assuming the area source to be set up of large number of single neutron point sources. An iterative algebraic reconstruction algorithm is developed, realized and verified by both simulated and measured projection data. The feasibility for improved reconstruction in fast neutron computerized tomography at the NECTAR facility is demonstrated.

Value of computerized tomography in the diagnosis of bone and musculoskeletal system tumors of the pelvis and extremities

International Nuclear Information System (INIS)

Langer, R.; Langer, M.

1983-01-01

49 cases of tumors of the musculoskeletal system of the pelvis and the extremities have been investigated by computerized tomography. The CT was performed only after conventional radiologic methods. The results are discussed and compared with those described in the literature. The advantages and disadvantages of CT of musculoskeletal disorders are discussed. We consider the CT to be of value in disorders of the musculoskeletal system, specially, if operative- or radiotherapy is planned. (orig.) [de

Clinical, endocrinological, and computerized tomography scans for symmetrical calcification of the basal ganglia

International Nuclear Information System (INIS)

Goldscheider, H.G.; Lischewski, R.; Claus, D.; Streibl, W.; Waiblinger, G.; Ulm Univ., Schwendi/Dietenbronn; Ulm Univ.

1980-01-01

Symmetrical calcification of the basal ganglia was found in 2 promille of 8000 computerized tomography (CT) scans. Of 19 cases, only 2 were detectable on conventional skull films. The less prominent calcifications were most often found in the region of the pallidum, the knee of the internal capsule. Also, the lesions were generally symmetrical. Thus these factors must be considered basic morphological characteristics of the pathophysiological process. Additional neurological disorders were present in 6 patients. Neurological symptoms in the remaining 13, when present, depended on the extent of the lesion. The most common finding was tremor, although disturbances of fine motor control, transient lateralizing signs, and seizures were also noted. No particular constellation of symptoms or signs permitted accurate clinical localization of the lesions. (orig./AJ) [de

Epiploic appendicitis and omental infarction. Findings in the ultrasonography and computerized tomography

International Nuclear Information System (INIS)

Migule, A.; Ripolles, T.; Martinez, M. J.; Morote, V.; Ruiz, A.

2001-01-01

Describe the findings in the ultrasonography and computerized tomography (CT) of the omental infarction and epiploic appendicitis. The clinical and radiological findings of the patients diagnosed in our hospital with epiploic appendicitis or omental infarctions between August 1994 and March 2001 were assessed retrospectively. We found a high incidence (42 cases) of these two diseases: 30 patients with diagnosis of epiploic appendicitis and 12 with the diagnosis of omental infarction. Four patients were treated surgically, while the remaining 38 were conservatively, without posterior complications. The ultrasonography and CT images is characteristics. making it possible to make a diagnosis of epiploic appendicitis or omental infarction with certainty. It is not necessary to make a differential diagnosis between the two entities because their prognosis and treatment are similar. Their incidence is much more frequent than that previously published. (Author) 19 refs

Computerized tomography of renal parenchymal disturbance following nephrolithotomy

International Nuclear Information System (INIS)

Fukuoka, Hiroshi; Ishizuka, Eiichi; Fukushima, Shuji.

1983-01-01

Staghorn calculi were removed by nephrolithotomy with the one-layer interrupted parenchymal suture method designed by Taguchi and renal parenchymal disturbance following the operation were evaluated by computerized tomography. Twenty kidneys in 17 cases were examined pre and postoperatively for changes in the incised and sutured part of the renal parenchyma. The postoperative CT scanning demonstrated the low density areas following enhancement and depression of the parenchyma. These changes were classified into the following 3 patterns: Type I-no changes were observed in the parenchyma, or a linear low density area was found (5 kidneys, 25.0%); type II-a long, narrow strip of low density area was found in accord with the excised and sutured part (5 kidneys, 25.0%); and type III-a wedge-shaped low density area or depression of the parenchyma was found (10 kidneys, 50.0%). The length of the parenchymal incision was analysed with reference to these patterns. The length of type I was significantly shorter than that of type II or III (p<0.05). Th e clamping time of the renal pedicle in type I was also shorter than that in type II and III, but the differences did not reach a statistically significant level. Type II pattern frequently was found shortly after the operation. It is, however, undeniable that type II may tramsform to type III. (J.P.N.)

Alterations found with computerized tomography in newly diagnosed type 2 diabetics

International Nuclear Information System (INIS)

Bruna, J.

1989-01-01

In 28 newly diagnosed type 2 diabetic patients (insulin-independent), computerized tomography (CT) was used to determine the density of the pancreas and the kidneys, densities of the liver, spleen and blood in the abdominal aorta, and to investigate pathological changes in the tissues mentioned above. The results were correlated with laboratory findings. The following changes were found: decreased density of the pancreas (29.4 H) and the liver (49.1 H) and increased density of the spleen (56.3 H) and blood in the abdominal aorta (43.7 H). The decreased density of the pancreas appears to be connected with disorders of lipoprotein metabolism. The decreased liver density was related to increased energy intake by food and to overweight evaluated by Broc's index. Other CT findings in the newly diagnosed type 2 diabetics (changes in the size of the pancreas, and kidneys, kidney cysts, nephrolithiasis, sclerotic plaques on aorta) were not significant. (author). 2 tabs., 11 refs

Characterization of filters and filtration process using X-ray computerized tomography

International Nuclear Information System (INIS)

Maschio, Celio; Arruda, Antonio Celso Fonseca de

1999-01-01

The objective of this work is to present the potential of X-Ray computerized tomography as a tool for internal characterization of filters used in the solid-liquid separation, mainly the water filters. Cartridge filters (for industrial and domestic applications) contaminated with glass beads were used. The scanning process was carried out both with and without contaminant in the filter to compare the attenuation coefficient of the clean filter and the contaminated filter. The images showed that is possible the mapping the internal structure of the filters and the distribution of the contaminant, permitting a local analysis, that is not possible through the standard tests used by the manufactures. These standard tests reveal only global characteristics of the filter media. The possibility of application for manufacturing process control was also shown, because the non invasive nature is a important advantage of the technique, which also permitted damage detection in filters submitted to severe operational conditions. (author)

Computerized tomography of pelvic osteomyelitis in patients with spinal cord injuries

International Nuclear Information System (INIS)

Firooznia, H.; Rafii, M.; Golimbu, C.; Sokolow, J.

1983-01-01

Computerized tomography (CT) was performed in 19 patients with spinal cord injury (SCI) who had large pressure sores and in whom other complications were suspected. CT detected the depth, extent, and degree of undermining of the edges of the pressure sores in 19 of 27 lesions. Conventional radiography detected four cases of pelvic osteomyelitis. CT detected eight additional cases of pelvic osteomyelitis, as well as eight clinically unsuspected peripelvic and intrapelvic abscesses. Technetium-99m bone scanning was not very helpful because of localization in chronic proliferative changes of bone and widespread foci of myositis ossificans, as well as in osteomyelitis. Gallium-67 scanning detected only one of six abscesses. It was not very helpful because of confusion of abscess and osteomyelitis with intense soft tissue swelling and cellulitis, which are often associated with pressure sores in patients with chronic SCI. CT was found to be, by far, the modality of choice for detection of pelvic osteomyelitis and abscess in patients with SCI

The use of computed tomography in brain damage testing

International Nuclear Information System (INIS)

De Villiers, J.F.K.

1980-01-01

The article deals with the diagnosis of brain damage by the use of computerized tomography - especially referring to the injuries of boxers. Three conditions may be evaluated with computerized tomography: i) fenestration of the septum pellucidum; ii) cortical atrophy; and, iii) cerebral atrophy. It also appears that computerized tomography has a place in the evaluation of injuries sustained in the ring, as well as the detection of accelerated ageing of the brain or atrophy

Tracker Readout ASIC for Proton Computed Tomography Data Acquisition.

Science.gov (United States)

Johnson, Robert P; Dewitt, Joel; Holcomb, Cole; Macafee, Scott; Sadrozinski, Hartmut F-W; Steinberg, David

2013-10-01

A unique CMOS chip has been designed to serve as the front-end of the tracking detector data acquisition system of a pre-clinical prototype scanner for proton computed tomography (pCT). The scanner is to be capable of measuring one to two million proton tracks per second, so the chip must be able to digitize the data and send it out rapidly while keeping the front-end amplifiers active at all times. One chip handles 64 consecutive channels, including logic for control, calibration, triggering, buffering, and zero suppression. It outputs a formatted cluster list for each trigger, and a set of field programmable gate arrays merges those lists from many chips to build the events to be sent to the data acquisition computer. The chip design has been fabricated, and subsequent tests have demonstrated that it meets all of its performance requirements, including excellent low-noise performance.

3D observation of the solidified structures by x-ray micro computerized tomography

International Nuclear Information System (INIS)

Yasuda, Hideyuki; Ohnaka, Itsuo; Tsuchiyama, Akira; Nakano, Tsukasa; Uesugi, Kentaro

2003-01-01

The high flux density of the monochromatized and well-collimated X-ray and the high-resolution detector provide a new 3D observation tool for microstructures of metallic alloys and ceramics. The X-ray micro computerized tomography in BL47XU of SPring-8 (SP-μCT) was applied to observe microstructures produced through the eutectic reaction for Sn-based alloys and an Al 2 O 3 -Y 2 O 3 oxide system. The constituent phases in the eutectic structures were three-dimensionally identified, in which the lamellar spacing ranged from several to 10 μm. Since the 3D structure of the unidirectionally solidified specimens contains history of the eutectic structure formation, the 3D structure obtained by SP-μCT gives useful information to consider the microstructure evolution. (author)

Evaluation of the soil-seed environment through computerized tomography

International Nuclear Information System (INIS)

Modolo, Alcir Jose; Fernandes, Haroldo Carlos; Schaefer, Carlos Ernesto G.R.; Santos, Nerilson Terra; Silveira, Joao Cleber Modernel da

2008-01-01

The physical conditioning of the soil around seeds is of great importance for an adequate initial development of a crop, ensuring a healthy plant population. A suitable soil-seed contact is a prerequisite for a fast crop germination and good establishment. In this study, computerized tomography of millimeter resolution was used to determine the soil-seed environment in a no tillage system, immediately after soybean planting. A split plot design was used, in which the plots consisted of three contents of soil water, corresponding to 0.27; 0,31 and 0.36 kg kg -1 , respectively, and the split plots of four load levels applied by the compaction wheel, corresponding to 0, 50, 90 and 140 N, respectively. It was used a random block design, with four replications. The medium soil density in the seed area and the medium density profile in the sowing furrow were evaluated. According to the results, it may be concluded that: the loads applied by the compaction wheel increased soil density at the vertical planting level beneath planting depth as compared with values obtained before planting, and; the combination of wheel loads and soil water contents did not influence the mean soil density in the seed area. (author)

Proton radiography to improve proton therapy treatment

NARCIS (Netherlands)

Takatsu, J.; van der Graaf, E. R.; van Goethem, Marc-Jan; van Beuzekom, M.; Klaver, T.; Visser, Jan; Brandenburg, S.; Biegun, A. K.

The quality of cancer treatment with protons critically depends on an accurate prediction of the proton stopping powers for the tissues traversed by the protons. Today, treatment planning in proton radiotherapy is based on stopping power calculations from densities of X-ray Computed Tomography (CT)

Micro-radiography and micro-computerized tomography with absorption and phase contrast for materials characterization; Mikro-Radiografie und Mikro-Computertomografie mit Absorptions- und Phasenkontrast fuer die Materialcharakterisierung

Energy Technology Data Exchange (ETDEWEB)

Kastner, Johann [FH Oberoesterreich, Wels (Austria)

2017-08-01

The contribution describes modern techniques in micro-radiography and micro-computerized tomography for materials characterization using absorption and phase contrast. Using micro- and nano-focus tubes and adequate high.-resolution detectors it is possible to reach resolutions significantly below 1 micron. The CT technology allows in-situ deformation testing to study the damaging mechanism of materials. The application of the Talbot-Lau interferometer with CT a differential phase contrast tomography is available. Dark-field tomography is used to study individual carbon fiber bundles in carbon fiber reinforced laminates.

Ultrasonic computerized tomography (CT) for temperature measurements with limited projection data based on extrapolated filtered back projection (FBP) method

International Nuclear Information System (INIS)

Zhu Ning; Jiang Yong; Kato, Seizo

2005-01-01

This study uses ultrasound in combination with tomography to obtain three-dimensional temperature measurements using projection data obtained from limited projection angle. The main feature of the new computerized tomography (CT) reconstruction algorithm is to employ extrapolation scheme to make up for the incomplete projection data, it is based on the conventional filtered back projection (FBP) method while on top of that taking into account the correlation between the projection data and Fourier transform-based extrapolation. Computer simulation is conducted to verify the above algorithm. An experimental 3D temperature distribution measurement is also carried out to validate the proposed algorithm. The simulation and experimental results demonstrate that the extrapolated FBP CT algorithm is highly effective in dealing with projection data from limited projection angle

Proton Radiography to Improve Proton Radiotherapy : Simulation Study at Different Proton Beam Energies

NARCIS (Netherlands)

Biegun, Aleksandra; Takatsu, Jun; van Goethem, Marc-Jan; van der Graaf, Emiel; van Beuzekom, Martin; Visser, Jan; Brandenburg, Sijtze

To improve the quality of cancer treatment with protons, a translation of X-ray Computed Tomography (CT) images into a map of the proton stopping powers needs to be more accurate. Proton stopping powers determined from CT images have systematic uncertainties in the calculated proton range in a

Pathogenesis of traumatic intracerebral hematoma with a sequential study of computerized tomography

Energy Technology Data Exchange (ETDEWEB)

Ohmori, H; Miyazaki, S; Munekata, K; Fukushima, H [Hitachi General Hospital, Hitachi, Ibaraki (Japan); Shohji, A

1981-04-01

A sequential study with computerized tomography (CT scan) of two cases of traumatic intracerebral hematoma is reported. Case 1 was a 69-year-old man who had a head injury. The initial CT scan, taken 1 hour after his injury, showed a left temporal salt-and-pepper appearance, which proved to be a cerebral contusion. The CT scan 4.5 hours after his injury showed a left temporal high density area instead. An operation was performed, and a massive intracerebral hematoma was observed. Case 2 was a 61-year-old man who was also admitted because of a head injury. The initial CT scan, taken 1 hour after his injury, revealed several bifrontal intracerebral hemorrhagic spots in the low-density areas, suggesting contusion. A secondary CT scan (23 hours) demonstrated that the traumatic intracerebral hematoma had developed into a posttraumatic cerebral contusion. The operation disclosed a hematoma surrounded by contusion. These cases prove that traumatic intracerebral hematoma is often caused by cerebral contusion.

Measuring irradiated lung and heart area in breast tangential fields using a simulator-based computerized tomography device

International Nuclear Information System (INIS)

Mallik, Raj; Fowler, Allan; Hunt, Peter

1995-01-01

Purpose: To illustrate the use of a simulator based computerized tomography system (SIMCT) in the simulation and planning of tangential breast fields. Methods and Materials: Forty-five consecutive patients underwent treatment planning using a radiotherapy simulator with computerized tomography attachment. One to three scans were obtained for each patient, calculations were made on the central axis scan. Due to the wide aperture of this system all patients were able to be scanned in the desired treatment position with arm abducted 90 deg. . Using available software tools the area of lung and/or heart included within the tangential fields was calculated. The greatest perpendicular distance (GPD) from the chest wall to posterior field edge was also measured. Results: The mean GPD for the group was 25.40 mm with 71% of patients having GPDs of ≤ 30 mm. The mean area of irradiated lung was 1780 sq mm which represented 18.0% of the total ipsilateral lung area seen in the central axis. Seven of the patients with left sided tumors had an average 1314 sq mm heart irradiated in the central axis. This represented 11.9% of total heart area in these patients. Conclusion: Measurements of irradiated lung and heart area can be easily and accurately made using a SIMCT device. Such measurements may help identify those patients potentially at risk for lung or heart toxicity as a consequence of their treatment. A major advantage of this device is the ability to scan patients in the actual treatment position

Measuring irradiated lung and heart area in breast tangential fields using a simulator-based computerized tomography device

Energy Technology Data Exchange (ETDEWEB)

Mallik, Raj; Fowler, Allan; Hunt, Peter

1995-01-15

Purpose: To illustrate the use of a simulator based computerized tomography system (SIMCT) in the simulation and planning of tangential breast fields. Methods and Materials: Forty-five consecutive patients underwent treatment planning using a radiotherapy simulator with computerized tomography attachment. One to three scans were obtained for each patient, calculations were made on the central axis scan. Due to the wide aperture of this system all patients were able to be scanned in the desired treatment position with arm abducted 90 deg. . Using available software tools the area of lung and/or heart included within the tangential fields was calculated. The greatest perpendicular distance (GPD) from the chest wall to posterior field edge was also measured. Results: The mean GPD for the group was 25.40 mm with 71% of patients having GPDs of {<=} 30 mm. The mean area of irradiated lung was 1780 sq mm which represented 18.0% of the total ipsilateral lung area seen in the central axis. Seven of the patients with left sided tumors had an average 1314 sq mm heart irradiated in the central axis. This represented 11.9% of total heart area in these patients. Conclusion: Measurements of irradiated lung and heart area can be easily and accurately made using a SIMCT device. Such measurements may help identify those patients potentially at risk for lung or heart toxicity as a consequence of their treatment. A major advantage of this device is the ability to scan patients in the actual treatment position.

Comparative evaluations of the results of common X-ray examinations and computerized tomography in patients with exogenous allergic alveolitis

International Nuclear Information System (INIS)

Khomenko, A.G.; Dmitrieva, L.I.; Khikkel', Kh.G.; Myuller, S.

1989-01-01

A correlative study of the results of x-ray examination using routine methods and computerized tomography (CT) was conducted to specify the roentgenomorphological substrate of changes in patients with exogenous allergic alveolitis. The established complex of routine methods is informative enough to interpret the revealed changes. However, at early stages CT helps to specify semiotics and permits obtaining additional information, particularly on quantitative, i.e. densitometric changes. In diffuse and disseminated pulmonary lesions CT can be used as an additional method

X-ray exposure dose for the gonadal gland by the examination of computerized tomography and its protection

International Nuclear Information System (INIS)

Moriuchi, Iwao; Kaiya, Hisanori; Hirata, Toshifumi; Asada, Shuichi

1978-01-01

Computerized tomography (CT) is very useful for neuroradiological examination, and so it may possibly be used for screening tests. But x-ray exposure dose by a examination of CT is considerable, especially for the male gonadal gland. This study showed that the dose from a complete CT examination of 10 - 15 scans for a male gonadal gland was about 1,800 times more than a single plain neuroradiography. But by only a 0.07 mm lead equivalent protecter, the exposure dose resulting from CT for a gonadal gland could be reduced to 0.0 mrad. (auth.)

FEASIBILITY OF POSITRON EMISSION TOMOGRAPHY OF DOSE DISTRIBUTION IN PROTON BEAM CANCER THERAPY

International Nuclear Information System (INIS)

BEEBE-WANG, J.J.; DILMANIAN, F.A.; PEGGS, S.G.; SCHLYEER, D.J.; VASKA, P.

2002-01-01

Proton therapy is a treatment modality of increasing utility in clinical radiation oncology mostly because its dose distribution conforms more tightly to the target volume than x-ray radiation therapy. One important feature of proton therapy is that it produces a small amount of positron-emitting isotopes along the beam-path through the non-elastic nuclear interaction of protons with target nuclei such as 12 C, 14 N, and 16 O. These radioisotopes, mainly 11 C, 13 N and 15 O, allow imaging the therapy dose distribution using positron emission tomography (PET). The resulting PET images provide a powerful tool for quality assurance of the treatment, especially when treating inhomogeneous organs such as the lungs or the head-and-neck, where the calculation of the dose distribution for treatment planning is more difficult. This paper uses Monte Carlo simulations to predict the yield of positron emitters produced by a 250 MeV proton beam, and to simulate the productions of the image in a clinical PET scanner

Diffuse lung neoplasms. Correlation between high resolution computerized tomography and anatomopathology; Neoplasias pulmonares difusas: correlacao da tomografia computadorizada de alta resolucao com a anatomopatologia

Energy Technology Data Exchange (ETDEWEB)

Marchiori, Edson [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia; Irion, Klaus L. [Complexo Hospitalar Santa Casa de Porto Alegre, RS (Brazil). Servico de Radiologia do Pavilhao Pereira Filho; Souza Junior, Arthur Soares [Faculdade de Medicina de Sao Jose do Rio Preto, SP (Brazil)]. E-mail: edmarchiori@zipmail.com.br

2002-08-01

A short comparative evaluation study between high resolution computerized tomography and anatomopathologic findings is presented. The association of these two diagnostic techniques is discussed as a factor to enhance the accuracy of diffuse lung diseases, such as carcinomatous lymphangitis, Kaposi's Sarcoma, lymphomas, hematogenic metastases, bronchiole-alveolar carcinoma and leukemia. (MAC)

Geometrical efficiency in computerized tomography: generalized model

International Nuclear Information System (INIS)

Costa, P.R.; Robilotta, C.C.

1992-01-01

A simplified model for producing sensitivity and exposure profiles in computerized tomographic system was recently developed allowing the forecast of profiles behaviour in the rotation center of the system. The generalization of this model for some point of the image plane was described, and the geometrical efficiency could be evaluated. (C.G.C.)

Possible application of computerized tomography and ultrasonography in diagnosing hyperparathyroidism

International Nuclear Information System (INIS)

Sotornik, I.; Sobota, J.; Kocandrle, V.; Drab, K.; Klima, J.; Zastava, V.; Mrhova, O.

1985-01-01

Initial experience is reported with the application of computerized tomography (CT) in the diagnosis of enlarged parathyroid glands in 19 patients with chronic renal failure who developed renal osteopathy in the course of hemodialysis treatment; in one patient an adenoma of the parathyroid associated with primary hyperparathyroidism was revealed. In the group of patients CT revealed enlarged parathyroid glands 14 times including 7 patients subjected to surgery of the parathyroid where the CT finding was confirmed in all instances. In patients with CT confirmed enlargement of the parathyroid glands, significantly higher levels of the bone isoenzyme ALP (p<0.05), total ACP (p<0.01), OH-proline in the blood (p<0.01) and C-terminal PTH (p<0.01) were found along with an advanced X-ray finding of hyperparathyroidism, as compared with patients with negative CT result. CT examination is a valuable noninvasive method which, together with the mentioned biochemical and X-ray findings, contributes in a fundamental way to the decision on whether surgery of the parathyroid glands should be undertaken. It is believed that at present it is difficult to provide evidence of enlarged parathyroids by means of sonographic examinations and the method calls for further investigation. (author)

Fast simulation of Proton Induced X-Ray Emission Tomography using CUDA

Energy Technology Data Exchange (ETDEWEB)

Beasley, D.G., E-mail: dgbeasley@itn.pt; Marques, A.C.; Alves, L.C.; Silva, R.C. da

2013-07-01

A new 3D Proton Induced X-Ray Emission Tomography (PIXE-T) and Scanning Transmission Ion Microscopy Tomography (STIM-T) simulation software has been developed in Java and uses NVIDIA™ Common Unified Device Architecture (CUDA) to calculate the X-ray attenuation for large detector areas. A challenge with PIXE-T is to get sufficient counts while retaining a small beam spot size. Therefore a high geometric efficiency is required. However, as the detector solid angle increases the calculations required for accurate reconstruction of the data increase substantially. To overcome this limitation, the CUDA parallel computing platform was used which enables general purpose programming of NVIDIA graphics processing units (GPUs) to perform computations traditionally handled by the central processing unit (CPU). For simulation performance evaluation, the results of a CPU- and a CUDA-based simulation of a phantom are presented. Furthermore, a comparison with the simulation code in the PIXE-Tomography reconstruction software DISRA (A. Sakellariou, D.N. Jamieson, G.J.F. Legge, 2001) is also shown. Compared to a CPU implementation, the CUDA based simulation is approximately 30× faster.

Fast simulation of Proton Induced X-Ray Emission Tomography using CUDA

International Nuclear Information System (INIS)

Beasley, D.G.; Marques, A.C.; Alves, L.C.; Silva, R.C. da

2013-01-01

A new 3D Proton Induced X-Ray Emission Tomography (PIXE-T) and Scanning Transmission Ion Microscopy Tomography (STIM-T) simulation software has been developed in Java and uses NVIDIA™ Common Unified Device Architecture (CUDA) to calculate the X-ray attenuation for large detector areas. A challenge with PIXE-T is to get sufficient counts while retaining a small beam spot size. Therefore a high geometric efficiency is required. However, as the detector solid angle increases the calculations required for accurate reconstruction of the data increase substantially. To overcome this limitation, the CUDA parallel computing platform was used which enables general purpose programming of NVIDIA graphics processing units (GPUs) to perform computations traditionally handled by the central processing unit (CPU). For simulation performance evaluation, the results of a CPU- and a CUDA-based simulation of a phantom are presented. Furthermore, a comparison with the simulation code in the PIXE-Tomography reconstruction software DISRA (A. Sakellariou, D.N. Jamieson, G.J.F. Legge, 2001) is also shown. Compared to a CPU implementation, the CUDA based simulation is approximately 30× faster

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

Imagenological characterization by Computerized Axial Tomography of the primary intracranial tumors

International Nuclear Information System (INIS)

Sosa Rivera, Manuel; Quintas Santana, Maria

2009-01-01

A descriptive observational study to 56 patients with imagenological diagnosis of primary intracranial neoplasia attended in the service of imagenology of the Provincial Docent Hospital 'Dr. Antonio Luaces Iraola' was carried out from March 1st 2006 to February 1st 2008, with the aim of characterizing these injuries by Computerized Axial Tomography and establishing an evaluation with the histological diagnosis. A questionnaire with the following variables was applied: sex, presuntive age, clinic, topographical characteristics (location, size, tumoral density, changes with administration of the resistance, calcifications, effect of mass and evaluation of the imagenological diagnosis with the histological diagnosis. Masculine sex and the group of ages of 60 are more predominated. The more frequent clinical manifestations were migraine, convulsions, difficulty to walk and vertigo. The size of the injury that prevailed was of 5, 9 and 2, 1 cm with supratentorial location. The majority of primary intracranial neoplasms were hypodense, and enhancement of the injuries with the administration of the resistance was observed. The mass effect bears a close relation with the location and size of the injury. The imagenological diagnosis fitted in with the histological one, being the gliomas the more frequent histological type

Computerized tomography with X-rays: an instrument in the analysis physico-chemical between formations and drilling fluids interactions; Tomografia computadorizada com raios-X: uma ferramenta na analise das interacoes fisico-quimicas entre as formacoes rochosas e fluidos de perfuracao

Energy Technology Data Exchange (ETDEWEB)

Coelho, Marcus Vinicius Cavalcante

1999-12-31

In this study it is demonstrated the applicability of the Computerized Tomography technique with x-rays to evaluate the reactivity degree between various drilling fluids and argillaceous sediments (Shales and Sandstones). The research has been conducted in the Rock-Fluid Interaction Pressure Simulator (RFIPS), where the possible physico-chemical alterations can be observed through successive tomography images, which are obtained during the flow of the fluid through the samples. In addition, it was noticed the formation of mud cake in Berea Sandstones samples in the RFIPS, though the Computerized Tomography with X-rays, when utilizing drilling fluids weighted with the baryte. (author) 35 refs., 38 figs., 5 tabs.

Computerized tomography with X-rays: an instrument in the analysis physico-chemical between formations and drilling fluids interactions; Tomografia computadorizada com raios-X: uma ferramenta na analise das interacoes fisico-quimicas entre as formacoes rochosas e fluidos de perfuracao

Energy Technology Data Exchange (ETDEWEB)

Coelho, Marcus Vinicius Cavalcante

1998-12-31

In this study it is demonstrated the applicability of the Computerized Tomography technique with x-rays to evaluate the reactivity degree between various drilling fluids and argillaceous sediments (Shales and Sandstones). The research has been conducted in the Rock-Fluid Interaction Pressure Simulator (RFIPS), where the possible physico-chemical alterations can be observed through successive tomography images, which are obtained during the flow of the fluid through the samples. In addition, it was noticed the formation of mud cake in Berea Sandstones samples in the RFIPS, though the Computerized Tomography with X-rays, when utilizing drilling fluids weighted with the baryte. (author) 35 refs., 38 figs., 5 tabs.

Calculating the number of shock waves, expulsion time, and optimum stone parameters based on noncontrast computerized tomography characteristics.

Science.gov (United States)

Foda, Khaled; Abdeldaeim, Hussein; Youssif, Mohamed; Assem, Akram

2013-11-01

To define the parameters that accompanied a successful extracorporeal shock wave lithotripsy (ESWL), namely the number of shock waves (SWs), expulsion time (ET), mean stone density (MSD), and the skin-to-stone distance (SSD). A total of 368 patients diagnosed with renal calculi using noncontrast computerized tomography had their MSD, diameter, and SSD recorded. All patients were treated using a Siemens lithotripter. ESWL success meant a stone-free status or presence of residual fragments 934 HUs and SSD >99 mm. The required number of SWs and the expected ET can be anticipated. Copyright © 2013 Elsevier Inc. All rights reserved.

Using three-dimensional-computerized tomography as a diagnostic tool for temporo-mandibular joint ankylosis: a case report.

Science.gov (United States)

Kao, S Y; Chou, J; Lo, J; Yang, J; Chou, A P; Joe, C J; Chang, R C

1999-04-01

Roentgenographic examination has long been a useful diagnostic tool for temporo-mandibular joint (TMJ) disease. The methods include TMJ tomography, panoramic radiography and computerized tomography (CT) scan with or without injection of contrast media. Recently, three-dimensional CT (3D-CT), reconstructed from the two-dimensional image of a CT scan to simulate the soft tissue or bony structure of the real target, was proposed. In this report, a case of TMJ ankylosis due to traumatic injury is presented. 3D-CT was employed as one of the presurgical roentgenographic diagnostic tools. The conventional radiographic examination including panoramic radiography and tomography showed lesions in both sides of the mandible. CT scanning further suggested that the right-sided lesion was more severe than that on the left. With 3D-CT image reconstruction the size and extent of the lesions were clearly observable. The decision was made to proceed with an initial surgical approach on the right side. With condylectomy and condylar replacement using an autogenous costochondral graft on the right side, the range of mouth opening improved significantly. In this case report, 3D-CT demonstrates its advantages as a tool for the correct and precise diagnosis of TMJ ankylosis.

Image reconstruction in computerized tomography using the convolution method

International Nuclear Information System (INIS)

Oliveira Rebelo, A.M. de.

1984-03-01

In the present work an algoritin was derived, using the analytical convolution method (filtered back-projection) for two-dimensional or three-dimensional image reconstruction in computerized tomography applied to non-destructive testing and to the medical use. This mathematical model is based on the analytical Fourier transform method for image reconstruction. This model consists of a discontinuous system formed by an NxN array of cells (pixels). The attenuation in the object under study of a colimated gamma ray beam has been determined for various positions and incidence angles (projections) in terms of the interaction of the beam with the intercepted pixels. The contribution of each pixel to beam attenuation was determined using the weight function W ij which was used for simulated tests. Simulated tests using standard objects with attenuation coefficients in the range of 0,2 to 0,7 cm -1 were carried out using cell arrays of up to 25x25. One application was carried out in the medical area simulating image reconstruction of an arm phantom with attenuation coefficients in the range of 0,2 to 0,5 cm -1 using cell arrays of 41x41. The simulated results show that, in objects with a great number of interfaces and great variations of attenuation coefficients at these interfaces, a good reconstruction is obtained with the number of projections equal to the reconstruction matrix dimension. A good reconstruction is otherwise obtained with fewer projections. (author) [pt

Value of intravenous injection of contrast media for computerized tomography of the thorax

International Nuclear Information System (INIS)

Beyer-Enke, S.A.; Goerich, J.; Mueller, M.; Kaick, G. van; Tuengerthal, S.

1988-01-01

107 patients with thoracal or mediastinal growths underwent computerized tomography of the thorax both in normal condition and after receiving intravenous applications of non-ionic X-ray contrast media. The additional information obtained by use of contrast media was established in relation to the histological findings. The method led to enhanced demarcation of the tumor of the mediastinum or hilus in 40% of the patients. Tumor perfusion was helpful in 20% of the cases for differential diagnosis. Vessel infiltrations or abnormal conditions were found in about 30% of patients. 24% of the tests yielded no additional information. Analysing CT as compared to the histological examination of lymph nodes proved CT under normal conditions to be a sensitive method in 29% of cases if the hilus was the site of the tumor; contrast media raised this sensitivity to 43%. In the mediastinal area, sensitivity was 44% without and 56% with contrast media. (orig.) [de

Quantitative computerized tomography for staging and follow up of patients with prostatic cancer

International Nuclear Information System (INIS)

Golimbu, C.; Golimbu, M.; Firooznia, H.; Rafii, M.; Morales, P.

1987-01-01

Prostate carcinoma has propensity to metastasize to skeleton, most frequently affecting the lumbar spine. The isotope bone scan and serum prostatic acid phosphatase (PAP) have been considered most reliable in documenting cancer spread. However, the former has been shown to have low specificity, and the latter was found to be increased in patients with localized disease or normal in patients with proven metastases. In a previous study of a group of patients at risk of having metastatic bone involvement, albeit not revealed by standard methods, the authors demonstrated the ability of quantitative computerized tomography (QCT) to depict early stages of bone metastases (Golimbu et. al., 1986). They also demonstrated its usefulness in assessing the response to treatment. The authors extended their study to further evaluate the accuracy of QCT in comparison with Tc99m bone scan and serum PAP for early detection of bone metastases and for quantitation of metastatic bone lesions response to therapy

A study of root canal morphology of human primary incisors and molars using cone beam computerized tomography: An in vitro study

OpenAIRE

Vivek Gaurav; Nikhil Srivastava; Vivek Rana; Vivek Kumar Adlakha

2013-01-01

Background: Variations in morphology of root canals in primary teeth usually leads to complications during and after endodontic therapy. To improve the success in endodontics, a thorough knowledge of the root canal morphology is essential. Aim: The aim of this study was to assess the variation in number and morphology of the root canals of primary incisors and molars and to study the applicability of cone beam computerized tomography (CBCT) in assessing the same. Settings and Design: A total ...

Muscle area and muscle density of osteoarthritis of the knee joint studied by computerized tomography

International Nuclear Information System (INIS)

Suzuki, Nobuharu; Onosawa, Toshihiro; Shibata, Minoru; Yamashita, Izumi; Yoshimura, Shinichiro; Muraoka, Shunichi; Asano, Akira

1985-01-01

In order to investigate the etiology and pathology of osteoarthritis of the knee joints (OA), the areas and density of the muscle 10 cm above the knee were compared using computerized tomography (CT) in 26 knees from 19 normal persons, 30 knees from 17 patients with OA, and 14 knees from 7 patients with rheumatoid arthritis. The areas of the quadriceps musculi of thigh were remarkably decreased and the areas of the flexor musculi were comparatively maintained in the patients with OA. Muscle density was markedly lowered in the musculi semimembranosus and biceps femoris long head. Fatty tissues were seen in the whole area of the venter on CT in some of the patients with OA. These findings are considered to be of major importance when studying the etiology of OA. (Namekawa, K.)

Single photon emission computerized tomography

International Nuclear Information System (INIS)

Hooge, P. de.

1983-01-01

In this thesis two single-photon emission tomographic techniques are presented: (a) longitudinal tomography with a rotating slanting-hole collimator, and (b) transversal tomography with a rotating gamma camera. These methods overcome the disadvantages of conventional scintigraphy. Both detection systems and the image construction methods are explained and comparisons with conventional scintigraphy are drawn. One chapter is dedicated to the determination of system parameters like spatial resolution, contrast, detector uniformity, and size of the object, by phantom studies. In separate chapters the results are presented of detection of tumors and metastases in the liver and the liver hilus; skeletal diseases; various pathological aberrations of the brain; and myocardial perfusion. The possible use of these two ect's for other organs and body areas is discussed in the last chapter. (Auth.)

Bragg peak prediction from quantitative proton computed tomography using different path estimates

International Nuclear Information System (INIS)

Wang Dongxu; Mackie, T Rockwell; Tome, Wolfgang A

2011-01-01

This paper characterizes the performance of the straight-line path (SLP) and cubic spline path (CSP) as path estimates used in reconstruction of proton computed tomography (pCT). The GEANT4 Monte Carlo simulation toolkit is employed to simulate the imaging phantom and proton projections. SLP, CSP and the most-probable path (MPP) are constructed based on the entrance and exit information of each proton. The physical deviations of SLP, CSP and MPP from the real path are calculated. Using a conditional proton path probability map, the relative probability of SLP, CSP and MPP are calculated and compared. The depth dose and Bragg peak are predicted on the pCT images reconstructed using SLP, CSP, and MPP and compared with the simulation result. The root-mean-square physical deviations and the cumulative distribution of the physical deviations show that the performance of CSP is comparable to MPP while SLP is slightly inferior. About 90% of the SLP pixels and 99% of the CSP pixels lie in the 99% relative probability envelope of the MPP. Even at an imaging dose of ∼0.1 mGy the proton Bragg peak for a given incoming energy can be predicted on the pCT image reconstructed using SLP, CSP, or MPP with 1 mm accuracy. This study shows that SLP and CSP, like MPP, are adequate path estimates for pCT reconstruction, and therefore can be chosen as the path estimation method for pCT reconstruction, which can aid the treatment planning and range prediction of proton radiation therapy.

Bragg peak prediction from quantitative proton computed tomography using different path estimates

Energy Technology Data Exchange (ETDEWEB)

Wang Dongxu; Mackie, T Rockwell; Tome, Wolfgang A, E-mail: tome@humonc.wisc.edu [Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705 (United States)

2011-02-07

This paper characterizes the performance of the straight-line path (SLP) and cubic spline path (CSP) as path estimates used in reconstruction of proton computed tomography (pCT). The GEANT4 Monte Carlo simulation toolkit is employed to simulate the imaging phantom and proton projections. SLP, CSP and the most-probable path (MPP) are constructed based on the entrance and exit information of each proton. The physical deviations of SLP, CSP and MPP from the real path are calculated. Using a conditional proton path probability map, the relative probability of SLP, CSP and MPP are calculated and compared. The depth dose and Bragg peak are predicted on the pCT images reconstructed using SLP, CSP, and MPP and compared with the simulation result. The root-mean-square physical deviations and the cumulative distribution of the physical deviations show that the performance of CSP is comparable to MPP while SLP is slightly inferior. About 90% of the SLP pixels and 99% of the CSP pixels lie in the 99% relative probability envelope of the MPP. Even at an imaging dose of {approx}0.1 mGy the proton Bragg peak for a given incoming energy can be predicted on the pCT image reconstructed using SLP, CSP, or MPP with 1 mm accuracy. This study shows that SLP and CSP, like MPP, are adequate path estimates for pCT reconstruction, and therefore can be chosen as the path estimation method for pCT reconstruction, which can aid the treatment planning and range prediction of proton radiation therapy.

Bragg peak prediction from quantitative proton computed tomography using different path estimates

Science.gov (United States)

Wang, Dongxu; Mackie, T Rockwell

2015-01-01

This paper characterizes the performance of the straight-line path (SLP) and cubic spline path (CSP) as path estimates used in reconstruction of proton computed tomography (pCT). The GEANT4 Monte Carlo simulation toolkit is employed to simulate the imaging phantom and proton projections. SLP, CSP and the most-probable path (MPP) are constructed based on the entrance and exit information of each proton. The physical deviations of SLP, CSP and MPP from the real path are calculated. Using a conditional proton path probability map, the relative probability of SLP, CSP and MPP are calculated and compared. The depth dose and Bragg peak are predicted on the pCT images reconstructed using SLP, CSP, and MPP and compared with the simulation result. The root-mean-square physical deviations and the cumulative distribution of the physical deviations show that the performance of CSP is comparable to MPP while SLP is slightly inferior. About 90% of the SLP pixels and 99% of the CSP pixels lie in the 99% relative probability envelope of the MPP. Even at an imaging dose of ~0.1 mGy the proton Bragg peak for a given incoming energy can be predicted on the pCT image reconstructed using SLP, CSP, or MPP with 1 mm accuracy. This study shows that SLP and CSP, like MPP, are adequate path estimates for pCT reconstruction, and therefore can be chosen as the path estimation method for pCT reconstruction, which can aid the treatment planning and range prediction of proton radiation therapy. PMID:21212472

Novel Application of Micro-Computerized Tomography for Morphologic Characterization of the Murine Penis.

Science.gov (United States)

O'Neill, Marisol; Huang, Gene O; Lamb, Dolores J

2017-12-01

The murine penis model has enriched our understanding of anomalous penile development. The morphologic characterization of the murine penis using conventional serial sectioning methods is labor intensive and prone to errors. To develop a novel application of micro-computerized tomography (micro-CT) with iodine staining for rapid, non-destructive morphologic study of murine penis structure. Penises were dissected from 10 adult wild-type mice and imaged using micro-CT with iodine staining. Images were acquired at 5-μm spatial resolution on a Bruker SkyScan 1272 micro-CT system. After images were acquired, the specimens were washed of any remaining iodine and embedded in paraffin for conventional histologic examination. Histologic and micro-CT measurements for all specimens were made by 2 independent observers. Measurements of penile structures were made on virtual micro-CT sections and histologic slides. The Lin concordance correlation coefficient demonstrated almost perfect strength of agreement for interobserver variability for histologic section (0.9995, 95% CI = 0.9990-0.9997) and micro-CT section (0.9982, 95% CI = 0.9963-0.9991) measurements. Bland-Altman analysis for agreement between the 2 modalities of measurement demonstrated mean differences of -0.029, 0.022, and -0.068 mm for male urogenital mating protuberance, baculum, and penile glans length, respectively. There did not appear to be a bias for overestimation or underestimation of measured lengths and limits of agreement were narrow. The enhanced ability offered by micro-CT to phenotype the murine penis has the potential to improve translational studies examining the molecular pathways contributing to anomalous penile development. The present study describes the first reported use of micro-CT with iodine staining for imaging the murine penis. Producing repeated histologic sections of identical orientation was limited by inherent imperfections in mounting and tissue sectioning, but this was

Repeatability of Computerized Tomography-Based Anthropomorphic Measurements of Frailty in Patients With Pulmonary Fibrosis Undergoing Lung Transplantation.

Science.gov (United States)

McClellan, Taylor; Allen, Brian C; Kappus, Matthew; Bhatti, Lubna; Dafalla, Randa A; Snyder, Laurie D; Bashir, Mustafa R

To determine interreader and intrareader repeatability and correlations among measurements of computerized tomography-based anthropomorphic measurements in patients with pulmonary fibrosis undergoing lung transplantation. This was an institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study of 23 randomly selected subjects (19 male and 4 female; median age = 69 years; range: 66-77 years) with idiopathic pulmonary fibrosis undergoing pulmonary transplantation, who had also undergone preoperative thoracoabdominal computerized tomography. Five readers of varying imaging experience independently performed the following cross-sectional area measurements at the inferior endplate of the L3 vertebral body: right and left psoas muscles, right and left paraspinal muscles, total abdominal musculature, and visceral and subcutaneous fat. The following measurements were obtained at the inferior endplate of T6: right and left paraspinal muscles with and without including the trapezius muscles and subcutaneous fat. Three readers repeated all measurements to assess intrareader repeatability. Intrareader repeatability was nearly perfect (interclass correlation coefficients = 0.99, P < 0.001). Interreader agreement was excellent across all 5 readers (interclass correlation coefficients: 0.71-0.99, P < 0.001). Coefficients of variance between measures ranged from 3.2%-6.8% for abdominal measurements, but were higher for thoracic measurements, up to 23.9%. Correlation between total paraspinal and total psoas muscle area was strong (r 2 = 0.67, P < 0.001). Thoracic and abdominal musculature had a weaker correlation (r 2 = 0.35-0.38, P < 0.001). Measures of thoracic and abdominal muscle and fat area are highly repeatable in patients with pulmonary fibrosis undergoing lung transplantation. Measures of muscle area are strongly correlated among abdominal locations, but inversely correlated between abdominal and thoracic locations

Computerized tomography of the traumatic hematoma in the corpus callosum

International Nuclear Information System (INIS)

Ogura, Koichiro; Yamamoto, Isao; Hara, Makoto; Suzuki, Yoshio; Nakane, Toshichi; Watanabe, Masao.

1982-01-01

The value of the computerized tomography (CT) in the diagnosis of the intracerebral hematoma has been well documented. However, there is little report about the CT findings of the hematoma of the corpus callosum. This report presents two cases of the traumatic hematoma in the corpus callosum and is discussed about their CT findings. Two patients, 52 year-old male and 40 year-old male, respectively, are the cases of blunt mechanical head trauma which were accompanied neither by skull fracture nor by scalp injury. In all these cases, the findings that hematoma occupied from the genu to the body of the corpus callosum were verified by surgery and the axial CT revealed the following two similar findings. First; the hematoma in the genu of the corpus callosum was shown as a cresent-shaped high density mass. This finding seems to be due to the following anatomical structure, that is, the genu of the corpus callosum is located just in front of the anterior horn of the lateral ventricles in the shape of the convex towards posteriorly. Second; as the midportion of the body of the corpus callosum tends to be appeared narrow in width between both lateral ventricles, the hematoma which extended from the genu towards the body of the corpus callosum was shown as a dumbbell-shaped high density mass. (author)

Pathologic assessment of computerized tomography accuracy for the evaluation of the laryngeal cartilagineous framework in laryngopharyngeal carcinomas

International Nuclear Information System (INIS)

Sulfaro, S.; Volpe, R.; Carbone, A.; Barzan, L.; Comoretto, R.

1989-01-01

Syxty-six whole-organ sectioned laryngopharyngectomy specimens removed for cancer during a seven-year period were uniformly examined to determine the accuracy of preoperative high resolution computerized tomography (CT) for detection of cartilaginous involvement. Results achived indicate that CT has a high overall specificity (88.2%) but a low sensitivity (47.1%); high false negative rate (26.5%) and a fairly low false-positive rate (5.9%) are observed. Massive cartilage destruction was easily assessed by CT, whereas both small macroscopic and microscopic neoplastic foci of cartilaginous invasion were missed on CT scans. Moreover, false-positive cases were mainly due to proximity of the tumor to the cartilage. Clinical implications of these results are discussed

Computerized tomographic evaluation of aortic prosthetic graft complications

International Nuclear Information System (INIS)

Kay, D.; Kalmar, J.A.

1985-01-01

Computerized tomography has been found to be an accurate and sensitive method of diagnosing complications of synthetic aortic grafts. Complications in this series of four cases included aortoesophageal fistula, aortoduodenal fistula, pseudoaneurysm, and retroperitoneal hematoma. 6 references, 5 figures

A Monte Carlo simulation of the possible use of Positron Emission Tomography in proton radiotherapy

International Nuclear Information System (INIS)

Del Guerra, Alberto; Di Domenico, Giovanni; Gambaccini, Mauro; Marziani, Michele

1994-01-01

We have used the Monte Carlo technique to evaluate the applicability of Positron Emission Tomography to in vivo dosimetry for proton radiotherapy. A fair agreement has been found between Monte Carlo results and experimental data. The simulation shows that PET can be useful especially for in vivo Bragg's peak localization. ((orig.))

Computerized tomography findings of acute traumatic epidural hematoma

International Nuclear Information System (INIS)

Kobayashi, Shiro; Nakazawa, Shozo; Yokota, Hiroyuki; Yajima, Kouzo; Yano, Masami; Otsuka, Toshibumi

1984-01-01

During four year period from April, 1977 to March, 1981, 53 cases with acute traumatic epidural hematoma had been encountered out of 430 acute head injured patients examined by computerized tomography (CT) within 24 hours after incurring the trauma. Besides the initial CT, the authors performed contrast enhanced CT (41 cases) and serial CT scanning (31 cases). There were 49 cases of epidural hematoma existing in the supratentorial region, Two cases infratentorial region and 2 cases in the both regions. Two cases of vertex epidural hematoma had been encountered, one of them required vertical scan technique. In 22 (41%) of the 53 patients, the initial CT showed evidence of other cerebral lesions. The most frequent lesion was pneumocephalus (11 cases), 3 cases of them existed in the epidural hematoma. There were also intracerebral hematoma (6 cases), subdural hematoma (4 cases), cerebral contusion (2 cases), intraventricular hemorrhage (2 cases) and 2 cases of them demonstrated ''diffuse traumatic cerebral injury''. During contrast enhanced CT, 11 cases out of 41 cases indicated several enhancement pattern. There were total enhancement of epidural hematoma (2 cases), partial enhancement of hematoma (2 cases) and enhancement of internal margin of hematoma (2 cases). Serial CT scans was performed in 36 out of the 53 patients. Common findings on the serial CT scans were decreased density collection in the subdural space such as subdural effusions or chronic subdural hematomas (8 cases) and enlargement of small epidural hematomas (3 cases). After evacuation of epidural hematoma, there were some cases showing the so-called ''delayed traumatic intracerebral hematoma'' (4 cases), appearance of other epidural hematoma (1 case) and development of small cerebral infarction in the basal ganglia. There was one case indicating appearance of a new epidural hematoma contra lateral to the side of evacuation of subdural hematoma. (J.P.N.)

Efficacy of virtual computerized tomography laparoscopy for retroperitoneoscopic nephrectomy

International Nuclear Information System (INIS)

Shigeta, Masanobu; Kadonishi, Yuichi; Yasumoto, Hiroaki; Mita, Koji; Usui, Tsuguru; Marukawa, Kazushi

2004-01-01

Retroperitoneoscopic nephrectomy is less invasive than open nephrectomy, and is an alternative surgical procedure for renal tumors and upper urothelial tumors. We evaluated the efficacy of virtual computerized tomography laparoscopy (VCTL) as a navigator for retroperitoneoscopic nephrectomy to ascertain the correct anatomy of the renal hilum pre-operatively under the retroperitoneoscopic view. Seventy-three kidneys with localized renal tumors (n=44), upper urothelial tumors (n=23), or benign renal disease (n=6) underwent multidetector-row CT. VCTL was carried out by the volume-rendered technique. The findings were compared with those of real retroperitoneoscopy. After the operation, each operator scored 1 to 5 in evaluating the usefulness of virtual retroperitoneoscopy (score 5 indicated very useful). The percentages of renal arteries depicted by VCTL compared with those noted during real surgery were 93% for kidneys with renal tumors, 100% for upper urothelial tumors and 83% for benign renal disease. Two renal arteries of 2 kidneys were not detected by virtual imaging. These were about 1 mm in diameter and directly branched from the aorta, however retroperitoneoscopic nephrectomy was performed uneventfully. VCTL depicted all the renal veins. The anatomy of the renal hilum seen on VCTL and real retroperitoneoscopy was identical, without the minor angle deviation caused by drawing the kidney during the operation. The average score for the usefulness of VCTL was 4.1, ranging from 3 to 5. The accurate surgical anatomy of the renal hilum could be predicted in almost all patients pre-operatively. VCTL is an excellent navigator for retroperitoneoscopic nephrectomy. (author)

What does the psychiatrist expect as to computerized tomography

International Nuclear Information System (INIS)

Huber, G.

1980-01-01

The computerized tomography (CT) can be applied also in psychiatry as an instrument of basic research. The problem of normative data as visualized by CT-scanning is up to now not yet satisfactory solved. Faulty appreciations especially on the cebral cortex in the sense of false-positive findings with possible serious social consequences are frequently. For judging of brain cortex as to atrophy primarily more basically situated sulci in various slices are taken into consideration, while the sulci of upper slices near the vertex just as the representations of cisterns, the interhemispheric fissure and Pacchionian granulations should not to be evaluated. On a new revision of the subject cerebral atrophy and irreversible psychosyndrome it is necessary and useful to compare the results of CT-scanning with those of pneumoencephalographic studies. The favourable possibilities which the CT offers also for diagnostic and research in psychiatry are to be used by critical appreciation of already existing experiences. The indication fpr TC requires complete psychiatric-neurological investigation. The interpretation of findings and the attempts to correlate them with the clinical data must take place in close cooperation with the clinical psychiatry. The neuroradiological evidence of cerebral atrophy can give hints concerning the diagnosis and prognosis only in connection with all clinical data. Findings of cerebral atrophy, combined cortical and subcortical, exclusively subcortical of preferably on the 3rd ventricle are non-specific and not characteristic of a certain disease. There are only correlations between certain types of cerebral atrophy and certain types of irreversible psychopathological syndromes. (orig.) [de

Geometrical optimization of a particle tracking system for proton computed tomography

International Nuclear Information System (INIS)

Penfold, S.N.; Rosenfeld, A.B.; Schulte, R.W.; Sadrozinksi, H.-F.W.

2011-01-01

Proton computed tomography (pCT) is currently being developed as an imaging modality for improving the accuracy of treatment planning in proton therapy. A tracking telescope comprising eight planes of single-sided silicon strip detectors (SSDs) forms an integral part of our present pCT design. Due to the currently maximum available Si wafer size, the sensitive area of 9 cm × 18 cm of the pCT tracker requires each tracking plane to be composed of two individual SSDs, which creates potential reconstruction problems due to overlap or gaps of the sensitive SSD areas. Furthermore, the spacing of the tracking planes creates competing design requirements between compactness and spatial resolution. Two Monte Carlo simulations were performed to study the effect of tracking detector location on pCT image quality. It was found that a “shingled” detector design suppressed reconstruction artefacts and, for the spatial resolution of the current detector hardware, reconstructed spatial resolution was not improved with a tracking separation of greater than 8 cm.

Cardiac Computed Tomography (Multidetector CT, or MDCT)

Science.gov (United States)

... Disease Venous Thromboembolism Aortic Aneurysm More Cardiac Computed Tomography (Multidetector CT, or MDCT) Updated:Sep 19,2016 What is Computerized Tomography (CT)? CT is a noninvasive test that uses ...

Proton imaging apparatus for proton therapy application

International Nuclear Information System (INIS)

Sipala, V.; Lo Presti, D.; Brianzi, M.; Civinini, C.; Bruzzi, M.; Scaringella, M.; Talamonti, C.; Bucciolini, M.; Cirrone, G.A.P.; Cuttone, G.; Randazzo, N.; Stancampiano, C.; Tesi, M.

2011-01-01

Radiotherapy with protons, due to the physical properties of these particles, offers several advantages for cancer therapy as compared to the traditional radiotherapy and photons. In the clinical use of proton beams, a p CT (Proton Computer Tomography) apparatus can contribute to improve the accuracy of the patient positioning and dose distribution calculation. In this paper a p CT apparatus built by the Prima (Proton Imaging) Italian Collaboration will be presented and the preliminary results will be discussed.

On the pathogenesis of traumatic intracerebral hematoma with a sequential study of computerized tomography

International Nuclear Information System (INIS)

Ohmori, Hidetoshi; Miyazaki, Shinichiro; Munekata, Katsuharu; Fukushima, Hiromi; Shohji, Akira.

1981-01-01

A sequential study with computerized tomography (CT scan) of two cases of traumatic intracerebral hematoma is reported. Case 1 was a 69-year-old man who had a head injury. The initial CT scan, taken 1 hour after his injury, showed a left temporal salt-and-pepper appearance, which proved to be a cerebral contusion. The CT scan 4.5 hours after his injury showed a left temporal high density area instead. An operation was performed, and a massive intracerebral hematoma was observed. Case 2 was a 61-year-old man who was also admitted because of a head injury. The initial CT scan, taken 1 hour after his injury, revealed several bifrontal intracerebral hemorrhagic spots in the low-density areas, suggesting contusion. A secondary CT scan (23 hours) demonstrated that the traumatic intracerebral hematoma had developed into a posttraumatic cerebral contusion. The operation disclosed a hematoma surrounded by contusion. These cases prove that traumatic intracerebral hematoma is often caused by cerebral contusion. (author)

Value of computerized tomography in the diagnosis of primary and recurrent pituitary gland tumors

International Nuclear Information System (INIS)

Imhof, H.; Kuester, W.; Eslami-Nejad, S.

1979-01-01

The results of cranial computerized tomography (CCT) of 33 patients with questionable space-occupying lesions in the sella-region are compared with clinical, radiological and surgical reports. Five pituitary gland tumors could be detected for the first time. Four of them are verified by surgery. In eight cases recurrent pituitary glant tumors are suspected. Surprisingly these tumors could be found by surgery only in three cases, while in the remaining five cases only scar-tissue was demonstrable. The high accuracy of CCT in the detection of pituitary gland tumors and the possibility to save the patient expensive and high invasive examinations as well, makes CCT in the presence of corresponding clinical signs to a diagnostic 'must'. It is undecided whether in the cases with possible recurrent tumors, there are real recurrent tumors, which could not be detected by surgery, or only scar tissue. In the latter case scar tissue and recurrent pituitary gland tumors are very similar with CCT. (orig.) 891 MG/orig. 892 CKA [de

Computerized tomography and pulmonary diffusing capacity in highly trained athletes after performing a triathlon.

Science.gov (United States)

Caillaud, C; Serre-Cousiné, O; Anselme, F; Capdevilla, X; Préfaut, C

1995-10-01

We investigated the computerized tomographies (CTs) of the thorax and the pulmonary diffusing capacity for CO (DLCO) in eight male athletes before and after a triathlon. DLCO and alveolar volume (VA) were simultaneously measured during 9 s of breath holding. The transfer coefficient (KCO = DLCO/VA) was then calculated. CT scanning was performed during breath holding with the subjects in the supine position. Scanner analysis was done by 1) counting the linear and polygonal opacities (index of interstitial fluid accumulation) and 2) calculating the physical mean lung density and the mean slice mass. Results showed a significant reduction in DLCO (44.9 +/- 2.3 vs. 42.9 +/- 1.7 ml.min-1.mmHg-1; P triathlon and an increase in mean lung density (0.21 +/- 0.009 vs. 0.25 +/- 0.01 g/cm3; P long-distance race and showed a concomitant increase in CT lung density and in the number of opacities.

Computerized axial tomography of the chest for visualization of ''absent'' pulmonary arteries

Energy Technology Data Exchange (ETDEWEB)

Sondheimer, H.M. (Upstate Medical Center, Syracuse, NY); Oliphant, M.; Schneider, B.; Kavey, R.E.W.; Blackman, M.S.; Parker, F.B. Jr.

1982-05-01

To expand the search for central pulmonary arteries in six patients with absence of cardiac-pulmonary continuity, computerized axial tomography (CAT) of the chest was performed. The CAT scans were compared with previous arteriograms and pulmonary vein wedge angiograms. Three patients with type IV truncus arteriosus were studied, and none had a central, right or left pulmonary artery on CAT scan. However, two patients with tetralogy of Fallot with pulmonary atresia and a patent ductus arteriosus to the right lung demonstrated the presence of a left pulmonary artery. In addition, one child with truncus arteriosus with ''absent'' left pulmonary artery demonstrated a left pulmonary artery on the CAT scan. The CAT scan may therefore enhance our ability to search for disconnected pulmonary arteries in children with complex cyanotic congenital heart disease.

Indirect computerized tomography sign of chronic subdural hematoma demonstrated in the posterior fossa

Energy Technology Data Exchange (ETDEWEB)

Machi, Takao; Fukui, Masashi; Maeyama, Ryutaro; Takaki, Tosuke; Yoshiura, Shogo; Kamoi, Itsuma

1985-03-01

In cases of chronic subdural hematoma (CSH), brain computerized tomography (CT) scans frequently disclose a low density band in the posterior fossa (LDBP) between the lateral margin of the cerebellum and the adjacent petrous bone/tentorium cerebelli. Out of 121 cases of CSH, 56 (46%) showed the LDBP. The LDBP was mostly ipsilateral to the side of the CSH or bilateral. The frequency of the LDBP had no correlation with the severity of the cerebral midline shift or the thickness of the hematoma. As normal controls, CT scans of 257 cases in which no organic lesions were detected were used. Also 30 cases with dementing diseases, 2 cases with spinocerebellar degeneration and 428 cases of other neurological diseases such as head trauma other than CSH, brain tumor, cerebrovascular disease etc. were studied as disease controls. The incidence of the LDBP in both controls was significantly lower than in CSH. Therefore, the LDBP in cases of CSH was considered to be a significant associated finding of CT scans. The mechanism of the LDBP is discussed.

The Pattern of Significant Lesions Found in Computerized ...

African Journals Online (AJOL)

Introduction: Seizures are common reasons for neurologic consultations and investigations. In the absence of magnetic resonance imaging, computerized tomography scanning of the brain is a reliable and cheaper alternative. Little is known about the pattern of brain lesions in patients with recurrent seizures in Nigeria.

Dose evaluation in diagnostic for computerized tomography; Evaluacion de dosis en diagnostico por tomografia computarizada

Energy Technology Data Exchange (ETDEWEB)

Flores, W.; Borges, J.C.; Mota, H. [Universidad Federal de Rio de Janeiro, PEN/COPPE/UFRJ. Caixa Postal 68509. 21945-970 Rio de Janeiro (Brazil)

1998-12-31

The patients which are subjected to computerized tomography tests are exposed to relatively high doses given as result doses on organs that are not matter to test. It was realized a dose levels raising in patients subjected to tests by T C, utilizing to measure this magnitude, TLD-100 thermoluminescent dosemeters which were put directly on the patient, in eye regions, thyroid, breast and navel; founding doses fluctuating between 29.10-49.39 mGy in organs examined and dose values between 0.21-29.10 mGy for organs that no matter to test. The applications of ionizing radiations in medicine do not have dose limits, but paying attention to the radiological protection optimization principle, it is recommended the use of clothes to anti-rays protection for zones not examined, getting with this to reduce the level doses as low as possible, without this to diminish the test quality. (Author)

A simulation study on proton computed tomography (CT) stopping power accuracy using dual energy CT scans as benchmark

DEFF Research Database (Denmark)

Hansen, David Christoffer; Seco, Joao; Sørensen, Thomas Sangild

2015-01-01

Background. Accurate stopping power estimation is crucial for treatment planning in proton therapy, and the uncertainties in stopping power are currently the largest contributor to the employed dose margins. Dual energy x-ray computed tomography (CT) (clinically available) and proton CT (in...... development) have both been proposed as methods for obtaining patient stopping power maps. The purpose of this work was to assess the accuracy of proton CT using dual energy CT scans of phantoms to establish reference accuracy levels. Material and methods. A CT calibration phantom and an abdomen cross section...... phantom containing inserts were scanned with dual energy and single energy CT with a state-of-the-art dual energy CT scanner. Proton CT scans were simulated using Monte Carlo methods. The simulations followed the setup used in current prototype proton CT scanners and included realistic modeling...

Significance of cranial computerized tomography for diagnosis and therapy of inflammatory diseases of the brain and meninges in children

Energy Technology Data Exchange (ETDEWEB)

Kotlarek, F; Hauke, P; Zeumer, H [Technische Hochschule Aachen (Germany, F.R.). Abt. Kinderheilkunde; Technische Hochschule Aachen (Germany, F.R.). Abt. Neurologie)

1979-01-01

The significance of cranial computerized tomography (CCT) for the diagnosis and therapy of inflammatory diseases of the central nervous system in children is discussed in connection with five characteristic case studies. CCT is shown to be superior to classical neuroradiological approaches, and to allow important diagnostic insights: 1. the early recognition of diffuse brain edema and the resulting possibility of an early begin of therapy - 2. the pathological expansions of the cerebral ventricles of various etiology before a pathological enlargement of the head can be detected, and the size of the ventricles after neurosurgical therapy can be measured - 3. the early recognition of space-occupying inflammatory complications.

The Pattern of Significant Lesions Found in Computerized ...

African Journals Online (AJOL)

2017-12-05

Dec 5, 2017 ... Introduction: Seizures are common reasons for neurologic consultations and investigations. In the absence of magnetic resonance imaging, computerized tomography scanning of the brain is a reliable and cheaper alternative. Little is known about the pattern of brain lesions in patients with recurrent ...

From 2D to 3D: Proton Radiography and Proton CT in proton therapy: A simulation study

NARCIS (Netherlands)

Takatsu, J.; van der Graaf, E.R.; van Goethem, M.-J.; Brandenburg, S.; Biegun, Aleksandra

(1) Purpose In order to reduce the uncertainty in translation of the X-ray Computed Tomography (CT) image into a map of proton stopping powers (3-4% and even up to 10% in regions containing bones [1-8]), proton radiography is being studied as an alternative imaging technique in proton therapy. We

Interstitial lung illness: Discoveries in x-ray of the thorax vs computerized tomography of high resolution

International Nuclear Information System (INIS)

Patino O, Maria Olga; Gomez Ramirez, Rafael

1993-01-01

This study wants to prove the advantages of the computerized axial tomography (TAC) of high resolution on the conventional radiography and the follow-up of the patients with interstitial pulmonary disease (IPD). 29 patients were studied with conventional RX and TAC with 17. $ % of high resolution which had normal radiography with clear abnormalities in the TAC of high resolution, the type of interstitial pulmonary disease (IPD). In the 68,9% of the cases it showed abnormality as well in TAC as in conventional RX. In the fact, that the TAC does not allow a specific etiologic diagnosis of the IPD type, as it is done in the biopsy. It allows identifying abnormality in those patients apparently normal by the radiography of the thorax and when it already exists the histopathologic diagnosis it allows the follow-up in a no invasive way

Computerized tomography in diagnosis of cerebrocranial injury

International Nuclear Information System (INIS)

Kornienko, V.N.; Vasin, N.Ya.; Kuz'menko, V.A.

1987-01-01

The method of computerized tomographical examination are presented. Th KT-characters of concussion of the brain, its contusion of different severity, compressions in case of traumatic intracranial hematomas, contusion injuries, brain edema and different aftereffects of cerebrocranial injury are given. On the basis of comparison of the data of clinical and KT examination the dynamics of intracranial traumatic injuries in the course of treatment is described. The problems of therapeutic and surgical tactics depending on the degree and form of intracranial structure injuries and the phase of clinical course of posttraumatic process are discussed

Development of direct observation aparatus of coal carbonization process by x-ray computerized tomography method

International Nuclear Information System (INIS)

Sakawa, Mitsuhiro; Shiraishi, Katsuhiko; Sakurai, Yoshihisa; Shimomura, Yasuto

1987-01-01

Coke production by chamber ovens has a long history and efforts are being continued to make the manufacturing process efficient and to preserve the environment. In this production by this method, however, it is hardly possible to obtain direct information during coal carbonization. Since the elements that compose coal and coke are carbon, hydrogen, oxygen, etc. and are similar to those of the human body, authors has developed a coke oven that permits the direct observation of the coal carbonization process using a soft X-ray computerized tomography (CT) apparatus used in medical treatment. The following phenomena can be observed as images by the coke oven for the CT method : 1) Changes in the bulk density of charge coal (including the difference in the water content), 2) Width of the plastic layer and movement of the plastic layer in the coke oven chamber, 3) Expansion and shrinkage of the charge in the coke oven chamber, 4) Initiation and growth of cracks. (author)

Percutaneous nephrolithotomy in pediatric patients: is computerized tomography a must?

Science.gov (United States)

Gedik, Abdullah; Tutus, Ali; Kayan, Devrim; Yılmaz, Yakup; Bircan, Kamuran

2011-02-01

The aim of this study was to retrospectively evaluate the results of pediatric percutaneous nephrolithotomy (PNL) cases, and discuss the results and necessity of non-contrast computerized tomography (CT) in these cases. In all, 48 pediatric patients who underwent PNL were retrospectively evaluated. Before PNL, either intravenous urography or CT was performed. In all patients, we evaluated the PNL time, scopy time with stone burden, and complications. During the PNL procedure, we switched to open surgery in two cases: in one because of renal pelvis perforation and in the other because of transcolonic access. In one patient who was scheduled to undergo PNL, we performed open surgery, primarily because we detected a retrorenal colon with CT. The stone burden in 45 patients who underwent PNL was 445 ± 225 mm(2), the PNL time was 51 ± 23 min, and the scopy time was 6.1 ± 2.7 min. We removed nephrostomy tubes 1-4 days after the procedure. In two patients, 24 h after removal of nephrostomy tubes, we inserted double J stents because of prolonged urine extravasation from the tract. In all, 34 of the 45 patients were stone-free, 5 patients had clinically insignificant stone fragments, and 6 patients had residual stones. PNL is a safe and effective method in the treatment of pediatric patients with kidney stones. Clinical experience is the most important factor in obtaining stone-free results. CT should be performed in all pediatric patients in order to prevent colon perforation.

Basilar expansion of the human sphenoidal sinus: an integrated anatomical and computerized tomography study

International Nuclear Information System (INIS)

Haetinger, Rainer G.; Navarro, Joao A.C.; Liberti, Edson A.

2006-01-01

Basilar expansion of the sphenoidal sinus (BESS) was studied in order to demonstrate its critical relevance in endoscopic or microscopic endonasal surgical interventions, including access to the sphenoidal sinus itself or in transsphenoidal pituitary approaches. Direct evaluation of anatomical specimens (25 dry skulls and 25 formalin-fixed hemi heads) and the use of computerized tomography (CT) (50 dry skulls and 750 patients) showed a high BESS frequency (69%). The authors considered BESS to be critical when the posterior wall of the clivus was 2-mm thick and found a high incidence of this important anatomical variation (44%). This study also evaluated the relationship between the sinonasal septa, the clivus, and the internal carotid arteries, and a considerable regularity in the location of these structures was seen. The septa were anatomically related to the internal carotid arteries in 55% and to the clivus in 33% of the cases. In conclusion, the high frequency of critical BESS here described is relevant to endoscopic or microscopic endonasal surgical interventions, including access to the sphenoidal sinus itself or in transsphenoidal pituitary approaches. (orig.)

Nonoperative treatment of splenic trauma: usefulness of computed tomography

International Nuclear Information System (INIS)

Resende, Vivian; Tavares Junior, Wilson Campos; Vieira, Jose Nelson Mendes; Drumond, Domingos Andre Fernandes

2005-01-01

Objective: to report the results of use of conservative treatment in patients with splenic trauma and to emphasize the usefulness of computed tomography in these cases. Material and method: sixty-nine cases of pediatric patients with blunt abdominal trauma seen from from January 2001 to June 2004 at the level I trauma center were retrospectively studied. Forty-four of these patients were submitted to nonoperative treatment and the clinical follow-up was performed by computerized tomography. All patients had been diagnosed with splenic injury by computerized tomography.Results: the causes of the injuries were motor vehicle accident in 12 (27.2%) patients, bicycle accident in nine (20.4%) patients, and falls in 23 (52.2%) patients. Two (3.7%) patients died from associated injuries. The mean duration of hospital stay was six days. The mean age of the patients was nine years. Conclusion: conservative treatment for blunt splenic trauma is performed with the aim of reducing costs and risks for the patients, and computerized tomography should be routinely used. No posterior complications were observed in this approach. (author)

Comparison of micro-computerized tomography and cone-beam computerized tomography in the detection of accessory canals in primary molars

OpenAIRE

Acar, Buket; Kamburo?lu, K?van?; Tatar, ?lkan; Ar?kan, Volkan; ?elik, Hakan Hamdi; Y?ksel, Selcen; ?zen, Tuncer

2015-01-01

Purpose This study was performed to compare the accuracy of micro-computed tomography (CT) and cone-beam computed tomography (CBCT) in detecting accessory canals in primary molars. Materials and Methods Forty-one extracted human primary first and second molars were embedded in wax blocks and scanned using micro-CT and CBCT. After the images were taken, the samples were processed using a clearing technique and examined under a stereomicroscope in order to establish the gold standard for this s...

Tomography methods for diagnostic examination of cerebrovascular disease: a comparative evaluation of SPECT, PET and MR/CT findings

International Nuclear Information System (INIS)

Reiche, W.; Kaiser, H.J.; Weiller, C.; Altehoefer, C.; Buell, U.; Isensee, C.

1991-01-01

Single Photon Emissions Computerized Tomography (SPECT), Positron Emissions Tomography (PET), Magnetic Resonance Tomography (MR), and Transmission Computerized Tomography (CT) complement each other and lead to a consideration of the cerebrovascular disease under patho-physiological aspects. Indications for the combined application of functionally oriented (SPECT/PET) and morphologically oriented (CT/MR) examination methods with cerebrovascular disease are presented. (orig./MG) [de

Clinical value of computerized tomography scanning in severe head injury

International Nuclear Information System (INIS)

Kobayashi, Shiro; Yano, Masami; Otsuka, Toshibumi; Nakazawa, Shozo

1982-01-01

Serial computerized tomography (SCT) was performed on 138 patients suffering from severe head injuries (8 or less on the Glasgow Coma Scale). Standard practice called for scans to be done upon admission (within hours of the injury), and after 1, 3, 7 days and 1 month. Subsequent CT's depended on the patient's condition. Clinical results at the time of discharge were graded according to the Glasgow Outcome Scale. Patients who died, were in a persistent vegetative state, or were severely disabled were considered to have a ''bad outcome''. On the other hand, patients who were somewhat disabled or made good recoveries were considered to have a ''good outcome''. During the serial CT scan, there were new findings (not visualized on the initial CT but appearing on subsequent ones) in 91 of the 138 patients. These new findings were classified as follows; 1) decreased density collection in the subdural space (DDC), 2) ventricular dilation (VD), 3) intracerebral hematoma (ICH), 4) intraventricular hemorrhage (IVH), 5) extracerebral hematoma (ECH), 6) edema (E), 7) infarction (I). We defined ICH, IVH, ECH, E and I as new lesions. Of the 60 patients with new lesions 12 had good outcomes and 48 had poor outcomes. There were 78 patients who did not have any new lesions, 60 with good outcomes and 18 with poor outcomes. A significant correlation was found between good outcomes and the absence of new lesions, and between bad outcomes and the development of new lesions (p 2 = 44.038). We conclude that SCT can help predict the outcome with severe head injury patients and may be very important in their examination and care. (J.P.N.)

Dental status of three Egyptian mummies: radiological investigation by multislice computerized tomography.

Science.gov (United States)

Gerloni, Alessandro; Cavalli, Fabio; Costantinides, Fulvio; Costantinides, Fulvia; Bonetti, Stefano; Paganelli, Corrado

2009-06-01

The aim of the study was to provide a paleopathologic and radiologic overview of the jaws and teeth of 3 Egyptian mummies preserved in the Civic Museum of History and Art in Trieste. Computerized tomography (CT) imaging and postprocessing techniques were used to examine the oral structures. A 16-slice CT scanner was used (Aquilion 16; Toshiba Medical Systems Europe, Zoetermeer, The Netherlands). Scans were obtained at high resolution. Orthogonal-plane and 3-dimensional (3D) reconstructions were created along with curved reconstructions of the lower and upper jaws. Determination of decayed/missing teeth (DMT) and decayed/missing/tooth surfaces (DMTs) were made with 3D images. Analyses revealed differences in the embalming techniques and state of preservation of the bodies. Marked wear of the occlusal surfaces was a characteristic finding in all of the mummies. The DMT and DMTs were low compared with values for contemporary populations. Two mummies had fully erupted third molars. All mummies exhibited bone changes consistent with periodontitis. The CT evaluations of the oral structures of the mummies provided insight into the dental status and oral diseases of these ancient Egyptians. The low DMT and DMTs values and indications of periodontitis may be associated with the lifestyle of these Egyptians. The fully erupted and well aligned third molars may represent a morphologic adaptation of the arches to the muscular activity associated with grinding tough foods.

MRI-Based Computed Tomography Metal Artifact Correction Method for Improving Proton Range Calculation Accuracy

International Nuclear Information System (INIS)

Park, Peter C.; Schreibmann, Eduard; Roper, Justin; Elder, Eric; Crocker, Ian; Fox, Tim; Zhu, X. Ronald; Dong, Lei; Dhabaan, Anees

2015-01-01

Purpose: Computed tomography (CT) artifacts can severely degrade dose calculation accuracy in proton therapy. Prompted by the recently increased popularity of magnetic resonance imaging (MRI) in the radiation therapy clinic, we developed an MRI-based CT artifact correction method for improving the accuracy of proton range calculations. Methods and Materials: The proposed method replaces corrupted CT data by mapping CT Hounsfield units (HU number) from a nearby artifact-free slice, using a coregistered MRI. MRI and CT volumetric images were registered with use of 3-dimensional (3D) deformable image registration (DIR). The registration was fine-tuned on a slice-by-slice basis by using 2D DIR. Based on the intensity of paired MRI pixel values and HU from an artifact-free slice, we performed a comprehensive analysis to predict the correct HU for the corrupted region. For a proof-of-concept validation, metal artifacts were simulated on a reference data set. Proton range was calculated using reference, artifactual, and corrected images to quantify the reduction in proton range error. The correction method was applied to 4 unique clinical cases. Results: The correction method resulted in substantial artifact reduction, both quantitatively and qualitatively. On respective simulated brain and head and neck CT images, the mean error was reduced from 495 and 370 HU to 108 and 92 HU after correction. Correspondingly, the absolute mean proton range errors of 2.4 cm and 1.7 cm were reduced to less than 2 mm in both cases. Conclusions: Our MRI-based CT artifact correction method can improve CT image quality and proton range calculation accuracy for patients with severe CT artifacts

Proposal for dose measurement in the crystalline lens and thyroid in computerized tomography of paranasal sinuses

International Nuclear Information System (INIS)

Mello, Ana Caroline; Machado Neto, Vicente

2014-01-01

With the evolution of diagnostic imaging equipment, a computerized tomography (CT) has become one of the most used tests to assess pathologies affecting the paranasal sinuses. This work aims at presenting a method of obtaining measurements of dose in the eye lenses and thyroid, from the execution of CT of the paranasal sinuses protocol. Experimental procedure will be used in an object simulator (phantom) head and neck made with accessible materials and thermoluminescent dosimeters (TLDs) of LiF: Mg,Ti for the absorbed dose in the regions of interest, when exposed to radiation in a CT scanner 16 channels. After the dosimetric evaluation with phantom use, this methodology will be applied in vivo, or in patients with medical request for the examination and approval by the Ethics Committee. Thus, at the end of this survey protocols and actions aimed at reducing the absorbed dose in the eye lenses and thyroid without impairing the diagnostic image quality can be proposed. (author)

Intellectual function, activities of daily living and computerized tomography of the brain in geriatric demented patients

Energy Technology Data Exchange (ETDEWEB)

Omura, Fumiaki; Ogura, Chikara; Kishimoto, Akira; Okubo, Masayo; Imamoto, Atsushi [Tottori Univ., Yonago (Japan). School of Medicine; Tsuchie, Harutaka; Sugihara, Kanichiro; Fujii, Shozo

1984-09-01

Thirty eight patients of geriatric dementia (mean age 74.9 years) were examined by computerized tomography (CT) and their intellectual functions and activities of daily living (ADL) were evaluated. CT was evaluated by both visual assessment method and direct measuring method. Intellectual function was evaluated by Jikei University dementia rating scale. ADL was evaluated by both Hasegawa's rating scale and Sengoku's rating scale. Results were as follows: significant influence by age was observed in intellectual functions and ADL of subjects above 75 years old. There were good correlations between the higher intellectual function, the better grooming and hygiene, and less needs of nursing care. The severe brain atrophy evaluated by the visual assessment method was correlated with the depressed level of intellectual function. When brain atrophy is mild despite high degree of dementia, reexamination should be made to explore somatic diseases inducing depression of mental activity. It also should be noted that sex and age difference is important in studying geriatric patients.

Intellectual function, activities of daily living and computerized tomography of the brain in geriatric demented patients

International Nuclear Information System (INIS)

Omura, Fumiaki; Ogura, Chikara; Kishimoto, Akira; Okubo, Masayo; Imamoto, Atsushi; Tsuchie, Harutaka; Sugihara, Kanichiro; Fujii, Shozo.

1984-01-01

Thirty eight patients of geriatric dementia (mean age 74.9 years) were examined by computerized tomography (CT) and their intellectual functions and activities of daily living (ADL) were evaluated. CT was evaluated by both visual assessment method and direct measuring method. Intellectual function was evaluated by Jikei University dementia rating scale. ADL was evaluated by both Hasegawa's rating scale and Sengoku's rating scale. Results were as follows: significant influence by age was observed in intellectual functions and ADL of subjects above 75 years old. There were good correlations between the higher intellectual function, the better grooming and hygiene, and less needs of nursing care. The severe brain atrophy evaluated by the visual assessment method was correlated with the depressed level of intellectual function. When brain atrophy is mild despite high degree of dementia, reexamination should be made to explore somatic diseases inducing depression of mental activity. It also should be noted that sex and age difference is important in studying geriatric patients. (author)

Clinical evaluation of 99mTc-CPI myocardial perfusion single photon emission computerized tomography in the diagnosis of coronary heart disease

International Nuclear Information System (INIS)

Peng Changping

1991-01-01

Two normal subjects, 5 patients with old myocardial infarction (OMI) and 4 patients with angina pectoris were examined by rest single photon emission computerized tomography revealed that the right ventricular was not imaged, the left ventricular was well exposed in the normal subjects. All the 9 patients had defects in the left ventricle. comparison of SPECT with 99m Tc-CPI with selective coronary arteriography (SCA), echocardiography (UCG), dynamic electrocardiography (DCG) and electrocardiographic (ECG)-exercise test in the diagnosis of myocardial ischemia or necrosis has demonstrated the former to be more significantly sensitive than the latter four. Good agreement between SPECT and SCA has been confirmed

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

International Nuclear Information System (INIS)

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

1978-01-01

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

Computerized tomography in the diagnosis of mechanical jaundice

International Nuclear Information System (INIS)

Grushin, Yu.V.; Manasov, T.Zh.; Raskolenko, A.A.; Nazyrova, N.K.; Dzhumashev, E.Z.

1987-01-01

A total of 51 patients with suspected mechanical jaundice were examined using the 3rd generation computerized tomograph. A correct conclusion as to the level and mechanism of obstruction was made in 77% of cases. The most serious problems arose in analysis of extrahepatic biliary ducts. The dilatation of the biliary passages was not always combined with their obturation. In cases which were difficult for interpretation, additional information could be obtained by using thin tomographic layers, i.v. contrast enhancement, and retrograde endoscopic cholangiography

Contribution of computerized tomography and nuclear magnetic resonance to the diagnosis of vascular dementia

Energy Technology Data Exchange (ETDEWEB)

Gallois, P; Pruvo, J P

1987-06-18

Nuclear magnetic resonance (NMR) and computerized tomography (CT) have become indispensable to the exploration of patients with vascular dementia. NMR is remarkable for its innocuity, its anatomical accuracy, its sensitivity and the three-dimensional approach it offers. CT is less sensitive, but the examinations are shorter and less costly. These two techniques seem to be about equally effective in visualizing multiple infarcts, although NMR gives a better contrast. In dementia due to multiple infarcts, the bilateral cortical and subcortical lesions coexist with moderate cortical atrophy. The cerebral lacunae of lacunar dementia are better visualized by NMR; they are distributed on both sides, predominate in the frontal lobes and only produce slight cortical atrophy, less pronounced than ventricular dilatation. The main advantage of NMR is its high sensitivity in detecting early changes in the white matter, changes which are particularly perceptible in juxta- and peri-ventricular areas in arteriosclerous subcortical leucoencephalopathy. NMR, not very specific here, does not readily separate these lesions from those of other types of leucoencephalopathy. The finding of hypodense areas at CT or hypersignals at NMR (T2) around the ventricles may help in differentiating between vascular dementia, irrespective of its mechanism, and primary dementia.

Effective radiation dose of ProMax 3D cone-beam computerized tomography scanner with different dental protocols.

Science.gov (United States)

Qu, Xing-min; Li, Gang; Ludlow, John B; Zhang, Zu-yan; Ma, Xu-chen

2010-12-01

The aim of this study was to compare effective doses resulting from different scan protocols for cone-beam computerized tomography (CBCT) using International Commission on Radiological Protection (ICRP) 1990 and 2007 calculations of dose. Average tissue-absorbed dose, equivalent dose, and effective dose for a ProMax 3D CBCT with different dental protocols were calculated using thermoluminescent dosimeter chips in a human equivalent phantom. Effective doses were derived using ICRP 1990 and the superseding 2007 recommendations. Effective doses (ICRP 2007) for default patient sizes from small to large ranged from 102 to 298 μSv. The coefficient of determination (R(2)) between tube current and effective dose (ICRP 2007) was 0.90. When scanning with lower resolution settings, the effective doses were reduced significantly (P radiation dose levels. Reduction in radiation dose can be achieved when using lower settings of exposure parameters. Copyright © 2010 Mosby, Inc. All rights reserved.

Reduced Calibration Curve for Proton Computed Tomography

International Nuclear Information System (INIS)

Yevseyeva, Olga; Assis, Joaquim de; Evseev, Ivan; Schelin, Hugo; Paschuk, Sergei; Milhoretto, Edney; Setti, Joao; Diaz, Katherin; Hormaza, Joel; Lopes, Ricardo

2010-01-01

The pCT deals with relatively thick targets like the human head or trunk. Thus, the fidelity of pCT as a tool for proton therapy planning depends on the accuracy of physical formulas used for proton interaction with thick absorbers. Although the actual overall accuracy of the proton stopping power in the Bethe-Bloch domain is about 1%, the analytical calculations and the Monte Carlo simulations with codes like TRIM/SRIM, MCNPX and GEANT4 do not agreed with each other. A tentative to validate the codes against experimental data for thick absorbers bring some difficulties: only a few data is available and the existing data sets have been acquired at different initial proton energies, and for different absorber materials. In this work we compare the results of our Monte Carlo simulations with existing experimental data in terms of reduced calibration curve, i.e. the range - energy dependence normalized on the range scale by the full projected CSDA range for given initial proton energy in a given material, taken from the NIST PSTAR database, and on the final proton energy scale - by the given initial energy of protons. This approach is almost energy and material independent. The results of our analysis are important for pCT development because the contradictions observed at arbitrary low initial proton energies could be easily scaled now to typical pCT energies.

Effectiveness of revascularization surgery evaluated by proton magnetic resonance spectroscopy and single photon emission computed tomography

Energy Technology Data Exchange (ETDEWEB)

Uno, Masaaki; Ueda, Shin; Hondo, Hideki; Matsumoto, Keizo; Harada, Masafumi [Tokushima Univ. (Japan). School of Medicine

1996-08-01

Proton magnetic resonance spectroscopy (MRS) and single photon emission computed tomography (SPECT) were used to evaluate chronic ischemic regions in 26 stroke patients before and 1, 3, and 6 months after revascularization surgery. The volume of interest for proton MRS was placed in an area including part of the frontal and temporal opercula, insular cortex, and basal ganglia. Twenty healthy volunteers served as controls for proton MRS. Patients were divided into three groups according to the preoperative proton MRS. Group A (n=12) had significantly lower N-acetylaspartate/choline (NAA/Cho) and N-acetylaspartate/creatine (NAA/Cr) ratios on the operative side compared to those on the contralateral side, and also lower than those in normal subjects. In seven patients in Group A, postoperative serial proton MRS demonstrated no recovery of these ratios on the operative side. However, proton MRS of the other five patients indicated gradual improvement in these ratios on the operative side at 3 to 6 months after surgery, and SPECT indicated an increase in cerebral blood flow on the operative side in four of these five patients. In Group B (n=9), proton MRS and SPECT showed no laterality before revascularization and no remarkable change during the postoperative course. In Group C (n=5), NAA/Cho or NAA/Cr decreased on the contralateral side preoperatively. Two patients showed fluctuating values of NAA/Cho or NAA/Cr during the postoperative period. Serial proton MRS and SPECT Studies may be useful for the evaluation of revascularization surgery on ischemic regions. The efficacy of revascularization surgery on the metabolism may appear gradually within 3-6 months. (author)

Proton energy and scattering angle radiographs to improve proton treatment planning : a Monte Carlo study

NARCIS (Netherlands)

Biegun, Aleksandra; Takatsu, Jun; Nakaji, Taku; van Goethem, Marc-Jan; van der Graaf, Emiel; Koffeman, E.; Visser, Jan; Brandenburg, Sijtze

2016-01-01

The novel proton radiography imaging technique has a large potential to be used in direct measurement of the proton energy loss (proton stopping power, PSP) in various tissues in the patient. The uncertainty of PSPs, currently obtained from translation of X-ray Computed Tomography (xCT) images,

Strut fracture and disc embolization of a Björk-Shiley mitral valve prosthesis: localization of embolized disc by computerized axial tomography.

Science.gov (United States)

Larrieu, A J; Puglia, E; Allen, P

1982-08-01

The case of a patient who survived strut fracture and embolization of a Björk-Shiley mitral prosthetic disc is presented. Prompt surgical treatment was directly responsible for survival. In addition, computerized axial tomography of the abdomen aided in localizing and retrieving the embolized disc, which was lodged at the origin of the superior mesenteric artery. A review of similar case reports from the literature supports our conclusions that the development of acute heart failure and absent or muffled prosthetic heart sounds in a patient with a Björk-Shiley prosthetic heart valve inserted prior to 1978 should raise the possibility of valve dysfunction and lead to early reoperation.

Dose profile study on computerized tomography scanning of skull with simulator object; Estudo do perfil de dose em varreduras de TC de cranio com objeto simulador

Energy Technology Data Exchange (ETDEWEB)

Mourao, A.P., E-mail: aprata@des.cefetmg.b [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET/MG), Belo Horizonte, MG (Brazil). Nucleo de Engenharia Hospitalar; Alonso, Thessa C.; Silva, Teogenes A. da, E-mail: alonso@cdtn.b, E-mail: silvata@@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2011-10-26

This work presents a comparison among the dose profiles in scanning of computerized tomography of a simulator object of PMMA in its periphery region. To obtain the deposited dose at the PMMA thermoluminescent dosemeters were used positioned at the interior of PMMA simulated object longitudinal to periphery and at the center of cylinder (positions denominated North, South, East, West and Center). Eight scanning were performed of simulator object using the routine protocol for skull in eight different services of radiodiagnostic by TC

Hybrid Single Photon Emission Computed Tomography/Computed Tomography Sulphur Colloid Scintigraphy in Focal Nodular Hyperplasia

International Nuclear Information System (INIS)

Bhoil, Amit; Gayana, Shankramurthy; Sood, Ashwani; Bhattacharya, Anish; Mittal, Bhagwant Rai

2013-01-01

It is important to differentiate focal nodular hyperplasia (FNH), a benign condition of liver most commonly affecting women, from other neoplasm such as hepatic adenoma and metastasis. The functional reticuloendothelial features of FNH can be demonstrated by scintigraphy. We present a case of breast cancer in whom fluorodeoxyglucose positron emission tomography/computerized tomography (CT) showed a homogenous hyperdense lesion in liver, which on Tc99m sulfur colloid single-photon emission computed tomography/CT was found to have increased focal tracer uptake suggestive of FNH

On proton CT reconstruction using MVCT-converted virtual proton projections

Energy Technology Data Exchange (ETDEWEB)

Wang Dongxu; Mackie, T. Rockwell; Tome, Wolfgang A. [Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705 and Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242 (United States); Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705 and Morgridge Institute of Research, University of Wisconsin, Madison, Wisconsin 53715 (United States); Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705 and Oncophysics Institute, Albert Einstein College of Medicine, Yeshiva University, Bronx, New York 10461 (United States)

2012-06-15

Purpose: To describe a novel methodology of converting megavoltage x-ray projections into virtual proton projections that are otherwise missing due to the proton range limit. These converted virtual proton projections can be used in the reconstruction of proton computed tomography (pCT). Methods: Relations exist between proton projections and multispectral megavoltage x-ray projections for human tissue. Based on these relations, these tissues can be categorized into: (a) adipose tissue; (b) nonadipose soft tissues; and (c) bone. These three tissue categories can be visibly identified on a regular megavoltage x-ray computed tomography (MVCT) image. With an MVCT image and its projection data available, the x-ray projections through heterogeneous anatomy can be converted to the corresponding proton projections using predetermined calibration curves for individual materials, aided by a coarse segmentation on the x-ray CT image. To show the feasibility of this approach, mathematical simulations were carried out. The converted proton projections, plotted on a proton sinogram, were compared to the simulated ground truth. Proton stopping power images were reconstructed using either the virtual proton projections only or a blend of physically available proton projections and virtual proton projections that make up for those missing due to the range limit. These images were compared to a reference image reconstructed from theoretically calculated proton projections. Results: The converted virtual projections had an uncertainty of {+-}0.8% compared to the calculated ground truth. Proton stopping power images reconstructed using a blend of converted virtual projections (48%) and physically available projections (52%) had an uncertainty of {+-}0.86% compared with that reconstructed from theoretically calculated projections. Reconstruction solely from converted virtual proton projections had an uncertainty of {+-}1.1% compared with that reconstructed from theoretical projections

On proton CT reconstruction using MVCT-converted virtual proton projections

International Nuclear Information System (INIS)

Wang Dongxu; Mackie, T. Rockwell; Tomé, Wolfgang A.

2012-01-01

Purpose: To describe a novel methodology of converting megavoltage x-ray projections into virtual proton projections that are otherwise missing due to the proton range limit. These converted virtual proton projections can be used in the reconstruction of proton computed tomography (pCT). Methods: Relations exist between proton projections and multispectral megavoltage x-ray projections for human tissue. Based on these relations, these tissues can be categorized into: (a) adipose tissue; (b) nonadipose soft tissues; and (c) bone. These three tissue categories can be visibly identified on a regular megavoltage x-ray computed tomography (MVCT) image. With an MVCT image and its projection data available, the x-ray projections through heterogeneous anatomy can be converted to the corresponding proton projections using predetermined calibration curves for individual materials, aided by a coarse segmentation on the x-ray CT image. To show the feasibility of this approach, mathematical simulations were carried out. The converted proton projections, plotted on a proton sinogram, were compared to the simulated ground truth. Proton stopping power images were reconstructed using either the virtual proton projections only or a blend of physically available proton projections and virtual proton projections that make up for those missing due to the range limit. These images were compared to a reference image reconstructed from theoretically calculated proton projections. Results: The converted virtual projections had an uncertainty of ±0.8% compared to the calculated ground truth. Proton stopping power images reconstructed using a blend of converted virtual projections (48%) and physically available projections (52%) had an uncertainty of ±0.86% compared with that reconstructed from theoretically calculated projections. Reconstruction solely from converted virtual proton projections had an uncertainty of ±1.1% compared with that reconstructed from theoretical projections. If

A simulation study on proton computed tomography (CT) stopping power accuracy using dual energy CT scans as benchmark.

Science.gov (United States)

Hansen, David C; Seco, Joao; Sørensen, Thomas Sangild; Petersen, Jørgen Breede Baltzer; Wildberger, Joachim E; Verhaegen, Frank; Landry, Guillaume

2015-01-01

Accurate stopping power estimation is crucial for treatment planning in proton therapy, and the uncertainties in stopping power are currently the largest contributor to the employed dose margins. Dual energy x-ray computed tomography (CT) (clinically available) and proton CT (in development) have both been proposed as methods for obtaining patient stopping power maps. The purpose of this work was to assess the accuracy of proton CT using dual energy CT scans of phantoms to establish reference accuracy levels. A CT calibration phantom and an abdomen cross section phantom containing inserts were scanned with dual energy and single energy CT with a state-of-the-art dual energy CT scanner. Proton CT scans were simulated using Monte Carlo methods. The simulations followed the setup used in current prototype proton CT scanners and included realistic modeling of detectors and the corresponding noise characteristics. Stopping power maps were calculated for all three scans, and compared with the ground truth stopping power from the phantoms. Proton CT gave slightly better stopping power estimates than the dual energy CT method, with root mean square errors of 0.2% and 0.5% (for each phantom) compared to 0.5% and 0.9%. Single energy CT root mean square errors were 2.7% and 1.6%. Maximal errors for proton, dual energy and single energy CT were 0.51%, 1.7% and 7.4%, respectively. Better stopping power estimates could significantly reduce the range errors in proton therapy, but requires a large improvement in current methods which may be achievable with proton CT.

Correlations between computerized tomography of the head and motor developmental disturbances of children with cerebral palsy

International Nuclear Information System (INIS)

Chen, Yu-Herng

1981-01-01

Two hundred and eighty-two children with cerebral palsy (C.P.) and thirty-seven normal children were studied by computerized tomography (C.T.) of the head for finding out the correlations between the organic damage of the brain and the motor developmental disturbance. The abnormal findings of C.T. were: enlargement of the ventricular system, high density area, low density area and porencephalus, enlargement of the sulcus and anomaly of the medial structure. Enlargement of the ventricular system seemed to have correlation with spasticity; the portion and the extent of the enlargement corresponded to the affected extremities and the severity of the spasticity. Children of other types also showed various abnormal C.T. findings but, in general, less than that of spastic types. The prognosis of the motor development of C.P. children cannot be predicted by serial C.T. examinations strictly, because early treatment could cause improvement to that of these children. However, it is of worthy notice that C.T. is an effective method of helping to diagnose the motor developmental disturbance in earlier childhood. (author)

Time to Computerized Tomography Scan, Age, and Mortality in Acute Stroke.

Science.gov (United States)

Myint, Phyo Kyaw; Kidd, Andrew C; Kwok, Chun Shing; Musgrave, Stanley D; Redmayne, Oliver; Metcalf, Anthony K; Ngeh, Joseph; Nicolson, Anne; Owusu-Agyei, Peter; Shekhar, Raj; Walsh, Kevin; Day, Diana J; Warburton, Elizabeth A; Bachmann, Max O; Potter, John F

2016-12-01

Time to computerized tomography (CT) is important to institute appropriate and timely hyperacute management in stroke. We aimed to evaluate mortality outcomes in relation to age and time to CT scan. We used routinely collected data in 8 National Health Service trusts in East of England between September 2008 and April 2011. Stroke cases were prospectively identified and confirmed. Odds ratios (ORs) for unadjusted and adjusted models for age categories (24 hours) and in-hospital and early (<7 days) mortality outcomes were calculated. Of the 7693 patients (mean age 76.1 years, 50% male) included, 1151 (16%) died as inpatients and 336 (4%) died within 7 days. Older patients and those admitted from care home had a significantly longer time from admission until CT (P < .001). Patients who had earlier CT scans were admitted to stroke units more frequently (P < .001) but had higher in-patient (P < .001) and 7-day mortality (P < .001). Whereas older age was associated with increased odds of mortality outcomes, longer time to CT was associated with significantly reduced mortality within 7 days (corresponding ORs for the above time periods were 1.00, .61 [95% confidence interval {CI}: .39-.95], .39 [.24-.64], and .16 [.08-.33]) and in-hospital mortality (ORs 1.00, .86 [.64-1.15], .57 [.42-.78] and .71 [.52-.98]). Older age was associated with a significantly longer time to CT. However, using CT scan time as a benchmarking tool in stroke may have inherent limitations and does not appear to be a suitable quality marker. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

A modified conjugate gradient method based on the Tikhonov system for computerized tomography (CT).

Science.gov (United States)

Wang, Qi; Wang, Huaxiang

2011-04-01

During the past few decades, computerized tomography (CT) was widely used for non-destructive testing (NDT) and non-destructive examination (NDE) in the industrial area because of its characteristics of non-invasiveness and visibility. Recently, CT technology has been applied to multi-phase flow measurement. Using the principle of radiation attenuation measurements along different directions through the investigated object with a special reconstruction algorithm, cross-sectional information of the scanned object can be worked out. It is a typical inverse problem and has always been a challenge for its nonlinearity and ill-conditions. The Tikhonov regulation method is widely used for similar ill-posed problems. However, the conventional Tikhonov method does not provide reconstructions with qualities good enough, the relative errors between the reconstructed images and the real distribution should be further reduced. In this paper, a modified conjugate gradient (CG) method is applied to a Tikhonov system (MCGT method) for reconstructing CT images. The computational load is dominated by the number of independent measurements m, and a preconditioner is imported to lower the condition number of the Tikhonov system. Both simulation and experiment results indicate that the proposed method can reduce the computational time and improve the quality of image reconstruction. Copyright © 2010 ISA. Published by Elsevier Ltd. All rights reserved.

Measurement on the density resolution of industrial computerized tomography by using disc specimen with holes

International Nuclear Information System (INIS)

Tian, Y.; Gao, D.; Zhang, W.; Xia, Z.; Yang, C.

2004-01-01

Several ways mainly used for measuring the density resolution of industrial computerized tomography (ICT) are briefly introduced. Based on the equivalent conversion between volume variation and density variation, a kind of disc specimen with holes is designed to measure the density resolution of ICT. In this experiment, a kind of high quality polymethyl methacylate (PMMA) is selected to make specimens with diameter of 250mm, in which six sets of holes with diameter separately 0.5mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, and 3.0mm are distributed in the radial directions with interval of 60 o between two neighboring sets, and in the same set, the distances of holes departing the center of the specimen are respectively 20mm, 40mm, 60mm, 80mm, and 100mm. The experiment shows that the method is sensitive, simple, flexible, and practical. About 0.2% density resolution of region of interest (ROI) with diameter 20mm can be verified, the relationship between CT value of ROI and its position can be obtained, and at the same time the spatial resolution of ICT can be measured in high quality. (author)

Post transplant urinary tract infection in Autosomal dominant polycystic kidney disease a perpetual diagnostic dilema - 18-fluorodeoxyglucose - Positron emission computerized tomography - A valuable tool

International Nuclear Information System (INIS)

Sainaresh, VV; Jain, SH; Patel, HV; Shah, PR; Vanikar, AV; Trivedi, HL

2011-01-01

Urinary tract infection (UTI) is the most common infection contracted by renal allograft recipients. In patients of autosomal dominant polycystic kidney disease (ADPKD), cyst infection presents a complex diagnostic and therapeutic challenge especially in the post transplant period. Accurate diagnosis forms the cornerstone in salvaging the graft from potentially catastrophic outcome. We describe a case of xanthogranulomatous pyelonephritis (XPN) in the native kidney in a patient of post transplant ADPKD which presented as frequently relapsing UTI with graft dysfunction where in accurate diagnosis was made possible with the aid of 18-fluorodeoxyglucose (FDG) - Positron emission computerized tomography (PET/CT)

An update in proton probe tomography

Energy Technology Data Exchange (ETDEWEB)

Sakellariou, A.; Cholewa, M.; Saint, A.; Legge, G.L.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Howard, J. [Australian National Univ., Canberra, ACT (Australia). Research School of Physical Sciences

1996-12-31

The analysis of scanning transmission ion microscopy (STIM) tomography data is improved. The volumetric density information is obtained directly from an iterative convolution and back-projection (BFP) reconstruction method. The iterative method allows the effects of stopping-power to be incorporated easily. One draw back is that a priori constituency information is required for the iterative method to work However, this is of no concern because the iterative method was designed with PIXE tomography in mind. In this light, the a priori information will be obtained as the zeroth iteration of a PIXE tomography iterative reconstruction method. 4 refs., 1 tab., 4 figs.

An update in proton probe tomography

Energy Technology Data Exchange (ETDEWEB)

Sakellariou, A; Cholewa, M; Saint, A; Legge, G L.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Howard, J [Australian National Univ., Canberra, ACT (Australia). Research School of Physical Sciences

1997-12-31

The analysis of scanning transmission ion microscopy (STIM) tomography data is improved. The volumetric density information is obtained directly from an iterative convolution and back-projection (BFP) reconstruction method. The iterative method allows the effects of stopping-power to be incorporated easily. One draw back is that a priori constituency information is required for the iterative method to work However, this is of no concern because the iterative method was designed with PIXE tomography in mind. In this light, the a priori information will be obtained as the zeroth iteration of a PIXE tomography iterative reconstruction method. 4 refs., 1 tab., 4 figs.

Computerized tomography of unipapillary kidney - case report

International Nuclear Information System (INIS)

Bauab Junior, T.; Crosera, P.C.; Zerati Filho, M.

1988-01-01

A case of unipapillary kidney which was evaluated by computed tomography is reported. A review of the literature shows 14 previously reported cases, but none evaluated by CT. The authors also emphasize the lesions that course along with the unipapillary kidney. (author)

Understanding proton-conducting perovskite interfaces using atom probe tomography

Science.gov (United States)

Clark, Daniel R.

Proton-conducting ceramics are under intense scientific investigation for a number of exciting applications, including fuel cells, electrolyzers, hydrogen separation membranes, membrane reactors, and sensors. However, commercial application requires deeper understanding and improvement of proton conductivity in these materials. It is well-known that proton conductivity in these materials is often limited by highly resistive grain boundaries (GBs). While these conductivity-limiting GBs are still not well understood, it is hypothesized that their blocking nature stems from the formation of a positive (proton-repelling) space-charge zone. Furthermore, it has been observed that the strength of the blocking behavior can change dramatically depending on the fabrication process used to make the ceramic. This thesis applies laser-assisted atom probe tomography (LAAPT) to provide new insights into the GB chemistry and resulting space-charge behavior of BaZr0.9Y0.1O 3--delta (BZY10), a prototypical proton-conducting ceramic. LAAPT is an exciting characterization technique that allows for three-dimensional nm-scale spatial resolution and very high chemical resolution (up to parts-per-million). While it is challenging to quantitatively apply LAAPT to complex, multi-cation oxide materials, this thesis successfully develops a method to accurately quantify the stoichiometry of BZY10 and maintain minimal quantitative cationic deviation at a laser energies of approximately 10--20 pJ. With the analysis technique specifically optimized for BZY10, GB chemistry is then examined for BZY10 samples prepared using four differing processing methods: (1) spark plasma sintering (SPS), (2) conventional sintering using powder prepared by solid-state reaction followed by high-temperature annealing (HT), (3) conventional sintering using powder prepared by solid-state reaction with NiO used as a sintering aid (SSR-Ni), and (4) solid-state reactive sintering directly from BaCO3, ZrO2, and Y2O3

Contrast Dose and Radiation Dose Reduction in Abdominal Enhanced Computerized Tomography Scans with Single-phase Dual-energy Spectral Computerized Tomography Mode for Children with Solid Tumors.

Science.gov (United States)

Yu, Tong; Gao, Jun; Liu, Zhi-Min; Zhang, Qi-Feng; Liu, Yong; Jiang, Ling; Peng, Yun

2017-04-05

Contrast dose and radiation dose reduction in computerized tomography (CT) scan for adult has been explored successfully, but there have been few studies on the application of low-concentration contrast in pediatric abdominal CT examinations. This was a feasibility study on the use of dual-energy spectral imaging and adaptive statistical iterative reconstruction (ASiR) for the reduction of radiation dose and iodine contrast dose in pediatric abdominal CT patients with solid tumors. Forty-five patients with solid tumors who had initial CT (Group B) and follow-up CT (Group A) after chemotherapy were enrolled. The initial diagnostic CT scan (Group B) was performed using the standard two-phase enhanced CT with 320 mgI/ml concentration contrast, and the follow-up scan (Group A) was performed using a single-phase enhanced CT at 45 s after the beginning of the 270 mgI/ml contrast injection using spectral mode. Forty percent ASiR was used for the images in Group B and monochromatic images with energy levels ≥60 keV in Group A. In addition, filtered back-projection (FBP) reconstruction was used for monochromatic images hounsfield unit (HU). The abdominal organs of Groups A and B had similar degrees of absolute and relative enhancement (t = 0.36 and -1.716 for liver, -0.153 and -1.546 for pancreas, and 2.427 and 0.866 for renal cortex, all P> 0.05). Signal-to-noise ratio of the abdominal organs was significantly lower in Group A than in Group B (t = -8.11 for liver, -7.83 for pancreas, and -5.38 for renal cortex, all P 3, indicating clinically acceptable image quality. Single-phase, dual-energy spectral CT used for children with solid abdominal tumors can reduce contrast dose and radiation dose and can also maintain clinically acceptable image quality.

Positron emission tomography for staging of oesophageal and gastroesophageal malignancy

NARCIS (Netherlands)

Kole, AC; Plukker, JT; Nieweg, OE; Vaalburg, W

Positron emission tomography (PET) with [F-18]-fluoro-2-deoxy-D-glucose (FDG) was prospectively investigated as a means of detecting metastatic disease in patients with oesophageal tumours and compared with computerized tomography (CT), with the surgical findings as a gold standard. Twenty-six

Contrast-enhanced multidetector computerized tomography for odontogenic cysts and cystic-appearing tumors of the jaws: is it useful?

Science.gov (United States)

Kakimoto, Naoya; Chindasombatjaroen, Jira; Tomita, Seiki; Shimamoto, Hiroaki; Uchiyama, Yuka; Hasegawa, Yoko; Kishino, Mitsunobu; Murakami, Shumei; Furukawa, Souhei

2013-01-01

The purpose of this study was to investigate the usefulness of computerized tomography (CT), particularly contrast-enhanced CT, in differentiation of jaw cysts and cystic-appearing tumors. We retrospectively analyzed contrast-enhanced CT images of 90 patients with odontogenic jaw cysts or cystic-appearing tumors. The lesion size and CT values were measured and the short axis to long axis (S/L) ratio, contrast enhancement (CE) ratio, and standard deviation ratio were calculated. The lesion size and the S/L ratio of keratocystic odontogenic tumors were significantly different from those of radicular cysts and follicular cysts. There were no significant differences in the CE ratio among the lesions. Multidetector CT provided diagnostic information about the size of odontogenic cysts and cystic-appearing tumors of the jaws that was related to the lesion type, but showed no relation between CE ratio and the type of these lesions. Copyright © 2013 Elsevier Inc. All rights reserved.

Development of a computerized tomographic system

International Nuclear Information System (INIS)

Borges, J.C.; Santos, C.A.C.

1986-01-01

The Nuclear Instrumentation Laboratory at COPPE/UFRJ has been developing techniques for detection and applications of nuclear radiations. A lot of research work has been done and resulted in several M.Sc. and D.Sc. thesis, concerning subjects like neutrongraphy, gammagraphy, image reconstruction, special detectors, etc. Recent progress and multiple applications of the computerized tomography to medical and industrial non-destructive tests, pushed the Laboratory to a vast program in this field of research. In this paper, we report what has been done and the results obtained. (Author) [pt

Proton gyromagnetic precision measurement system

International Nuclear Information System (INIS)

Zhu Deming; Deming Zhu

1991-01-01

A computerized control and measurement system used in the proton gyromagnetic precision meausrement is descirbed. It adopts the CAMAC data acquisition equipment, using on-line control and analysis with the HP85 and PDP-11/60 computer systems. It also adopts the RSX11M computer operation system, and the control software is written in FORTRAN language

Evaluation of the normal thoracic and abdominal aorta diameters by computerized tomography; Avaliacao dos diametros normais da aorta toracica e abdominal pela tomografia computadorizada

Energy Technology Data Exchange (ETDEWEB)

Lucarelli, Claudio Luiz

1995-07-01

The study was undertaken to evaluate, through computerized tomography, the diameters of the normal thoracic and abdominal aorta, as well as they are connected to gender, age and body surface area; and the ratio between measurements obtained at the ascending and descending limbs of the thoracic aorta, and between the abdominal aortic diameters. For that reason, we measured the widest anteroposterior diameters of the thoracic aortas at the levels of the arch, the root, the pulmonary artery, and the thoracic-abdominal transition, as well as the level of the emergence of the superior mesenteric artery, of the renal hila and just cephalad to the bifurcation of the abdominal aortas of 350 patients without cardiovascular diseases who had undergone computerized tomography of the thorax and/or abdomen for any other reasons. Observation and statistic analyses led us to conclude that: 1) both the thoracic and abdominal aortic diameters are reduced from their proximal to their distal portions; 2) the body surface influences the size of the aorta, although only extreme variations alter the vessel's caliber; 3) vessel diameter was observed to gradually increase with age; 4) men were found to have larger diameters than age matched women; 5) the ratio between the ascending and descending aortic diameters varies according to gender and age; 6) the relations between abdominal aortic diameters measured at the level of renal hila and cephalad to the bifurcation are independent from gender and age. But the relation between those measured at the level of the superior mesenteric artery and cephalad to the bifurcation are linked to gender, but not to age. (author)

Evaluation of the normal thoracic and abdominal aorta diameters by computerized tomography; Avaliacao dos diametros normais da aorta toracica e abdominal pela tomografia computadorizada

Energy Technology Data Exchange (ETDEWEB)

Lucarelli, Claudio Luiz

1995-07-01

The study was undertaken to evaluate, through computerized tomography, the diameters of the normal thoracic and abdominal aorta, as well as they are connected to gender, age and body surface area; and the ratio between measurements obtained at the ascending and descending limbs of the thoracic aorta, and between the abdominal aortic diameters. For that reason, we measured the widest anteroposterior diameters of the thoracic aortas at the levels of the arch, the root, the pulmonary artery, and the thoracic-abdominal transition, as well as the level of the emergence of the superior mesenteric artery, of the renal hila and just cephalad to the bifurcation of the abdominal aortas of 350 patients without cardiovascular diseases who had undergone computerized tomography of the thorax and/or abdomen for any other reasons. Observation and statistic analyses led us to conclude that: 1) both the thoracic and abdominal aortic diameters are reduced from their proximal to their distal portions; 2) the body surface influences the size of the aorta, although only extreme variations alter the vessel's caliber; 3) vessel diameter was observed to gradually increase with age; 4) men were found to have larger diameters than age matched women; 5) the ratio between the ascending and descending aortic diameters varies according to gender and age; 6) the relations between abdominal aortic diameters measured at the level of renal hila and cephalad to the bifurcation are independent from gender and age. But the relation between those measured at the level of the superior mesenteric artery and cephalad to the bifurcation are linked to gender, but not to age. (author)

Computerized tomography in Community of Madrid. Reference dosimetric measurements

International Nuclear Information System (INIS)

Ruiz Sanz, S.; Calzado, A.; Melchor, M.; Marco, M.

1994-01-01

A total of about 43 computed tomography scanners were operating in the Autonomous Community of Madrid during 1991. A sample of 14 facilities was selected to perform dosimetric measurements in order to obtain characteristic dose profiles. From these, some quantities as the computed tomography dose index and the enhancement factor were calculated and analysed for the most common technique settings. Relations were established between the dosimetric results and technical characteristics of the scanners. (Author)

Determination of elemental tissue composition following proton treatment using positron emission tomography

International Nuclear Information System (INIS)

Cho, Jongmin; Ibbott, Geoffrey; Gillin, Michael; Gonzalez-Lepera, Carlos; Min, Chul Hee; Zhu, Xuping; El Fakhri, Georges; Paganetti, Harald; Mawlawi, Osama

2013-01-01

Positron emission tomography (PET) has been suggested as an imaging technique for in vivo proton dose and range verification after proton induced-tissue activation. During proton treatment, irradiated tissue is activated and decays while emitting positrons. In this paper, we assessed the feasibility of using PET imaging after proton treatment to determine tissue elemental composition by evaluating the resultant composite decay curve of activated tissue. A phantom consisting of sections composed of different combinations of 1 H, 12 C, 14 N, and 16 O was irradiated using a pristine Bragg peak and a 6 cm spread-out Bragg-peak (SOBP) proton beam. The beam ranges defined at 90% distal dose were 10 cm; the delivered dose was 1.6 Gy for the near monoenergetic beam and 2 Gy for the SOBP beam. After irradiation, activated phantom decay was measured using an in-room PET scanner for 30 min in list mode. Decay curves from the activated 12 C and 16 O sections were first decomposed into multiple simple exponential decay curves, each curve corresponding to a constituent radioisotope, using a least-squares method. The relative radioisotope fractions from each section were determined. These fractions were used to guide the decay curve decomposition from the section consisting mainly of 12 C + 16 O and calculate the relative elemental composition of 12 C and 16 O. A Monte Carlo simulation was also used to determine the elemental composition of the 12 C + 16 O section. The calculated compositions of the 12 C + 16 O section using both approaches (PET and Monte Carlo) were compared with the true known phantom composition. Finally, two patients were imaged using an in-room PET scanner after proton therapy of the head. Their PET data and the technique described above were used to construct elemental composition ( 12 C and 16 O) maps that corresponded to the proton-activated regions. We compared the 12 C and 16 O compositions of seven ROIs that corresponded to the vitreous humor, adipose

Staging of pharyngeal cancer by computerized tomography during phonation. Comparison of CT findings with endoscopy and pharyngography

International Nuclear Information System (INIS)

Warmuth-Metz, M.; Feyerabend, T.; Schmitt, R.; Richter, E.

1989-01-01

46 patients with histologically proven carcinoma of the oro- and/or hypopharynx underwent clinical and endoscopic examination as well as double-contrast-pharyngography and computerized tomography (CT). The results of the different diagnostic procedures according to the TNM-classification (UICC) were compared with each other. Additional information by CT was obtained in 40% of cases. In 30%, the TNM-classification had to be changed up to one or even up to two T-categories. Major improvement of the CT-evaluation of carcinoma of the pharynx can be achieved by the additional use of CT during phonation: in our study 50% of pharyngeal cancers were thus better delimited in their extent and relations to the surrounding anatomical structures. Especially for the evaluation of the base of the tongue, the hypopharynx and the epiglottis CT during phonation (similar to the use of the double-contrast technique in pharyngography) is superior to CT at rest because the anatomy of the pharynx and therefore the extent of a mass is much better demonstrated. (orig.) [de

Multidetector computerized tomography enema versus magnetic resonance enema in the diagnosis of rectosigmoid endometriosis

Energy Technology Data Exchange (ETDEWEB)

Biscaldi, Ennio, E-mail: ennio.biscaldi@gmail.com [Department of Radiology, Galliera Hospital, via Mura delle Capuccine 14, 16128 Genoa (Italy); Ferrero, Simone, E-mail: simone.ferrero@unige.it [Department of Obstetrics and Gynecology, San Martino Hospital and National Institute for Cancer Research, University of Genoa, Largo Rosanna Benzi, 1, 16132 Genoa (Italy); Leone Roberti Maggiore, Umberto, E-mail: ulrm@libero.it [Department of Obstetrics and Gynecology, San Martino Hospital and National Institute for Cancer Research, University of Genoa, Largo Rosanna Benzi, 1, 16132 Genoa (Italy); Remorgida, Valentino, E-mail: vremorgida@yahoo.it [Department of Obstetrics and Gynecology, San Martino Hospital and National Institute for Cancer Research, University of Genoa, Largo Rosanna Benzi, 1, 16132 Genoa (Italy); Venturini, Pier Luigi, E-mail: venturini@unige.it [Department of Obstetrics and Gynecology, San Martino Hospital and National Institute for Cancer Research, University of Genoa, Largo Rosanna Benzi, 1, 16132 Genoa (Italy); Rollandi, Gian Andrea, E-mail: rollandi@galliera.it [Department of Radiology, Galliera Hospital, via Mura delle Capuccine 14, 16128 Genoa (Italy)

2014-02-15

Purpose: To compare the accuracy of multidetector computerized tomography enema (MDCT-e) and magnetic resonance enema (MRI-e) in determining the presence of sigmoid and rectal endometriotic nodules. Materials and methods: 260 women (32.6 ± 4.3 years) with symptoms suggestive of rectosigmoid endometriosis underwent MDCT-e and MRI-e prior to laparoscopy. After retrograde colonic distention and injection of intravenous contrast medium, patients were scanned on a 64-row MDCT scanner. MRI-e was performed on a 1.5 T magnet using an 8 channels phased array coil; intestinal distention was achieved by introducing in the rectum 250–300 ml of ultrasonographic gel diluted with saline solution. Radiological findings were compared with surgical and histological results. Results: 176 women had rectosigmoid endometriosis at surgery. There was no significant difference in the accuracy of MDCT-e (98.5%) and MRI-e (96.9%) in the diagnosis of sigmoid and rectal endometriosis (p = 0.248). The sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio of MDCT-e and MRI-e were respectively 98.3%, 98.8%, 99.4%, 96.5%, 81.59, 0.02 and 97.2%, 96.4%, 98.3%, 94.1%, 26.89, 0.03. Conclusions: Both MDCT-e and MRI-e are accurate in the diagnosis of rectal and sigmoid endometriosis.

Multidetector computerized tomography enema versus magnetic resonance enema in the diagnosis of rectosigmoid endometriosis

International Nuclear Information System (INIS)

Biscaldi, Ennio; Ferrero, Simone; Leone Roberti Maggiore, Umberto; Remorgida, Valentino; Venturini, Pier Luigi; Rollandi, Gian Andrea

2014-01-01

Purpose: To compare the accuracy of multidetector computerized tomography enema (MDCT-e) and magnetic resonance enema (MRI-e) in determining the presence of sigmoid and rectal endometriotic nodules. Materials and methods: 260 women (32.6 ± 4.3 years) with symptoms suggestive of rectosigmoid endometriosis underwent MDCT-e and MRI-e prior to laparoscopy. After retrograde colonic distention and injection of intravenous contrast medium, patients were scanned on a 64-row MDCT scanner. MRI-e was performed on a 1.5 T magnet using an 8 channels phased array coil; intestinal distention was achieved by introducing in the rectum 250–300 ml of ultrasonographic gel diluted with saline solution. Radiological findings were compared with surgical and histological results. Results: 176 women had rectosigmoid endometriosis at surgery. There was no significant difference in the accuracy of MDCT-e (98.5%) and MRI-e (96.9%) in the diagnosis of sigmoid and rectal endometriosis (p = 0.248). The sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio of MDCT-e and MRI-e were respectively 98.3%, 98.8%, 99.4%, 96.5%, 81.59, 0.02 and 97.2%, 96.4%, 98.3%, 94.1%, 26.89, 0.03. Conclusions: Both MDCT-e and MRI-e are accurate in the diagnosis of rectal and sigmoid endometriosis

Evaluation for computerized axial tomography to three anthropomorphic methods to estimate the thigh muscle area

International Nuclear Information System (INIS)

Fernandez Vieitez, Jorge Alberto; Alvarez Cuesta, Jose Alberto; Williams Wilson, Luis

2001-01-01

Three anthropometric methods to estimate the thigh muscle area (TMA, cm) were evaluated. Seventeen young males were taken as a sample. The TMA was estimated by using the formulas of Gurney-Jellife, Jones-Pearson, Housh, and others. In the same place where the measurements of circumferences and skinfolds were made, the TAM was determined by computerized axial tomography. It was used as a reference criterion with which the anthropometric values were compared. The methods of Gurney-Jellife and Jones-Pearson significantly overestimated the TAM obtained by CAT (9.0 + - 12.8 cm 2 [4.4 %]; p = 0.01 and 22.0 + - 14.9 cm 2 [10.9 %]; p = 1.6 . 10-5, respectively), whereas that of Housh and others underestimated the values of CAT (-48.8 + - 11.7 cm 2 [24.1 %]; p = 9.4 . 10-12). The Gurney-Jellife equation was the only one that proved to be interchangeable with CAT, on obtaining a coefficient of correlation (r) and a slope of regression (b) for the difference and the average between both methods that were not statistically significant (r 0,421; b = 0,21 + - 0.12, p = 0.09). It was concluded that of the 3 studied anthropometric methods, the Gurney-Jellife method offers the most accurate TAM values

Expected proton signal sizes in the PRaVDA Range Telescope for proton Computed Tomography

International Nuclear Information System (INIS)

Price, T.; Parker, D.J.; Green, S.; Esposito, M.; Waltham, C.; Allinson, N.M.; Poludniowski, G.; Evans, P.; Taylor, J.; Manolopoulos, S.; Anaxagoras, T.; Nieto-Camero, J.

2015-01-01

Proton radiotherapy has demonstrated benefits in the treatment of certain cancers. Accurate measurements of the proton stopping powers in body tissues are required in order to fully optimise the delivery of such treaments. The PRaVDA Consortium is developing a novel, fully solid state device to measure these stopping powers. The PRaVDA Range Telescope (RT), uses a stack of 24 CMOS Active Pixel Sensors (APS) to measure the residual proton energy after the patient. We present here the ability of the CMOS sensors to detect changes in the signal sizes as the proton traverses the RT, compare the results with theory, and discuss the implications of these results on the reconstruction of proton tracks

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)

SU-E-J-63: Feasibility Study of Proton Digital Tomosynthesis in Proton Beam Therapy.

Science.gov (United States)

Min, B; Kwak, J; Lee, J; Cho, S; Park, S; Yoo, S; Chung, K; Cho, S; Lim, Y; Shin, D; Lee, S; Kim, J

2012-06-01

We investigated the feasibility of proton tomosynthesis as daily positioning of patients and compared the results with photon tomosynthesis as an alternative to conventional portal imaging or on-board cone-beam computed tomography. Dedicated photon-like proton beam using the passively scattered proton beams by the cyclotron was generated for proton imaging. The eleven projections were acquired over 30 degree with 3 degree increment in order to investigate the performance of proton tomosynthesis. The cylinder blocks and resolution phantom were used to evaluate imaging performance. Resolution phantom of a cylinder of diameter 12 cm was used to investigate the reconstructed imaging characteristics. Electron density cylinder blocks with diameter of 28 mm and height of 70 mm were employed to assess the imaging quality. The solid water, breast, bone, adipose, lung, muscle, and liver, which were tissue equivalent inserts, were positioned around the resolution phantom. The images were reconstructed by projection onto convex sets (POCS) algorithm and total variation minimization (TVM) methods. The Gafchromic EBT films were utilized for measuring the photon-like proton beams as a proton detector. In addition, the photon tomosynthesis images were obtained for a comparison with proton tomosynthesis images. The same angular sampling data were acquired for both proton and photon tomosynthesis. In the resolution phantom image obtained proton tomosynthesis, down to 1.6 mm diameter rods were resolved visually, although the separation between adjacent rods was less distinct. In contrast, down to 1.2 mm diameter rods were resolved visually in the reconstructed image obtained photon tomosynthesis. Both proton and photon tomosynthesis images were similar in intensities of different density blocks. Our results demonstrated that proton tomosynthesis could make it possible to provide comparable tomography imaging to photon tomosynthesis for positioning as determined by manual registration

Polarized proton target-IV. Operations manual

International Nuclear Information System (INIS)

Hill, D.; Fletcher, O.; Moretti, A.; Onesto, F.

1976-01-01

Standard operating procedures are presented for the vacuum, cryogenic, and electronic systems of a polarized proton target. The systems are comprised of (1) a target cryostat; (2) a 4 He pumping system; (3) a 3 He pumping system; (4) a microwave system; (5) a magnet and power supply; (6) a computerized polarization monitor; and (7) miscellaneous auxiliary equipment

Comparison of micro-computerized tomography and cone-beam computerized tomography in the detection of accessory canals in primary molars.

Science.gov (United States)

Acar, Buket; Kamburoğlu, Kıvanç; Tatar, İlkan; Arıkan, Volkan; Çelik, Hakan Hamdi; Yüksel, Selcen; Özen, Tuncer

2015-12-01

This study was performed to compare the accuracy of micro-computed tomography (CT) and cone-beam computed tomography (CBCT) in detecting accessory canals in primary molars. Forty-one extracted human primary first and second molars were embedded in wax blocks and scanned using micro-CT and CBCT. After the images were taken, the samples were processed using a clearing technique and examined under a stereomicroscope in order to establish the gold standard for this study. The specimens were classified into three groups: maxillary molars, mandibular molars with three canals, and mandibular molars with four canals. Differences between the gold standard and the observations made using the imaging methods were calculated using Spearman's rho correlation coefficient test. The presence of accessory canals in micro-CT images of maxillary and mandibular root canals showed a statistically significant correlation with the stereomicroscopic images used as a gold standard. No statistically significant correlation was found between the CBCT findings and the stereomicroscopic images. Although micro-CT is not suitable for clinical use, it provides more detailed information about minor anatomical structures. However, CBCT is convenient for clinical use but may not be capable of adequately analyzing the internal anatomy of primary teeth.

Computed tomography for radiographers

International Nuclear Information System (INIS)

Brooker, M.J.

1986-01-01

This book is directed towards giving radiographers an introduction to and basic knowledge of computerized tomography. The technical section discusses gantries and x-ray production, computer and disc drive image display, storage, artefacts quality assurance and design of departments. The clinical section includes patient preparation, radiotherapy planning, and interpretation of images from various areas of the anatomy. (U.K.)

2D histomorphometric quantification from 3D computerized tomography

International Nuclear Information System (INIS)

Lima, Inaya; Oliveira, Luis Fernando de; Lopes, Ricardo T.; Jesus, Edgar Francisco O. de; Alves, Jose Marcos

2002-01-01

In the present article, preliminary results are presented showing the application of the tridimensional computerized microtomographic technique (3D-μCT) to bone tissue characterization, through histomorphometric quantification which are based on stereologic concepts. Two samples of human bone were correctly prepared to be submitted to the tomographic system. The system used to realize that process were a radiographic system with a microfocus X-ray tube. Through these three processes, acquisition, reconstruction and quantification, it was possible to get the good results and coherent to the literature data. From this point, it is intended to compare these results with the information due the conventional method, that is, conventional histomorphometry. (author)

The magnetic field gradients generation for magnetic resonance tomography; Generacja gradientow pola magnetyczbego dla tomografii MR

Energy Technology Data Exchange (ETDEWEB)

Jasinski, A.; Skorka, T.; Kwiecinski, S. [Institute of Nuclear Physics, Cracow (Poland)

1994-12-31

To obtain three-dimensional images in the computerized tomography a gradient of magnetic field should be generated. In this paper the analytical as well as computerized calculations of magnetic coils for such purposes are presented. 4 refs, 8 figs.

The optimal balance between quality and efficiency in proton radiography imaging technique at various proton beam energies : A Monte Carlo study

NARCIS (Netherlands)

Biegun, A K; van Goethem, M-J; van der Graaf, E R; van Beuzekom, M; Koffeman, E N; Nakaji, T; Takatsu, J; Visser, J; Brandenburg, S

Proton radiography is a novel imaging modality that allows direct measurement of the proton energy loss in various tissues. Currently, due to the conversion of so-called Hounsfield units from X-ray Computed Tomography (CT) into relative proton stopping powers (RPSP), the uncertainties of RPSP are

The radiologic finding in pneumomediastinum. Value of conventional radiography and comparison with computerized tomography

International Nuclear Information System (INIS)

Martin, M.F.; Hlawatsch, A.; Heussel, C.P.; Schweden, F.; Kauczor, H.U.

1997-01-01

Pneumomediastinum, or mediastinal emphysema, may be difficult to demonstrate and is not always easy to differentiate from pneumothorax and pneumopericardium by conventional radiography, especially in severely ill patients. In this article, we evaluate the sensitivity of plain films in detecting pneumomediastinum, and describe the conventional radiography and computerized tomography (CT) findings associated with this entity. The etiology and CT findings in 24 patients who had been diagnosed as having pneumomediastinum by CT were reviewed. Conventional radiographs were available for review in 19 of these cases. Radiographic and CT findings were retrospectively compared, using CT as reference technique. We looked for abnormal mediastinal air collections and their location, as well as pathologic findings such as pneumothorax or pneumopericardium. Classical radiographic signs were also evaluated. Conventional radiography showed mediastinal air in 17 patients (89,5%) and classical radiographic signs were observed in 13 (68,4%). The results of the comparative study of plain films and CT revealed the following sites of mediastinal air: superior mediastinum (9/15), anterior mediastinum (14/19), middle mediastinum (7/12) and posterior mediastinum (4/14). The incidences of pneumothorax (7/12) and pneumopericardium (1/4) were also recorded. The comparative study of conventional radiography and CT demonstrated that Ct is a more reliable technique for determining the diagnosis, location and extent of pneumomediastinum and differentiating it from pneumothorax and pneumopericardium, especially in severely ill patients. Therefore, CT is recommended in patients with evident clinical suspicion of pneumomediastinum. (Author) 23 refs

A high-speed computerized tomography image reconstruction using direct two-dimensional Fourier transform method

International Nuclear Information System (INIS)

Niki, Noboru; Mizutani, Toshio; Takahashi, Yoshizo; Inouye, Tamon.

1983-01-01

The nescessity for developing real-time computerized tomography (CT) aiming at the dynamic observation of organs such as hearts has lately been advocated. It is necessary for its realization to reconstruct the images which are markedly faster than present CTs. Although various reconstructing methods have been proposed so far, the method practically employed at present is the filtered backprojection (FBP) method only, which can give high quality image reconstruction, but takes much computing time. In the past, the two-dimensional Fourier transform (TFT) method was regarded as unsuitable to practical use because the quality of images obtained was not good, in spite of the promising method for high speed reconstruction because of its less computing time. However, since it was revealed that the image quality by TFT method depended greatly on interpolation accuracy in two-dimensional Fourier space, the authors have developed a high-speed calculation algorithm that can obtain high quality images by pursuing the relationship between the image quality and the interpolation method. In this case, radial data sampling points in Fourier space are increased to β-th power of 2 times, and the linear or spline interpolation is used. Comparison of this method with the present FBP method resulted in the conclusion that the image quality is almost the same in practical image matrix, the computational time by TFT method becomes about 1/10 of FBP method, and the memory capacity also reduces by about 20 %. (Wakatsuki, Y.)

Computerized tomography attenuation values can be used to differentiate hydronephrosis from pyonephrosis.

Science.gov (United States)

Yuruk, Emrah; Tuken, Murat; Sulejman, Suhejb; Colakerol, Aykut; Serefoglu, Ege Can; Sarica, Kemal; Muslumanoglu, Ahmet Yaser

2017-03-01

To determine the diagnostic value of computerized tomography (CT) in differentiating pyonephrosis from hydronephrosis on the basis of attenuation values (Hounsfield unit-HU). Data of the patients with grades 1-3 hydronephrosis on abdominopelvic CT, who underwent nephrostomy tube placement for decompression of the collecting system, were retrospectively analyzed. Patient demographics and CT findings were recorded along with the first access urine culture results. Three physicians calculated the surface areas and the attenuation values of the dilated collecting systems using the system software. Mean HU of pyonephrosis and hydronephrosis cases was compared. A total of 105 patients with the mean age of 47.7 ± 15.5 (range 20-80) were included. The interclass correlation coefficient of three physicians was 0.981 for HU measurement and 0.999 for calculation of collecting system surface area. Of the patients, 47 (44.8 %) had pyonephrosis. Mean surface areas of the collecting system were similar in patients with pyonephrosis and hydronephrosis (1481.13 ± 1562.94 vs. 1612.94 ± 2261.4 mm 2 , p = 0.735). Urine cultures were positive in all patients with pyonephrosis, whereas 12.7 % of hydronephrosis cases had bacterial in first access urine culture. The HU of the patients with pyonephrosis was significantly higher that that of patients with hydronephrosis (13.51 ± 13.29 vs. 4.67 ± 5.37, p = 0.0001). Having a HU of 9.21 or over diagnosed pyonephrosis accurately with 65.96 % sensitivity and 87.93 % specificity. Measuring attenuation values of the collecting system may be useful to differentiate pyonephrosis from hydronephrosis. Diagnosing pyonephrosis accurately may avoid septic complications.

Comparison of micro-computerized tomography and cone-beam computerized tomography in the detection of accessory canals in primary molars

Energy Technology Data Exchange (ETDEWEB)

Acar, Buket; Kamburoglu, Kivanc [Dept. of Dentomaxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara (Turkmenistan); Tatar, Ilkan [Dept. of Anatomy, Faculty of Medicine, Hacettepe University, Ankara (Turkmenistan); Arikan, Volkan [Dept. of Anatomy, Faculty of Medicine, Hacettepe University, Ankara (Turkmenistan); Celik, Hakan Hamid [Dept. of Pediatric Dentistry, Faculty of Dentistry, Kirikkale Unversity, Ankara (Turkmenistan); Yuksel, Selcen [Dept. of Biostatistics, Faculty of Medicine, Yildirim Beyazit University, Ankara (Turkmenistan); Ozen, Tuncer [Dept. of Dentomaxillofacial Radiology, Gulhane Military Hospital, Dental Clinics, Ankara (Turkmenistan)

2015-12-15

This study was performed to compare the accuracy of micro-computed tomography (CT) and cone-beam computed tomography (CBCT) in detecting accessory canals in primary molars. Forty-one extracted human primary first and second molars were embedded in wax blocks and scanned using micro-CT and CBCT. After the images were taken, the samples were processed using a clearing technique and examined under a stereomicroscope in order to establish the gold standard for this study. The specimens were classified into three groups: maxillary molars, mandibular molars with three canals, and mandibular molars with four canals. Differences between the gold standard and the observations made using the imaging methods were calculated using Spearman's rho correlation coefficient test. The presence of accessory canals in micro-CT images of maxillary and mandibular root canals showed a statistically significant correlation with the stereomicroscopic images used as a gold standard. No statistically significant correlation was found between the CBCT findings and the stereomicroscopic images.Although micro-CT is not suitable for clinical use, it provides more detailed information about minor anatomical structures. However, CBCT is convenient for clinical use but may not be capable of adequately analyzing the internal anatomy of primary teeth.

Comparison of micro-computerized tomography and cone-beam computerized tomography in the detection of accessory canals in primary molars

International Nuclear Information System (INIS)

Acar, Buket; Kamburoglu, Kivanc; Tatar, Ilkan; Arikan, Volkan; Celik, Hakan Hamid; Yuksel, Selcen; Ozen, Tuncer

2015-01-01

This study was performed to compare the accuracy of micro-computed tomography (CT) and cone-beam computed tomography (CBCT) in detecting accessory canals in primary molars. Forty-one extracted human primary first and second molars were embedded in wax blocks and scanned using micro-CT and CBCT. After the images were taken, the samples were processed using a clearing technique and examined under a stereomicroscope in order to establish the gold standard for this study. The specimens were classified into three groups: maxillary molars, mandibular molars with three canals, and mandibular molars with four canals. Differences between the gold standard and the observations made using the imaging methods were calculated using Spearman's rho correlation coefficient test. The presence of accessory canals in micro-CT images of maxillary and mandibular root canals showed a statistically significant correlation with the stereomicroscopic images used as a gold standard. No statistically significant correlation was found between the CBCT findings and the stereomicroscopic images.Although micro-CT is not suitable for clinical use, it provides more detailed information about minor anatomical structures. However, CBCT is convenient for clinical use but may not be capable of adequately analyzing the internal anatomy of primary teeth

Non-contrast computerized tomography (NCCT) and dynamic renal scintigraphy (DRS) in the patients with refractory renal colic

International Nuclear Information System (INIS)

Kravchick, Sergey; Stepnov, Eugeny; Lebedev, Valery; Linov, Lina; Leibovici, Octavian; Ben-Horin, Clara L. Dosoretz; Trejo, Leonardo; Peled, Ronit; Cytron, Shmuel

2006-01-01

Objectives: To assess the importance of combined use of non-contrast computerized tomography (NCCT) and dynamic renal scintigraphy (DRS) in evaluation of patients with refractory flank pain in the emergency department. Methods: The study involved 64 consecutive patients with refractory renal colic. All patients were evaluated with plain abdominal films kidneys, ureters and bladder (KUB), NCCT and DRS. We assessed the accuracy of different diagnostic procedures and their combinations; in addition, we determined their importance for different steps of evaluation. Results: Urololithiasis was diagnosed in 76.6% (n = 49) of the patients. Twenty-nine percent of calculi were >4 mm. Surgical intervention were performed in 20 patients (40.8%). A combination of NCCT plus DRS yielded the greatest sensitivity (96%) in establishing final diagnosis, however clinical, laboratory and KUB data in combination with DRS, yielded greater specificity (93%) and PPV (97%). Sex (male), WBC (mean 10.2 x 10 3 ± 3.1) and KUB (calculus > 4 mm) were chosen in the three-step multi-variant analysis, while only male sex was found to be the strongest predictor (p 3 and calculi > 4 mm on the KUB

Computed Tomography Status

Science.gov (United States)

Hansche, B. D.

1983-01-01

Computed tomography (CT) is a relatively new radiographic technique which has become widely used in the medical field, where it is better known as computerized axial tomographic (CAT) scanning. This technique is also being adopted by the industrial radiographic community, although the greater range of densities, variation in samples sizes, plus possible requirement for finer resolution make it difficult to duplicate the excellent results that the medical scanners have achieved.

Problems of cranial computer-tomography

Energy Technology Data Exchange (ETDEWEB)

Seitz, D [Allgemeines Krankenhaus St. Georg, Hamburg (Germany, F.R.). Neurologische Abt.

1979-07-01

The author discusses the problems that have cropped up since the introduction of computerized tomography 5 years ago. To begin with, problems of contrast and object resolution are discussed with a special view to the importance of amipague imaging of cisterns, in particular in the detection of basal growing and displacing, intracranial processes. After this, the tasks of computerized tomography in neurological and neurosurgical emergencies, cerebrocranial injuries, cerebral circulation disturbances, inflammatory diseases of the central nervous systems, epileptic seizures, and chronical headaches are reviewed. Special regard is given to the problem of recurrent examinations and course control, especially in cerebral tumours and aresorptive hydrocephalus. Another paragraph deals with the correlation between CT findings, clinical symptoms, and clinical findings. The importance of cranial CT for neurological diagnoses is illustrated by the change of indications for conventional methods of examination. The limits of the method are shown and it is pointed out that cranial CT is not a search technique but that it requires previous examinations by a neurologist, neurosurgeon, or neuropaediatrician.

Problems of cranial computer-tomography

International Nuclear Information System (INIS)

Seitz, D.

1979-01-01

The author discusses the problems that have cropped up since the introduction of computerized tomography 5 years ago. To begin with, problems of contrast and object resolution are discussed with a special view to the importance of amipague imaging of cisterns, in particular in the detection of basal growing and displacing, intracranial processes. After this, the tasks of computerized tomography in neurological and neurosurgical emergencies, cerebrocranial injuries, cerebral circulation disturbances, inflammatory diseases of the central nervous systems, epileptic seizures, and chronical headaches are reviewed. Special regard is given to the problem of recurrent examinations and course control, especially in cerebral tumours and aresorptive hydrocephalus. Another paragraph deals with the correlation between CT findings, clinical symptoms, and clinical findings. The importance of cranial CT for neurological diagnoses is illustrated by the change of indications for conventional methods of examination. The limits of the method are shown and it is pointed out that cranial CT is not a search technique but that it requires previous examinations by a neurologist, neurosurgeon, or neuropaediatrician. (orig.) [de

Nonoperative treatment of splenic trauma: usefulness of computed tomography; Tratamento conservador do trauma esplenico: utilidade da tomografia computadorizada

Energy Technology Data Exchange (ETDEWEB)

Resende, Vivian [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Faculdade de Medicina; Tavares Junior, Wilson Campos; Vieira, Jose Nelson Mendes [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Hospital das Clinicas. Dept. de Radiologia e Diagnostico por Imagem]. E-mail: wilsontavaresjrmd@yahoo.fr; Drumond, Domingos Andre Fernandes [Hospital Joao XXIII, Belo Horizonte, MG (Brazil). Setor de Clinica Cirurgica

2005-04-15

Objective: to report the results of use of conservative treatment in patients with splenic trauma and to emphasize the usefulness of computed tomography in these cases. Material and method: sixty-nine cases of pediatric patients with blunt abdominal trauma seen from from January 2001 to June 2004 at the level I trauma center were retrospectively studied. Forty-four of these patients were submitted to nonoperative treatment and the clinical follow-up was performed by computerized tomography. All patients had been diagnosed with splenic injury by computerized tomography.Results: the causes of the injuries were motor vehicle accident in 12 (27.2%) patients, bicycle accident in nine (20.4%) patients, and falls in 23 (52.2%) patients. Two (3.7%) patients died from associated injuries. The mean duration of hospital stay was six days. The mean age of the patients was nine years. Conclusion: conservative treatment for blunt splenic trauma is performed with the aim of reducing costs and risks for the patients, and computerized tomography should be routinely used. No posterior complications were observed in this approach. (author)

Interictal "patchy" regional cerebral blood flow patterns in migraine patients. A single photon emission computerized tomographic study

DEFF Research Database (Denmark)

Friberg, L; Olesen, J; Iversen, Helle Klingenberg

1994-01-01

In 92 migraine patients and 44 healthy control subjects we recorded regional cerebral blood flow (rCBF) with single photon emission computerized tomography and (133) Xe inhalation or with i.v. (99m) Tc-HMPAO. Migraine patients were studied interictally. A quantitated analysis of right-left asymme......In 92 migraine patients and 44 healthy control subjects we recorded regional cerebral blood flow (rCBF) with single photon emission computerized tomography and (133) Xe inhalation or with i.v. (99m) Tc-HMPAO. Migraine patients were studied interictally. A quantitated analysis of right...... rCBF images is insufficient to pick up abnormalities; (2) almost 50% of the migraine sufferers had abnormal rCBF/asymmetries. However, these are discrete compared with those typically seen during the aura phase of a migraine attack. One explanation to the patchy rCBF patterns might...

Ultrasonic and computerized tomographic semiotics of cholelithiasis

International Nuclear Information System (INIS)

Kishkovskij, A.N.; Kuznetsov, S.V.; Fadeev, V.D.

1986-01-01

Altogether 447 patients with suspected cholelithiasis were examined by means of routine X-ray methods, ultrasound (US) and computerized tomography (CT).Of them in 104 (23.3%) chole- and/or choledocholithiasis were later confirmed. An US and CT-picture of the biliferous tracts in health were described.In cholelithiasis during US examination echogenic concrements producing a stable acoustic shadow were defined in the gall bladder cavity and/or in the biliferous ducts. A study was made of the features of the US picture with relation to size, quantity, echodensity and grouping of concrements in the biliferous ducts. CT-symptomatology of cholelithiasis was described

Mapping local cerebral blood flow by means of computerized tomography with a short inhalation of low-dose stable xenon

International Nuclear Information System (INIS)

Nakagawara, Jyoji; Karasawa, Jun; Tasawa, Toshiaki; Touho, Hajime; Nakauchi, Mikio; Kagawa, Masa-aki; Asai, Masa-aki; Kuriyama, Yoshihiro; Kikuchi, Haruhiko.

1986-01-01

A non-invasive technique has been developed for mapping the local blood-brain partition coefficient (λi), the local build-up rate constant (κi), and the local cerebral blood flow (l-CBF) by means of xenon-enhanced computerized tomography (CT) using a YMS CT 9000 scanner. After denitrogenation for 10 minutes, a 30 % xenon/oxygen mixture is inhaled for 4 - 8 minutes through a rubber face-mask and a delivery system of stable xenon. The time course of local cerebral CT enhancement is utilized in order to calculate, the λi, κi, and l-CBF values. The CT enhancement data during the washin-washout phase are fitted to the mathematical functions, based on Kety's formula, using least-squares curve-fitting analysis. Several case studies of patients with cerebral vascular accidents are presented to demonstrate the characterization of the λi and l-CBF patterns in various tissues; the results are of sufficient quality for the management of patients. The theoretical assumptions underlying stable xenon CT CBF measurements are discussed. (author)

Computerized tomography of the otic capsule and otoliths in the oyster toadfish, Opsanus tau.

Science.gov (United States)

Edds-Walton, Peggy L; Arruda, Julie; Fay, Richard R; Ketten, Darlene R

2015-02-01

The neurocranium of the toadfish (Opsanus tau) exhibits a distinct translucent region in the otic capsule (OC) that may have functional significance for the auditory pathway. This study used ultrahigh resolution computerized tomography (100 µm voxels) to compare the relative density of three sites along the OC (dorsolateral, midlateral, and ventromedial) and two reference sites (dorsal: supraoccipital crest; ventral: parasphenoid bone) in the neurocranium. Higher attenuation occurs where structural density is greater; thus, we compared the X-ray attenuations measured, which provided a measure of relative density. The maximum attenuation value was recorded for each of the five sites (x and y) on consecutive sections throughout the OC and for each of the three calcareous otoliths associated with the sensory maculae (lagena, saccule, and utricle) in the OC. All three otoliths had higher attenuations than any sites in the neurocranium. Both dorsal and ventral reference sites (supraoccipital crest and parasphenoid bone, respectively) had attenuation levels consistent with calcified bone and had relatively small, irregular variations along the length of the OC in all individuals. The lowest relative attenuations (lowest densities) occurred consistently at the three sites along the OC. In addition, the lowest attenuations measured along the OC occurred at the ventromedial site around the saccular otolith for all seven fish. The decrease in bone density along the OC is consistent with the hypothesis that there is a low-density channel in the skull to facilitate transmission of acoustic stimuli to the auditory endorgans of the ear. © 2014 Wiley Periodicals, Inc.

A Computerized Tomography Study of Vocal Tract Setting in Hyperfunctional Dysphonia and in Belting.

Science.gov (United States)

Saldias, Marcelo; Guzman, Marco; Miranda, Gonzalo; Laukkanen, Anne-Maria

2018-04-03

Vocal tract setting in hyperfunctional patients is characterized by a high larynx and narrowing of the epilaryngeal and pharyngeal region. Similar observations have been made for various singing styles, eg, belting. The voice quality in belting has been described to be loud, speech like, and high pitched. It is also often described as sounding "pressed" or "tense". The above mentioned has led to the hypothesis that belting may be strenuous to the vocal folds. However, singers and teachers of belting do not regard belting as particularly strenuous. This study investigates possible similarities and differences between hyperfunctional voice production and belting. This study concerns vocal tract setting. Four male patients with hyperfunctional dysphonia and one male contemporary commercial music singer were registered with computerized tomography while phonating on [a:] in their habitual speaking pitch. Additionally, the singer used the pitch G4 in belting. The scannings were studied in sagittal and transversal dimensions by measuring lengths, widths, and areas. Various similarities were found between belting and hyperfunction: high vertical larynx position, small hypopharyngeal width, and epilaryngeal outlet. On the other hand, belting differed from dysphonia (in addition to higher pitch) by a wider lip and jaw opening, and larger volumes of the oral cavity. Belting takes advantage of "megaphone shape" of the vocal tract. Future studies should focus on modeling and simulation to address sound energy transfer. Also, they should consider aerodynamic variables and vocal fold vibration to evaluate the "price of decibels" in these phonation types. Copyright © 2018. Published by Elsevier Inc.

Cerebral perfusion computerized tomography: influence of reference vessels, regions of interest and interobserver variability

International Nuclear Information System (INIS)

Soustiel, Jean F.; Mor, Nadav; Zaaroor, Menashe; Goldsher, Dorith

2006-01-01

There are still no standardized guidelines for perfusion computerized tomography (PCT) analysis. A total of 61 PCT studies were analyzed using either the anterior cerebral artery (ACA) or the middle cerebral artery (MCA) as the arterial reference, and the superior sagittal sinus (SSS) or the vein of Galen (VG) as the venous reference. The sizes of regions of interest (ROI) were investigated comparing PCT results obtained using a hemispheric ROI combined with vascular pixel elimination with those obtained using five smaller ROIs located over the cortex and basal ganglia. In addition, interobserver variations were explored using a standardized protocol. MCA-based measurements of cerebral blood flow (CBF) and blood volume (CBV) were in accordance with those obtained with the ACA except in 16 patients with ischemic stroke, in whom CBF was overestimated by the ipsilateral MCA. Venous maximal intensity was significantly lower with the VG when compared with the SSS, resulting in overestimation of CBF and CBV. However, in 13.3% of patients the VG ROI yielded higher maximal intensities than the SSS ROI. There was no difference in PCT results between hemispheric ROI and averaged separate ROI when vascular pixel elimination was used. Finally, interobserver variations were as high as 11% for CBF and 12% for CBV. The present results suggest that pathological rather than anatomical considerations should dictate the choice of the arterial ROI. For venous ROI, although SSS seems to be adequate in most instances, deep cerebral veins may occasionally generate higher maximal intensities and should therefore be selected. Importantly, significant user-dependency should be taken into account. (orig.)

Value of conventional tomography and computerized tomography in therapy resistant affections of the nasal sinuses

International Nuclear Information System (INIS)

Rieden, K.; Frey, M.; Mayer, B.

1986-01-01

The informational value of conventional tomography as primary diagnostic method is pointed out in diseases of nasal sinuses resistant to therapy. 5 cases demonstrate the additional information gained by CT-differentiation of soft tissue structures, intraorbital and intracranial expansion. In 78.4% of the examined group of 51 patients conventional tomography allowed the diagnosis of a process limited to the nasal sinuses, further evidence by CT could be omitted. In 11 patients examined by CT additionally, the expansion of the process was defined more precisely and the assumed intraorbital and intracranial growth confirmed. (orig.) [de

Computed tomography of tibial plateau fractures

International Nuclear Information System (INIS)

Rafii, M.; Firooznia, H.; Golimbu, C.; Bonamo, J.

1984-01-01

Twenty patients with tibial plateau fractures were studied by conventional tomography and computed tomography (CT) in order to determine the role and feasibility of CT in management of such patients. CT resulted in less discomfort to the patient and provided optimal visualization of the plateau defect and the split fragments. It proved more accurate than conventional tomography in assessing depressed and split fractures when they involved the anterior or posterior border of the plateau and in demonstrating the extent of fracture comminution. Split fragments with an oblique plane of fracture also were seen better by CT. The degree of fracture depression and separation as measured by the computerized technique was often more accurate than measurements obtained from conventional tomograms

Principles of medical imaging with emphasis on tomography

Energy Technology Data Exchange (ETDEWEB)

Kouris, K [Institute of Nuclear Medicine, University College, London Medical School, Mortimer Street, London W1N 8AA (United Kingdom)

1994-12-31

Medical imaging with ionizing and non-ionizing radiations belongs to the class of problems known as indirect sensing. This article is concerned with imaging methods known as image reconstruction from projections or computerized tomography. A brief comparative study of the theory is presented. Depending on the nature and modes of propagation of the employed radiation, methods are discussed either under transmission tomography (with gamma rays and X rays) or emission tomography (with gamma rays and positrons). Magnetic resonance Imaging (MRI) is described as resonant absorption and re-emission of radiofrequency energy. (author). 6 refs, 1 fig.

The use of computed tomography in the differential diagnosis of late epilepsy

International Nuclear Information System (INIS)

Annewanter, B.

1981-01-01

The report refers to 299 patients suffering from late epilepsies who were examined both clinically and by computed tomography. The cases were classified according to clinical tentative diagnoses and types of attacks. The objective was to find out how useful computerized tomography is in differential diagnosis concerning the aetiology of late epilepsies. (orig./MG) [de

Preoperative evaluation of hilar vessel anatomy with 3-D computerized tomography in living kidney donors.

Science.gov (United States)

Tombul, S T; Aki, F T; Gunay, M; Inci, K; Hazirolan, T; Karcaaltincaba, M; Erkan, I; Bakkaloglu, A; Yasavul, U; Bakkaloglu, M

2008-01-01

Digital subtract angiography is the gold standard for anatomic assessment of renal vasculature for living renal donors. However, multidetector-row computerized tomography (MDCT) is less invasive than digital subtract angiography and provides information of kidney stones and other intra-abdominal organs. In this study, preoperative MDCT angiography results were compared with the peroperative findings to evaluate the accuracy of MDCT for the evaluation of renal anatomy. From December 2002 to May 2007, all 60 consecutive living kidney donors were evaluated with MDCT angiography preoperatively. We reported the number and origin of renal arteries, presence of early branching arteries, and any intrinsic renal artery disease. Renal venous anatomy was evaluated for the presence of accessory, retroaortic, and circumaortic veins using venous phase axial images. The calyces and ureters were assessed with delayed topograms. The results of the MDCT angiography were compared with the peroperative findings. A total of 67 renal arteries were seen peroperatively in 60 renal units. Preoperative MDCT angiography detected 64 of them. The two arteries not detected by MDCT had diameters less than 3 mm. Anatomic variations were present in nine veins, five of which were detected by CT angiography. Sensitivity of MDCT angiography for arteries and veins was 95% and 93%, respectively. Positive predictive values were 100% for both arteries and veins. MDCT angiography offers a less invasive, rapid, and accurate preoperative investigation modality for vascular anatomy in living kidney donors. It also provides sufficient information about extrarenal anatomy important for donor surgery.

Evaluation of Biomaterials Using Micro-Computerized Tomography

International Nuclear Information System (INIS)

Torris, A. T. Arun; Columbus, K. C. Soumya; Saaj, U. S.; Krishnan, Kalliyana V.; Nair, Manitha B.

2008-01-01

Micro-computed tomography or Micro-CT is a high resolution, non-invasive, x-ray scanning technique that allows precise three-dimensional imaging and quantification of micro-architectural and structural parameters of objects. Tomographic reconstruction is based on a cone-beam convolution-back-projection algorithm. Micro-architectural and structural parameters such as porosity, surface area to volume ratio, interconnectivity, pore size, wall thickness, anisotropy and cross-section area of biomaterials and bio-specimens such as trabecular bone, polymer scaffold, bio-ceramics and dental restorative were evaluated through imaging and computer aided manipulation of the object scan data sets.

Examinations with computerized cranial axial tomography carried out on patients with epileptic seizures, taking into consideration the EEG and the clinical picture

International Nuclear Information System (INIS)

Geiser, R.

1982-01-01

204 patients suffering from epileptic seizures were examined with the help of computerized cranial X-ray tomography; the results were compared with anamnestic, clinical, and EEC-findings. In good agreement with results published in literature, in 54% of the patients pathologic CT's such as tumours, attack scars, changes in ventricles and arachnoid spaces etc. were found. A pathological CT is very likely to appear in male patients who are 30 or even 50 years of age, having partial attacks with elementary symptoms, focal diagnosis in the EEG and a neurological unilateral finding. Especially noteworthy is the tumour detecting rate achieved by CT and the fact that in nearly 5% of the cases CT detected a cerebral lesion which has not been suspected, neither clinically nor in the EEG (4 tumours). This shows clearly that CT represents a heighly valuable diagnostic help, especially for patients with epileptic seizures. (orig./MG) [de

Epiploic appendicitis and omental infarction. Findings in the ultrasonography and computerized tomography; Apendicitis epiploica e infarto omental. Hallazgos en ecografia y tomografia computarizada

Energy Technology Data Exchange (ETDEWEB)

Migule, A.; Ripolles, T.; Martinez, M. J.; Morote, V.; Ruiz, A. [Hospital Universitario Dr. Peset. Valencia (Spain)

2001-07-01

Describe the findings in the ultrasonography and computerized tomography (CT) of the omental infarction and epiploic appendicitis. The clinical and radiological findings of the patients diagnosed in our hospital with epiploic appendicitis or omental infarctions between August 1994 and March 2001 were assessed retrospectively. We found a high incidence (42 cases) of these two diseases: 30 patients with diagnosis of epiploic appendicitis and 12 with the diagnosis of omental infarction. Four patients were treated surgically, while the remaining 38 were conservatively, without posterior complications. The ultrasonography and CT images is characteristics. making it possible to make a diagnosis of epiploic appendicitis or omental infarction with certainty. It is not necessary to make a differential diagnosis between the two entities because their prognosis and treatment are similar. Their incidence is much more frequent than that previously published. (Author) 19 refs.

Contemporary imaging: Magnetic resonance imaging, computed tomography, and interventional radiology

International Nuclear Information System (INIS)

Goldberg, H.I.; Higgins, C.; Ring, E.J.

1985-01-01

In addition to discussing the most recent advances in magnetic resonance imaging (MRI), computerized tomography (CT), and the vast array of interventional procedures, this book explores the appropriate clinical applications of each of these important modalities

Patient surface doses in computerized tomography examinations

International Nuclear Information System (INIS)

Vekic, B.; Kovacevic, S.; Ranogajec Komor, M.; Duvnjak, N.; Marusic, P.; Anic, P.; Dolencic, P.

1996-01-01

Computed tomography (CT) has become a major source of the population exposure to diagnostic x-rays, and acknowledge of the doses delivered by the CT equipment has become very important. Considerable efforts should be made to keep these doses to a reasonable minimum, without sacrificing the image quality. The conditions of exposure in CT are quite different from dose in conventional x-ray imaging. This has required the development of specific techniques for assessing patient dose from CT. The aims of this work were to determine the dose delivered to various organs of patients undergoing computed tomography of abdomen, thorax, pelvis and kidney as measured on the surface of the body and to estimate the risk to the patients. Dosimetric measurements were performed at two different CT scanners (Siemens SOMATOM DR-H ver. HC-1 and Shimadzu SCT-4500TE). The dose absorbed by different organs (gonads, chest, thyroid and eye lens) and by the examined part of the body of 95 patients of various sex and age were measured with TLD-700. The doses absorbed by different organs during the diagnostic CT examination of the body depend on the technical parameters, such as the number of scan, mAs, the thickness of scans, scanning times, tube voltage and other characteristics, some of each depend on the type and severity of illness. Clinical parameters, such as patient size and composition, and patient cooperation with regard to the control and motion, also influence the dose and the image quality. The highest dose measured in this study (89.19 mGy) was delivered to kidney during CT examination of this organ. (author)

New applications to computerized tomography: analysis of solid dosage forms produced by pharmaceutical industry

International Nuclear Information System (INIS)

Oliveira Junior, Jose Martins de; Martins, Antonio Cesar Germano

2009-01-01

Full text: In recent years, computerized tomography (CT) has been used as a new probe to study solid dosage forms (tablets) produced by pharmaceutical industry. This new approach to study tablet and powder, or granulation, properties used in pharmaceutical industry is very suitable. First because CT can generate information that traditional technologies used in this kind of analysis can not, such as, density distribution of internal structures and tablet dimensions, pore size distribution, particle shape information, and also investigation of official and unofficial (counterfeit) copies of solid dosage forms. Second because CT is a nondestructive technique, allowing the use of tablets or granules in others analysis. In this work we discus how CT can be used to acquire and reconstruct internal microstructure of tablets and granules. CT is a technique that is based on attenuation of X-rays passing through matter. Attenuation depends on the density and atomic number of the material that is scanned. In this work, a micro-CT X-ray scanner (manufactured by the group of Applied Nuclear Physics at University of Sorocaba) was used to obtain three-dimensional images of the tablets and granules for nondestructive analysis. These images showed a non uniform density distribution of material inside some tablets, the morphology of some granules analyzed, the integrity of the liquid-filled soft-gelatin capsule and so on. It could also be observed that the distribution of different constituents presents an osmotic controlled-release dosage form. The present work shows that it is possible to use X-ray microtomography to obtain useful qualitative and quantitative information on the structure of pharmaceutical dosage forms. (author)

An industrial demonstration of computer assisted tomography

International Nuclear Information System (INIS)

Lupton, L.R.

1985-09-01

Computerized tomography (CT) is a nondestructive testing technique for generating quantitative density (linear attenuation coefficient) maps of a cross section through an object. By using a series of parallel tomographic images taken at different elevations, a three-dimensional (3-D) map of the object can be obtained. To demonstrate the power of tomography, a 3-D region of a motorcycle carburetor has been imaged using twenty-four parallel two-dimensional images. From these data, new images in planes orthogonal to the original planes have been generated, thereby improving the user's ability to visualize the position of components within the carburetor. The data have also been used to demonstrate the relationship between tomography and radiography

Determination of the dose index in computerized tomography using thermoluminescent dosemeters

International Nuclear Information System (INIS)

Azorin, J.C.; Calderon, A.; Azorin, J.

2004-01-01

In this work the obtained results of the determination of the dose index are presented in thorax studies in computed tomography and helical tomography carried out in Mexico using thermoluminescent dosemeters of LiF: Mg,Cu,P + Ptfe developed and manufactured in our country. The results showed that under similar conditions of irradiation and operation (pitch = 1), significant differences don't exist among the doses absorbed measures in the phantom due to the two types of used tomographs. (Author)

Computerized tomographic evaluation of cerebral cysticercosis

Energy Technology Data Exchange (ETDEWEB)

Kim, Bo Young; Lee, Mi Sook; Jeon, Doo Sung; Kim, Hong Soo; Rhee, Hak Song [Precbyterian Medical Center, Chonju (Korea, Republic of)

1988-08-15

Cerebral cysticercosis, unfortunately frequent in Korea, is a parastic disease in which man serve as the intermediate host of taenia solium. The larvae have a predilection for the central nervous system and can cause a variety of neurologic symptoms. The authors reviewed 19 cases of surgically proven cerebral cysticercosis and following results were obtained. 1. The most frequent age distribution was 5th and 6th decade and male to female ratio was 14:5. 2. The most frevalent involving site was cerebral parenchyme and following by ventricles. 3. Clinical manifestations were symtom and sign of increased ICP, seizure and focal neurological dificit. 4. It was assumed that computerized tomography was the procedure of choice for the diagnosis of these parasitic brain disease.

Investigating the correlation between computerized tomography changes and quantitative consciousness disturbances in stroke patients

International Nuclear Information System (INIS)

Toneva, Yu.; Manchev, I.; Tsolova, M.

1997-01-01

One-hundred and nine patients undergo computerized tomographic (CT) and clinical investigations. The correlation between CT finding and quantitative consciousness disturbances has been studied. The somatic, neurologic and mental states are evaluated, and the changes in consciousness are classified according to a 4-degree rating system adopted in this country, namely: obnubilation, somnolence, sopor and coma. For the purpose a computerized tomograph CE 10000 is used. Cerebral infarctions in the right middle cerebral artery pool predominate. Here the disturbances are of a milder degree - obnubilation and somnolence. In stroke syndrome cases the states of sopor and coma are more frequent which may be explained with the rather severely manifested brain edema. In either form of cerebrovascular disease the quantitative disorders of consciousness are not dependent on the location of the accident in the dominant hemisphere. They are directly related to the CT documented size of pathological focus

Echography and computed tomography in the diagnosis of gastric leiomyoma

International Nuclear Information System (INIS)

Bujlov, V.M.; Borisanov, A.V.; Bessarab, A.V.

1998-01-01

Case of the diagnosis of gastric leiomyoma identified by ultrasonic scanning (USS) and computerized tomography (CT) (X-ray and endoscopic data are negative) is described. Presented observation shows the high efficiency of transabdominal USS and CT in revealing exogastric neoplasm

Three-dimensional computerized tomography. Clinical value in the case of skeletal diseases

Energy Technology Data Exchange (ETDEWEB)

Lang, P.; Genant, H.K.

1988-01-07

Three-dimensional computed tomography (3-D CT) was performed in 157 patients with disorders of the musculoskeletal system. 3-D CT facilitated the understanding of complex abnormalities of osseous structures. 3-D CT was particularly useful in evaluating trauma, bone tumors and the postoperative spine. Three-dimensional imaging is a useful adjunct imaging method supplementing conventional computed tomography. 3-D CT facilitates preoperative planning and intraoperative localization. The combination of three-dimensional computed tomography, computer assisted design and computer assisted modelling (CAD/CAM) allows the generation of plastic models for preoperative surgical planning and simulation as well as the generation of custom-molded prostheses.

Computerized tomography findings in Fahr's syndrome Achados da tomografia computadorizada na síndrome de Fahr

Directory of Open Access Journals (Sweden)

Andréia V. Faria

2004-09-01

Full Text Available We analyzed computerized tomography (CT findings in six patients with Fahr's syndrome. They presented calcifications in basal ganglia, dentate nucleus, subcortical region and semioval center, due to alteration in calcium metabolism or due to senile relative hypoxemic state. The image pattern was not strictly related with etiology, although some differences in dystrophic senile calcifications (the only one present in semioval center and absent in subcortical region. CT is an easy exam, has maximum sensitivity and allows diagnosis, contributing to early treatment of many etiologies of Fahr's syndrome.Analisamos os achados de tomografia computadorizada (TC de seis pacientes com síndrome de Fahr. Eles apresentaram calcificações nos gânglios da base, núcleo denteado, região subcortical e centro semi-oval, devidas a distúrbios no metabolismo do cálcio ou a estado de hipóxia relativa, por senilidade. O padrão de imagem não apresenta relação clara com a etiologia, apesar de algumas diferenças no caso das calcificações distróficas senis (as únicas presentes nos centros semi-ovais e ausentes na região subcortical. TC é um exame de fácil realização, máxima sensibilidade e permite o diagnóstico, contribuindo para o tratamento precoce de muitas das etiologias da síndrome de Fahr.

Health physics aspects of the EMI computerized tomography brain scanner

International Nuclear Information System (INIS)

Villafana, T.; Scouras, J.; Kirkland, L.; McElroy, N.; Paras, P.

1978-01-01

The EMI computerized tomographic cranial scanner is one of the first radiological systems incorporating an on-line computer. The result is an increase in the ability to visualize such tissues as grey matter and white matter as well as blood pools and tumor volumes. This advance has already begun to revolutionize radiological practice. Because of the totally different configuration of this unit, concern has been expressed over the dosages received by the patient, consequently the health physics aspects of this unit have been studied. Specifically, doses received by the surface of head and interior brain points as well as by the lens of the eye and gonads are reported here. X-ray output, beam half-value layers and barrier shielding requirements are also reported and discussed. (author)

Computerized tomography and staging of bladder tumors

International Nuclear Information System (INIS)

Wozniak, A.; Luongo, A.; Nogueira, A.

1982-01-01

Computed Tomography (CT) has been employed in 13 patients with bladder tumors; 8 of them subsequently underwent surgery. Concordance between CT and pathological staging ranged in 90% of accurate results. Our data are discussed and compared to those of other authors in the literature. Staging was carried out according to the International Union Against Cancer. CT proved to be very accurate in the assessment of local and regional spread of tumor, limphatic progression and early detection of ureteral obstruction, as well as diagnosis of distant metastasis in selected patients. In poor candidates for surgery CT provided invaluable data to be used for localizing fields of radiation therapy. CT is a very well tolerated procedure, it is therefore suitable in subsequent treatment control. (Author) [pt

Computerized tomography in diagnosis of mammary gland cancer

International Nuclear Information System (INIS)

Ternovoj, S.K.; Shishmareva, N.F.

1987-01-01

A total of 103 women with suspected malignant breast tumors were examined using combined methods including computed tomography (CT). Cancer was diagnosed in 81 patients benign breast tumors in 22. The authors obtained data concerning CT superiority in the diagnosis of tumors localized in the retromammary space, as well as infinitrative-edematous forms of cancer and breast cancer recurrences. A high reliability of the method in the detection of metastatic involvement of the axillary lymph nodes made it possible to give up transmission axillography

Polarized proton Target-III operators manual, revision A

International Nuclear Information System (INIS)

Hill, D.; Moretti, A.; Onesto, F.; Rynes, P.

1976-04-01

A revision is given of a manual containing standard operating procedures for the vacuum, cryogenic, and electronic systems of a polarized proton target. The discussion includes the target cryostat, the 3 He and 4 He pumping systems, remote monitors and controls, the microwave system, the magnet and power supply, the computerized polarization monitor, the 4 He liquifier and gas recovery system, and miscellaneous auxiliary equipment

Brain Computed Tomography evaluation of patients with syncopal ...

African Journals Online (AJOL)

Objective: The aim of our study is to determine the value of using brain computerized tomography as a routine investigation in patients presenting with syncope to the emergency department at King Hussein Medical Center Amman Jordon. Methods: In the time period between March 2006 and April 2008, a total of 254 ...

Impact of renal anatomy on shock wave lithotripsy outcomes for lower pole kidney stones: results of a prospective multifactorial analysis controlled by computerized tomography.

Science.gov (United States)

Torricelli, Fabio C M; Marchini, Giovanni S; Yamauchi, Fernando I; Danilovic, Alexandre; Vicentini, Fabio C; Srougi, Miguel; Monga, Manoj; Mazzucchi, Eduardo

2015-06-01

We evaluated which variables impact fragmentation and clearance of lower pole calculi after shock wave lithotripsy. We prospectively evaluated patients undergoing shock wave lithotripsy for a solitary 5 to 20 mm lower pole kidney stone between June 2012 and August 2014. Patient body mass index and abdominal waist circumference were recorded. One radiologist blinded to shock wave lithotripsy outcomes measured stone size, area and density, stone-to-skin distance, infundibular length, width and height, and infundibulopelvic angle based on baseline noncontrast computerized tomography. Fragmentation, success (defined as residual fragments less than 4 mm in asymptomatic patients) and the stone-free rate were evaluated by noncontrast computerized tomography 12 weeks postoperatively. Univariate and multivariate analysis was performed. A total of 100 patients were enrolled in the study. Mean stone size was 9.1 mm. Overall fragmentation, success and stone-free rates were 76%, 54% and 37%, respectively. On logistic regression body mass index (OR 1.27, 95% CI 1.11-1.49, p = 0.004) and stone density (OR 1.0026, 95% CI 1.0008-1.0046, p = 0.005) significantly impacted fragmentation. Stone size (OR 1.24, 95% CI 1.07-1.48, p = 0.039) and stone density (OR 1.0021, 95% CI 1.0007-1.0037, p = 0.012) impacted the success rate while stone size (OR 1.24, 95% CI 1.04-1.50, p = 0.029), stone density (OR 1.0015, 95% CI 1.0001-1.0032, p = 0.046) and infundibular length (OR 1.1035, 95% CI 1.015-1.217, p = 0.015) impacted the stone-free rate. The best outcomes were found in patients with a body mass index of 30 kg/m(2) or less, stones 10 mm or less and 900 HU or less, and an infundibular length of 25 mm or less. The coexistence of significant unfavorable variables led to a stone-free rate of less than 20%. Obese patients with higher than 10 mm density stones (greater than 900 HU) in the lower pole of the kidney with an infundibular length of greater than 25 mm should be discouraged from

Image reconstruction. Application to transverse axial tomography

International Nuclear Information System (INIS)

Aubry, Florent.

1977-09-01

A method of computerized tridimensional image reconstruction from their projection, especially in the computerized transverse axial tomography is suggested. First, the different techniques actually developped and presented in the literature are analyzed. Then, the equipment used is briefly described. The reconstruction algorithm developped is presented. This algorithm is based on the convolution method, well adapted to the real conditions of exploitation. It is an extension of SHEPP and LOGAN's algorithm. A correction of the self absorption and of the detector's response is proposed. Finally, the first results obtained which are satisfactory are given. The simplicity of the method which does not need a too long computation time makes possible the implementation of the algorithm on a mini-computer [fr

SU-F-T-133: Uniform Scanning Proton Therapy for Lung Cancer: Toxicity and Its Correlation with Dosimetry

International Nuclear Information System (INIS)

Zheng, Y; Rana, S; Larson, G

2016-01-01

Purpose: To analyze the toxicity of uniform scanning proton therapy for lung cancer patients and its correlation with dose distribution. Methods: In this study, we analyzed the toxicity of 128 lung cancer patients, including 18 small cell lung cancer and 110 non small cell lung cancer patients. Each patient was treated with uniform scanning proton beams at our center using typically 2–4 fields. The prescription was typically 74 Cobalt gray equivalent (CGE) at 2 CGE per fraction. 4D Computerized Tomography (CT) scans were used to evaluate the target motion and contour the internal target volume, and repeated 3 times during the course of treatment to evaluate the need for plan adaptation. Toxicity data for these patients were obtained from the proton collaborative group (PCG) database. For cases of grade 3 toxicities or toxicities of interest such as esophagitis and radiation dermatitis, dose distributions were reviewed and analyzed in attempt to correlate the toxicity with radiation dose. Results: At a median follow up time of about 21 months, none of the patients had experienced Grade 4 or 5 toxicity. The most common adverse effect was dermatitis (81%: 52%-Grade 1, 28%-Grade 2, and 1% Grade 3), followed by fatigue (48%), Cough (46%), and Esophagitis (45%), as shown in Figure 1. Severe toxicities, such as Grade 3 dermatitis or pain of skin, had a clear correlation with high radiation dose. Conclusion: Uniform scanning proton therapy is well tolerated by lung cancer patients. Preliminary analysis indicates there is correlation between severe toxicity and high radiation dose. Understanding of radiation resulted toxicities and careful choice of beam arrangement are critical in minimizing toxicity of skin and other organs.

SU-F-T-133: Uniform Scanning Proton Therapy for Lung Cancer: Toxicity and Its Correlation with Dosimetry

Energy Technology Data Exchange (ETDEWEB)

Zheng, Y; Rana, S; Larson, G [Procure Proton Therapy Center, Oklahoma City, OK (United States)

2016-06-15

Purpose: To analyze the toxicity of uniform scanning proton therapy for lung cancer patients and its correlation with dose distribution. Methods: In this study, we analyzed the toxicity of 128 lung cancer patients, including 18 small cell lung cancer and 110 non small cell lung cancer patients. Each patient was treated with uniform scanning proton beams at our center using typically 2–4 fields. The prescription was typically 74 Cobalt gray equivalent (CGE) at 2 CGE per fraction. 4D Computerized Tomography (CT) scans were used to evaluate the target motion and contour the internal target volume, and repeated 3 times during the course of treatment to evaluate the need for plan adaptation. Toxicity data for these patients were obtained from the proton collaborative group (PCG) database. For cases of grade 3 toxicities or toxicities of interest such as esophagitis and radiation dermatitis, dose distributions were reviewed and analyzed in attempt to correlate the toxicity with radiation dose. Results: At a median follow up time of about 21 months, none of the patients had experienced Grade 4 or 5 toxicity. The most common adverse effect was dermatitis (81%: 52%-Grade 1, 28%-Grade 2, and 1% Grade 3), followed by fatigue (48%), Cough (46%), and Esophagitis (45%), as shown in Figure 1. Severe toxicities, such as Grade 3 dermatitis or pain of skin, had a clear correlation with high radiation dose. Conclusion: Uniform scanning proton therapy is well tolerated by lung cancer patients. Preliminary analysis indicates there is correlation between severe toxicity and high radiation dose. Understanding of radiation resulted toxicities and careful choice of beam arrangement are critical in minimizing toxicity of skin and other organs.

Computerized adaptive testing item selection in computerized adaptive learning systems

NARCIS (Netherlands)

Eggen, Theodorus Johannes Hendrikus Maria; Eggen, T.J.H.M.; Veldkamp, B.P.

2012-01-01

Item selection methods traditionally developed for computerized adaptive testing (CAT) are explored for their usefulness in item-based computerized adaptive learning (CAL) systems. While in CAT Fisher information-based selection is optimal, for recovering learning populations in CAL systems item

Thirteen-Year Evaluation of Highly Cross-Linked Polyethylene Articulating With Either 28-mm or 36-mm Femoral Heads Using Radiostereometric Analysis and Computerized Tomography

DEFF Research Database (Denmark)

Nebergall, Audrey K; Greene, Meridith E; Rubash, Harry E

2016-01-01

BACKGROUND: The objective of this 13-year prospective evaluation of highly cross-linked ultra high molecular weight polyethylene (HXLPE) was to (1) assess the long-term wear of HXLPE articulating with 2 femoral head sizes using radiostereometric analysis (RSA) and to (2) determine if osteolysis...... is a concern with this material through the use of plain radiographs and computerized tomography (CT). METHODS: All patients received a Longevity HXLPE liner with tantalum beads and either a 28-mm or 36-mm femoral head. Twelve patients (6 in each head size group) agreed to return for 13-year RSA, plain...... scan revealed areas of remodeling of this graft. One patient's 13-year plain radiographs showed evidence of cup loosening and linear radiolucencies in zones 2 and 3. CONCLUSION: There was no evidence of significant wear over time using RSA. The CT scans did not show evidence of osteolysis due to wear...

Sequential computerized tomography changes and related final outcome in severe head injury patients

International Nuclear Information System (INIS)

Lobato, R.D.; Gomez, P.A.; Alday, R.

1997-01-01

The authors analyzed the serial computerized tomography (CT) findings in a large series of severely head injured patients in order to assess the variability in gross intracranial pathology through the acute posttraumatic period and determine the most common patterns of CT change. A second aim was to compare the prognostic significance of the different CT diagnostic categories used in the study (Traumatic Coma Data Bank CT pathological classification) when gleaned either from the initial (postadmission) or the control CT scans, and determine the extent to which having a second CT scan provides more prognostic information than only one scan. 92 patients (13.3 % of the total population) died soon after injury. Of the 587 who survived long enough to have at least one control CT scan 23.6 % developed new diffuse brain swelling, and 20.9 % new focal mass lesions most of which had to be evacuated. The relative risk for requiring a delayed operation as related to the diagnostic category established by using the initial CT scans was by decreasing order: diffuse injury IV (30.7 %), diffuse injury III (30.5 %), non evacuated mass (20 %), evacuated mass (20.2 %), diffuse injury II (12.1 %), and diffuse injury I (8.6 %). Overall, 51.2 % of the patients developed significant CT changes (for worse or better) occurring either spontaneously or following surgery, and their final outcomes were more closely related to the control than to the initial CT diagnoses. In fact, the final outcome was more accurately predicted by using the control CT scans (81.2 % of the cases) than by using the initial CT scans (71.5 % of the cases only). Since the majority of relevant CT changes developed within 48 hours after injury a pathological categorization made by using an early control CT scan seems to be most useful for prognostic purposes. Prognosis associated with the CT pathological categories used in the study was similar independently of the moment of the acute posttraumatic period at which

Prognostic value of technetium-99m-labeled single-photon emission computerized tomography in the follow-up of patients after their first myocardial revascularization surgery

Directory of Open Access Journals (Sweden)

Márcia Maria Sales dos Santos

2003-01-01

Full Text Available OBJECTIVE: To assess the prognostic value of Technetium-99m-labeled single-photon emission computerized tomography (SPECT in the follow-up of patients who had undergone their first myocardial revascularization. METHODS: We carried out a retrospective study of 280 revascularized patients undergoing myocardial scintigraphy under stress (exercise or pharmacological stress with dipyridamole and at rest according to a 2-day protocol. A set of clinical, stress electrocardiographic and scintigraphic variables was assessed. Cardiac events were classified as "major" (death, infarction, unstable angina and "any" (major event or coronary angioplasty or new myocardial revascularization surgery. RESULTS: Thirty-six major events occurred as follows: 3 deaths, 11 infarctions, and 22 unstable anginas. In regard to any event, 22 angioplasties and 7 new surgeries occurred in addition to major events, resulting a total of 65 events. The sensitivity of scintigraphy in prognosticating a major event or any event was, respectively, 55% and 58%, showing a negative predictive value of 90% and 83%, respectively. Diabetes mellitus, inconclusive stress electrocardiography, and a scintigraphic visualization of left ventricular enlargement were significant variables for the occurrence of a major event. On multivariate analysis, abnormal myocardial scintigraphy was a predictor of any event. CONCLUSION: Myocardial perfusion tomography with Technetium-99m may be used to identify high-risk patients after their first myocardial revascularization surgery.

Computed tomography by reconstruction. Brain CT scanning. I. Basic physics, equipment, normal aspects, artefacts

International Nuclear Information System (INIS)

Chiras, J.; Palmieri, P.; Saudinos, J.; Salamon, G.

1980-01-01

The authors describe the physical basis, apparatus, normal images, and artefacts of computed tomography by reconstruction. Radio-anatomical sections enable clear comprehension of the computed tomography images. Other methods using computer reconstruction are outlined: tomography by Compton effect, tomography by positrons, tomography by gamma emission, tomography by protons, tomography by nuclear magnetic resonance [fr

Diagnostic value of sectional images obtained by emission tomography

International Nuclear Information System (INIS)

Roucayrol, J.C.

1981-01-01

It is now possible to obtain clear images of the various planes in and around a structure with ultra-sounds (echotomography), X-rays (computerized tomography) and recently, gamma-rays from radioactive substances (emission tomography). Axial transverse tomography, which is described here, is to conventional scintigraphy what CT scan is to radiography. It provides images of any structure capable of concentrating sufficiently a radioactive substance administered intravenously. These images are perpendicular to the longitudinal axis of the body. As shown by examples in the liver, lungs and myocardium, lesions which had passed unnoticed with other exploratory techniques can now be demonstrated, and the location, shape and extension of known lesions can be more accurately assessed. Emission tomography already has its place in modern diagnostic procedures side by side with echotomography and CT scan [fr

Filtered Bessel functions in computerized tomography

International Nuclear Information System (INIS)

Rathore, R.K.S.; Munshi, P.; Bhatia, V.K.; Pandimani, S.

1988-01-01

Computer Aided Tomography (CAT) is widely used in the medical imaging area for the detection of cancerous tissues. It has also proved to be a good technique for measuring point-density (void-fraction) in two-phase flow systems. The present day CAT-scanners employ alogorithms which are essentially a discrete implementation of the Radon Inversion Formulae. These methods of reconstructing density distributions are fast and easy to implement. The present work is an attempt to simplify (and consequently to speed-up) the existing algorithms for the cases of radially symmetric density distribution. The method uses Radon Inversion Formulae and involves Bessels's Function of Fourier frequency. The algorithm was tested on some known distributions and the reconstruction is excellent. Data for bubbly-flow was also processed to obtain a point density distribution. The range of investigation was 0.6 ≤ ≤ 0.9 g/cm 3 , where ' ' denotes average cross-sectional value. The values of CT > are within ±0.03 g/cm 3 of the true values , for the data sets considered. The results are comparable with another simple method involving radial polynominals. It is observed that the simplified Radon Inversion Formulae for the radially symmetric case gives good results and can be implemented with ease. (orig.)

Temporal evolution of hypoxic-ischiaemic brain lesions in asphyxiated full-term newborns as assessed by computerized tomography

International Nuclear Information System (INIS)

Lipp-Zwahlen, A.E.; Zurich Univ.; Deonna, T.; Micheli, J.L.; Calame, A.; Chrzanowski, R.

1985-01-01

Hypoxic-ischaemic brain lesions may be detected as low density (LD) areas by means of computerized tomography (CT), but the clinical significance of such LD areas has been controversial. Since timing might be a critical factor, we studied the temporal evolution of LD areas in 9 asphyxiated term babies who had two or more CT, and compared the changes to the neurodevelopmental outcome. Scans were classified according to the elapsed time after asphyxia as early (day 1-7, n=6), intermediate (week 2-4, n=7; week 4-7, n=3) and late CT (3 months or more, n=7). In early scans, no, or only ill defined, LD areas were seen in the periventricular region. In intermediate CT's, LD-zones were further diminshed in those babies who later were normal. Sharply accentuated LD areas, however appeared in those who later suffered from neurodevelopmental disorders. These LD areas, probably representing hypoxic-ischaemic lesions, were located periventricularly, extending into the subcortical white matter and the cortex. They began to disappear at 4 to 7 weaks in some regions. LD persisting more than 4-7 weeks tended to transform into cyst-like lesions, or marked atrophy. We conclude (1) that hypoxic-ischaemic lesions appear as zones of low density on CT scans performed after the first week and (2) that the extent of such lesions can best be assessed between 9 to 23 days after asphyxia. (orig./GSH)

Temporal evolution of hypoxic-ischiaemic brain lesions in asphyxiated full-term newborns as assessed by computerized tomography

Energy Technology Data Exchange (ETDEWEB)

Lipp-Zwahlen, A.E.; Deonna, T.; Micheli, J.L.; Calame, A.; Chrzanowski, R.

1985-03-01

Hypoxic-ischemic brain lesions may be detected as low density (LD) areas by means of computerized tomography (CT), but the clinical significance of such LD areas has been controversial. Since timing might be a critical factor, the temporal evolution of LD areas was studied in 9 asphyxiated term babies who had two or more CT, and the changes were compared to the neurodevelopmental outcome. Scans were classified according to the elapsed time after asphyxia as early (day 1-7, n=6), intermediate (week 2-4, n=7; week 4-7, n=3) and late CT (3 months or more, n=7). In early scans, no, or only ill defined, LD areas were seen in the periventricular region. In intermediate CT's, LD-zones were further diminshed in those babies who later were normal. Sharply accentuated LD areas, however appeared in those who later suffered from neurodevelopmental disorders. These LD areas, probably representing hypoxic-ischemic lesions, were located periventricularly, extending into the subcortical white matter and the cortex. They began to disappear at 4 to 7 weaks in some regions. LD persisting more than 4-7 weeks tended to transform into cyst-like lesions, or marked atrophy. The authors conclude (1) that hypoxic-ischemic lesions appear as zones of low density on CT scans performed after the first week and (2) that the extent of such lesions can best be assessed between 9 to 23 days after asphyxia.

Tomografía axial computarizada en pacientes con enfermedades cerebrovasculares hemorrágicas Computerized axial tomography in patients with hemorrhagic cerebrovascular diseases

Directory of Open Access Journals (Sweden)

Solángel Bolaños Vaillant

2009-10-01

Full Text Available Se efectuó un estudio descriptivo y transversal de 196 pacientes con enfermedad cerebrovascular hemorrágica, que abarcó desde enero del 2004 hasta igual mes del 2005 en el Hospital Provincial Docente “Saturnino Lora” de Santiago de Cuba, a los cuales se indicó una tomografía axial computarizada. Al relacionar las imágenes tomográficas con los síntomas y signos presentados por los enfermos, se halló lenguaje tropeloso en todos ellos; predominio de hematomas intraparenquimatosos, generalmente en ganglios basales y región temporal, así como primacía de la hipertensión arterial entre los antecedentes patológicos más importantes. Se concluyó que la tomografía axial computarizada es un medio para diagnóstico certero en las urgencias médicas por esa grave afección.A descriptive and cross sectional study of 196 patients with cerebrovascular hemorrhagic disease was carried out from January, 2004 to the same month of 2005 in "Saturnino Lora" Teaching Provincial Hospital from Santiago de Cuba, to whom a computerized axial tomography was indicated. When relating the tomographic images with the symptoms and signs which they presented, trouble speaking was detected in all of them; prevalence of intraparenchymatous hematomas, generally in basal ganglia and temporal region, as well as prevalence of hypertension among the most important pathological history. It was concluded that computarized axial tomography is a mean for precise diagnosis in medical emergencies due to that serious disorder.

Complaints of the lumbar spine: The value of myelography and computerized tomography

International Nuclear Information System (INIS)

Rittmeyer, K.; Dralle, A.

1988-01-01

In the radiological examination of the lumbar spine and vertebral canal there are currently two methods of choice, computer tomography and myelography. Comparing the advantages of one method over another reveals that computer tomography is particularly useful in especially diagnosing a lateral process of the intervertebral disk, whereas myelography is especially applicable in the case of an intervertebrals disk prolapse within the narrow confines of the spinal canal proper. Myelography also has the additional advantage of visualizing a number of segments at once, although repeated use increases the risk of arachnitis despite the high tolerance of current contrast medium. However, myelography should be performed, if there is clinical evidence of nerve root compression even though the computer tomography was negative. The reverse is also true. Myelography is also useful initially, due to the lower radiation dosis, if the clinical symptoms don't allow a specific localisation of the process. (orig.) [de

Utilization of special computerized tomography and nuclear medicine techniques for quality control and for the optimization of combined precision chemotherapy and precision radiation therapy

International Nuclear Information System (INIS)

Wiley, A.L. Jr.; Wirtanen, G.W.; Chien, I.-C.

1984-01-01

A combination of precision (selective, intra-arterial) chemotherapy and precision radiotherapy can be used for advanced pancreatic, biliary tract, and sarcomatous malignancies. There were some remarkable responses, but also a few poor responses and even some morbidity. Accordingly, methods are developed of pre-selecting those patients whose tumors are likely to respond to such therapy, as well as methods for improving the therapeutic ratio by the rational optimization of combined therapy. Specifically, clinical tumor blood flow characteristics (monitored with nuclear medicine techniques) may provide useful criteria for such selection. The authors also evaluate qualitatively the drug distribution or exposure space with specialized color-coded computerized tomography images, which demonstrate spatially dependent enhancement of intra-arterial contrast in tumor and in adjacent normal tissues. Such clinical data can improve the quality control aspects of intra-arterial chemotherapy administration, as well as the possibility of achievement of a significant therapeutic ratio by the integration of precision chemotherapy and precision radiation therapy. (Auth.)

Primary muscular hydatid: preoperative diagnosis Throught computerized tomography and ultrasonography

International Nuclear Information System (INIS)

Macho Fernandez, J.M.; Marin Cardenas, M.A.; Mazas Artasona, L.; Lample Lacasa, C.; Otero Sierra, C.; Hernandez Navarrete, M.J.; Gomez-Pereda, R.

1995-01-01

Primary muscular hydatid disease, is extremely rare,- but not exceptional-, comparatively with other atypical localization. In this article the authors revised 474 patients with hydatid disease over a ten years period. Three cases of primary muscular localization were found. The ultrasonography and computed tomography facilitates the preoperative diagnosis. (Author) 40 refs

Non-destructive analysis and detection of internal characteristics of spruce logs through X computerized tomography

International Nuclear Information System (INIS)

Longuetaud, F.

2005-10-01

Computerized tomography allows a direct access to internal features of scanned logs on the basis of density and moisture content variations. The objective of this work is to assess the feasibility of an automatic detection of internal characteristics with the final aim of conducting scientific analyses. The database is constituted by CT images of 24 spruces obtained with a medical CT scanner. Studied trees are representative of several social status and are coming from four stands located in North-Eastern France, themselves are representative of several age, density and fertility classes. The automatic processing developed are the following. First, pith detection in logs dealing with the problem of knot presence and ring eccentricity. The accuracy of the localisation was less than one mm. Secondly, the detection of the sapwood/heart-wood limit in logs dealing with the problem of knot presence (main source of difficulty). The error on the diameter was 1.8 mm which corresponds to a relative error of 1.3 per cent. Thirdly, the detection of the whorls location and comparison with an optical method. Fourthly the detection of individualized knots. This process allows to count knots and to locate them in a log (longitudinal position and azimuth); however, the validation of the method and extraction of branch diameter and inclination are still to be developed. An application of this work was a variability analysis of the sapwood content in the trunk: at the within-tree level, the sapwood width was found to be constant under the living crown; at the between-tree level, a strong correlation was found with the amount of living branches. A great number of analyses are possible from our work results, among others: architectural analysis with the pith tracking and the apex death occurrence; analysis of radial variations of the heart-wood shape; analysis of the knot distribution in logs. (author)

Patient Study of In Vivo Verification of Beam Delivery and Range, Using Positron Emission Tomography and Computed Tomography Imaging After Proton Therapy

International Nuclear Information System (INIS)

Parodi, Katia; Paganetti, Harald; Shih, Helen A.; Michaud, Susan; Loeffler, Jay S.; DeLaney, Thomas F.; Liebsch, Norbert J.; Munzenrider, John E.; Fischman, Alan J.; Knopf, Antje; Bortfeld, Thomas

2007-01-01

Purpose: To investigate the feasibility and value of positron emission tomography and computed tomography (PET/CT) for treatment verification after proton radiotherapy. Methods and Materials: This study included 9 patients with tumors in the cranial base, spine, orbit, and eye. Total doses of 1.8-3 GyE and 10 GyE (for an ocular melanoma) per fraction were delivered in 1 or 2 fields. Imaging was performed with a commercial PET/CT scanner for 30 min, starting within 20 min after treatment. The same treatment immobilization device was used during imaging for all but 2 patients. Measured PET/CT images were coregistered to the planning CT and compared with the corresponding PET expectation, obtained from CT-based Monte Carlo calculations complemented by functional information. For the ocular case, treatment position was approximately replicated, and spatial correlation was deduced from reference clips visible in both the planning radiographs and imaging CT. Here, the expected PET image was obtained from an analytical model. Results: Good spatial correlation and quantitative agreement within 30% were found between the measured and expected activity. For head-and-neck patients, the beam range could be verified with an accuracy of 1-2 mm in well-coregistered bony structures. Low spine and eye sites indicated the need for better fixation and coregistration methods. An analysis of activity decay revealed as tissue-effective half-lives of 800-1,150 s. Conclusions: This study demonstrates the feasibility of postradiation PET/CT for in vivo treatment verification. It also indicates some technological and methodological improvements needed for optimal clinical application

Proton-counting radiography for proton therapy: a proof of principle using CMOS APS technology

International Nuclear Information System (INIS)

Poludniowski, G; Esposito, M; Evans, P M; Allinson, N M; Anaxagoras, T; Green, S; Parker, D J; Price, T; Manolopoulos, S; Nieto-Camero, J

2014-01-01

Despite the early recognition of the potential of proton imaging to assist proton therapy (Cormack 1963 J. Appl. Phys. 34 2722), the modality is still removed from clinical practice, with various approaches in development. For proton-counting radiography applications such as computed tomography (CT), the water-equivalent-path-length that each proton has travelled through an imaged object must be inferred. Typically, scintillator-based technology has been used in various energy/range telescope designs. Here we propose a very different alternative of using radiation-hard CMOS active pixel sensor technology. The ability of such a sensor to resolve the passage of individual protons in a therapy beam has not been previously shown. Here, such capability is demonstrated using a 36 MeV cyclotron beam (University of Birmingham Cyclotron, Birmingham, UK) and a 200 MeV clinical radiotherapy beam (iThemba LABS, Cape Town, SA). The feasibility of tracking individual protons through multiple CMOS layers is also demonstrated using a two-layer stack of sensors. The chief advantages of this solution are the spatial discrimination of events intrinsic to pixelated sensors, combined with the potential provision of information on both the range and residual energy of a proton. The challenges in developing a practical system are discussed. (paper)

Proton-counting radiography for proton therapy: a proof of principle using CMOS APS technology.

Science.gov (United States)

Poludniowski, G; Allinson, N M; Anaxagoras, T; Esposito, M; Green, S; Manolopoulos, S; Nieto-Camero, J; Parker, D J; Price, T; Evans, P M

2014-06-07

Despite the early recognition of the potential of proton imaging to assist proton therapy (Cormack 1963 J. Appl. Phys. 34 2722), the modality is still removed from clinical practice, with various approaches in development. For proton-counting radiography applications such as computed tomography (CT), the water-equivalent-path-length that each proton has travelled through an imaged object must be inferred. Typically, scintillator-based technology has been used in various energy/range telescope designs. Here we propose a very different alternative of using radiation-hard CMOS active pixel sensor technology. The ability of such a sensor to resolve the passage of individual protons in a therapy beam has not been previously shown. Here, such capability is demonstrated using a 36 MeV cyclotron beam (University of Birmingham Cyclotron, Birmingham, UK) and a 200 MeV clinical radiotherapy beam (iThemba LABS, Cape Town, SA). The feasibility of tracking individual protons through multiple CMOS layers is also demonstrated using a two-layer stack of sensors. The chief advantages of this solution are the spatial discrimination of events intrinsic to pixelated sensors, combined with the potential provision of information on both the range and residual energy of a proton. The challenges in developing a practical system are discussed.

Rupture of Ovarian Mature Cystic Teratoma: Computerized Tomography Findings

International Nuclear Information System (INIS)

Sebastia, C.; Sarrias, M.; Sanchez-Aliaga, E.; Quiroga, S.; Boye, R.; Alvarez-Castells, A.

2004-01-01

We present computed tomography findings of three cases of intraperitoneal rupture of ovarian mature cystic teratoma. Acute-phase radiological findings include presence of intraabdominal liquid, infiltration of mesenteric fat and calcified pelvic mass which also showed interior fatty content. Chronic-phase findings include infiltration of peritoneal fat, as well as increase in the size of adjacent ganglion due to chronic inflammatory response to histologically verified foreign bodies. Differential diagnoses between chronic and acute intraperitoneal ruptures of mature teratoma have been reviewed. (Author)

Computerized mini-tomography scanner for X-ray and gamma-ray for multipurpose applications

International Nuclear Information System (INIS)

Cruvinel, P.E.

1987-01-01

The main results of this thesis is the development, implementation and use of an X-ray and γ-ray computerized minitomography scanner with possible applications in multidisciplinary fields particularly in soil physics. The hardware is basically a mechanical table with two step motors, one for rotation and another for translation motions, radioactive source, collimators, radiation detector with NaI(Tl) crystal, electronic pulse handling system and microcomputer with two floppy disk-units (5 1/4''), video with high resolution and graphic printer.(author)

Shielding of medically used proton accelerators; Abschirmung von medizinisch genutzten Protonenbeschleunigern

Energy Technology Data Exchange (ETDEWEB)

Ewen, Klaus

2014-10-01

In several standards of the standards committee radiology (NRA) the shielding of proton accelerators (cyclotrons) for medical utilization is described. Proton beams can be used in nuclear medicine for PET (proton emission tomography) isotope production or for radiotherapeutic use. The dominating radiation from proton induced nuclear reactions is fast neutron radiation. The calculation procedure for appropriate shielding measures according to the NAR standards is described step-by-step. AN adequate shielding of fast neutrons is also sufficient for the generated gamma radiation.

[The role of multidetector computer tomography in diagnosis of acute pancreatitis].

Science.gov (United States)

Lohanikhina, K Iu; Hordiienko, K P; Kozarenko, T M

2014-10-01

With the objective to improve the diagnostic semiotics of an acute pancreatitis (AP) 35 patients were examined, using 64-cut computeric tomograph Lightspeed VCT (GE, USA) with intravenous augmentation in arterial and portal phases. Basing on analysis of the investigations conducted, using multidetector computeric tomography (MDCT), the AP semiotics was systematized, which is characteristic for oedematous and destructive forms, diagnosed in 19 (44.2%) and 16 (45.8%) patients, accordingly. The procedure for estimation of preservation of the organ functional capacity in pancreonecrosis pres- ence was elaborated, promoting rising of the method diagnostic efficacy by 5.3 - 9.4%.

CMOS Active Pixel Sensors as energy-range detectors for proton Computed Tomography

International Nuclear Information System (INIS)

Esposito, M.; Waltham, C.; Allinson, N.M.; Anaxagoras, T.; Evans, P.M.; Poludniowski, G.; Green, S.; Parker, D.J.; Price, T.; Manolopoulos, S.; Nieto-Camero, J.

2015-01-01

Since the first proof of concept in the early 70s, a number of technologies has been proposed to perform proton CT (pCT), as a means of mapping tissue stopping power for accurate treatment planning in proton therapy. Previous prototypes of energy-range detectors for pCT have been mainly based on the use of scintillator-based calorimeters, to measure proton residual energy after passing through the patient. However, such an approach is limited by the need for only a single proton passing through the energy-range detector in a read-out cycle. A novel approach to this problem could be the use of pixelated detectors, where the independent read-out of each pixel allows to measure simultaneously the residual energy of a number of protons in the same read-out cycle, facilitating a faster and more efficient pCT scan. This paper investigates the suitability of CMOS Active Pixel Sensors (APSs) to track individual protons as they go through a number of CMOS layers, forming an energy-range telescope. Measurements performed at the iThemba Laboratories will be presented and analysed in terms of correlation, to confirm capability of proton tracking for CMOS APSs

CMOS Active Pixel Sensors as energy-range detectors for proton Computed Tomography.

Science.gov (United States)

Esposito, M; Anaxagoras, T; Evans, P M; Green, S; Manolopoulos, S; Nieto-Camero, J; Parker, D J; Poludniowski, G; Price, T; Waltham, C; Allinson, N M

2015-06-03

Since the first proof of concept in the early 70s, a number of technologies has been proposed to perform proton CT (pCT), as a means of mapping tissue stopping power for accurate treatment planning in proton therapy. Previous prototypes of energy-range detectors for pCT have been mainly based on the use of scintillator-based calorimeters, to measure proton residual energy after passing through the patient. However, such an approach is limited by the need for only a single proton passing through the energy-range detector in a read-out cycle. A novel approach to this problem could be the use of pixelated detectors, where the independent read-out of each pixel allows to measure simultaneously the residual energy of a number of protons in the same read-out cycle, facilitating a faster and more efficient pCT scan. This paper investigates the suitability of CMOS Active Pixel Sensors (APSs) to track individual protons as they go through a number of CMOS layers, forming an energy-range telescope. Measurements performed at the iThemba Laboratories will be presented and analysed in terms of correlation, to confirm capability of proton tracking for CMOS APSs.

Optimization of special heart disease diagnosis by combined computerized tomography, echocardiography and intracardiac scintiscanning

International Nuclear Information System (INIS)

Freitag, J.; Schmidt, H.; Otto, H.J.; Punrich, R.; Gunkel, H.; Mann, D.; Freitag, G.; Waigand, J.; Eger, H.; Zentralklinik fuer Herz- u. Lungenkrankheiten, Bad Berka; Akademie der Wissenschaften der DDR, Berlin-Buch. Zentralinstitut fuer Herz-Kreislaufforschung)

1986-01-01

Cardiac computer tomography, echocardiography and radionuclide heart diagnosis are growing more and more important in cardiologic diagnostics. The value of the procedures was tested in 74 patients by combined application. Concordant morphologic findings could be obtained with echocardiography and cardiac computer tomography in the cases of chronic ischemic heart disease, cardiomyopathy and valvular heart diseases. Localized kinetic disturbances could be registered echocardiographically and by scintiscanning. The passableness of an aortocoronary bypass can be controlled first of all non-invasively by cardiac computer tomography. (author)

Computerized axial tomography and diagnosis of multiple sclerosis

Directory of Open Access Journals (Sweden)

Paulo R.M. Bittencourt

1983-06-01

Full Text Available Computed axial tomography (C.T. findings are illustrated in 3 patients who presented with C.T. changes suggesting respectively chronic M.S., acute M.S., and an appearance simulating a malignant tumour. Review of the literature shows that the chronic form with cerebral atrophy and low density lesions in the hemispheres is common in patients with a long history and is unlikely to cause diagnostic difficulty. The acute presentation is less common and could be confused with a variety of causes of multiple low density enhancing lesions. The C.T. diagnosis of M.S. is more difficult in rare cases in which plaques cause mass effect and show ring enhancement; all 3 such cases in the literature were subjected to cerebral biopsy.

Review: Pre- and postinterventional control of stent grafts by means of single and multislice spiral computerized tomography

International Nuclear Information System (INIS)

Gebauer, B.; Knollmann, F.; Steinkamp, H.; Felix, R.

2003-01-01

Purpose. Could contrast enhanced computed tomography replace conventional catheter angiography in the preoperative evaluation of aortic aneurysms before stentgraft implantation? Does multi slice computed tomography have advantages comparing to single slice computed tomography? Methods. We compared 15 single slice with 13 multi slice computed tomography studies and reconstructions according to their ability to replace conventional catheter angiography in the preoperative evaluation. In the postoperative follow-up 60 single slice computed tomography studies were compared to 60 multi slice studies. Results. By using appropriate reconstructions the spiral computed tomography studies could deliver all information necessary for implantation. In our study no advantage of multi slice computed tomography could be detected. In the postoperative evaluation of stengrafts our computed tomography scan protocol could detect all relevant complications in single and multi slice computed tomography. No significant advantage of multi slice computed tomography could be detected. Conclusion. Contrast enhanced computed tomography is equal to conventional catheter angiography in the pre- and postoperative evaluation of stentgrafts. No significant advantage of multi slice versus single slice could be detected. (orig.) [de

Quantitation of size of myocardial infarctions by computerized transmission tomography. Comparison with hot-spot and cold-spot radionuclide scans

International Nuclear Information System (INIS)

Gerber, K.H.; Higgins, C.B.

1983-01-01

The current study evaluated the ability to quantitate the volume of myocardial infarctions when they are outlined by intravenously administered contrast media in the myocardial perfusion phase and in the phase of delayed contrast enhancement of the infarct. Quantitation by contrast media was assessed from computerized transmission tomography (CTT) scans of the ex situ heart and compared with quantitation by technetium-99m (/sup 99m/Tc)pyrophosphate (/sup 99m/Tc PYP) and thallium-201 (201Tl) scans of the same ex situ hearts. True volume was defined by histochemical morphometry. CTT during the contrast perfusion phase uniformly underestimated infarct size but had a good correlation with true volume. CTT during enhancement phase correlated closely with true volume (r . 0.98) and most precisely measured true size (y . 1.06 X 0.23). The /sup 99m/Tc PYP scan overestimated infarct volume (predictive overestimation of 6 to 199%) but had a good correlation with true volume. 201Tl underestimated infarct volume but correlated well with true volume. Thus, quantitation of infarct volume from CTT scans performed during either the perfusion or infarct enhancement phase after intravenous contrast media provides a good estimate of true infarct volume. Delineation of the infarct by contrast media in the ex situ heart is more precise during the phase of delayed enhancement of the infarct

Preoperative computed tomography and scintigraphy to facilitate the detection of accessory spleen in patients with hematologic disorders

International Nuclear Information System (INIS)

Koyanagi, Nobuhiro; Kanematsu, Takashi; Sugimachi, Keizo

1988-01-01

Accessory spleens of 1.5 cm in size were preoperatively identified by the combined use of computerized tomography and splenic scintigraphy in two patients with hematologic diseases. After the accessory spleen had been removed from the first patient, who had persistent hereditary spherocytosis and had undergone a splenectomy 15 months before, a postoperative decrease in hyperbilirubinemia was noted. In the other patient who had idiopathic thrombocytopenic purpura, a successful accessory splenectomy was done at the same time as her splenectomy, and was followed by 6 months' complete remission. These events indicate that preoperative investigations using computerized tomography and scintigraphy are indispensable for ruling out an accessory spleen in those patients for whom splenectomy needs to be done in order to alleviate hematologic disorders. (author)

Cranial computerized tomography aspects of neuro-cysticercosis in infancy

International Nuclear Information System (INIS)

Guerreiro, M.M.; Facure, N.O.; Guerreiro, C.A.M.

1989-01-01

The analysis of 27 computed tomography scans (CT) is presented. Eighteen children were divided in three groups according to clinical and tomographic criteria. Group 1 was characterized mainly by epilepsy and calcifications. Group 2 was characterized by intracranial hypertension and several tomographic aspects: edema, cysts and nodules were seen in three patients; hydrocephaly and calcifications were seen in two patients and CT was normal is one patient. Group 3 had patients with epilepsy or headache and variable tomographic patterns. The results are discussed based on the available literature. (author)

Study of computerized tomography using neutron beam

International Nuclear Information System (INIS)

Pereira, W.W.

1991-05-01

This paper aims to demonstrate the advantages, shortcomings and complementaries of a tomography development using neutrons over the one employing gamma rays in the context of their applications to non destructive essays. A simulated experimental study was performed in order to compare the two aforementioned tomographic procedures as applied to some materials. These materials were chosen for their clear advantages and complementaries as, for instance, aluminium, iron, plastic and aluminium hydroxide. In this work two tomographic systems, are employed both with parallel beams. The first with a gamma radiation source (Caesium-137), with an energy of 662 KeV and an activity of 3,9 x 10 9 Bq (100 mCi) and the second one employing a neutron source, the Argonaut Reactor of the Instituto de Engenharia Nuclear, IEN/CNEN, from where the thermal neutron beam of about 10 5 n/(cm.s) was obtained. It is possible to conclude from the simulated and experimental results, by means of image analysis and distortion measurements, that for a given material the adequate radiation and its energy may be chosen so as to better characterize it. (author)

Dosimetric characterization of computerized tomography of 64 channels

International Nuclear Information System (INIS)

Gimeno-Fernandez, V.; Sotil-Baylos, J.; Garcia-Pazos, M.; Garcia-Pena, P.

2006-01-01

As a first step in the evaluation of effective dose to patients in Computed Tomography (CT) examinations, the purpose of this work was the assessment of the dose delivered by a new multislice scanner of 64 channels (Philips Brilliance 64c). This was done through the measurement of the CT Dose Index free in air, normalized to the unit of applied charge, using different beam collimations and tube voltages. Fitting nonlinear models to the observed data, kilo voltage and over beaming (penumbra) parameters have been elicited. The kilo voltage exponent of the relationship between CT dose index and kilo voltage varies from 2,84 to 2,88. The obtained penumbra with was 2,04 nm. Finally, corrections factors that must be applied to the measured dose indexes as a function of the applied collimation have been established from the estimated analytical relationships. (Author)

Neutron Tomography Application for Aircraft-parts and Root of Ginseng

Energy Technology Data Exchange (ETDEWEB)

Kim, Yi Kyung; Lee, Seung Wook; Sim, Chul Mu; Jeon, Jin Su; Kim, Tae Ju [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

2005-07-01

The neutron computerized tomography is considered to be a complementary tool to X-ray tomography in the sense that neutron interacts with atomic nucleus, otherwise X-ray interacts with an orbital electron of atom. The neutron tomography compared with X-ray tomography has a relatively short history. It is employed in stationary, as neutron sources are produced by the nuclear reactor. The full potential of the neutron tomography has yet to be investigated. Since, HANARO NRF was installed in 1995, the neutron radiography research group of KAERI has been developed the non-destructive testing methods by the computer tomography served for aerospace industry and agricultural industry. Concerning to NDT for aerospace, research was cooperated with Korean Air force. At the first stage, research was focused to find the micro-cracks based on internal passages inside aircraft parts and residual core of turbine blade. Concerning to NDT for agriculture, research was cooperated with the Agricultural Development and Technology Center. Research was focused to find the alive roots of Korean ginseng.

Physics of x-ray computed tomography

International Nuclear Information System (INIS)

Akutagawa, W.M.; Huth, G.C.

1976-01-01

Sections are included on theoretical limits of x-ray computed tomography and the relationship of these limits to human organ imaging and specific disease diagnosis; potential of x-ray computed tomography in detection of small calcified particles in early breast cancer detection; early lung cancer measurement and detection; advanced materials for ionizing radiation detection; positron system with circular ring transaxial tomographic camera; contrast mechanism of transmission scanner and algorithms; and status of design on a 200 keV scanning proton microprobe

Brain metastasis of small cell lung carcinoma. Comparison of Gd-DTPA enhanced magnetic resonance imaging and enhanced computerized tomography

International Nuclear Information System (INIS)

Nomoto, Yasushi; Yamaguchi, Yutaka; Miyamoto, Tadaaki.

1994-01-01

Small cell carcinoma of the lung (SCLC) frequently metastasizes into the brain, resulting in serious influences upon prognosis. Delayed brain damage caused by prophylactic cranial irradiation (PCI) is also problematic. Gadolinium diethylene triamine pentaacetic acid (Gd-DTPA) enhanced magnetic resonance imaging (MRI) was performed to detect early brain metastasis from SCLC, and its usefulness was compared with contrast computerized tomography (CT). Among 25 SCLC patients, brain metastasis was detected in 11 by MRI and in 10 by CT, although six of them were completely asymptomatic. In the 11 patients, 6.3 and 2.4 lesions were respectively detected on average by MRI and CT. The ability of MRI to detect metastatic lesions of ≥15 mm diameter did not differ from that of CT, but became different as lesions became smaller (P<0.002), and MRI had a decided advantage over CT because as many as 30 lesions of ≤5 mm diameter were detected by MRI, whereas such lesions visualized on CT numbered only one (P<0.0001). MRI was incomparably superior to CT (P<0.0004) for subtentorial lesions since 18 lesions were detected on MRI, but only three, measuring ≥25 mm in diameter, were demonstrated on CT. Gd-DTPA enhanced MRI was determined to be extremely useful in the early diagnosis of SCLC brain metastasis. MRI was thought to reduce delayed brain damage caused by PCI if performed according to an adequate schedule. (author)

Dose assessment in pediatric computerized tomography

International Nuclear Information System (INIS)

Vilarinho, Luisa Maria Auredine Lima

2004-01-01

The objective of this work was the evaluation of radiation doses in paediatric computed tomography scans, considering the high doses usually involved and the absence of any previous evaluation in Brazil. Dose values were determined for skull and abdomen examinations, for different age ranges, by using the radiographic techniques routinely used in the clinical centers investigated. Measurements were done using pencil shape ionization chambers inserted in polymethylmethacrylate (PMMA) phantoms. These were compact phantoms of different diameters were specially designed and constructed for this work, which simulate different age ranges. Comparison of results with published values showed that doses were lower than the diagnostic reference levels established to adults exams by the European Commission. Nevertheless, doses in paediatric phantoms were higher than those obtained in adult phantoms. The paediatric dose values obtained in Hospitals A and B were lower than the reference level (DRL) adopted by SHIMPTON for different age ranges. In the range 0 - 0.5 year (neonatal), the values of DLP in Hospital B were 94 por cent superior to the DRL For the 10 years old children the values of CTDI w obtained were inferior in 89 por cent for skull and 83 por cent for abdomen examinations, compared to the values published by SHRIMPTON and WALL. Our measured CTDI w values were inferior to the values presented for SHRIMPTON and HUDA, for all the age ranges and types of examinations. It was observed that the normalized dose descriptors values in children in the neonatal range were always superior to the values of doses for the adult patient. In abdomen examinations, the difference was approximately 90% for the effective dose (E) and of 57%.for CTDI w . (author)

Characterizing proton-activated materials to develop PET-mediated proton range verification markers

Science.gov (United States)

Cho, Jongmin; Ibbott, Geoffrey S.; Kerr, Matthew D.; Amos, Richard A.; Stingo, Francesco C.; Marom, Edith M.; Truong, Mylene T.; Palacio, Diana M.; Betancourt, Sonia L.; Erasmus, Jeremy J.; DeGroot, Patricia M.; Carter, Brett W.; Gladish, Gregory W.; Sabloff, Bradley S.; Benveniste, Marcelo F.; Godoy, Myrna C.; Patil, Shekhar; Sorensen, James; Mawlawi, Osama R.

2016-06-01

Conventional proton beam range verification using positron emission tomography (PET) relies on tissue activation alone and therefore requires particle therapy PET whose installation can represent a large financial burden for many centers. Previously, we showed the feasibility of developing patient implantable markers using high proton cross-section materials (18O, Cu, and 68Zn) for in vivo proton range verification using conventional PET scanners. In this technical note, we characterize those materials to test their usability in more clinically relevant conditions. Two phantoms made of low-density balsa wood (~0.1 g cm-3) and beef (~1.0 g cm-3) were embedded with Cu or 68Zn foils of several volumes (10-50 mm3). The metal foils were positioned at several depths in the dose fall-off region, which had been determined from our previous study. The phantoms were then irradiated with different proton doses (1-5 Gy). After irradiation, the phantoms with the embedded foils were moved to a diagnostic PET scanner and imaged. The acquired data were reconstructed with 20-40 min of scan time using various delay times (30-150 min) to determine the maximum contrast-to-noise ratio. The resultant PET/computed tomography (CT) fusion images of the activated foils were then examined and the foils’ PET signal strength/visibility was scored on a 5 point scale by 13 radiologists experienced in nuclear medicine. For both phantoms, the visibility of activated foils increased in proportion to the foil volume, dose, and PET scan time. A linear model was constructed with visibility scores as the response variable and all other factors (marker material, phantom material, dose, and PET scan time) as covariates. Using the linear model, volumes of foils that provided adequate visibility (score 3) were determined for each dose and PET scan time. The foil volumes that were determined will be used as a guideline in developing practical implantable markers.

Quality of computerized tomography exams proposed by a quality certification program

International Nuclear Information System (INIS)

Carlos, Marcia Terezinha

1999-01-01

Brazilian College of Radiologists (CBR) is concerned about the quality of radiological practices in the country. Actions in direction of accreditation programmes and standardization of the performance in imaging modalities have been implemented. The first accreditation programme was in mammography. In Brazil, computed tomography spread all over the country. Due high radiation dose to the patient and the continuous technological development, an accreditation programme in CT practice is necessary. A pilot programme has been carried out in the area of Rio de Janeiro with the participation of 11 CT facilities with 12 CT units. The background information follows Document EUR 16262 E uropean Guidelines of Quality Criteria for Computed Tomography . Initially practice data were collected through structured interviews using a standardized questionnaire. In regard to the assessment of clinical image quality, two examinations were selected: brain general and abdomen general. Three radiologists specialized in computed tomography evaluated the image quality criteria from a sample of examinations from the participant facilities. Other aspects selected to the assessment of the overall performance are: technical parameters of the examinations; image physical parameters (noise, spatial resolution, sensitivity profile) and radiation dose. Radiation dose and image quality criteria were fulfilled by 7 of 12 brain general examinations analyzed and only 5 of 10 abdomen general examinations analyzed. At the moment, it was not possible to get a conclusion about image quality based on measurements of physical parameters. Other factors affecting overall image quality were: technical limitation of CT units and practitioners are not able to fully handle the technical parameters of the examination. Dose and image quality criteria shall be the basis of an accreditation programme in CT and Brazilian College of Radiology has to use the experience of this work to implement a programme at national

Computerized tomography data on CNS affection in systemic lupus erythematosus

International Nuclear Information System (INIS)

Ivanova, M.M.; Bliznyuk, O.I.; Todua, F.I.; Tumanova, A.A.

1989-01-01

Computed tomography (CT) of the brain was employed in 40 patients with systemic lupus erythematosus (SLE). Clinical cerebral pathology was obvious in 30 and absent in 10 patients. By CT cerebral symptoms were divided of 4 groups. Clinical symptom complexes of CNS defects and SLE were reflected on definite CT images correlated with focal damage to the brain. CT picture of enlarged subarachnoid space, ventricles and basal cisterns can be observed in SLE patients without neurological symptoms. This indicated likely subclinical cerebral affection

Computerizing primary schools in rural kenya

DEFF Research Database (Denmark)

Ogembo, J.G.; Ngugi, B.; Pelowski, Matthew John

2012-01-01

questions surrounding this endeavour. Specifically: 1.) what problems do rural schools actually want to solve with computerization; 2.) is computerization the most important priority for rural schools; 3.) are schools ready, in terms of infrastructure, for a computer in the classroom; or 4.) might...... and protective roofing -posing severe challenges to the outstanding conception of computerization. We consider these results and make recommendations for better adapting programs for computer introduction, and also suggest the use of new innovative devices, such as cell phones, which might already have overcome......This paper investigates the outstanding challenges facing primary schools' computerization in rural Kenya. Computerization of schools is often envisaged as a 'magic', or at least a particularly efficient, solution to many of the problems that developing countries face in improving primary school...

Strategies of reconstruction algorithms for computerized tomography

International Nuclear Information System (INIS)

Garderet, P.

1984-10-01

Image reconstruction from projections has progressively spread out over all fields of medical imaging. As the mathematical aspects of the problem become more and more comprehensively explored a great variety of numerical solutions have been developed best suited to such-and-such imaging medical application and taking into account the physical phenomena related to data collection (a priori properties for signal and noise). The purpose of that survey is to present the general mathematical frame and the fundamental assumptions of various strategies; Fourier methods approximate explicit deterministic inversion formula for the Radon transform. Algebraic reconstruction techniques set up an a priori discrete model through a series expansion approach of the solution. The numerical system to be solved is huge when a fine grid of pixels is to be reconstructed; iterative solutions may then be found. Recently some least square procedures have been shown to be tractable which avoid the use of iterative methods. Finally maximum like hood approach incorporates accurately the Poisson nature of photon noise and are well adapted to emission computed tomography. The various strategies will be analysed from both aspects of theoretical assumptions needed for suitable use and of computing facilities, actual performance and cost. In the end we take a glimpse of the extension of the algorithms from two dimensional imaging to fully three dimensional volume analysis in preparation of the future medical imaging technologies

The precision of proton range calculations in proton radiotherapy treatment planning: experimental verification of the relation between CT-HU and proton stopping power

International Nuclear Information System (INIS)

Schaffner, B.; Pedroni, E.

1998-01-01

The precision in proton radiotherapy treatment planning depends on the accuracy of the information used to calculate the stopping power properties of the tissues in the patient's body. This information is obtained from computed tomography (CT) images using a calibration curve to convert CT Hounsfield units into relative proton stopping power values. The validity of a stoichiometric method to create the calibration curve has been verified by measuring pairs of Hounsfield units and stopping power values for animal tissue samples. It was found that the agreement between measurement and calibration curve is better than 1% if beam hardening effects in the acquisition of the CT images can be neglected. The influence of beam hardening effects on the quantitative reading of the CT measurements is discussed and an estimation for the overall range precision of proton beams is given. It is expected that the range of protons in the human body can be controlled to better than ±1.1% of the water equivalent range in soft tissue and ±1.8% in bone, which translates into a range precision of about 1-3 mm in typical treatment situations. (author)

Improvements in high energy computed tomography

International Nuclear Information System (INIS)

Burstein, P.; Krieger, A.; Annis, M.

1984-01-01

In computerized axial tomography employed with large relatively dense objects such as a solid fuel rocket engine, using high energy x-rays, such as a 15 MeV source, a collimator is employed with an acceptance angle substantially less than 1 0 , in a preferred embodiment 7 minutes of a degree. In a preferred embodiment, the collimator may be located between the object and the detector, although in other embodiments, a pre-collimator may also be used, that is between the x-ray source and the object being illuminated. (author)

Effective Heart Disease Detection Based on Quantitative Computerized Traditional Chinese Medicine Using Representation Based Classifiers

Directory of Open Access Journals (Sweden)

Ting Shu

2017-01-01

Full Text Available At present, heart disease is the number one cause of death worldwide. Traditionally, heart disease is commonly detected using blood tests, electrocardiogram, cardiac computerized tomography scan, cardiac magnetic resonance imaging, and so on. However, these traditional diagnostic methods are time consuming and/or invasive. In this paper, we propose an effective noninvasive computerized method based on facial images to quantitatively detect heart disease. Specifically, facial key block color features are extracted from facial images and analyzed using the Probabilistic Collaborative Representation Based Classifier. The idea of facial key block color analysis is founded in Traditional Chinese Medicine. A new dataset consisting of 581 heart disease and 581 healthy samples was experimented by the proposed method. In order to optimize the Probabilistic Collaborative Representation Based Classifier, an analysis of its parameters was performed. According to the experimental results, the proposed method obtains the highest accuracy compared with other classifiers and is proven to be effective at heart disease detection.

Clinical diagnosis of bone metastases of cervical cancer by sup(99m)Tc scintigraphy and computerized tomography

Energy Technology Data Exchange (ETDEWEB)

Doi, S; Okamura, S; Ueki, M; Sugimoto, O [Osaka Medical Coll., Takatsuki (Japan)

1980-05-01

Early diagnosis of recurrence after treatment of cervical cancer has large influence on the prognosis. Local recurrence can be easily discovered by speculum inspection and palpation and also by association with cytodiagnosis and colposcopy. However, remote metastases, especially bone metastasis, though not highly frequent, have been difficult to diagnose. Therefore, we attempted the combination of computerized tomography and bone scintigraphy using sup(99m)Tc-labeled phosphate in 79 cases treated for cervical cancer at stage I to III. As a result, bone metastases was found in 16.7% of the 79 patients. Out of these 79 cases, bone metastases was considered as positive by bone scintigraphy in 15 cases (20.0%), as false positive in 9 cases (11.4%) and as negative, in 55 cases (69.6%). In 24 cases consisting of 15 positive and 9 false-negative cases of bone scintigraphy, CT was performed; 13 cases were proved positive and 11 cases, negative. Thirteen cases, proved positive by both bone scintigraphy and CT were diagnosed to surely have bone metastases. Metastases was found most frequently in the vertebral column (42.1%), and the ribs (26.3%). It was found also in the pelvis and in the femur in some cases. In the cases confirmed in operation to have metastases into the lymphatic glands, the incidence of bone metastases was higher (22.5%) than in the cases without. Metastases were discovered in many cases within 1 year after operation. From the above results, it was found that bone scintigraphy was useful for early discovery of bone metastases after treatment of cervical cancer, and that the additional application with CT would be very valuable in raising the success rate for discovery.

MDCT for computerized volumetry of pneumothoraces in pediatric patients.

Science.gov (United States)

Cai, Wenli; Lee, Edward Y; Vij, Abhinav; Mahmood, Soran A; Yoshida, Hiroyuki

2011-03-01

Our purpose in this study was to develop an automated computer-aided volumetry (CAV) scheme for quantifying pneumothorax in multidetector computed tomography (MDCT) images for pediatric patients and to investigate the imaging parameters that may affect its accuracy. Fifty-eight consecutive pediatric patients (mean age 12 ± 6 years) with pneumothorax who underwent MDCT for evaluation were collected retrospectively for this study. All cases were imaged by a 16- or 64-MDCT scanner with weight-based kilovoltage, low-dose tube current, 1.0-1.5 pitch, 0.6-5.0 mm slice thickness, and a B70f (sharp) or B31f (soft) reconstruction kernel. Sixty-three pneumothoraces ≥1 mL were visually identified in the left (n = 30) and right (n = 33) lungs. Each identified pneumothorax was contoured manually on an Amira workstation V4.1.1 (Mercury Computer Systems, Chelmsford, MA) by two radiologists in consensus. The computerized volumes of the pneumothoraces were determined by application of our CAV scheme. The accuracy of our automated CAV scheme was evaluated by comparison between computerized volumetry and manual volumetry, for the total volume of pneumothoraces in the left and right lungs. The mean difference between the computerized volumetry and the manual volumetry for all 63 pneumothoraces ≥1 mL was 8.2%. For pneumothoraces ≥10 mL, ≥50 mL, and ≥200 mL, the mean differences were 7.7% (n = 57), 7.3% (n = 33), and 6.4% (n = 13), respectively. The correlation coefficient was 0.99 between the computerized volume and the manual volume of pneumothoraces. Bland-Altman analysis showed that computerized volumetry has a mean difference of -5.1% compared to manual volumetry. For all pneumothoraces ≥10 mL, the mean differences for slice thickness ≤1.25 mm, = 1.5 mm, and = 5.0 mm were 6.1% (n = 28), 3.5% (n = 10), and 12.2% (n = 19), respectively. For the two reconstruction kernels, B70f and B31f, the mean differences were 6.3% (n = 42, B70f) and 11.7% (n = 15, B31f

Clinical features and computerized tomography in chronic schizophrenia

International Nuclear Information System (INIS)

Shimada, Hitoshi; Nagayama, Motowo; Hori, Akira

1990-01-01

Computed tomography (CT) scans and clinical manifestations were compared in severe (53) and mild (42) schizophrenic patients. Severe patients were defined as having been hospitalized during the previous 3 years or more, and mild patients as having lived at home. Regarding psychiatric symptoms, behavior, dosage of antipsychotic agents, and admission duration or disease duration, there were significant differences between the severe and mild groups. Both Hasegawa's and Moriya's dementia rating scales were significantly lower in the severe group than the mild group. Cranial CT scans were analyzed for the Sylvian fissure, third ventricle, body of the lateral ventricle, frontal lobe, and parietofrontal cortex. There were significant differences in CT scans for the Sylvian fissure, third ventricle, and body of the lateral ventricle between the severe and mild groups. For the other two sites, no significant differences were observed. The Sylvian fissure was significantly dilatated in the severe group. Dilatation of the Sylvian fissure was well correlated with clinical manifestations, such as language, feeling expression, decreased will, strange behavior, and disease recognition, reflecting clinical severity. (N.K.)

Computerized tomography with 3-dimensional reconstruction for the evaluation of renal size and arterial anatomy in the living kidney donor.

Science.gov (United States)

Janoff, Daniel M; Davol, Patrick; Hazzard, James; Lemmers, Michael J; Paduch, Darius A; Barry, John M

2004-01-01

Computerized tomography (CT) with 3-dimensional (3-D) reconstruction has gained acceptance as an imaging study to evaluate living renal donors. We report our experience with this technique in 199 consecutive patients to validate its predictions of arterial anatomy and kidney volumes. Between January 1997 and March 2002, 199 living donor nephrectomies were performed at our institution using an open technique. During the operation arterial anatomy was recorded as well as kidney weight in 98 patients and displacement volume in 27. Each donor had been evaluated preoperatively by CT angiography with 3-D reconstruction. Arterial anatomy described by a staff radiologist was compared with intraoperative findings. CT estimated volumes were reported. Linear correlation graphs were generated to assess the reliability of CT volume predictions. The accuracy of CT angiography for predicting arterial anatomy was 90.5%. However, as the number of renal arteries increased, predictive accuracy decreased. The ability of CT to predict multiple arteries remained high with a positive predictive value of 95.2%. Calculated CT volume and kidney weight significantly correlated (0.654). However, the coefficient of variation index (how much average CT volume differed from measured intraoperative volume) was 17.8%. CT angiography with 3-D reconstruction accurately predicts arterial vasculature in more than 90% of patients and it can be used to compare renal volumes. However, accuracy decreases with multiple renal arteries and volume comparisons may be inaccurate when the difference in kidney volumes is within 17.8%.

Computerized adaptive testing in computer assisted learning?

NARCIS (Netherlands)

Veldkamp, Bernard P.; Matteucci, Mariagiulia; Eggen, Theodorus Johannes Hendrikus Maria; De Wannemacker, Stefan; Clarebout, Geraldine; De Causmaecker, Patrick

2011-01-01

A major goal in computerized learning systems is to optimize learning, while in computerized adaptive tests (CAT) efficient measurement of the proficiency of students is the main focus. There seems to be a common interest to integrate computerized adaptive item selection in learning systems and

Experimental study of mechanisms of sand production using X-ray computerized tomography; Estudo experimental dos mecanismos da producao de areia empregando tomografia computadorizada de raios X

Energy Technology Data Exchange (ETDEWEB)

Santos, Janaina B.; Vargas Junior, Euripedes [Pontificia Univ. Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil). Dept. de Engenharia Civil; Barroso, Emilio V. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. de Geologia; Campos, Elisabete; Goncalves, Clemente; Tavares, Andre [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

2004-07-01

During productive phase of the well, many times there is simultaneous production of the solid particles detached from matrix of the reservoir rock. This phenomenon receives the name of the sand production. In this case stress and flow conditions around of the well are fundamental factors for deflagration of the process. Stress concentration in the wall of the well lead to the loss of cohesion between grains arising, consequently, a granular material region susceptible for dragging by seepage forces derived from fluid flow. The objective of this work was to perform sand production tests in Rio Bonito and synthetic sandstone samples using real-time X-Ray Computerized Tomography. The tests investigated the initial and the evolution of failure at the cavity wall of samples. These are initial stages of the sand production process. The analysis of the CT-scans obtained during tests allowed the visualization of breakouts and collapses of the wells. From studies more details were possible estimate the sand production and produce 3-D images of the propagation of the failure. (author)

Hyperplanar Morphological Clustering of a Hippocampus by Using Volumetric Computerized Tomography in Early Alzheimer’s Disease

Directory of Open Access Journals (Sweden)

Sarawut Suksuphew

2017-11-01

Full Text Available Background: On diagnosing Alzheimer’s disease (AD, most existing imaging-based schemes have relied on analyzing the hippocampus and its peripheral structures. Recent studies have confirmed that volumetric variations are one of the primary indicators in differentiating symptomatic AD from healthy aging. In this study, we focused on deriving discriminative shape-based parameters that could effectively identify early AD from volumetric computerized tomography (VCT delineation, which was previously almost intangible. Methods: Participants were 63 volunteers of Thai nationality, whose ages were between 40 and 90 years old. Thirty subjects (age 68.51 ± 5.5 were diagnosed with early AD, by using Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV criteria and the National Institute of Neurological and Communicative Disorders and the Stroke and the Alzheimer’s disease and Related Disorders Association (NINCDS-ADRDA criteria, while the remaining 33 were in the healthy control group (age 67.93 ± 5.5. The structural imaging study was conducted by using VCT. Three uninformed readers were asked to draw left and right hippocampal outlines on a coronal section. The resultant shapes were aligned and then analyzed with statistical shape analysis to obtain the first few dominant variational parameters, residing in hyperplanes. A supervised machine learning, i.e., support vector machine (SVM was then employed to elucidate the proposed scheme. Results: Provided trivial delineations, relatively as low as 5 to 7 implicit model parameters could be extracted and used as discriminants. Clinical verification showed that the model could differentiate early AD from aging, with high sensitivity, specificity, accuracy and F-measure of 0.970, 0.968, 0.983 and 0.983, respectively, with no apparent effect of left-right asymmetry. Thanks to a less laborious task required, yet high discriminating capability, the proposed scheme is expected to be applicable in a

Optimization of Proton CT Detector System and Image Reconstruction Algorithm for On-Line Proton Therapy.

Directory of Open Access Journals (Sweden)

Chae Young Lee

Full Text Available The purposes of this study were to optimize a proton computed tomography system (pCT for proton range verification and to confirm the pCT image reconstruction algorithm based on projection images generated with optimized parameters. For this purpose, we developed a new pCT scanner using the Geometry and Tracking (GEANT 4.9.6 simulation toolkit. GEANT4 simulations were performed to optimize the geometric parameters representing the detector thickness and the distance between the detectors for pCT. The system consisted of four silicon strip detectors for particle tracking and a calorimeter to measure the residual energies of the individual protons. The optimized pCT system design was then adjusted to ensure that the solution to a CS-based convex optimization problem would converge to yield the desired pCT images after a reasonable number of iterative corrections. In particular, we used a total variation-based formulation that has been useful in exploiting prior knowledge about the minimal variations of proton attenuation characteristics in the human body. Examinations performed using our CS algorithm showed that high-quality pCT images could be reconstructed using sets of 72 projections within 20 iterations and without any streaks or noise, which can be caused by under-sampling and proton starvation. Moreover, the images yielded by this CS algorithm were found to be of higher quality than those obtained using other reconstruction algorithms. The optimized pCT scanner system demonstrated the potential to perform high-quality pCT during on-line image-guided proton therapy, without increasing the imaging dose, by applying our CS based proton CT reconstruction algorithm. Further, we make our optimized detector system and CS-based proton CT reconstruction algorithm potentially useful in on-line proton therapy.

Human Reliability Analysis For Computerized Procedures

International Nuclear Information System (INIS)

Boring, Ronald L.; Gertman, David I.; Le Blanc, Katya

2011-01-01

This paper provides a characterization of human reliability analysis (HRA) issues for computerized procedures in nuclear power plant control rooms. It is beyond the scope of this paper to propose a new HRA approach or to recommend specific methods or refinements to those methods. Rather, this paper provides a review of HRA as applied to traditional paper-based procedures, followed by a discussion of what specific factors should additionally be considered in HRAs for computerized procedures. Performance shaping factors and failure modes unique to computerized procedures are highlighted. Since there is no definitive guide to HRA for paper-based procedures, this paper also serves to clarify the existing guidance on paper-based procedures before delving into the unique aspects of computerized procedures.

Computerized Adaptive Personality Testing: A Review and Illustration With the MMPI-2 Computerized Adaptive Version.

Science.gov (United States)

Forbey, Johnathan D.; Ben-Porath, Yossef S.

2007-01-01

Computerized adaptive testing in personality assessment can improve efficiency by significantly reducing the number of items administered to answer an assessment question. Two approaches have been explored for adaptive testing in computerized personality assessment: item response theory and the countdown method. In this article, the authors…

Comparison of SRIM, MCNPX and GEANT simulations with experimental data for thick Al absorbers

International Nuclear Information System (INIS)

Evseev, Ivan G.; Schelin, Hugo R.; Paschuk, Sergei A.; Milhoretto, Edney; Setti, Joao A.P.; Yevseyeva, Olga; Assis, Joaquim T. de; Hormaza, Joel M.; Diaz, Katherin S.; Lopes, Ricardo T.

2010-01-01

Proton computerized tomography deals with relatively thick targets like the human head or trunk. In this case precise analytical calculation of the proton final energy is a rather complicated task, thus the Monte Carlo simulation stands out as a solution. We used the GEANT4.8.2 code to calculate the proton final energy spectra after passing a thick Al absorber and compared it with the same conditions of the experimental data. The ICRU49, Ziegler85 and Ziegler2000 models from the low energy extension pack were used. The results were also compared with the SRIM2008 and MCNPX2.4 simulations, and with solutions of the Boltzmann transport equation in the Fokker-Planck approximation.

Comparison of SRIM, MCNPX and GEANT simulations with experimental data for thick Al absorbers

Energy Technology Data Exchange (ETDEWEB)

Evseev, Ivan G. [Federal University of Technology-Parana-UTFPR, Av.7 de Setembro 3165, Curitiba-PR (Brazil); Schelin, Hugo R. [Federal University of Technology-Parana-UTFPR, Av.7 de Setembro 3165, Curitiba-PR (Brazil)], E-mail: schelin@utfpr.edu.br; Paschuk, Sergei A.; Milhoretto, Edney; Setti, Joao A.P. [Federal University of Technology-Parana-UTFPR, Av.7 de Setembro 3165, Curitiba-PR (Brazil); Yevseyeva, Olga; Assis, Joaquim T. de [Instituto Politecnico da UERJ, Rua Alberto Rangel s/n, Nova Friburgo-RJ (Brazil); Hormaza, Joel M. [Instituto de Biociencias da UNESP, Distrito de Rubiao Junior s/n, Botucatu-SP (Brazil); Diaz, Katherin S. [CEADEN, Calle 30 502 e/5ta y 7ma Avenida, Playa, Ciudad Habana (Cuba); Lopes, Ricardo T. [Laboratorio de Instrumentacao Nuclear, COPPE, UFRJ, Rio de Janeiro-RJ (Brazil)

2010-04-15

Proton computerized tomography deals with relatively thick targets like the human head or trunk. In this case precise analytical calculation of the proton final energy is a rather complicated task, thus the Monte Carlo simulation stands out as a solution. We used the GEANT4.8.2 code to calculate the proton final energy spectra after passing a thick Al absorber and compared it with the same conditions of the experimental data. The ICRU49, Ziegler85 and Ziegler2000 models from the low energy extension pack were used. The results were also compared with the SRIM2008 and MCNPX2.4 simulations, and with solutions of the Boltzmann transport equation in the Fokker-Planck approximation.

Single photon emission computed tomography in AIDS dementia complex

International Nuclear Information System (INIS)

Pohl, P.; Vogl, G.; Fill, H.; Roessler, H.Z.; Zangerle, R.; Gerstenbrand, F.

1988-01-01

Single photon emission computed tomography (SPECT) studies were performed in AIDS dementia complex using IMP in 12 patients (and HM-PAO in four of these same patients). In all patients, SPECT revealed either multiple or focal uptake defects, the latter corresponding with focal signs or symptoms in all but one case. Computerized tomography showed a diffuse cerebral atrophy in eight of 12 patients, magnetic resonance imaging exhibited changes like atrophy and/or leukoencephalopathy in two of five cases. Our data indicate that both disturbance of cerebral amine metabolism and alteration of local perfusion share in the pathogenesis of AIDS dementia complex. SPECT is an important aid in the diagnosis of AIDS dementia complex and contributes to the understanding of the pathophysiological mechanisms of this disorder

A review of X-ray computed axial tomography

International Nuclear Information System (INIS)

Schmidt, M.

1989-01-01

A review of Computed axial tomography (CAT) scanning literature outlining the theoretical and practical aspects of this technique with application in both medical diagnosis and industrial non-destructive inspection (NDI) is presented. Practical aspects of CAT scanning discussed include : radiation sources, currently available spatial and contrast resolution limits and the evolution of the computerized tomography (CT) system. It was found that monochromatic gamma rays are preferred to X-rays, especially for very high density materials, and that in medical CAT scanning, the special resolution is only, 0.5 mm while spatial resolutions of less than 50μm have been achieved in NDI. An increased number of scientific and industrial applications are anticipated (e.g. for studying sintering reactions), as the capital cost of CAT scanning decreased. 13 refs., 9 figs., 2 tabs

Intracranial arterial anatomy: evaluation by computed tomography angiography

International Nuclear Information System (INIS)

Regattieri, Neysa Aparecida Tinoco; Haetinger, Rainer Guilherme; Liberti, Edson Aparecido

2010-01-01

By many decades, the intracranial arteries study was realized exclusively by angiography through selective arterial catheterization. Nowadays, with the technologic evaluation of computerized tomography devices with multi detectors allowing acquisitions with even more thinner slices, higher speed and better resolution, it had appeared a new modality of investigation: the computed tomography angiography, less invasive and with minor morbidity than conventional arteriography. Many studies in the literature have been analyzing the sensibility of the new method for the detection of intracranial aneurysms and comparing them with the conventional arteriography. There is a necessity to recognize the normal intracranial arterial anatomy and its variations using images obtained from multiplanar reformations, in order to give important information for surgeries strategies, such as wall calcifications, aneurismatic neck position and relationships with surrounding anatomical structures. (author)

Prediction of differential creatinine clearance in chronically obstructed kidneys by non-contrast helical computerized tomography

International Nuclear Information System (INIS)

Ng, Cheuk Fan; Chan, L.W.; Cheng, C.W.; Yu, S.C.H.; Wong, W.S.; Wong, K.T.

2004-01-01

Purpose: We investigate the use of non-contrast helical computerized tomography (NCHCT) in the measurement of differential renal parenchymal volume as a surrogate for differential creatinine clearance (Cr Cl) for unilateral chronically obstructed kidney. Materials And Methods: Patients with unilateral chronically obstructed kidneys with normal contralateral kidneys were enrolled. Ultrasonography (USG) of the kidneys was first done with the cortical thickness of the site with the most renal substance in the upper pole, mid-kidney, and lower pole of both kidneys were measured, and the mean cortical thickness of each kidney was calculated. NCHCT was subsequently performed for each patient. The CT images were individually reviewed with the area of renal parenchyma measured for each kidney. Then the volume of the slices was summated to give the renal parenchymal volume of both the obstructed and normal kidneys. Finally, a percutaneous nephrostomy (PCN) was inserted to the obstructed kidney, and Cr Cl of both the obstructed kidney (PCN urine) and the normal side (voided urine) were measured two 2 after the relief of obstruction. Results: From March 1999 to February 2001, thirty patients were enrolled into the study. Ninety percent of them had ureteral calculi. The differential Cr Cl of the obstructed kidney (%CrCl) was defined as the percentage of Cr Cl of the obstructed kidney as of the total Cr Cl, measured 2 weeks after relief of obstruction. The differential renal parenchymal volume of the obstructed kidney (%CTvol) was the percentage of renal parenchymal volume as of the total parenchymal volume. The differential USG cortical thickness of the obstructed kidney (%USGcort) was the percentage of mean cortical thickness as of the total mean cortical thickness. The Pearson's correlation coefficient (r) between %CTvol and %CrCl and that between %USGcort and %CrCl were 0.756 and 0.543 respectively. The regression line was %CrCl = (1.00) x %CTvol - 14.27. The %CTvol

Prediction of differential creatinine clearance in chronically obstructed kidneys by non-contrast helical computerized tomography

Directory of Open Access Journals (Sweden)

Ng C.F.

2004-01-01

Full Text Available PURPOSE: We investigate the use of non-contrast helical computerized tomography (NCHCT in the measurement of differential renal parenchymal volume as a surrogate for differential creatinine clearance (CrCl for unilateral chronically obstructed kidney. MATERIALS AND METHODS: Patients with unilateral chronically obstructed kidneys with normal contralateral kidneys were enrolled. Ultrasonography (USG of the kidneys was first done with the cortical thickness of the site with the most renal substance in the upper pole, mid-kidney, and lower pole of both kidneys were measured, and the mean cortical thickness of each kidney was calculated. NCHCT was subsequently performed for each patient. The CT images were individually reviewed with the area of renal parenchyma measured for each kidney. Then the volume of the slices was summated to give the renal parenchymal volume of both the obstructed and normal kidneys. Finally, a percutaneous nephrostomy (PCN was inserted to the obstructed kidney, and CrCl of both the obstructed kidney (PCN urine and the normal side (voided urine were measured two 2 after the relief of obstruction. RESULTS: From March 1999 to February 2001, thirty patients were enrolled into the study. Ninety percent of them had ureteral calculi. The differential CrCl of the obstructed kidney (%CrCl was defined as the percentage of CrCl of the obstructed kidney as of the total CrCl, measured 2 weeks after relief of obstruction. The differential renal parenchymal volume of the obstructed kidney (%CTvol was the percentage of renal parenchymal volume as of the total parenchymal volume. The differential USG cortical thickness of the obstructed kidney (%USGcort was the percentage of mean cortical thickness as of the total mean cortical thickness. The Pearson's correlation coefficient (r between %CTvol and %CrCl and that between %USGcort and %CrCl were 0.756 and 0.543 respectively. The regression line was %CrCl = (1.00 x %CTvol - 14.27. The %CTvol

Application of random numbers at computerized simulation of proton magnetic resonance signals

International Nuclear Information System (INIS)

Populyakh, S.N.; Sapiga, A.V.

2006-01-01

One calculated numerically spectra of proton magnetic resonance of water molecules diffusing along the regular positions in a natrolite. One reached adequate conformity of the experimental and the calculated spectra within wide temperature range including a transition region. To ensure calculations one used generators of the pseudorandom Markov sequences. The numerical analysis, in particular, has shown that at the binary Markov process the time period when physical value remains unchanged is described by the random value with exponential distribution [ru

Ultrasonography and computed tomography in the study of orbital tumors and pseudo-tumoral lesions

International Nuclear Information System (INIS)

Marins, J.L.C.; Pereira, R.M.; Prando, A.; Selos Moreira, A.R. de

1987-01-01

The computerized tomography and the ultrasonography in the ocular and orbital patologies were considered as complementary each other. the ultrasonography method as choice for the detection of the eye lesions in the adult, particularly of vascular origin and in the follow-up of inflammatory and pseudo-tumoral lesions was chosen. (L.M.J.) [pt

X-ray computerized tomography based on the method of reciprocal projection with filtration by double differentiation. Procedure and information peculiarities

International Nuclear Information System (INIS)

Vajnberg, Eh.I.; Kazak, I.A.; Fajngojz, M.L.

1985-01-01

The results of experimental evaluation of procedure and information peculiarities of the method of reciprocal projection with filtration of projections by double differentiation (RPFDD) for the monitoring of industrial products are generalized. Succession of stages n the RPFDD method permits to separately optimize reconstruction of high-frequeny and low-frequency tomogram structure which sharply reduces the acuteness of contradictions of conventional scheme between the required increase of accuracy and intolerable growth of computerized charges. High accuracy of evaluation of the linear attenuation factor of low-frequency structures in a wide range of densities at the last stage of RPFDD scheme is attained despite the non-conventionally small range of values at earlier stages of computerized processing

The use of computerized tomography in patients showing tardive dyskinesia

International Nuclear Information System (INIS)

Themelis, I.

1983-01-01

29 patients showing moderate to markedly pronounced tardive dyskinesia (TD) and a further 29 control patients (C) under a similar long-term medication with neuroleptics that had been so chosen as to match the age and sex distributions of the former group were subjected to computered tomography, neurological examination and psychological testing. The results did not point to any correlations between the structural changes and duration of treatment and the clinical signs or symptoms of extrapyramidal disorder. This was taken as further evidence in support of the theory that the initial damage in tardive dyskinesia mainly is at the level of the basal ganglia. (orig./MG) [de

Radiation condition in computerized tomography (CT): determination and calibration of dosemeters

International Nuclear Information System (INIS)

Adrade, L.C.; Peixoto, J.G.P.

2016-01-01

RQT is the standard for radiation conditions in computed tomography . It simulates a beam unrelieved of a CT scanner . The camera pencil ionization dosimeter is used in CT. The LNMRI become known characterization of RQT radiation conditions and the secondary standard calibration for type pencil ionisation chambers in its lab. The obtained beam has the characteristics required by IEC 61267. The results of the calibration presented combined uncertainty expanded to 95.45% from 2.22% . (author)

Computed Tomography of the complications of prosthetic surgery of the abdominal aorta

International Nuclear Information System (INIS)

Giovagnorio, Francesco; Andreoli, Chiara; De Cicco, Maria Luisa

1997-01-01

Computerized Tomography has gained an important role in the diagnosis of the complications of prosthetic surgery of the abdominal aorta: the importance of such complications come from their frequency, which is proportional to the increasing number of interventions, and their severity. The authors investigated the CT patterns of the most frequent complications. 24 patients referred for strongly suspected postoperative complications were examined in 2 years: fever and leukocytosis (20 cases) and progressive anemia (4 cases) were the most frequent findings. The operation had been performed 7± 12 weeks before (2 patients were excluded because surgery dated less than 3 weeks. 14 patients had infective complications: thickening (57%) and inhomogeneity (43%) of the periprosthetic wrap and ectopic gas bubble (78%) were the most frequent Computerized Tomography findings. The authors also observed 2 periprosthetic hematomas, 1 aneurysm relapse and 1 prosthetic graft rupture. In conclusion, CT confirmed its important role in the study of the complications of prosthetic aortic surgery, despite its know poor specificity in the demonstration of the aorta in the first 2-3 months postoperatively, in the initial stages of infection and in the diagnosis of aorta-enteric fistulas

Findings of bedside swallowing assessment and brain computerized tomography in patients with chronic cerebral infarction, and their outcome

Energy Technology Data Exchange (ETDEWEB)

Iwamoto, Toshihiko; Koshibu, Junko; Kikawada, Masayuki; Yoneda, Youichi; Uno, Masanobu; Takasaki, Masaru [Tokyo Medical Coll. (Japan); Imamura, Toshiharu

2001-09-01

To estimate the usefulness of the bedside swallowing assessment proposed by Smithard et al and neuroimaging findings characteristic for dysphagia, we studied the outcome of 102 patients with chronic cerebral infarction after assessment of swallowing by this test with brain computerized tomography (CT). All patients had a variety of motor disturbance and were admitted on a long-term medicare basis. They were divided into two groups according to the findings: the positive group (n=33), who showed any of the listed types of difficulty in swallowing water, and the negative group (n=69). Followed up to 2.2 years, their outcomes were studied. CT findings were studied on type of infarction, number and laterality of infarction, grade of periventricular lucency (PVL), presence of ventricular dilatation (VD), and severity of cortical atrophy (CA). The mean age was 76.4 years at registration and 61 were men. The frequency of severe dementia and disturbed ADL were significantly higher in the positive group. Eighteen patients died during the observation period and 15 of those were in the positive group, indicating higher, annual death rate (29.9% vs 2.2% in the negative group). All of the 15 patients in the positive group died of pneumonia. CT findings showed high incidence of multiple infarction, bilateral hemispheric lesion, severe PVL, VD, and severe CA in the positive group. These findings indicated that this evaluation method was useful in screening swallow function for patients with cerebral infarction in the chronic phase. Furthermore, CT findings suggested that severe white matter lesion, VD, and severe CA as well as multiple infarction seen in bilateral hemisphere was related to dysphagia, probably due to multiple factors involving pyramidal- and extrapyramidal-tracts with higher brain function. (author)

Findings of bedside swallowing assessment and brain computerized tomography in patients with chronic cerebral infarction, and their outcome

International Nuclear Information System (INIS)

Iwamoto, Toshihiko; Koshibu, Junko; Kikawada, Masayuki; Yoneda, Youichi; Uno, Masanobu; Takasaki, Masaru; Imamura, Toshiharu

2001-01-01

To estimate the usefulness of the bedside swallowing assessment proposed by Smithard et al and neuroimaging findings characteristic for dysphagia, we studied the outcome of 102 patients with chronic cerebral infarction after assessment of swallowing by this test with brain computerized tomography (CT). All patients had a variety of motor disturbance and were admitted on a long-term medicare basis. They were divided into two groups according to the findings: the positive group (n=33), who showed any of the listed types of difficulty in swallowing water, and the negative group (n=69). Followed up to 2.2 years, their outcomes were studied. CT findings were studied on type of infarction, number and laterality of infarction, grade of periventricular lucency (PVL), presence of ventricular dilatation (VD), and severity of cortical atrophy (CA). The mean age was 76.4 years at registration and 61 were men. The frequency of severe dementia and disturbed ADL were significantly higher in the positive group. Eighteen patients died during the observation period and 15 of those were in the positive group, indicating higher, annual death rate (29.9% vs 2.2% in the negative group). All of the 15 patients in the positive group died of pneumonia. CT findings showed high incidence of multiple infarction, bilateral hemispheric lesion, severe PVL, VD, and severe CA in the positive group. These findings indicated that this evaluation method was useful in screening swallow function for patients with cerebral infarction in the chronic phase. Furthermore, CT findings suggested that severe white matter lesion, VD, and severe CA as well as multiple infarction seen in bilateral hemisphere was related to dysphagia, probably due to multiple factors involving pyramidal- and extrapyramidal-tracts with higher brain function. (author)

A study of root canal morphology of human primary incisors and molars using cone beam computerized tomography: an in vitro study.

Science.gov (United States)

Gaurav, Vivek; Srivastava, Nikhil; Rana, Vivek; Adlakha, Vivek Kumar

2013-01-01

Variations in morphology of root canals in primary teeth usually leads to complications during and after endodontic therapy. To improve the success in endodontics, a thorough knowledge of the root canal morphology is essential. The aim of this study was to assess the variation in number and morphology of the root canals of primary incisors and molars and to study the applicability of cone beam computerized tomography (CBCT) in assessing the same. A total of 60 primary molars and incisors with full root length were collected and various parameters such as the number of roots, number of canals, diameter of root canal at cementoenamel junction and middle-third, length and angulations of roots of primary molars and incisors were studied using CBCT. The observations were put to descriptive statistics to find out the frequency, mean, standard deviation and range for all four subgroups. Further, unpaired t-test was used to compare these parameters between subgroups and analysis of variance test was implemented to evaluate the parameters within the subgroups. The CBCT showed the presence of bifurcation of root canal at middle third in 13% of mandibular incisors while 20% of mandibular molars had two canals in distal root. The diameter of distobuccal root canal of maxillary molars and mesiolingual canal of mandibular molars was found to be minimum. CBCT is a relatively new and effective technology, which provides an auxiliary imaging modality to supplement conventional radiography for assessing the variation in root canal morphology of primary teeth.

Formal Verification of Computerized Procedure with Colored Petri Nets

International Nuclear Information System (INIS)

Kim, Yun Goo; Shin, Yeong Cheol

2008-01-01

Computerized Procedure System (CPS) supports nuclear power plant operators in performing operating procedures which are instructions to guide in monitoring, decision making and controlling nuclear power plants. Computerized Procedure (CP) should be loaded to CPS. Due to its execution characteristic, computerized procedure acts like a software in CPS. For example, procedure flows are determined by operator evaluation and computerized procedure logic which are pre-defined. So the verification of Computerized Procedure logic and execution flow is needed before computerized procedures are installed in the system. Formal verification methods are proposed and the modeling of operating procedures with Coloured Petri Nets(CP-nets) is presented

A computerized tomography system for transcranial ultrasound imaging.

Science.gov (United States)

Tang, Sai Chun; Clement, Gregory T

Hardware for tomographic imaging presents both challenge and opportunity for simplification when compared with traditional pulse-echo imaging systems. Specifically, point diffraction tomography does not require simultaneous powering of elements, in theory allowing just a single transmit channel and a single receive channel to be coupled with a switching or multiplexing network. In our ongoing work on transcranial imaging, we have developed a 512-channel system designed to transmit and/or receive a high voltage signal from/to arbitrary elements of an imaging array. The overall design follows a hierarchy of modules including a software interface, microcontroller, pulse generator, pulse amplifier, high-voltage power converter, switching mother board, switching daughter board, receiver amplifier, analog-to-digital converter, peak detector, memory, and USB communication. Two pulse amplifiers are included, each capable of producing up to 400Vpp via power MOSFETS. Switching is based around mechanical relays that allow passage of 200V, while still achieving switching times of under 2ms, with an operating frequency ranging from below 100kHz to 10MHz. The system is demonstrated through ex vivo human skulls using 1MHz transducers. The overall system design is applicable to planned human studies in transcranial image acquisition, and may have additional tomographic applications for other materials necessitating a high signal output.

Technologies in computerized lexicography | Kruyt | Lexikos

African Journals Online (AJOL)

Although the topic of this paper is technology, focus is on functional rather than technical aspects of computerized lexicography. Keywords: computerized lexicography, electronic dictionary, electronic text corpus, lexicographer's workbench, integrated language database, automatic linguistic analysis, information retrieval, ...

[Computerized medical record: deontology and legislation].

Science.gov (United States)

Allaert, F A; Dusserre, L

1996-02-01

Computerization of medical records is making headway for patients' follow-up, scientific research, and health expenses control, but it must not alter the guarantees provided to the patients by the medical code of ethics and the law of January 6, 1978. This law, modified on July 1, 1994, requires to register all computerized records of personal data and establishes rights to protect privacy against computer misdemeanor. All medical practitioners using computerized medical records must be aware that the infringement of this law may provoke suing in professional, civil or criminal court.

39 CFR 501.15 - Computerized Meter Resetting System.

Science.gov (United States)

2010-07-01

... 39 Postal Service 1 2010-07-01 2010-07-01 false Computerized Meter Resetting System. 501.15... AND DISTRIBUTE POSTAGE EVIDENCING SYSTEMS § 501.15 Computerized Meter Resetting System. (a) Description. The Computerized Meter Resetting System (CMRS) permits customers to reset their postage meters at...

Emission computed tomography

International Nuclear Information System (INIS)

Phelps, M.E.

1977-01-01

Although there are many common aspects to x-ray transmission and radionuclide emission (ECT) computerized tomography, there are added difficulties and a number of particular factors which form the basis of ECT. The relationship between the physical factors, system design, methodologic approach and assumptions of ECT is discussed. The instrumentation design and application strategies in ECT at this time are diverse and in a rapid stage of development. The approaches are divided into two major categories of Single Photon Counting (SPC) employing scanner and camera concepts with radionuclides of 99 /sup m/Tc, 201 Tl, 123 I etc., and Annihilation Coincidence Detection (ACD) of positron-emitting radionuclides. Six systems in the former and ten systems in the latter category, with examples of typical studies, illustrate the different approaches

YAP(Ce) crystal characterization with proton beam up to 60 MeV

Energy Technology Data Exchange (ETDEWEB)

Randazzo, N. [Istituto Nazionale di Fisica Nucleare, Sezione di Catania (I), Via S. Sofia, 64-I-95123 Catania (Italy)], E-mail: nunzio.randazzo@ct.infn.it; Sipala, V.; Aiello, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Catania (I), Via S. Sofia, 64-I-95123 Catania (Italy); Lo Presti, D. [Istituto Nazionale di Fisica Nucleare, Sezione di Catania (I), Via S. Sofia, 64-I-95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Universita di Catania, Catania (Italy); Cirrone, G.A.P.; Cuttone, G.; Di Rosa, F. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud (Italy)

2008-02-21

A YAP(Ce) crystal was characterized with a proton beam up to 60 MeV. Tests were performed to investigate the possibility of using this detector as a proton calorimeter. The size of the crystal was chosen so that the proton energy is totally lost inside the medium. The authors propose to use the YAP(Ce) crystal in medical applications for proton therapy. In particular, in proton computed tomography (pCT) project it is necessary as a calorimeter in order to measure the proton residual energy after the phantom. Energy resolution, linearity, and light yield were measured in the Laboratori Nazionali del Sud with the CATANA proton beam [ (http://www.lns.infn.it/CATANA/CATANA)] and the results are shown in this paper. The crystal shows a good resolution (3% at 60 MeV proton beam) and it shows good linearity for different proton beam energies (1% at 30-60 MeV energy range). The crystal performances confirm that the YAP(Ce) crystal represents a good solution for these kinds of application.

YAP(Ce) crystal characterization with proton beam up to 60 MeV

International Nuclear Information System (INIS)

Randazzo, N.; Sipala, V.; Aiello, S.; Lo Presti, D.; Cirrone, G.A.P.; Cuttone, G.; Di Rosa, F.

2008-01-01

A YAP(Ce) crystal was characterized with a proton beam up to 60 MeV. Tests were performed to investigate the possibility of using this detector as a proton calorimeter. The size of the crystal was chosen so that the proton energy is totally lost inside the medium. The authors propose to use the YAP(Ce) crystal in medical applications for proton therapy. In particular, in proton computed tomography (pCT) project it is necessary as a calorimeter in order to measure the proton residual energy after the phantom. Energy resolution, linearity, and light yield were measured in the Laboratori Nazionali del Sud with the CATANA proton beam [ (http://www.lns.infn.it/CATANA/CATANA)] and the results are shown in this paper. The crystal shows a good resolution (3% at 60 MeV proton beam) and it shows good linearity for different proton beam energies (1% at 30-60 MeV energy range). The crystal performances confirm that the YAP(Ce) crystal represents a good solution for these kinds of application

YAP(Ce) crystal characterization with proton beam up to 60 MeV

Science.gov (United States)

Randazzo, N.; Sipala, V.; Aiello, S.; Lo Presti, D.; Cirrone, G. A. P.; Cuttone, G.; Di Rosa, F.

2008-02-01

A YAP(Ce) crystal was characterized with a proton beam up to 60 MeV. Tests were performed to investigate the possibility of using this detector as a proton calorimeter. The size of the crystal was chosen so that the proton energy is totally lost inside the medium. The authors propose to use the YAP(Ce) crystal in medical applications for proton therapy. In particular, in proton computed tomography (pCT) project it is necessary as a calorimeter in order to measure the proton residual energy after the phantom. Energy resolution, linearity, and light yield were measured in the Laboratori Nazionali del Sud with the CATANA proton beam [ http://www.lns.infn.it/CATANA/CATANA] and the results are shown in this paper. The crystal shows a good resolution (3% at 60 MeV proton beam) and it shows good linearity for different proton beam energies (1% at 30-60 MeV energy range). The crystal performances confirm that the YAP(Ce) crystal represents a good solution for these kinds of application.

The Indiana University proton radiation therapy project

International Nuclear Information System (INIS)

Bloch, C.; Derenchuk, V.; Cameron, J.; Fasano, M.; Gilmore, J.; Hashemian, R.; Hornback, N.; Low, D.A.; Morphis, J.; Peterson, C.; Rosselot, D.; Sandison, G.; Shen, R.N.; Shidnia, H.

1993-01-01

A fixed horizontal beam line at the Indiana University cyclotron facility (IUCF) has been equipped for proton radiation therapy treatment of head, neck, and brain tumors. The complete system will be commissioned and ready to treat patients early in 1993. IUCF can produce external proton beams from 45 to 200 MeV in energy, which corresponds to a maximum range in water of 26 cm. Beam currents over 100 nA are easily attained, allowing dose rates in excess of 200 cGy/min, even for large fields. Beam spreading systems have been tested which provide uniform fields up to 20 cm in diameter. Range modulation is accomplished with a rotating acrylic device, which provides uniform depth dose distributions from 3 to 18 cm in extent. Tests have been conducted on detectors which monitor the beam position and current, and the dose symmetry. This report discusses those devices, as well as the cyclotron characteristics, measured beam properties, safety interlocks, computerized dose delivery/monitoring system, and future plans. (orig.)

Comparison of short-lived medical isotopes activation by laser thin target induced protons and conventional cyclotron proton beams

Science.gov (United States)

Murray, Joseph; Dudnikova, Galina; Liu, Tung-Chang; Papadopoulos, Dennis; Sagdeev, Roald; Su, J. J.; UMD MicroPET Team

2014-10-01

Production diagnostic or therapeutic nuclear medicines are either by nuclear reactors or by ion accelerators. In general, diagnostic nuclear radioisotopes have a very short half-life varying from tens of minutes for PET tracers and few hours for SPECT tracers. Thus supplies of PET and SPECT radiotracers are limited by regional production facilities. For example 18F-fluorodeoxyglucose (FDG) is the most desired tracer for positron emission tomography because its 110 minutes half-life is sufficient long for transport from production facilities to nearby users. From nuclear activation to completing image taking must be done within 4 hours. Decentralized production of diagnostic radioisotopes will be idea to make high specific activity radiotracers available to researches and clinicians. 11 C, 13 N, 15 O and 18 F can be produced in the energy range from 10-20 MeV by protons. Protons of energies up to tens of MeV generated by intense laser interacting with hydrogen containing targets have been demonstrated by many groups in the past decade. We use 2D PIC code for proton acceleration, Geant4 Monte Carlo code for nuclei activation to compare the yields and specific activities of short-lived isotopes produced by cyclotron proton beams and laser driven protons.

Near-Infrared Diffuse Optical Tomography

Directory of Open Access Journals (Sweden)

A. H. Hielscher

2002-01-01

Full Text Available Diffuse optical tomography (DOT is emerging as a viable new biomedical imaging modality. Using near-infrared (NIR light, this technique probes absorption as well as scattering properties of biological tissues. First commercial instruments are now available that allow users to obtain cross-sectional and volumetric views of various body parts. Currently, the main applications are brain, breast, limb, joint, and fluorescence/bioluminescence imaging. Although the spatial resolution is limited when compared with other imaging modalities, such as magnetic resonance imaging (MRI or X-ray computerized tomography (CT, DOT provides access to a variety of physiological parameters that otherwise are not accessible, including sub-second imaging of hemodynamics and other fast-changing processes. Furthermore, DOT can be realized in compact, portable instrumentation that allows for bedside monitoring at relatively low cost. In this paper, we present an overview of current state-of-the -art technology, including hardware and image-reconstruction algorithms, and focus on applications in brain and joint imaging. In addition, we present recent results of work on optical tomographic imaging in small animals.

Cost-effectiveness analysis of 3-D computerized tomography colonography versus optical colonoscopy for imaging symptomatic gastroenterology patients.

Science.gov (United States)

Gomes, Manuel; Aldridge, Robert W; Wylie, Peter; Bell, James; Epstein, Owen

2013-04-01

When symptomatic gastroenterology patients have an indication for colonic imaging, clinicians have a choice between optical colonoscopy (OC) and computerized tomography colonography with three-dimensional reconstruction (3-D CTC). 3-D CTC provides a minimally invasive and rapid evaluation of the entire colon, and it can be an efficient modality for diagnosing symptoms. It allows for a more targeted use of OC, which is associated with a higher risk of major adverse events and higher procedural costs. A case can be made for 3-D CTC as a primary test for colonic imaging followed if necessary by targeted therapeutic OC; however, the relative long-term costs and benefits of introducing 3-D CTC as a first-line investigation are unknown. The aim of this study was to assess the cost effectiveness of 3-D CTC versus OC for colonic imaging of symptomatic gastroenterology patients in the UK NHS. We used a Markov model to follow a cohort of 100,000 symptomatic gastroenterology patients, aged 50 years or older, and estimate the expected lifetime outcomes, life years (LYs) and quality-adjusted life years (QALYs), and costs (£, 2010-2011) associated with 3-D CTC and OC. Sensitivity analyses were performed to assess the robustness of the base-case cost-effectiveness results to variation in input parameters and methodological assumptions. 3D-CTC provided a similar number of LYs (7.737 vs 7.739) and QALYs (7.013 vs 7.018) per individual compared with OC, and it was associated with substantially lower mean costs per patient (£467 vs £583), leading to a positive incremental net benefit. After accounting for the overall uncertainty, the probability of 3-D CTC being cost effective was around 60 %, at typical willingness-to-pay values of £20,000-£30,000 per QALY gained. 3-D CTC is a cost-saving and cost-effective option for colonic imaging of symptomatic gastroenterology patients compared with OC.

WE-EF-303-10: Single- Detector Proton Radiography as a Portal Imaging Equivalent for Proton Therapy

Energy Technology Data Exchange (ETDEWEB)

Doolan, P [University College London Hospital, London (United Kingdom); Bentefour, E [Ion Beam Applications, Louvain-la-Neuve (Belgium); Testa, M; Cascio, E; Lu, H [Massachussetts General Hospital, Boston, MA (United States); Royle, G [University College London, London (United Kingdom); Gottschalk, B [Harvard University, Cambridge, MA (United States)

2015-06-15

Purpose: In proton therapy, patient alignment is of critical importance due to the sensitivity of the proton range to tissue heterogeneities. Traditionally proton radiography is used for verification of the water-equivalent path length (WEPL), which dictates the depth protons reach. In this work we propose its use for alignment. Additionally, many new proton centers have cone-beam computed tomography in place of beamline X-ray imaging and so proton radiography offers a unique patient alignment verification similar to portal imaging in photon therapy. Method: Proton radiographs of a CIRS head phantom were acquired using the Beam Imaging System (BIS) (IBA, Louvain-la-Neuve) in a horizontal beamline. A scattered beam was produced using a small, dedicated, range modulator (RM) wheel fabricated out of aluminum. The RM wheel was rotated slowly (20 sec/rev) using a stepper motor to compensate for the frame rate of the BIS (120 ms). Dose rate functions (DRFs) over two RM wheel rotations were acquired. Calibration was made with known thicknesses of homogeneous solid water. For each pixel the time width, skewness and kurtosis of the DRFs were computed. The time width was used to compute the object WEPL. In the heterogeneous phantom, the excess skewness and excess kurtosis (i.e. difference from homogeneous cases) were computed and assessed for suitability for patient set up. Results: The technique allowed for the simultaneous production of images that can be used for WEPL verification, showing few internal details, and excess skewness and kurtosis images that can be used for soft tissue alignment. These latter images highlight areas where range mixing has occurred, correlating with phantom heterogeneities. Conclusion: The excess skewness and kurtosis images contain details that are not visible in the WET images. These images, unique to the time-resolved proton radiographic method, could be used for patient set up according to soft tissues.

Microcomputer Network for Computerized Adaptive Testing (CAT)

Science.gov (United States)

1984-03-01

PRDC TR 84-33 \\Q.�d-33- \\ MICROCOMPUTER NETWOJlt FOR COMPUTERIZED ADAPTIVE TESTING ( CAT ) Baldwin Quan Thomas A . Park Gary Sandahl John H...ACCEIIION NO NPRDC TR 84-33 4. TITLE (-d Sul>tlllo) MICROCOMP UTER NETWORK FOR COMPUTERIZED ADA PTIVE TESTING ( CAT ) 1. Q B. uan T. A . Park...adaptive testing ( CAT ) Bayesian sequential testing 20. ABSTitACT (Continuo on ro•••• aide II noco .. _, _., ld-tlly ,.,. t.loclt _._.) DO Computerized

A Micro-Scale Investigation on the Behaviors of Asphalt Mixtures under Freeze-Thaw Cycles Using Entropy Theory and a Computerized Tomography Scanning Technique

Directory of Open Access Journals (Sweden)

Huining Xu

2018-01-01

Full Text Available The thermodynamic behavior of asphalt mixtures is critical to the engineers since it directly relates to the damage in asphalt mixtures. However, most of the current research of the freeze-thaw damage of asphalt mixtures is focused on the bulk body from the macroscale and lacks a fundamental understanding of the thermodynamic behaviors of asphalt mixtures from the microscale perspective. In this paper, to identify the important thermodynamic behaviors of asphalt mixtures under freeze-thaw loading cycle, the information entropy theory, an X-ray computerized tomography (CT scanner and digital image processing technology are employed. The voids, the average size of the voids, the connected porosity, and the void number are extracted according to the scanned images. Based on the experiments and the CT scanned images, the information entropy evolution of the asphalt mixtures under different freeze-thaw cycles is calculated and the relationship between the change of information entropy and the pore structure characteristics is established. Then, the influences of different freezing and thawing conditions on the thermodynamic behaviors of asphalt mixtures are compared. The combination of information entropy theory and CT scanning technique proposed in this paper provides an innovative approach to investigate the thermodynamics behaviors of asphalt mixtures and a new way to analyze the freeze-thaw damage in asphalt mixtures.

Neutron tomography using projection data obtained by Monte Carlo simulation for nondestructive evaluation

International Nuclear Information System (INIS)

Silva, A.X. da; Crispim, V.R.

2002-01-01

This work present the application of a computer package for generating of projection data for neutron computerized tomography, and in second part, discusses an application of neutron tomography, using the projection data obtained by Monte Carlo technique, for the detection and localization of light materials such as those containing hydrogen, concealed by heavy materials such as iron and lead. For tomographic reconstructions of the samples simulated use was made of only six equal projection angles distributed between 0 deg C and 180 deg C, with reconstruction making use of an algorithm (ARIEM), based on the principle of maximum entropy. With the neutron tomography it was possible to detect and locate polyethylene and water hidden by lead and iron (with 1 cm-thick). Thus, it is demonstrated that thermal neutrons tomography is a viable test method which can provide important interior information about test components, so, extremely useful in routine industrial applications.(author)

Absorbed dose to the patient by computerized whole body X-ray tomography

International Nuclear Information System (INIS)

Krauss, O.; Schuhmacher, H.

1977-01-01

The absorbed dose to the patient was measured for several medical investigations by computerized whole body scanning. An Alderson-phantom mounted with LiF-TLD was irradiated with a Delta-Scan (Ohio-Nuclear, 120 kV, 30 mA). The integral dose to the brain during a full examination (6 scans, filtration 3 mm Al) was measured to 5x10 -2 J. The maximum absorbed dose at the entrance was found to be 3.2 rd and at the exit 0.6 rd. The dose to the eyes is 0.7 rd and to the thyroid gland 0.03 rd. The integral dose to the trunk (5 scans in the region of liver and kidneys, filtration 6 mm Al) was measured to 5x10 -2 J. The maximum absorbed dose at the entrance was found to be 2.4 rd and at the exit 0.25 rd. The dose to the gonads is less than 2 and 4 mrd if the distance between the last scan and the gonads is more than 15 cm

Computerized system for measuring cerebral metabolism

International Nuclear Information System (INIS)

McGlone, J.S.; Hibbard, L.S.; Hawkins, R.A.; Kasturi, R.

1987-01-01

A computerized stereotactic measurement system for evaluating rat brain metabolism was developed to utilize the large amount of data generated by quantitative autoradiography. Conventional methods of measurement only analyze a small percent of these data because these methods are limited by instrument design and the subjectiveness of the investigator. However, a computerized system allows digital images to be analyzed by placing data at their appropriate three-dimensional stereotactic coordinates. The system automatically registers experimental data to a standard three-dimensional image using alignment, scaling, and matching operations. Metabolic activity in different neuronal structures is then measured by generating digital masks and superimposing them on to experimental data. Several experimental data sets were evaluated and it was noticed that the structures measured by the computerized system, had in general, lower metabolic activity than manual measurements had indicated. This was expected because the computerized system measured the structure over its volume while the manual readings were taken from the most active metabolic area of a particular structure

Clinical significance of bone scintigraphy and computerized tomography (CT scan) in the evaluation of renal osteodystrophy in haemodialysed and non-haemodialysed patients

International Nuclear Information System (INIS)

Yatsuboshi, Motohiko

1978-01-01

For the evaluation of renal osteodystophy in both haemodialysed and non-haemodialysed patients, bone scintigraphy and computerized tomography (CT) scan were performed. Twenty-six patients with chronic renal failure were objectives of the study. For the control study of CT scan, patients with brain tumor without renal disease were selected. Bone scan was performed approximately 3 hours after sup(99m) Tc-EHDP (ethane-1-hydroxy-1, 1-diphosphonate) administration. The numericals which were printed out from CT scanner were analyzed in the area of frontal bone. The number of positive group was 9 and that of negative was 17. Positive group in non-haemodialysed patients showed lower serum calcium level and creatinine clearance and higher serum levels of inorganic phosphate and BUN compared with those of negative group. Positive scan group showed longer duration of dialysis and higher serum levels of parathyroid hormone and alkaline phosphatase than those of negative group. Frequency of abnormal findings detected by bone scan was higher than that elicited by roentgenographic examination. CT number of positive scan group was lower than that of negative group or control group. CT number in patients with subperiosteal resorption of phalanx and abnormal findings of calvarium was lower than that of patients without such roentgenographic abnormalities. These findings indicate that bone scan is useful in detecting bone changes of secondary hyperparathyroidism in chronic renal failure. CT scan could also help to estimate the decrease of bone density of calvarium in chronic renal failure. (author)

Dosimetry in computerized tomography and evaluation of doses in organs in thorax scanning

International Nuclear Information System (INIS)

Alonso, Thêssa Cristina

2016-01-01

Computed tomography has promoted improvement of the diagnostic process by producing anatomical cut images with high quality and contrast between soft tissues which have very similar absorption of the X-ray beams. The objective of this study is to evaluate the technological park of CT in Brazil correlated with the wide world, and carry out studies of experimental dosimetry to understand the dose distribution feature using phantoms and different methods of measurement of kerma index, as well as perform measures of local doses in sensitive organs. To study the scanner geographic distribution and supply of computed tomography tests in Brazil, a comparison has been made with results found with the specified reference by Brazilian law (Ordinance GM / MS No. 1101, 2002; Resolution RE nº1016, 2006). For dosimetry studies, It was used a standard chest phantom and the anthropomorphic phantom. For image quality evaluation, it was used the CATPHAN-600 phantom. Scans were performed in a GE scanner, Discovery model with 64 channels. Dose measurements have been performed by using a pencil ionization chamber, thermoluminescent dosimeters and radiochromic film strips. Sensitive organ shielding devices were evaluated in order to verify their efficiency in organ dose reduction and its influence in the quality of image. Considering Brazilian population, the scanner park showed a greater amount than the minimum parameter recommended by Brazilian law. Dose measurements using three different methods showed the correct procedure of metrological reliability of the measurement system. The findings and conclusions of this study may contribute to the improvement of local practices in Computed Tomography tests, inserted in context of radiological protection in order to define reference levels for optimized diagnosis, and image quality control. (author)

Computerized reactor monitor and control for research reactors

International Nuclear Information System (INIS)

Buerger, L.; Vegh, E.

1981-09-01

The computerized process control system developed in the Central Research Institute for Physics, Budapest, Hungary, is described together with its special applications at research reactors. The nuclear power of the Hungarian research reactor is controlled by this computerized system, too, while in Lybia many interesting reactor-hpysical calculations are built into the computerized monitor system. (author)

Clinical manifestations in patients with computerized tomography diagnosis of neurocysticercosis

International Nuclear Information System (INIS)

Pfuetzenreiter, Marcia Regina; Avila-Pires, Fernando Dias de

1999-01-01

A survey was conducted in the urban area of Lages using patients who had been submitted to a computed tomography of the skull in the period of March-December, 1996, for different reasons. Forty-two patients with a provisional diagnosis of neurocysticercosis, and 57 negatives were personally interviewed by one of the authors (Pfuetzenreiter), using a semi-structured procedure. More individuals with a provisional diagnostic of neurocysticercosis reported clinical manifestations related to this infection than those found negative. this difference is more marked among women, except in relation to convulsions, more frequently reported by men (19.05%) than by women (7.14%). The greater percentage of inactive forms (83.33%0 and a longer history of perceived symptoms among those positives suggest that the condition is not new. (author)

Comparison of Volumes between Four-Dimensional Computed Tomography and Cone-Beam Computed Tomography Images using Dynamic Phantom

Energy Technology Data Exchange (ETDEWEB)

Kim, Seong Eun; Won, Hui Su; Hong, Joo Wan; Chang, Nam Jun; Jung, Woo Hyun; Choi, Byeong Don [Dept. of Radiation Oncology, Seoul National University Bundang Hospital, Sungnam (Korea, Republic of)

2016-12-15

The aim of this study was to compare the differences between the volumes acquired with four-dimensional computed tomography (4DCT)images with a reconstruction image-filtering algorithm and cone-beam computed tomography (CBCT) images with dynamic phantom. The 4DCT images were obtained from the computerized imaging reference systems (CIRS) phantom using a computed tomography (CT) simulator. We analyzed the volumes for maximum intensity projection (MIP), minimum intensity projection (MinIP) and average intensity projection (AVG) of the images obtained with the 4DCT scanner against those acquired from CBCT images with CT ranger tools. Difference in volume for node of 1, 2 and 3 cm between CBCT and 4DCT was 0.54⁓2.33, 5.16⁓8.06, 9.03⁓20.11 ml in MIP, respectively, 0.00⁓1.48, 0.00⁓8.47, 1.42⁓24.85 ml in MinIP, respectively and 0.00⁓1.17, 0.00⁓2.19, 0.04⁓3.35 ml in AVG, respectively. After a comparative analysis of the volumes for each nodal size, it was apparent that the CBCT images were similar to the AVG images acquired using 4DCT.

A study of root canal morphology of human primary incisors and molars using cone beam computerized tomography: An in vitro study

Directory of Open Access Journals (Sweden)

Vivek Gaurav

2013-01-01

Full Text Available Background: Variations in morphology of root canals in primary teeth usually leads to complications during and after endodontic therapy. To improve the success in endodontics, a thorough knowledge of the root canal morphology is essential. Aim: The aim of this study was to assess the variation in number and morphology of the root canals of primary incisors and molars and to study the applicability of cone beam computerized tomography (CBCT in assessing the same. Settings and Design: A total of 60 primary molars and incisors with full root length were collected and various parameters such as the number of roots, number of canals, diameter of root canal at cementoenamel junction and middle-third, length and angulations of roots of primary molars and incisors were studied using CBCT. Statistical analysis used: The observations were put to descriptive statistics to find out the frequency, mean, standard deviation and range for all four subgroups. Further, unpaired t-test was used to compare these parameters between subgroups and analysis of variance test was implemented to evaluate the parameters within the subgroups. Results and Conclusion: The CBCT showed the presence of bifurcation of root canal at middle third in 13% of mandibular incisors while 20% of mandibular molars had two canals in distal root. The diameter of distobuccal root canal of maxillary molars and mesiolingual canal of mandibular molars was found to be minimum. CBCT is a relatively new and effective technology, which provides an auxiliary imaging modality to supplement conventional radiography for assessing the variation in root canal morphology of primary teeth.

Regional cerebral blood flow during rest and skilled hand movements by xenon-133 inhalation and emission computerized tomography

DEFF Research Database (Denmark)

Lauritzen, M; Henriksen, L; Lassen, N A

1981-01-01

Regional cerebral blood flow (CBF) was studied in 16 normal adult volunteers during rest and in 10 the study was repeated during skilled hand movements. A fast-rotating ("dynamic"), single-photon emission computerized tomograph (ECT) with four detector heads was used. Xenon-133 was inhaled over a 1...... motor area on both sides by 34 +/- 15% (p less than 0.025)....

Feasibility of proton-activated implantable markers for proton range verification using PET

Science.gov (United States)

Cho, Jongmin; Ibbott, Geoffrey; Gillin, Michael; Gonzalez-Lepera, Carlos; Titt, Uwe; Paganetti, Harald; Kerr, Matthew; Mawlawi, Osama

2013-11-01

Proton beam range verification using positron emission tomography (PET) currently relies on proton activation of tissue, the products of which decay with a short half-life and necessitate an on-site PET scanner. Tissue activation is, however, negligible near the distal dose fall-off region of the proton beam range due to their high interaction energy thresholds. Therefore Monte Carlo simulation is often supplemented for comparison with measurement; however, this also may be associated with systematic and statistical uncertainties. Therefore, we sought to test the feasibility of using long-lived proton-activated external materials that are inserted or infused into the target volume for more accurate proton beam range verification that could be performed at an off-site PET scanner. We irradiated samples of ≥98% 18O-enriched water, natural Cu foils, and >97% 68Zn-enriched foils as candidate materials, along with samples of tissue-equivalent materials including 16O water, heptane (C7H16), and polycarbonate (C16H14O3)n, at four depths (ranging from 100% to 3% of center of modulation (COM) dose) along the distal fall-off of a modulated 160 MeV proton beam. Samples were irradiated either directly or after being embedded in Plastic Water® or balsa wood. We then measured the activity of the samples using PET imaging for 20 or 30 min after various delay times. Measured activities of candidate materials were up to 100 times greater than those of the tissue-equivalent materials at the four distal dose fall-off depths. The differences between candidate materials and tissue-equivalent materials became more apparent after longer delays between irradiation and PET imaging, due to the longer half-lives of the candidate materials. Furthermore, the activation of the candidate materials closely mimicked the distal dose fall-off with offsets of 1 to 2 mm. Also, signals from the foils were clearly visible compared to the background from the activated Plastic Water® and balsa wood

Positron transaxial emission tomograph with computerized image reconstruction

International Nuclear Information System (INIS)

Jatteau, Michel.

1981-01-01

This invention concerns a positron transaxial emission tomography apparatus with computerized image reconstruction, like those used in nuclear medicine for studying the metabolism of organs, in physiological examinations and as a diagnosis aid. The operation is based on the principle of the detection of photons emitted when the positrons are annihilated by impact with an electron. The appliance is mainly composed of: (a) - a set of gamma ray detectors distributed on a polygonal arrangement around the body area to be examined, (b) - circuits for amplifying the signals delivered by the gamma ray detectors, (c) - computers essentially comprising energy integration and discrimination circuits and provided at the output of the detectors for calculating and delivering, as from the amplified signals, information on the position and energy relative to each occurrence constituted by the detections of photons, (d) - time coincidence circuits for selecting by emission of detector validation signals, only those occurrences, among the ensemble of those detected, which effectively result from the annihilation of positrons inside the area examined, (e) - a data processing system [fr

Comparison Between In-Beam and Offline Positron Emission Tomography Imaging of Proton and Carbon Ion Therapeutic Irradiation at Synchrotron- and Cyclotron-Based Facilities

International Nuclear Information System (INIS)

Parodi, Katia; Bortfeld, Thomas; Haberer, Thomas

2008-01-01

Purpose: The benefit of using dedicated in-beam positron emission tomography (PET) detectors in the treatment room instead of commercial tomographs nearby is an open question. This work quantitatively compares the measurable signal for in-beam and offline PET imaging, taking into account realistic acquisition strategies at different ion beam facilities. Both scenarios of pulsed and continuous irradiation from synchrotron and cyclotron accelerators are considered, because of their widespread use in most carbon ion and proton therapy centers. Methods and Materials: A mathematical framework is introduced to compare the time-dependent amount and spatial distribution of decays from irradiation-induced isotope production. The latter is calculated with Monte Carlo techniques for real proton treatments of head-and-neck and paraspinal tumors. Extrapolation to carbon ion irradiation is based on results of previous phantom experiments. Biologic clearance is modeled taking into account available data from previous animal and clinical studies. Results: Ratios between the amount of physical decays available for in-beam and offline detection range from 40% to 60% for cyclotron-based facilities, to 65% to 110% (carbon ions) and 94% to 166% (protons) at synchrotron-based facilities, and increase when including biologic clearance. Spatial distributions of decays during irradiation exhibit better correlation with the dose delivery and reduced influence of biologic processes. Conclusions: In-beam imaging can be advantageous for synchrotron-based facilities, provided that efficient PET systems enabling detection of isotope decays during beam extraction are implemented. For very short (<2 min) irradiation times at cyclotron-based facilities, a few minutes of acquisition time after the end of irradiation are needed for counting statistics, thus affecting patient throughput

Assessment of radiation exposure in dental cone-beam computerized tomography with the use of metal-oxide semiconductor field-effect transistor (MOSFET) dosimeters and Monte Carlo simulations.

Science.gov (United States)

Koivisto, J; Kiljunen, T; Tapiovaara, M; Wolff, J; Kortesniemi, M

2012-09-01

The aims of this study were to assess the organ and effective dose (International Commission on Radiological Protection (ICRP) 103) resulting from dental cone-beam computerized tomography (CBCT) imaging using a novel metal-oxide semiconductor field-effect transistor (MOSFET) dosimeter device, and to assess the reliability of the MOSFET measurements by comparing the results with Monte Carlo PCXMC simulations. Organ dose measurements were performed using 20 MOSFET dosimeters that were embedded in the 8 most radiosensitive organs in the maxillofacial and neck area. The dose-area product (DAP) values attained from CBCT scans were used for PCXMC simulations. The acquired MOSFET doses were then compared with the Monte Carlo simulations. The effective dose measurements using MOSFET dosimeters yielded, using 0.5-cm steps, a value of 153 μSv and the PCXMC simulations resulted in a value of 136 μSv. The MOSFET dosimeters placed in a head phantom gave results similar to Monte Carlo simulations. Minor vertical changes in the positioning of the phantom had a substantial affect on the overall effective dose. Therefore, the MOSFET dosimeters constitute a feasible method for dose assessment of CBCT units in the maxillofacial region. Copyright © 2012 Elsevier Inc. All rights reserved.

A study of the imaging of atomic elements by computerised axial tomography

OpenAIRE

McCarthy, K. J

1989-01-01

Conventional computerized axial tomography images show the spatial variation in the linear attenuation coefficient in a cross-section of a specimen. However, no information is present to enable one to predict the location nor concentration of an atomic element in the image. Differential X-ray absorptiometry is a well established analytic technique for determining the concentration of an atomic element in a specimen. In this thesis, it is shown that by applying differential X-ray absorpt...

Technetium-99m-HMPAO labeled leukocyte single photon emission computerized tomography (SPECT) for assessing Crohn's disease extent and intestinal infiltration.

Science.gov (United States)

Biancone, L; Schillaci, O; Capoccetti, F; Bozzi, R M; Fina, D; Petruzziello, C; Geremia, A; Simonetti, G; Pallone, F

2005-02-01

Scintigraphy using radiolabeled leukocytes is a useful technique for assessing intestinal infiltration in Crohn's disease (CD). However, limits of planar images include overlapping activity in other organs and low specificity. To investigate the usefulness of (99m)Tc-HMPAO (hexametyl propylene amine oxime) labeled leukocyte single photon emission computerized tomography (SPECT) for assessing CD lesions, in comparison with planar images. Twenty-two inflammatory bowel disease patients (19 CD; 2 ulcerative colitis, UC; 1 ileal pouch) assessed by conventional endoscopy or radiology were enrolled. Leukocytes were labeled with (99m)Tc-HMPAO. SPECT images were acquired at 2 h and planar images at 30 min and 2 h. Bowel uptake was quantitated in nine regions (score 0-3). Both SPECT and planar images detected a negative scintigraphy (score 0) in the UC patient with no pouchitis and a positive scintigraphy (score 1-3) in the 21 patients showing active inflammation by conventional techniques. SPECT showed a higher global score than planar images (0.71 +/- 0.09 vs 0.30 +/- 0.05; p < 0.001), and in particular in the right iliac fossa (p= 0.003), right and left flank (p < 0.001; p= 0.02), hypogastrium (p= 0.002), and mesogastrium (p < 0.001). SPECT provided a better visualization and a higher uptake than planar images in patients with ileal and ileocolonic CD (6.45 +/- 0.82 vs 2.8 +/- 0.55, p < 0.001; 5.5 +/- 1.6 vs 2.6 +/- 0.7, p= 0.03), and with perianal CD (6.6 +/- 1.6 vs 3.4 +/- 1.2; p= 0.03). (99m)Tc-HMPAO labeled leukocyte SPECT provides a more detailed visualization of CD lesions than planar images. This technique may better discriminate between intestinal and bone marrow uptake, thus being useful for assessing CD lesions within the pelvis, including perianal disease.

Evaluation of parapharyngeal space by computerized tomography and magnetic resonance. Part 1: anatomy

International Nuclear Information System (INIS)

Souza, Ricardo Pires de; Rapoport, Abrao

1994-01-01

The authors, through a comprehensive review of the literature, intend to establish an anatomical concept of the parapharyngeal space and its surroundings spaces in the supra-hyoid neck, based on its division by the fascial planes. The correlation between the anatomically defined parapharyngeal space and the findings of the sectional imaging procedures (computed tomography and magnetic resonance) is established, evidencing clear anatomic-radiologic correspondence. (author)

Quantification of Soil Physical Properties by Using X-Ray Computerized Tomography (CT) and Standard Laboratory (STD) Methods

Energy Technology Data Exchange (ETDEWEB)

Sanchez, Maria Ambert [Iowa State Univ., Ames, IA (United States)

2003-12-12

The implementation of x-ray computerized tomography (CT) on agricultural soils has been used in this research to quantify soil physical properties to be compared with standard laboratory (STD) methods. The overall research objective was to more accurately quantify soil physical properties for long-term management systems. Two field studies were conducted at Iowa State University's Northeast Research and Demonstration Farm near Nashua, IA using two different soil management strategies. The first field study was conducted in 1999 using continuous corn crop rotation for soil under chisel plow with no-till treatments. The second study was conducted in 2001 and on soybean crop rotation for the same soil but under chisel plow and no-till practices with wheel track and no-wheel track compaction treatments induced by a tractor-manure wagon. In addition, saturated hydraulic (K{sub s}) conductivity and the convection-dispersion (CDE) model were also applied using long-term soil management systems only during 2001. The results obtained for the 1999 field study revealed no significant differences between treatments and laboratory methods, but significant differences were found at deeper depths of the soil column for tillage treatments. The results for standard laboratory procedure versus CT method showed significant differences at deeper depths for the chisel plow treatment and at the second lower depth for no-till treatment for both laboratory methods. The macroporosity distribution experiment showed significant differences at the two lower depths between tillage practices. Bulk density and percent porosity had significant differences at the two lower depths of the soil column. The results obtained for the 2001 field study showed no significant differences between tillage practices and compaction practices for both laboratory methods, but significant differences between tillage practices with wheel track and no-wheel compaction treatments were found along the soil

Pseudomeningocele in communication with the facet joint: demonstration by computerized tomography-arthrography

International Nuclear Information System (INIS)

Ganiyusufoglu, Kursat; Ozturk, Cagatay; Sirvanci, Mustafa; Aksu, Neslihan; Hamzaoglu, Azmi

2008-01-01

Pseudomeningocele is an uncommon but well-known complication of lumbar spine operations. Although it is mostly asymptomatic and managed conservatively in most cases, it is claimed as a causative factor of failed back surgery syndrome and requires surgery in some cases. Usually, its diagnosis is confidently done with imaging modalities such as magnetic resonance imaging, computed tomography and myelography. In this report, we describe a case of pseudomeningocele that communicated with a facet joint. The diagnostic approach for this unusual lesion and its probable causes are discussed. (orig.)

Pseudomeningocele in communication with the facet joint: demonstration by computerized tomography-arthrography

Energy Technology Data Exchange (ETDEWEB)

Ganiyusufoglu, Kursat; Ozturk, Cagatay; Sirvanci, Mustafa; Aksu, Neslihan; Hamzaoglu, Azmi [Florence Nightingale Hospital, Istanbul Bilim University, Istanbul Spine Center, Istanbul (Turkey)

2008-08-15

Pseudomeningocele is an uncommon but well-known complication of lumbar spine operations. Although it is mostly asymptomatic and managed conservatively in most cases, it is claimed as a causative factor of failed back surgery syndrome and requires surgery in some cases. Usually, its diagnosis is confidently done with imaging modalities such as magnetic resonance imaging, computed tomography and myelography. In this report, we describe a case of pseudomeningocele that communicated with a facet joint. The diagnostic approach for this unusual lesion and its probable causes are discussed. (orig.)

Computerized Classification Testing with the Rasch Model

Science.gov (United States)

Eggen, Theo J. H. M.

2011-01-01

If classification in a limited number of categories is the purpose of testing, computerized adaptive tests (CATs) with algorithms based on sequential statistical testing perform better than estimation-based CATs (e.g., Eggen & Straetmans, 2000). In these computerized classification tests (CCTs), the Sequential Probability Ratio Test (SPRT) (Wald,…

Comparison of x ray computed tomography number to proton relative linear stopping power conversion functions using a standard phantom.

Science.gov (United States)

Moyers, M F

2014-06-01

Adequate evaluation of the results from multi-institutional trials involving light ion beam treatments requires consideration of the planning margins applied to both targets and organs at risk. A major uncertainty that affects the size of these margins is the conversion of x ray computed tomography numbers (XCTNs) to relative linear stopping powers (RLSPs). Various facilities engaged in multi-institutional clinical trials involving proton beams have been applying significantly different margins in their patient planning. This study was performed to determine the variance in the conversion functions used at proton facilities in the U.S.A. wishing to participate in National Cancer Institute sponsored clinical trials. A simplified method of determining the conversion function was developed using a standard phantom containing only water and aluminum. The new method was based on the premise that all scanners have their XCTNs for air and water calibrated daily to constant values but that the XCTNs for high density/high atomic number materials are variable with different scanning conditions. The standard phantom was taken to 10 different proton facilities and scanned with the local protocols resulting in 14 derived conversion functions which were compared to the conversion functions used at the local facilities. For tissues within ±300 XCTN of water, all facility functions produced converted RLSP values within ±6% of the values produced by the standard function and within 8% of the values from any other facility's function. For XCTNs corresponding to lung tissue, converted RLSP values differed by as great as ±8% from the standard and up to 16% from the values of other facilities. For XCTNs corresponding to low-density immobilization foam, the maximum to minimum values differed by as much as 40%. The new method greatly simplifies determination of the conversion function, reduces ambiguity, and in the future could promote standardization between facilities. Although it

Classification of lymph nodes in computerized tomography scans using extracting tools

International Nuclear Information System (INIS)

Alves, Allan F.F.; Pina, Diana R. de; Altemani, Joao M.C.

2016-01-01

Lymph node changes in the neck region may be originated by both inflammatory and tumor causes. Diagnostic imaging method such as computed tomography are used to distinguish between these two main causes of lymph nodes alterations. In this work we used feature extracting tools I CT scans such as the average value of pixels, wavelet entropy, skewness and kurtosis to assist the radiologist in diagnosing lymph nodes alterations. The wavelet entropy proved to be the best image characteristic parameter to differentiate between the two groups of patients evaluated in this study. The study of cervical lymph nodes changes by features extraction methods may prove to be an excellent tool to assist in differentiating between infectious / inflammatory and tumor causes in CT scans. (author)

Is it possible to verify directly a proton-treatment plan using positron emission tomography?

International Nuclear Information System (INIS)

Vynckier, S.; Derreumaux, S.; Richard, F.; Wambersie, A.; Bol, A.; Michel, C.

1993-01-01

A PET camera is used to visualize the positron activity induced during protonbeam therapy in order to verify directly the proton-treatment plans. The positron emitters created are predominantly the 15 O and 11 C, whose total activity amounts to 12 MBq after an irradiation with 85 MeV protons, delivering 3 Gy in a volume of approximately 300 cm 3 . Although this method is a useful verification of patient setup, care must be taken when deriving dose distributions from activity distributions. Correlation between both quantities is difficult, moreover at the last millimeters of their range, protons will no longer activate tissue. Due to the short half-lives the PET camera must be located close to the treatment facility. (author) 17 refs

Computed tomography in the diagnosis of gastric cancer: review of literature

International Nuclear Information System (INIS)

Portnoj, L.M.; Nefedova, V.O.; Chekunova, E.V.; Denisova, L.B.; Stashuk, G.A.

2000-01-01

Based on the available data and results of authors proper investigations the problem of assessing computerized tomography (CT) potentialities in revealing of stomach neoplasms is considered. It is shown that CT of stomach possesses a grave diagnostic information on stomach carcinoma. CT permits to determine the stage of stomach tumor, though it is connected with a number of difficulties. Biomedical radiography procedure is necessary before CT. It is concluded that modern endoscopy and conventional biomedical radiography and the main diagnostic techniques for stomach carcinoma at present [ru

Stratification of mammographic computerized analysis by BI-RADS categories

International Nuclear Information System (INIS)

Lederman, Richard; Leichter, Isaac; Buchbinder, Shalom; Novak, Boris; Bamberger, Philippe; Fields, Scott

2003-01-01

The Breast Imaging Reporting and Data System (BI-RADS) was implemented to standardize characterization of mammographic findings. The purpose of the present study was to evaluate in which BI-RADS categories the changes recommended by computerized mammographic analysis are most beneficial. Archival cases including, 170 masses (101 malignant, 69 benign) and 63 clusters of microcalcifications (MCs; 36 malignant, 27 benign), were evaluated retrospectively, using the BI-RADS categories, by several radiologists, blinded to the pathology results. A computerized system then automatically extracted from the digitized mammogram features characterizing mammographic lesions, which were used to classify the lesions. The results of the computerized classification scheme were compared, by receiver operating characteristics (ROC) analysis, to the conventional interpretation. In the ''low probability of malignancy group'' (excluding BI-RADS categories 4 and 5), computerized analysis improved the A z of the ROC curve significantly, from 0.57 to 0.89. In the ''high probability of malignancy group'' (mostly category 5) the computerized analysis yielded an ROC curve with an A z of 0.99. In the ''intermediate probability of malignancy group'' computerized analysis improved the A z significantly, from 0.66 for to 0.83. Pair-wise analysis showed that in the latter group the modifications resulting from computerized analysis were correct in 83% of cases. Computerized analysis has the ability to improve the performance of the radiologists exactly in the BI-RADS categories with the greatest difficulties in arriving at a correct diagnosis. It increased the performance significantly in the problematic group of ''intermediate probability of malignancy'' and pinpointed all the cases with missed cancers in the ''low probability'' group. (orig.)

Positron emission tomography studies in the normal and abnormal ageing of human brain

International Nuclear Information System (INIS)

Comar, D.; Baron, J.C.

1987-01-01

Until recently, the investigation of the neurophysiological correlates of normal and abnormal ageing of the human brain was limited by methodological constraints, as the technics available provided only a few parameters (e.g. electroencephalograms, cerebral blood flow) monitored in superficial brain structures in a grossly regional and poorly quantitative way. Lately several non invasive techniques have been developed which allow to investigate in vivo both quantitatively and on local basis a number of previously inaccessible important aspects of brain function. Among these techniques, such as single photon emission tomography imaging of computerized electric events, nuclear magnetic resonance, positron emission tomography stands out as the most powerful and promising method since it allows the in vivo measurement of biochemical and pharmacological parameters

Use of SMT phototransistors for dosimetry in computerized tomography

International Nuclear Information System (INIS)

Magalhaes, C.M.S. de; Silva, J.O. da; Antonio Filho, J.; Santos, L.A.P. dos

2007-01-01

A dosimetry system using commercially available SMT (Surface-Mount Technology) phototransistors is evaluated for dose measurements in X-ray computed tomography. First, the phototransistors were characterized at the laboratory using a Pantak X-ray in the standard radiation quality RQR9 from IEC61267. The following tests were realized: energy dependence, response with dose rate and repetitiveness. The phototransistors yielded a real-time readout and a 6430 Sub-femto-ammeter Keithley was used to obtain their electrical current. This methodology allowed the correlating of their results with a standard ionisation chamber, a NE2571 ionization chamber coupled to a NE2670 electrometer that measured the applied dose at the detector position. After the characterization of the phototransistors, free-in-air and in head phantom dose measurements were carried out with the dosimetry system at the Hospital. Phototransistors were used to determine the dose profile measurements along the axis of rotation undergoing CT head examination. A Flip-Flop electrometer was used to obtain these measurements. The results indicated that the current values were reliable when compared with the results of doses of CT ionization chamber under the same conditions. The loss of radiation sensitivity, postirradiation, with time is not significant and the SMT phototransistor brings some features to CT dosimetry including high sensitivity, small size, real-time measurements and linearity. (author)

Computerized Italian criticality guide, description and validation

International Nuclear Information System (INIS)

Carotenuto, M.; Landeyro, P.A.

1988-10-01

Our group is developing an 'expert system' for collecting engineering know-how on back-end nuclear plant design. An expert system is the most suitable software tool for our problem. During the analysis, the design process was divided into different branches. At each branch of the design process the Expert System relates a computerized design procedure. Any design procedure is composed of a set of design methods, together with their condition of application and reliability limits. In the framework of this expert system, the nuclear criticality safety analysis procedure was developed, in the form of a computerized criticality guide, attempting to reproduce the designer's normal 'reasoning' process. The criticality guide is composed of two parts: A computerized text, including theory, a description of the accidents occurred in the past and a description of the italian design experience; An interactive computer aided calculation module, containing a graphical facility for critical parameter curves. In the present report are presented the criticality guide (computerized Italian Criticality Guide) and its validation test. (author)

Computerized Italian criticality guide, description and validation

Energy Technology Data Exchange (ETDEWEB)

Carotenuto, M; Landeyro, P A [ENEA - Dipartimento Ciclo del Combustibile, Centro Ricerche Energia, Casaccia (Italy)

1988-10-15

Our group is developing an 'expert system' for collecting engineering know-how on back-end nuclear plant design. An expert system is the most suitable software tool for our problem. During the analysis, the design process was divided into different branches. At each branch of the design process the Expert System relates a computerized design procedure. Any design procedure is composed of a set of design methods, together with their condition of application and reliability limits. In the framework of this expert system, the nuclear criticality safety analysis procedure was developed, in the form of a computerized criticality guide, attempting to reproduce the designer's normal 'reasoning' process. The criticality guide is composed of two parts: A computerized text, including theory, a description of the accidents occurred in the past and a description of the italian design experience; An interactive computer aided calculation module, containing a graphical facility for critical parameter curves. In the present report are presented the criticality guide (computerized Italian Criticality Guide) and its validation test. (author)

Sensitivity of computer assisted radionuclide angiography in transient ischemic attack and prolonged reversible ischemic neurological deficit. Comparison with findings in radiographic angiography and transmission computerized axial tomography

International Nuclear Information System (INIS)

Buell, U.; Scheid, K.F.; Lanksch, W.; Kleinhans, E.; Ulbert, V.; Reger, U.; Rath, M.; Moser, E.A.

1981-01-01

Computer assisted radionuclide angiography (CARNA) with 99mTc-DTPA was employed to study 143 patients with transient ischemic attacks (TIA) and 79 patients with prolonged reversible ischemic neurologic deficit (PRIND). The results of CARNA were compared with findings from radiographic angiography (RGA) in 173 patients and with findings in transmission computerized axial tomography (T-CAT) in 154 patients. In patients with TIA, CARNA showed a hemispherical perfusion deficit in 74.8%, and with PRIND 87.3%. This deficit, determined as the relative difference between the involved and the non-involved hemisphere, was significantly (p less than 0.0025) greater in PRIND (minus 23%) than in TIA (minus 17%). Sensitivity of CARNA was independent of the interval from ictus to examination for more than 4 months. RGA in TIA revealed true positives in 82.0%, in PRIND it was 89.5%. T-CAT was positive in TIA in only 16.8% but in PRIND it was 64.4%. Combined sensitivities in TIA (92.4%) and in PRIND (94.0%) were highest with the combination of CARNA and RGA. However, in PRIND the combination of non-invasive methods (CARNA and T-CAT) revealed 93.2% positive findings. Combinations of these evaluation methods may be used to detect cerebrovascular disease in patients with such dysfunction

Srna-Monte Carlo codes for proton transport simulation in combined and voxelized geometries

CERN Document Server

Ilic, R D; Stankovic, S J

2002-01-01

This paper describes new Monte Carlo codes for proton transport simulations in complex geometrical forms and in materials of different composition. The SRNA codes were developed for three dimensional (3D) dose distribution calculation in proton therapy and dosimetry. The model of these codes is based on the theory of proton multiple scattering and a simple model of compound nucleus decay. The developed package consists of two codes: SRNA-2KG and SRNA-VOX. The first code simulates proton transport in combined geometry that can be described by planes and second order surfaces. The second one uses the voxelized geometry of material zones and is specifically adopted for the application of patient computer tomography data. Transition probabilities for both codes are given by the SRNADAT program. In this paper, we will present the models and algorithms of our programs, as well as the results of the numerical experiments we have carried out applying them, along with the results of proton transport simulation obtaine...

Stratification of mammographic computerized analysis by BI-RADS categories

Energy Technology Data Exchange (ETDEWEB)

Lederman, Richard [Department of Radiology, Hadassah University Hospital, Ein Kerem, Jerusalem (Israel); Leichter, Isaac [Department of Electro-Optics, Jerusalem College of Technology, P.O.B. 16031, Jerusalem (Israel); Buchbinder, Shalom [Department of Radiology of The Montefiore Medical Center, The University Hospital for the Albert Einstein College of Medicine, Bronx, New York (United States); Novak, Boris [Department of Applied Mathematics, Jerusalem College of Technology, P.O.B. 16031, Jerusalem 91160 (Israel); Bamberger, Philippe [Department of Electronics, Jerusalem College of Technology, POB 16031, Jerusalem (Israel); Fields, Scott [Department of Radiology, Hadassah University Hospital, Mt. Scopus, Jerusalem (Israel)

2003-02-01

The Breast Imaging Reporting and Data System (BI-RADS) was implemented to standardize characterization of mammographic findings. The purpose of the present study was to evaluate in which BI-RADS categories the changes recommended by computerized mammographic analysis are most beneficial. Archival cases including, 170 masses (101 malignant, 69 benign) and 63 clusters of microcalcifications (MCs; 36 malignant, 27 benign), were evaluated retrospectively, using the BI-RADS categories, by several radiologists, blinded to the pathology results. A computerized system then automatically extracted from the digitized mammogram features characterizing mammographic lesions, which were used to classify the lesions. The results of the computerized classification scheme were compared, by receiver operating characteristics (ROC) analysis, to the conventional interpretation. In the ''low probability of malignancy group'' (excluding BI-RADS categories 4 and 5), computerized analysis improved the A{sub z}of the ROC curve significantly, from 0.57 to 0.89. In the ''high probability of malignancy group'' (mostly category 5) the computerized analysis yielded an ROC curve with an A {sub z}of 0.99. In the ''intermediate probability of malignancy group'' computerized analysis improved the A {sub z}significantly, from 0.66 for to 0.83. Pair-wise analysis showed that in the latter group the modifications resulting from computerized analysis were correct in 83% of cases. Computerized analysis has the ability to improve the performance of the radiologists exactly in the BI-RADS categories with the greatest difficulties in arriving at a correct diagnosis. It increased the performance significantly in the problematic group of ''intermediate probability of malignancy'' and pinpointed all the cases with missed cancers in the ''low probability'' group. (orig.)

Correction of the X-ray tube spot movement as a tool for improvement of the micro-tomography quality

Czech Academy of Sciences Publication Activity Database

Vavřík, Daniel; Jandejsek, Ivan; Pichotka, M.

2016-01-01

Roč. 11, č. 1 (2016), C01029 ISSN 1748-0221 R&D Projects: GA MŠk(CZ) LO1219 Keywords : computerized tomography (CT) * computed radiography (CR) * inspection with x-rays * detector alignment and calibration methods Subject RIV: AL - Art, Architecture, Cultural Heritage Impact factor: 1.220, year: 2016 http://iopscience.iop.org/article/10.1088/1748-0221/11/01/C01029

Comparative analysis of brain X-ray computed tomography in patients with acromegaly before and after gamma-ray teletherapy

International Nuclear Information System (INIS)

Balkanov, A.S.; Stashuk, G.A.; Polyakov, P.Yu.; Sherman, L.A.; Bychenkov, O.A.

1999-01-01

Results are analysed of the application of X-ray computerized tomography (KT) of brain in acromegaly patients before and after remote gamma therapy (RGT). Efficiency is shown of the KT method permitting both to reveal pituitary adenomas in case of acromegaly and to be applicable in the combination with other methods to assessment of the RGT efficiency when treating acromegaly [ru

Technical aspects of positron emission tomography/computed tomography in radiotherapy treatment planning.

Science.gov (United States)

Scripes, Paola G; Yaparpalvi, Ravindra

2012-09-01

The usage of functional data in radiation therapy (RT) treatment planning (RTP) process is currently the focus of significant technical, scientific, and clinical development. Positron emission tomography (PET) using ((18)F) fluorodeoxyglucose is being increasingly used in RT planning in recent years. Fluorodeoxyglucose is the most commonly used radiotracer for diagnosis, staging, recurrent disease detection, and monitoring of tumor response to therapy (Lung Cancer 2012;76:344-349; Lung Cancer 2009;64:301-307; J Nucl Med 2008;49:532-540; J Nucl Med 2007;48:58S-67S). All the efforts to improve both PET and computed tomography (CT) image quality and, consequently, lesion detectability have a common objective to increase the accuracy in functional imaging and thus of coregistration into RT planning systems. In radiotherapy, improvement in target localization permits reduction of tumor margins, consequently reducing volume of normal tissue irradiated. Furthermore, smaller treated target volumes create the possibility of dose escalation, leading to increased chances of tumor cure and control. This article focuses on the technical aspects of PET/CT image acquisition, fusion, usage, and impact on the physics of RTP. The authors review the basic elements of RTP, modern radiation delivery, and the technical parameters of coregistration of PET/CT into RT computerized planning systems. Copyright © 2012 Elsevier Inc. All rights reserved.

Computed Tomography Imaging of the Topographical Anatomy of Canine Prostate

International Nuclear Information System (INIS)

Dimtrox, R.; Yonkova, P.; Vladova, D.; Kostov, D.

2010-01-01

AIM: To investigate the topographical anatomy of canine prostate gland by computed tomography (CT) for diagnostic imaging purposes. ÐœATERIAL AND METHODS: Seven clinically healthy mongrel male dogs at the age of 3−4 years and body weight of 10−15 kg were submitted to transverse computerized axial tomography (CAT) with cross section thickness of 5 mm. RESULTS: The CT image of canine prostate is visualized throughout the scans of the pelvis in the planes through the first sacral vertebra (S1) dorsally; the bodies of iliac bones laterally and cranially to the pelvic brim (ventrally). The body of prostate appears as an oval homogenous relatively hypo dense finding with soft tissue density. The gland is well differentiated from the adjacent soft tissues. CONCLUSION: By means of CT, the cranial part of prostate gland in adult dogs aged 3−4 years exhibited an abdominal localization. (author)

Current and future applications of protons in medical imaging and treatment

Energy Technology Data Exchange (ETDEWEB)

Schulte, Reinhard W. [Loma Linda University Medical Center, CA (United States). Dept. of Radiation Medicine

2011-07-01

Protons have a more than 50-year history of applications in medical therapy and more recently also in imaging. Therapy with protons became possible after proton accelerators capable of accelerating protons to energies higher than 150 MeV had been built during the 1940s in a few places around the world. Proton radiography experiments started at the Harvard Cyclotron in the early 1960s. Physicist Allan Cormack, who shared the Nobel Prize for laying the foundation of computed tomography together with Sir Godfrey Hounsfield in 1979, suggested that protons can be used for tomographic imaging for the first time in 1963. Proton CT requires a rotating proton gantry, which did not become available until 1991, at our institution. The interest in proton CT has been renewed due to the fact that exact proton treatment planning is only possible with accurate knowledge of the relative proton stopping power distribution (with respect to water) of the patient, which is best derived by using protons for imaging. Early attempts to do proton CT were hampered by the lack of high-resolution particle trackers, fast data acquisition electronics, and sufficient computing power. Also, efficient proton CT reconstruction algorithms had to be developed that can handle reconstruction based on a large number of proton histories, taking into account the non-straight probabilistic paths of multiply scattered protons. Most of these challenges have been or are about to be solved with the help of high-energy and particle physicists, computer science engineers, and applied mathematicians. In this talk, I will give an update on the development of proton CT for applications in proton therapy. This is an update from a talk I gave at the Annual Brazilian Physics Meeting in 2001, when I first suggested that physicists should contribute to the development of modern proton CT. Brazilian physicists have provided many valuable ideas and discussions for this exciting development. (author)

Current and future applications of protons in medical imaging and treatment

International Nuclear Information System (INIS)

Schulte, Reinhard W.

2011-01-01

Protons have a more than 50-year history of applications in medical therapy and more recently also in imaging. Therapy with protons became possible after proton accelerators capable of accelerating protons to energies higher than 150 MeV had been built during the 1940s in a few places around the world. Proton radiography experiments started at the Harvard Cyclotron in the early 1960s. Physicist Allan Cormack, who shared the Nobel Prize for laying the foundation of computed tomography together with Sir Godfrey Hounsfield in 1979, suggested that protons can be used for tomographic imaging for the first time in 1963. Proton CT requires a rotating proton gantry, which did not become available until 1991, at our institution. The interest in proton CT has been renewed due to the fact that exact proton treatment planning is only possible with accurate knowledge of the relative proton stopping power distribution (with respect to water) of the patient, which is best derived by using protons for imaging. Early attempts to do proton CT were hampered by the lack of high-resolution particle trackers, fast data acquisition electronics, and sufficient computing power. Also, efficient proton CT reconstruction algorithms had to be developed that can handle reconstruction based on a large number of proton histories, taking into account the non-straight probabilistic paths of multiply scattered protons. Most of these challenges have been or are about to be solved with the help of high-energy and particle physicists, computer science engineers, and applied mathematicians. In this talk, I will give an update on the development of proton CT for applications in proton therapy. This is an update from a talk I gave at the Annual Brazilian Physics Meeting in 2001, when I first suggested that physicists should contribute to the development of modern proton CT. Brazilian physicists have provided many valuable ideas and discussions for this exciting development. (author)

Computerized tomography of the painting 'The first mass in Brazil' (Vitor Meireles)

International Nuclear Information System (INIS)

Oliveira, Davi F.; Calza, Cristiane; Rocha, Henrique S.; Lopes, Ricardo T.

2007-01-01

In this work it was performed the radiographic analysis of the painting 'The First Mass in Brazil' ('Primeira Missa no Brasil) executed by Vitor Meireles, in 1860. Radiographic techniques have been used in museums to the study of cultural heritage objects in order to reveal internal details that would otherwise be invisible. This work used Computerized Radiography with an Imaging Plate detector (IP). It consists of a thin layer of photostimulable phosphor crystals (BaFBr:Eu 2+ ) deposited on a flexible polyester support film. When the IP is exposed to an x-ray source, part of the energy is stored as a latent image in the phosphor. Analyzing the radiographic images it is possible to observe the canvas weave, including stretching marks generated when the fabric was fixed on the wooden support. Several regions with detachment and cracking of painting were also revealed. When occurred losses of fabric, the holes were filled with mortar before the retouching; these areas, with higher density than the original painting support, can be clearly observed at the radiographs. The knowledge of all changes and its location is very important to the restoration process, especially in the first stage when the old reinforcement of the fabric will be replaced, in order to avoid the remove of painting pieces together to the reinforcement. (author)

Monte Carlo simulation of gamma ray tomography for image reconstruction

Energy Technology Data Exchange (ETDEWEB)

Guedes, Karlos A.N.; Moura, Alex; Dantas, Carlos; Melo, Silvio; Lima, Emerson, E-mail: karlosguedes@hotmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Meric, Ilker [University of Bergen (Norway)

2015-07-01

The Monte Carlo simulations of known density and shape object was validate with Gamma Ray Tomography in static experiments. An aluminum half-moon piece placed inside a steel pipe was the MC simulation test object that was also measured by means of gamma ray transmission. Wall effect of the steel pipe due to irradiation geometry in a single pair source-detector tomography was evaluated by comparison with theoretical data. MCNPX code requires a defined geometry to each photon trajectory which practically prevents this usage for tomography reconstruction simulation. The solution was found by writing a program in Delphi language to create input files automation code. Simulations of tomography data by automated MNCPX code were carried out and validated by experimental data. Working in this sequence the produced data needed a databank to be stored. Experimental setup used a Cesium-137 isotopic radioactive source (7.4 × 109 Bq), and NaI(Tl) scintillation detector of (51 × 51) × 10−3 m crystal size coupled to a multichannel analyzer. A stainless steel tubes of 0,154 m internal diameter, 0.014 m thickness wall. The results show that the MCNPX simulation code adapted to automated input file is useful for generating a matrix data M(θ,t), of a computerized gamma ray tomography for any known density and regular shape object. Experimental validation used RMSE from gamma ray paths and from attenuation coefficient data. (author)

Bronchial asthma: correlation of high resolution computerized tomography findings with clinical data

International Nuclear Information System (INIS)

Mogami, Roberto; Marchiori, Edson; Kirk, Kennedy; Capone, Domenico; Daltro, Pedro

1999-01-01

In this work we did a sectional study of 31 asthmatic patients with several levels of disease severity, which were submitted to high resolution computed tomography of the thorax and spirometry, between the months of July, 1995 and August, 1997. The tomographic findings were correlated with the clinical classification of the patients and the most frequent tomographic findings were bronchial wall thickening, bronchial dilatation, air trapping, centrilobular opacities, cicatricial linear shadows, mucoid impaction, emphysema and atelectasis. In asthmatic patients of long duration we observed small airway disease and irreversible lesions as the predominant findings. In smoking patients there was no high frequency of emphysema. (author)

Cranial computerized tomography. A synoptical atlas. Kranielle Computertomographie. Ein synoptischer Atlas

Energy Technology Data Exchange (ETDEWEB)

Nadjmi, M; Piepgras, U; Vogelsang, H

1981-01-01

The introductory chapters of the book cover, insofar as they differ from conventional radiology, the physico-technical fundamentals, the investigative procedure, as well as the anatomy and pathology. The anatomic pathology and classic neuroradiology of the individual groups are described in each chapter. These descriptions form the basis for interpreting the results obtained with computed tomography. This synoptical presentation makes it possible for non-neuroradiologists to obtain an overall impression on an often heterogeneous subject. The chapter on tumors also covers tumors in infants and children. The chapters on inflammatory diseases, traumatology and orbita include coverage of all age groups. The chapter of neuropediatrics deals mainly with the aspects of birth trauma and abnormal development. The legends to the illustrations comprise clinical data insofar as they contribute to a didactically important synthesis between syndrome, diagnosis and therapy.

Research on accounting transition from computerization to informationization

Directory of Open Access Journals (Sweden)

Shu Chen

2017-11-01

Full Text Available The application for computer technology, digitalization technology and network technology in the accounting field has promoted the development of accounting informationization. Accounting informationization is a product integrated with traditional accounting theory and modern information technology, which is an inevitable trend of continuous development of modern accounting. This paper discusses the basic concepts and characteristics of accounting computerization and informationization based on the normative research method and literature data method, analyzes the feasibility of accounting transition from computerization to informationization, and finally puts forward the specific approaches and ultimate goals of accounting transition from computerization to informationization.

High-resolution time-lapse tomography of rat vertebrae during compressive loading: deformation response analysis

Czech Academy of Sciences Publication Activity Database

Fíla, Tomáš; Kytýř, Daniel; Zlámal, Petr; Kumpová, Ivana; Doktor, Tomáš; Koudelka_ml., Petr; Jiroušek, Ondřej

2014-01-01

Roč. 9, May (2014), C05054 ISSN 1748-0221. [International workshop on radiation imaging detectors /15./. Paris, 23.06.2013-27.06.2013] R&D Projects: GA ČR(CZ) GAP105/10/2305; GA MŠk(CZ) LO1219 Institutional support: RVO:68378297 Keywords : image reconstruction in medical imaging * computerized tomography * computed radiography Subject RIV: JJ - Other Materials Impact factor: 1.399, year: 2014 http://iopscience.iop.org/1748-0221/9/05/C05054

Proton linac for hospital-based fast neutron therapy and radioisotope production

International Nuclear Information System (INIS)

Lennox, A.J.; Hendrickson, F.R.; Swenson, D.A.; Winje, R.A.; Young, D.E.

1989-09-01

Recent developments in linac technology have led to the design of a hospital-based proton linac for fast neutron therapy. The 180 microamp average current allows beam to be diverted for radioisotope production during treatments while maintaining an acceptable dose rate. During dedicated operation, dose rates greater than 280 neutron rads per minute are achievable at depth, DMAX = 1.6 cm with source to axis distance, SAD = 190 cm. Maximum machine energy is 70 MeV and several intermediate energies are available for optimizing production of isotopes for Positron Emission Tomography and other medical applications. The linac can be used to produce a horizontal or a gantry can be added to the downstream end of the linac for conventional patient positioning. The 70 MeV protons can also be used for proton therapy for ocular melanomas. 17 refs., 1 fig., 1 tab

Computerized adaptive testing--ready for ambulatory monitoring?

DEFF Research Database (Denmark)

Rose, Matthias; Bjørner, Jakob; Fischer, Felix

2012-01-01

Computerized adaptive tests (CATs) have abundant theoretical advantages over established static instruments, which could improve ambulatory monitoring of patient-reported outcomes (PROs). However, an empirical demonstration of their practical benefits is warranted.......Computerized adaptive tests (CATs) have abundant theoretical advantages over established static instruments, which could improve ambulatory monitoring of patient-reported outcomes (PROs). However, an empirical demonstration of their practical benefits is warranted....

Electronic stopping power calculation for water under the Lindhard formalism for application in proton computed tomography

Energy Technology Data Exchange (ETDEWEB)

Guerrero, A. F., E-mail: afguerreror@uqvirtual.edu.co [Departamento de Física, Universidad Del Quindío Cra 15 # 12N Armenia, Quindío (Colombia); Mesa, J., E-mail: jmesa@ibb.unesp.br [Instituto de Biociências de Botucatu da UNESP Distrito de Rubião Jr. s/n°, 18618-000, Botucatu, SP (Brazil)

2016-07-07

Because of the behavior that charged particles have when they interact with biological material, proton therapy is shaping the future of radiation therapy in cancer treatment. The planning of radiation therapy is made up of several stages. The first one is the diagnostic image, in which you have an idea of the density, size and type of tumor being treated; to understand this it is important to know how the particles beam interacts with the tissue. In this work, by using de Lindhard formalism and the Y.R. Waghmare model for the charge distribution of the proton, the electronic stopping power (SP) for a proton beam interacting with a liquid water target in the range of proton energies 10{sup 1} eV - 10{sup 10} eV taking into account all the charge states is calculated.

Proton-air and proton-proton cross sections

Directory of Open Access Journals (Sweden)

Ulrich Ralf

2013-06-01

Full Text Available Different attempts to measure hadronic cross sections with cosmic ray data are reviewed. The major results are compared to each other and the differences in the corresponding analyses are discussed. Besides some important differences, it is crucial to see that all analyses are based on the same fundamental relation of longitudinal air shower development to the observed fluctuation of experimental observables. Furthermore, the relation of the measured proton-air to the more fundamental proton-proton cross section is discussed. The current global picture combines hadronic proton-proton cross section data from accelerator and cosmic ray measurements and indicates a good consistency with predictions of models up to the highest energies.