Novel light-guide-PMT geometries to reduce dead edges of a scintillation camera

Although powdered phosphor screens are usually used for scintillators of STEM, it has been found that the phosphor screen of appropriate thickness should be used depending on the accelerating voltage, in order to keep high detective quantum efficiency. 1 It has been also found that the variation in sensitivity, due to granularity of phosphor screens, makes the measurement of fine electron probe difficult and that the sensitivity reduces with electron irradiation specially at high voltages.In order to find out a preferable scintillator for STEM, single crystals of YAG (yttrium aluminum garnet), which are used for detecting secondary and backscattered electrons in SEM were investigated and compared with powdered phosphor screens, at the accelerating voltages of 100kV and 1 MV. A conventional electron detection system, consisting of scintillator, light guide and PMT (Hamamatsu Photonics R268) was used for measurements. Scintillators used are YAG single crystals of 1.0 to 3.2mm thicknesses (with surfaces matted for good interface to the light guide) and of 0.8mm thickness (with polished surface), and powdered P-46 phosphor screens of 0.07mm and 1.0mm thicknesses for 100kV and 1MV, respectively. Surfaces on electron-incidence side of all scintillators are coated with reflecting layers.

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Tc-99m Labeled Complexes of Aldehydes and Glutamate as Cholescintigraphic Agents

Nuklearmedizin ◽

10.1055/s-0038-1624914 ◽

1975 ◽

Vol 14 (04) ◽

pp. 330-338

Author(s):

L. G. Colombetti ◽

J. S. Arnold ◽

W. E. Barnes

Keyword(s):

Nuclear Medicine ◽

Gall Bladder ◽

Rose Bengal ◽

Valence State ◽

Monosodium Glutamate ◽

Kinetic Studies ◽

Scintillation Camera ◽

Blood Clearance ◽

Lower Valence ◽

Wire Basket

SummaryTc-99m pyridoxylidene glutamate has proven to be an excellent biliary scanning agent, far superior in many respect to the commonly used 1-131 rose bengal. The preparation of the compound as previously reported by Baker et al is too time consuming and requires the use of an autoclave which is not available in most nuclear medicine departments. In our facility, we have been preparing similar compounds using several aldehydes and monosodium glutamate to make labeled complexes having the same pharmacological characteristics. The mixture of monosodium glutamate, aldehyde, and Tc-99m pertechnetate is made slightly alkaline, purged with helium, and placed in a sealed vial. The vial, which is protected by a wire basket, is then heated in a laboratory oven at 130° C for a period of 15 to 20 minutes. During this time, the technetium is reduced to a lower valence state and bound to the complex formed. Chromatographic data show that these compounds are chemically similar to that previously reported. The compounds prepared concentrate in the gall bladder of the rabbit in less than 10 minutes. Kinetic studies have been performed on dogs with a scintillation camera and small digital computer to measure rates of blood clearance, liver and gall bladder uptake, and excretion into the intestine. The aldehyde — glutamate complex promises to be a useful scanning agent for the diagnosis of biliary and hepatocellular diseases.

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99mTc Technetium Sulfide and the Scintillation Camera in the Rapid Diagnosis of Pericardial Effusion

Nuklearmedizin ◽

10.1055/s-0038-1624740 ◽

1971 ◽

Vol 10 (02) ◽

pp. 122-128

Author(s):

W. H. Blahd ◽

M. A. Winston ◽

G. T. Krishnamurthy ◽

P. B. Thomas ◽

E. Weiss

Keyword(s):

Pericardial Effusion ◽

Patient Positioning ◽

Rapid Diagnosis ◽

Scintillation Camera ◽

Technical Error ◽

Technetium 99M ◽

Sodium Pertechnetate ◽

Specific Uptake ◽

Speed Accuracy

SummaryBecause of its speed, accuracy, and reproducibility, radioisotopic angiocardiography appears to be the method of choice for the diagnosis of pericardial effusion. Technetium-99m sulfide is preferable to 99mTc sodium pertechnetate in these studies for the following reasons: (1) its specific uptake by the liver aids both in patient positioning and in the accuracy of diagnosis; and (2), studies can be repeated within 15—20 minutes should there be equiment or technical error.

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Instant 99mTc-Labelled Glucoheptonate Kit for Kidney Imaging

Nuklearmedizin ◽

10.1055/s-0038-1624139 ◽

1983 ◽

Vol 22 (05) ◽

pp. 246-250 ◽

Cited By ~ 2

Author(s):

M. Al-Hilli ◽

H. M. A. Karim ◽

M. H. S. Al-Hissoni ◽

M. N. Jassim ◽

N. H. Agha

Keyword(s):

Sodium Hydroxide Solution ◽

Normal Subjects ◽

Organ Distribution ◽

Stable Complex ◽

Scintillation Camera ◽

Ph Adjustment ◽

The Mean ◽

The Stability ◽

Kidney Imaging ◽

Mean Concentration

Gelchromatography column scanning has been used to study the fractions of reduced hydrolyzed 99mTc, 99mTc-pertechnetate and 99mTc-chelate in a 99mTc-glucoheptonate (GH) preparation. A stable high labelling yield of 99mTc-GH complex in the radiopharmaceutical has been obtained with a concentration of 40-50 mg of glucoheptonic acid-calcium salt and not less than 0.45 mg of SnCl2 2 H2O at an optimal pH between 6.5 and 7.0. The stability of the complex has been found significantly affected when sodium hydroxide solution was used for the pH adjustment. However, an alternative procedure for final pH adjustment of the preparation has been investigated providing a stable complex for the usual period of time prior to the injection. The organ distribution and the blood clearance data of 99mTc-GH in rabbits were relatively similar to those reported earlier. The mean concentration of the radiopharmaceutical in both kidneys has been studied in normal subjects for one hour with a scintillation camera and the results were satisfactory.

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Hemophilic Bledding Evaluated by Blood Pool Scanning

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650171 ◽

1981 ◽

Vol 45 (03) ◽

pp. 208-210 ◽

Cited By ~ 4

Author(s):

D Green ◽

S M Spies ◽

N A Rana ◽

J W Milgram ◽

R Mintzer

Keyword(s):

Blood Volume ◽

Blood Pool ◽

Invasive Technique ◽

Scintillation Camera ◽

Knee Prostheses ◽

Hemophilic Patient ◽

Chronic Arthropathy ◽

Image Density ◽

Regional Blood Volume

SummaryThe technique of blood pool scanning was used to examine 15 hemophilic subjects. Employing an in vivo method for erythrocyte labeling with Technetium-99 m, a dynamic perfusion sequence is obtained using a scintillation camera positioned over the area to be examined. This demonstrates the vascularity of the tissue. Subsequently, equilibrium blood pool images of the area are obtained and analyzed with a densitometer to assess relative regional blood volume. In patients who were not bleeding but had chronic arthropathy, vascularity was not increased, and the blood volume of comparable joints was similar. By contrast, marked increases in vascularity and image density were observed in studies of acutely bleeding joints. Chronic hemarthroses were associated with persistent, but less marked increases in joint perfusion. Transient increases in joint vascularity were demonstrated after insertion of knee prostheses. In a patient with a thigh hematoma, the dimensions of the hemorrhage were clearly delineated. Since only a tracer dose of nuclide is infused intravenously, there are no allergic reactions or other side effects of the procedure. Blood pool scanning is a safe, non-invasive technique that augments clinical and radiographic evaluations, and provides a new dimension in the assessment of the hemophilic patient.

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Studies of Suloctidil in Experimental Thrombosis in Baboons

Thrombosis and Haemostasis ◽

10.1055/s-0038-1661329 ◽

1985 ◽

Vol 53 (03) ◽

pp. 423-427 ◽

Cited By ~ 15

Author(s):

Stephen R Hanson ◽

Laurence A Harker

Keyword(s):

Oral Administration ◽

Thrombus Formation ◽

Vascular Grafts ◽

Scintillation Camera ◽

Control Data ◽

Experimental Thrombosis ◽

Arteriovenous Shunts ◽

Platelet Deposition ◽

Heparin Anticoagulation ◽

Antithrombotic Efficacy

SummarySuloctidil has been evaluated in the baboon for its antithrombotic efficacy using models of both acute and chronic arterial thrombogenesis. Acute thrombus formation was initiated by Dacron vascular grafts inserted as extension segments into chronic arteriovenous shunts. 111In-platelet deposition was measured by scintillation camera imaging for one hour. The results after oral administration of suloctidil (100 mg/kg/d in two divided doses) were not different from control studies. Moreover, concurrent heparin anticoagulation did not affect 111In-platelet deposition compared with control data. In contrast, ticlopidine (20 mg/ kg/d) significantly decreased platelet deposition that was reduced further by the addition of heparin.Chronic arterial-thromboembolism was initiated by segments of polyurethane (Biomer) cannula introduced into chronic arteriovenous shunts. Thrombus formation by the polyurethane cannula was measured as 111In-platelet turnover (corrected for removal of senescent platelets). Cannula platelet consumption was unaffected by suloctidil (20 mg/kg/d given in two divided doses for two days preceding and throughout the period of platelet survival measurement). In contrast, dipyridamole (10 mg/ kg/d) and sulfinpyrazone (100 mg/kg/d) completely interrupted cannula platelet consumption.We conclude that suloctidil probably has little or no effect on platelet-dependent thrombus formation.

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Daylight in Underground Spaces

Light & Engineering ◽

10.33383/2017-028 ◽

2018 ◽

pp. 156-161

Author(s):

Alexei K. Solovyov

Keyword(s):

Light Guide ◽

Heat Losses ◽

Internal Environment ◽

Method Of Calculation ◽

Natural Lighting ◽

Different Depths ◽

The Common ◽

Different Diameters

Underground spaces in town centres present a big attraction for investors. However, they put special requirements to the internal environment. Those requirements can be fulfilled by means of daylighting. Examples of lighting of underground spaces are discussed. It is shown that the common systems of natural lighting are not always possible to use and cause big heat losses. Hollow light guide pipes allow avoid the shortcomings of common daylight systems. Method of calculation of daylight factors from hollow light guide pipes is shown. The results of calculation of daylight factors under the light guide pipes of different diameters in the different depths are presented.

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Development of On-line Fiber Orientation Meter Based on the Light Guide Effect

JAPAN TAPPI JOURNAL ◽

10.2524/jtappij.58.220 ◽

2004 ◽

Vol 58 (2) ◽

pp. 220-225

Author(s):

Yuji Abe ◽

Hidenobu Todoroki

Keyword(s):

Fiber Orientation ◽

Light Guide ◽

On Line

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Moldability improvement in microinjection molding via film lamination

Polymers and Polymer Composites ◽

10.1177/0967391120986503 ◽

2021 ◽

pp. 096739112098650

Author(s):

Dah Hee Kim ◽

Young Seok Song

Keyword(s):

Heat Transfer ◽

Light Guide ◽

Wall Slip ◽

Skin Layer ◽

Pattern Transfer ◽

Plastic Plate ◽

Resin Infusion ◽

Microinjection Molding ◽

Insulation Effect ◽

Thin Plastic

The purpose of this study is to integrate a polymeric film onto a mold to impede thermal heat transfer during resin infusion. A thin plastic plate was fabricated by using microinjection molding. A polyimide (PI) film was laminated onto a mold in an effort to produce a thin light guide plate (LGP). The film could decelerate the solidification of molten polymer in the cavity of mold and enhance the wall slip of resin on the mold. The insulation effect was modeled numerically. The surface roughness and pattern transfer characteristics of the LGP were evaluated. It was found that the fluidity of the resin increased due to the decreased skin layer during mold filling. The results showed that the strategy proposed in this study could help decrease the thickness of LGP effectively when manufacturing the part via injection molding.

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