Planar imaging of the mixing characteristics of a multi-element triplet injector

1991 ◽  
Author(s):  
D. MAKEL ◽  
I. KENNEDY
Keyword(s):  
Planar Imaging ◽  
Mixing Characteristics

Immunszintigraphie mit 111ln-DTPA-markierten monoklonalen Antikörpern: Vergleich zwischen ECT und planarer Szintigraphie

1987 ◽  
Vol 26 (06) ◽  
pp. 258-262
Author(s):  
J. Happi ◽  
R. P. Baum ◽  
J. Frohn ◽  
B. Weimer ◽  
A. Halbsguth ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Diagnostic Procedures ◽  
Undifferentiated Carcinoma ◽  
Whole Body ◽  
Acquisition Time ◽  
Planar Imaging ◽  
Primary Tumors ◽  
Intraindividual Comparison ◽  
Single Detector ◽  
Increased Sensitivity

The present study was done in order to examine if the use of111ln-DTPA- labeled MAb fragments in place of 131l-labeled MAb fragments increases the sensitivity of tomographic immunoscintigraphy to reach the level of that of planar imaging techniques. In 11 patients with various primary tumors, local recurrences or metastases [colorectal carcinoma (n = 7), ovarian carcinoma (n = 2), papillary thyroid carcinoma (n = 1), undifferentiated carcinoma of the lung (n = 1)], immunoscintigraphy (IS) was carried out using 111ln-DTPA- labeled F(ab’)2 fragments of various MAbs (anti-CEA, OC 125, anti-hTG) and planar and tomographic imaging were compared intraindividually. By conventional diagnostic procedures, the presence of a tumor mass was confirmed (transmission computer tomography, ultrasound) or verified (131l whole-body scintigraphy, histology) in all cases. Immunoscintigraphy was positive in 9 out of 11 cases by ECT and in 10 out of 11 cases by planar imaging. When using 111 In-labeled MAb fragments, intraindividual comparison of ECT and planar imaging resulted in a similar sensitivity. The increased sensitivity of ECT using this tracer in contrast to 131l-labeled MAb fragments may be attributed to the fact that the physical properties of111 In are much more suitable for the gamma cameras most commonly used (single detector, 3/8” crystal); using 111 In-labeled MAb fragments, count rates sufficient for ECT can be obtained within a reasonable acquisition time. This allows to combine IS with the advantages of ECT regarding tumour localization and prevention of artefacts due to superposition of background.

Mixing characteristics of twin impinging circular jets

1994 ◽  
Author(s):  
P. Disimile ◽  
E. Savory ◽  
N. Toy
Keyword(s):  
Mixing Characteristics ◽  
Circular Jets

99mTc-DPD SPECT/CT for localisation of inflammatory and chronic osteoarthritis of the foot and ankle

2016 ◽  
Vol 55 (04) ◽  
pp. 145-150 ◽  
Author(s):  
Lutz Freudenberg ◽  
Hinrich Wieder ◽  
Jens Stollfuss
Keyword(s):  
Bone Metabolism ◽  
Late Phase ◽  
Blood Pool ◽  
Phase Imaging ◽  
Bone Imaging ◽  
Foot And Ankle ◽  
Planar Imaging ◽  
Selective Treatment ◽  
Complex Anatomy ◽  
Three Phase

SummaryAim: The precise localisation of osteoarthritic and inflammatory changes is crucial for selective treatment planning of radiosynovectomy (RSV). The present study evaluated the diagnostic accuracy of planar bone imaging and SPECT for the detection of pathological bone metabolism and inflammation in joints of the foot and ankle, compared with SPECT/CT. Patients, methods: 39 patients (mean age 65.6 ± 11.1 years) with suspected inflammatory osteoarthritis underwent SPECT/CT of the feet. After injection of approximately 500 MBq 99mTc DPD, all patients had three-phase planar bone imaging and late-phase hybrid SPECT/CT. late-phase SPECT, and CT of the foot. Increased bone metabolism and blood-pool was assigned to the respective joint of the fore-, mid-, and hindfoot, using SPECT/CT as the reference standard. Results: Overall, SPECT had a higher sensitivity than planar imaging (0.80 vs 0.68, n.s.). The advantage of SPECT was most obvious in the anatomically complex midfoot area (0.63 vs 0.26, p < 0.05) and less obvious in the forefoot (0.85 vs 0.79, n.s.) and hindfoot (0.89 vs 0.89, n.s.). The overall concordance (Cohen`s Kappa) between SPECT/CT and planar (late-phase) imaging and SPECT was high for the forefoot and the hindfoot (planar: 0.78/0.81; SPECT 0.86/0.88) and comparatively low for the midfoot (planar: 0.27; SPECT 0.61). Conclusion: SPECT was significantly superior to planar bone imaging for the detection of joint lesions in the midfoot. The differences between SPECT and planar imaging in the fore- and hindfoot were not significant, most likely due to the inherently less complex anatomy. Compared with SPECT alone, a benefit from the use of SPECT/CT can be observed in the midfoot region where it facilitates the identification of the correct joint for RSV.

Absolute SPECT/CT quantification of cerebral uptake of 99mTc-HMPAO for patients with neurocognitive disorders

2016 ◽  
Vol 55 (04) ◽  
pp. 158-165 ◽  
Author(s):  
Friedrich Welz ◽  
James Sanders ◽  
Torsten Kuwert ◽  
Juan Maler ◽  
Johannes Kornhuber ◽  
...  
Keyword(s):  
Tissue Concentration ◽  
Tracer Uptake ◽  
Planar Imaging ◽  
Quantitative Spect ◽  
Dementia Patients ◽  
Hmpao Spect ◽  
Patient Groups ◽  
The Absolute ◽  
99Mtc Hmpao

SummaryIt was reported from planar imaging studies that the cerebral uptake of injected 99mTc-HMPAO activity is about 4–7% in humans. Recent work has shown that modern SPECT/ CT devices are able to quantify the tissue concentration of radioactivity in vivo in absolute units (Bq/ml), while avoiding the limitations of planar techniques. The aims of this study were (a) to determine the cerebral uptake of 99mTc-HMPAO in absolute units in SPECT/CT, (b) to investigate potential differences in absolute tracer uptake for patients suspected of dementia. Patients, methods: We performed 99mTc-HMPAO SPECT/CT in 65 patients with suspected dementia. 99mTc-HMPAO uptake was determined using a previously published quantitative SPECT/CT protocol. The absolute HMPAO uptake and the results of a regionalized analysis were compared for MMSE and NINCDS-ADRDA based patient groups. Results: The mean absolute uptake of 99mTc-HMPAO for our patient population was 4.3 ± 0.8% of the injected dose. The uptake, as well as the regionalized analysis yielded significantly different results for low ( 23) and high (>23) MMSE groups and also for some of the NINCDS-ADRDA groups. Conclusion: Our results show that the absolute cerebral uptake of 99mTc-HMPAO is in the range of previously reported results, obtained by planar techniques. Absolute uptake is significantly different between the patient groups.

Mixing and Detention Time Distribution in Activated Sludge Tanks

1985 ◽  
Vol 17 (2-3) ◽  
pp. 197-208 ◽  
Author(s):  
H. Bode ◽  
C. F. Seyfried
Keyword(s):  
Activated Sludge ◽  
Time Distribution ◽  
Strong Influence ◽  
Tracer Tests ◽  
Tracer Test ◽  
Evaluation Procedure ◽  
Response Curves ◽  
Detention Time ◽  
Test Study ◽  
Mixing Characteristics

The interrelationship between mixing characteristics and tracer response curves in activated sludge tanks is explained. In some cases the return sludge cycle has a strong influence on the tracer response curves. Results from tracer tests in the field are hard to interpret because the tracer in the return sludge interferes with the initial tracer. Therefore a special evaluation procedure has to be applied. The paper closes with results from a field tracer test study.

Sign in / Sign up

Export Citation Format

Share Document