| 1. |
|
|
| 2. |
|
|
| 3. |
- Aitken, Candice L., et al.
(författare)
-
Tumor localization and image registration of 18-FDG SPECT scans with CT scans
- 1999
-
Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667. ; 40:5, s. 290P-291P
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The aim of this study was to determine the feasibility of registering routine clinical F-18 fluorodeoxyglucose (FDG) coincidence detection (CD) scans with computed tomographic (CT) scans for radiation treatment planning and case management. METHODS: F-18 FDG CD and chest CT scans, performed in 10 randomly selected patients with confirmed or possible adenocarcinoma of the lung, were evaluated. The quality of the matches was verified by comparisons of the center-to-center distance between a region of interest (ROI) manually drawn on the CT slice and warped onto the CD slice with an ROI drawn manually directly on the CD slice. In addition, the overlap between the two ROIs was calculated. RESULTS: All 10 F-18 FDG CD and CT scans were registered with good superimposition of soft tissue density on increased radionuclide activity. The center-to-center distance between the ROIs ranged from 0.29 mm to 8.08 mm, with an average center-to-center distance of 3.89 mm +/- 2.42 mm (0.69 pixels +/- 0.34 pixels). The ROI overlap ranged from 77% to 99%, with an average of 90% +/- 5.6%. CONCLUSIONS: Although the use of F-18 FDG CD shows great promise for the identification of tumors, it shares the same drawbacks as those associated with radiolabeled monoclonal antibody SPECT and ligand-based positron emission tomographic scans in that anatomic markers are limited. This study shows that image registration is feasible and may improve the clinical relevance of CD images.
|
|
| 4. |
- ANDERSSON, JLR, et al.
(författare)
-
A METHOD FOR COREGISTRATION OF PET AND MR BRAIN IMAGES
- 1995
-
Ingår i: JOURNAL OF NUCLEAR MEDICINE. - : SOC NUCLEAR MEDICINE INC. - 0161-5505. ; 36:7, s. 1307-1315
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Combining MRI morphological data with functional PET data offers significant advantages in research as well as in many clinical situations. Automatic methods are needed, however, to coregister the data from the two modalities. Methods: Simulated PET imag
|
|
| 5. |
- Andersson, Jesper L, et al.
(författare)
-
A method for coregistration of PET and MR brain images
- 1995
-
Ingår i: Journal of Nuclear Medicine. - 0161-5505 .- 1535-5667. ; 36:7, s. 1307-1315
-
Tidskriftsartikel (refereegranskat)abstract
- Combining MRI morphological data with functional PET data offers significant advantages in research as well as in many clinical situations. Automatic methods are needed, however, to coregister the data from the two modalities.METHODS:Simulated PET images were created by simple and automatic segmentation of MR images followed by the assignment of different uptake values to various tissue types. The simulated PET images were registered to actual PET images using a pixel-by-pixel, PET-PET registration method. The transformation matrix was then applied to the MR images. The method was used to register MRI data to PET transmission scans and emission scans obtained with FDG, nomifensine and raclopride. Validation was performed by comparing the results to those obtained by matching internal points manually defined in both volumes.RESULTS:Emission and transmission PET images were successfully registered to MR data. Comparison to the manual method indicated a registration accuracy on the order of 1-2 mm in each direction. No difference in accuracy between the different tracers was found. The error sensitivity for the method's assumptions seemed to be sufficiently low to allow complete automation of the method.CONCLUSION:We present a rapid, robust and fully automated method to register PET and MR brain images with sufficient accuracy for most clinical applications.
|
|
| 6. |
- Andersson, JLR, et al.
(författare)
-
Weighted summation of oxygen-15-water PET data to increase signal-to-noise ratio for activation studies
- 1997
-
Ingår i: JOURNAL OF NUCLEAR MEDICINE. - : SOC NUCLEAR MEDICINE INC. - 0161-5505. ; 38:2, s. 334-340
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Data with the highest possible signal-to-noise (S/N) ratios are desirable when performing nonquantitative perturbation studies with PET and O-15-water. To achieve this, protocols have been suggested in which the stimulus is switched off before the washout
|
|
| 7. |
- Andersson, P, et al.
(författare)
-
Internalization of indium-111 into human neuroendocrine tumor cells after incubation with indium-111-DTPA-D-Phe1-octreotide.
- 1996
-
Ingår i: Journal of nuclear medicine : official publication, Society of Nuclear Medicine. - 0161-5505. ; 37:12, s. 2002-6
-
Tidskriftsartikel (refereegranskat)abstract
- Neuroendocrine tumor cells frequently overexpress somatostatin receptors at their cell surfaces. To evaluate the possibility of using the somatostatin analog 111In-DTPA-D-Phe1-octreotide for radiation therapy, we studied the binding and subsequent internalization of 111In into three types of cultured human neuroendocrine tumor cells.
|
|
| 8. |
- Benjegård, S A, et al.
(författare)
-
Evaluation of three gamma detectors for intraoperative detection of tumors using 111In-labeled radiopharmaceuticals.
- 1999
-
Ingår i: Journal of nuclear medicine : official publication, Society of Nuclear Medicine. - 0161-5505. ; 40:12, s. 2094-101
-
Tidskriftsartikel (refereegranskat)abstract
- Attempts to detect tumors with intraoperative scintillation using tumor-binding radiopharmaceuticals have intensified recently. In some cases previously unknown lesions were found, but in most cases no additional lesions were detected. In this study the physical characteristics of three detector systems and their ability to detect tumors through accumulation of an 111In-labeled radiopharmaceutical were investigated. The first was a sodium iodide (NaI[TI]) detector; the second, a cesium iodide (CsI[TI]) detector; and the third, a cadmium telluride (CdTe) detector.
|
|
| 9. |
- Bergström, Mats, et al.
(författare)
-
In vitro and animal validation of bromine-76-bromodeoxyuridine as a proliferation marker
- 1998
-
Ingår i: Journal of Nuclear Medicine. - 0161-5505 .- 1535-5667. ; 39:7, s. 1273-9
-
Tidskriftsartikel (refereegranskat)abstract
- The potential of 76Br-bromodeoxyuridine as a PET tracer for characterizing proliferation potential was investigated in multicellular tumor aggregates and in healthy rats and pigs. METHODS: Bromine-76-bromide was produced by proton irradiation of a 76Se-enriched target using a 17-MeV cyclotron and recovered by thermal diffusion. Bromine-76-BrdU was prepared from the corresponding trimethylstannate by an oxidative bromination. Multicellular aggregates from a carcinoid cell line and two bladder cancer cell lines were co-incubated with 76Br-BrdU and 3H-thymidine and the uptake and DNA incorporation analyzed. About 0.5 MBq 76Br-BrdU were injected in the tail vein of unanaesthetised Sprague-Dawley rats. Two to 36 hr later they were decapitated and the radioactivity concentration and fraction of radioactivity incorporated into DNA determined in five different organs and the blood. Parallel studies were performed in animals pretreated with hydroxyurea. In separate experiments, rats were given an injection of 76Br-bromide and organ uptake was evaluated after 20 hr. PET studies were performed in two pigs and the uptake in different organs was investigated after injection of 76Br-BrdU. In these studies, diuresis was induced by furosemide and mannitol and radioactivity in blood and organs was followed during 10 hr. RESULTS: In the cell aggregates, 30%-90% of the radioactivity was extracted in the DNA fraction. A good correlation was found between 76Br-BrdU and 3H-thymidine with respect to total uptake and DNA fraction. The DNA fraction increased from 2-10 hr after incubation. With in vivo injection in the rat, relatively high uptake of radioactivity was found in all organs, unrelated to the degree of DNA synthesis. However, inhibition by hydroxyurea occurred only in the spleen and intestines, organs which also showed a high degree of incorporation of 76Br-BrdU into DNA. In the pig, the highest in vivo uptake was observed in the red bone marrow and the intestines. In these organs, 70%-80% of the radioactivity was recovered in the DNA fraction. The concentration of radioactivity in the heart, liver and kidney was 3-10 times lower, and here the DNA fraction accounted for 10%-20% of the radioactivity. The decay-corrected radioactivity in blood and nonproliferating organs decreased with diuresis with a half-life of 13 and 16 hr, respectively. CONCLUSION: It is suggested that the radioactivity uptake as seen after the administration of 76Br-BrdU, is constituted by two parts: one relating to incorporation into DNA and one existing as free 76Br- or metabolites of 76Br-BrdU. If sufficient time has passed, 76Br- dominates other metabolites. A correct assessment of DNA-incorporated radioactivity using PET with 76Br-BrdU is not trivial and can only be made with due correction for 76Br-, using either a complementary investigation after hydroxyurea pretreatment (in animal studies) or a separate 76Br-bromide investigation. Alternatively, the free bromide can be eliminated partially through forced diuresis.
|
|
| 10. |
- Bergström, Mats, et al.
(författare)
-
In vivo demonstration of enzyme activity in endocrine pancreatic tumors : decarboxylation of carbon-11-DOPA to carbon-11-dopamine
- 1996
-
Ingår i: Journal of Nuclear Medicine. - 0161-5505 .- 1535-5667. ; 37:1, s. 32-37
-
Tidskriftsartikel (refereegranskat)abstract
- METHODS:We used PET to characterize the uptake and decarboxylation of 11C-L-DOPA in vivo in two patients with endocrine pancreatic tumors: one glucagonoma and one gastrinoma.RESULTS:With L-DOPA labeled with 11C in the beta position, in which the radioactive label follows the molecule through decarboxylation to dopamine, significant uptake was observed in the tumors. With L-DOPA labeled in the carboxyl group, in which the label is rapidly eliminated from the tissue as 11CO2 if decarboxylation takes place, an almost complete lack of uptake is noted.CONCLUSION:This study shows that, using selective position labeling, an in vivo action of enzymatic activity can be observed with PET and that significant decarboxylation occurs in the tested endocrine pancreatic tumors. Also, marked retention of radioactivity occurs after treatment with somatostatin analogs. It is hypothesized that this is a reflection of a reduction of exocytosis which is induced by this treatment.
|
|
