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| 2. |
- Haj-Hosseini, Neda, et al.
(författare)
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Detection of brain tumor using fluorescence and optical coherence tomography
- 2015
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Konferensbidrag (refereegranskat)abstract
- Resection of brain tumor is a challenging task as the tumor does not have clear borders and the malignant types specifically have often a diffuse and infiltrative pattern of growth. We have previously implemented and evaluated a fluorescence spectroscopy based handheld probe for detecting the 5-aminolevulinic acid induced protoporphyrin IX (PpIX) in the gliomas. To add another dimension to the brain tumor detection and volumetric analysis of the tissue that exhibits fluorescence, optical coherence tomography was investigated on tumor specimens.Material and Methods:A fluorescence microscopy and a spectroscopy system as reported previously were used for detecting the fluorescence signals [1, 2]. A total of 50 patients have been included for intraoperative assessment of the tumor borders using the fluorescence techniques. A spectral domain OCT imaging system (TELESTO II, Thorlabs, Inc., NJ, USA) with central wavelength of 1325 nm was used to study the tissue microstructure post operatively. The system has a resolution of 13 and 5.5 μm in the lateral and axial directions, respectively. Tissue specimens from three patients undergoing brain tumor surgery were studied using the OCT system.Results and Conclusion:Using fluorescence spectroscopy the tumor could be detected with a sensitivity of 0.84 which was significantly higher than that of the surgical microscope (0.30). Brain tissue appeared rather homogeneous in the OCT images however the highly malignant tissue showed a clear structural difference from the non-malignant or low malignant brain tumor tissue which could be related to the fluorescence signal intensities.
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| 3. |
- Haj-Hosseini, Neda, et al.
(författare)
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Fluorescence Guidance for Brain Tumor Biopsies
- 2018
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Konferensbidrag (refereegranskat)abstract
- To provide guidance during stereotactic biopsy in brain tumors, fluorescence spectroscopy was used in ten patients. It was shown that the fiber optical probe could provide real-time guidance with clear fluorescence in all patients.
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| 4. |
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| 5. |
- Haj-Hosseini, Neda, et al.
(författare)
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Fluorescence spectroscopy and optical coherence tomography for brain tumor detection
- 2016
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Konferensbidrag (refereegranskat)abstract
- Resection of brain tumor is a challenging task as the tumor does not have clear borders and the malignant types specifically have often a diffuse and infiltrative pattern of growth. Recently, neurosurgical microscopes have been modified to incorporate fluorescence modules for detection of tumor when 5-aminolevulinic acid (5-ALA) is used as a contrast. We have in combination with the fluorescence microscopes implemented and evaluated a fluorescence spectroscopy based handheld probe for detecting the 5-aminolevulinic acid (ALA) induced protoporphyrin IX (PpIX) in the gliomas in 50 patients intraoperatively. The results show a significantly high sensitivity for differentiating tumor from the healthy tissue and distinguished fluorescence intensity levels in the tumor cell infiltration zone around the tumor. However, knowledge on association of the quantified fluorescence signals specifically in the intermediate inflammatory zone with the infiltrative tumor cells can be complemented with volumetric tissue imaging and a higher precision histopathological analysis. In this work, a spectral domain optical coherence tomography (OCT) system with central wavelength of 1325nm has been used to image the tissue volume that the fluorescence is collected from and is evaluated against histopathological analysis for a higher precision slicing. The results show that although healthy brain has a homogenous microstructure in the OCT images, the brain tumor shows a distinguished texture in the images correlated with the PpIX fluorescence intensity and histopathology.
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| 7. |
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| 8. |
- Haj-Hosseini, Neda, et al.
(författare)
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Optical guidance for stereotactic brain tumor biopsy procedures-preliminary clinical evaluation
- 2017
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Konferensbidrag (refereegranskat)abstract
- During stereotactic biopsy on suspected tumors in the brain, tissue samples are harvested to determine the malignancy. To provide guidance for finding the diagnostic tumor sites and to avoid vessel rupture, an application specific probe was developed. The setup incorporated spectroscopy for detection of 5-aminolevulinic acid induced protoporphyrin (PpIX) fluorescence and blood flow using laser Doppler flowmetry. The PpIX fluorescence was significantly different in the tumor compared to the gliotic marginal zone (p < 0.05). In conclusion, the systems made real-time tumor detection and vessel tracking possible. Moreover, the autofluorescence and blood perfusion could be studied in the tumor.
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| 9. |
- Haj-Hosseini, Neda, 1980-, et al.
(författare)
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Stereotactic Brain Tumor Optical Biopsy
- 2018
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- To provide guidance for targeting diagnostic tumor tissue and to avoid vessel rupture during the biopsy procedure an application specific fiber optic probe was devel-oped. The setup incorporated an in-house developed fluorescence spectroscopy system for 5-aminolevulinic acid (5-ALA) induced protopophyrin IX (PpIX) for detection in the tumor, and laser Doppler flowmeter (LDF) system for measurement of blood perfusion. Fluorescence and blood flow were recorded millimeter-wise towards the pre-calculated target. In conclusion, the optical probe made real-time detection of tumor possible and has a potential for vessel detection during the biopsy procedures. Moreover, the PpIX fluorescence, autofluorescence and blood flow in the tumor could be studied at precise positions in the brain and the tumor. In the next step, further anal-ysis will be added.
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| 10. |
- Wahl, Joel, et al.
(författare)
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Raman spectroscopic analysis of fresh tissue samples from brain tumors
- 2021
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Ingår i: Diffuse Optical Spectroscopy and Imaging VIII. - : SPIE - International Society for Optical Engineering. - 9781510647077 - 9781510647060
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Konferensbidrag (refereegranskat)abstract
- We have applied a CNN to preprocess Raman spectra from fresh tissue samples from brain tumors. The neural network can handle the variations that occur naturally, which enables explorative data analysis methods such as PCA.
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