Browsing by Subject "Tomography, Emission-Computed, Single-Photon"
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Item Basal and activational tcm-hmpao brain spect in alzheimer's disease(2000) SAYIT E.; YENER G.; ÇAPA G.; ERTAY T.; KESKIN B.; FADILOĞLU S.; DURAK H.Early diagnosis in Alzheimer's disease (AD) is important for the administration of new treatments. The purpose of this study was to differentiate mildly/moderately demented AD patients from normal controls by means of activational brain SPECT, and to investigate the correlation between regional cerebral blood flow and dementia severity. Activational brain SPECT was performed 1 week after basal brain SPECT in 12 mild/moderate AD patients according to NINCDS-ADRDA criteria (mean age 69±7 years) and in seven healthy, age-matched, volunteer controls (mean age 65±9 years). In order to activate the parietal cortex, patients were asked to subtract serial 5's from 100, 2 min before and after the intravenous administration of 925 MBq technetium-99m labelled D,L-hexamethyl-propylene amine oxime (Tcm-HMPAO). Using a three-headed gamma camera equipped with high resolution collimators, 128 images of 35 s duration in a 64×64 matrix were obtained over 360°. Region to whole brain ratios (R/WB) were calculated in three consecutive transaxial slices 2 pixels thick above the orbitomeatal line, and the activation percentage was calculated. No statistical difference was detected between AD patients and normal controls for parietal cortex activation. The correlation coefficient between the Mini-Mental State Examination (MMSE) scoring and the activation percentage was 0.475 in normal controls and 0.175 in AD patients for the left anterior parietal cortex, and 0.353 in normal controls and 0.146 in AD patients for the right anterior parietal cortex. In a visual evaluation of parietal cortex activation, 50% of AD patients were able to activate the parietal cortex, whereas 86% of the normal controls could do so. In our current study, the subtraction of serial 5's was not regarded as a promising task. Further studies are needed to clarify the importance of such tasks in the differential diagnosis of mild/moderate AD patients from normal elderly. © 2000 Lippincott Williams & Wilkins, Inc.Item The role of Tc-99m RBC scintigraphy in the differential diagnosis of orbital cavernous hemangioma(2001) Sayit E.; Durak I.; Capakaya G.; Yilmaz M.; Durak H.The cavernous hemangioma is the most common benign orbital tumor in adults. Its presentation is during the forth to fifth decades with a slowly progressive unilateral proptosis. Intraconal cavernous hemangiomas may be difficult to differentiate from other intraconal lesions such as schwannomas, meningiomas and hemangiopericytomas. We report a case of orbital cavernous hemangioma diagnosed by Tc-99m RBC scintigraphy. Tc-99m RBC scintigraphy revealed a typical scintigraphic pattern in which there is intense focally increased uptake on the delayed image. We conclude that Tc-99m RBC scintigraphy can be a useful method in the differential diagnosis of orbital cavernous hemangioma as in hepatic hemangioma.Item Comparison of brain perfusion SPECT and MRI findings in children with neuronal ceroid-lipofuscinosis and in their families(2002) Sayit E.; Yorulmaz I.; Bekis G.; Kaya G.; Gumuser F.G.; Dirik E.; Durak H.Purpose: Neuronal ceroid-lipofuscinoses (NCL) are among the progressive encephalopathies of childhood that are inherited in an autosomal recessive manner. In this study we specifically aimed to investigate any white-matter changes in the carriers (parents) and the healthy siblings of individuals with neuronal ceroid lipofuscinosis disease and whether we may be able to predict the occurrence of any neurological symptoms in healthy children in the future thus enabling early management. Materials and Methods: Since the NCLs are genetically determined diseases, we investigated fifteen individuals in three families that had diseased children of the juvenile type, with brain perfusion SPECT and MRI. Brain perfusion SPECT was performed after administering 222-555 MBq (6-15 mCi) Tc-99m HMPAO intravenously in a dimmed and quiet room. Imaging was performed at least one hour after injection, with a three headed gamma camera equipped with high resolution collimators. A Metz filter (FWHM: 11 mm) was used for processing. Cranial MRI was performed with an imager operating at 1.5 Tesla. Spin-echo T1- and T2-weighted and FLAIR slices were obtained for each individual. Results: In all of the five diseased children we observed pathologic findings both on MRI and Tc-99m HMPAO SPECT. The findings on MRI were mainly features of cerebral and cerebellar atrophy and the observations on Tc-99m HMPAO SPECT were regional perfusion abnormalities. We observed some structural abnormalities on MRI in four of the parents and two of the four healthy siblings. We also noted perfusion abnormalities on Tc-99m HMPAO SPECT in two of the parents and two of the healthy siblings. Conclusion: Because the disease is inherited in an autosomal recessive manner, the parents and the healthy siblings were not supposed to exhibit any demonstrable brain lesions, but the brain perfusion SPECT and MRI examinations clearly revealed multiple lesions in some of the parents and healthy siblings. Detailed neurological examinations of these individuals were normal except for one apparently healthy sibling (EY). Follow-up imaging of these families is being undertaken and further studies are essential in understanding the pathogenesis and genetics of neuronal ceroid-lipofuscinoses.Item Novel 99mTc(III)-azide complexes [99mTc(N3)(CDO)(CDOH)2B-R] (CDOH2 = cyclohexanedione dioxime) as potential radiotracers for heart imaging(Elsevier Inc., 2016) Liu M.; Zheng Y.; Avcibasi U.; Liu S.Introduction In this study, novel 99mTc(III)-azide complexes [99mTc(N3)(CDO)(CDOH)2B-R] (99mTc-ISboroxime-N3: R = IS; 99mTc-MPboroxime-N3: R = MP; 99mTc-PAboroxime-N3: R = PA; 99mTc-PYboroxime-N3: R = PY; and 99mTc-Uboroxime-N3: R = 5U) were evaluated as heart imaging agents. Methods Complexes [99mTc(N3)(CDO)(CDOH)2B-R] (R = IS, MP, PA, PY and 5U) were prepared by ligand exchange between NaN3 and [99mTcCl(CDO)(CDOH)2B-R]. Biodistribution and imaging studies were carried out in Sprague–Dawley rats. Image quantification was performed to compare their initial heart uptake and myocardial retention. Results 99mTc-ISboroxime-N3, 99mTc-PYboroxime-N3 and 99mTc-Uboroxime-N3 were prepared with high RCP (93–98%) while the RCP of 99mTc-MPboroxime-N3 and 99mTc-PAboroxime-N3 was 80–85%. The myocardial retention curves of 99mTc-ISboroxime-N3, 99mTc-PYboroxime-N3 and 99mTc-Uboroxime-N3 were best fitted to the bi-exponential decay function. The half-time of the fast component was 1.6 ± 0.4 min for 99mTc-ISboroxime-N3, 0.7 ± 0.1 min for 99mTc-PYboroxime-N3 and 0.9 ± 0.4 min for 99mTc-Uboroxime-N3. The 2-min heart uptake from biodistribution studies followed the ranking order of 99mTc-ISboroxime-N3 (3.60 ± 0.68%ID/g) > 99mTc-PYboroxime-N3 (2.35 ± 0.37%ID/g) ≫ 99mTc-Uboroxime-N3 (1.29 ± 0.06%ID/g). 99mTc-ISboroxime-N3 had the highest 2-min heart uptake among 99mTc radiotracers revaluated in SD rats. High quality SPECT images were obtained with the right and left ventricular walls being clearly delineated. The best image acquisition window was 0–5 min for 99mTc-ISboroxime-N3. Conclusion Both azide coligand and boronate caps had significant impact on the heart uptake and myocardial retention of complexes [99mTc(N3)(CDO)(CDOH)2B-R]. Among the radiotracers evaluated in SD rats, 99mTc-ISboroxime-N3 has the highest initial heart uptake with the heart retention comparable to that of 99mTc-Teboroxime. 99mTc-ISboroxime-N3 is a promising alternative to 99mTc-Teboroxime for SPECT MPI. © 2016 Elsevier Inc.Item Thymoquinone glucuronide conjugated magnetic nanoparticle for bimo-dal imaging and treatment of cancer as a novel theranostic platform(Bentham Science Publishers, 2021) İnce İ.; Müftüler Z.B.; Medine E.İ.; Güldü Ö.K.; Takan G.; Ergönül A.; Parlak Y.; Yıldırım Y.; Çakar B.; Bilgin E.S.; Aras Ö.; Göker E.; Ünak P.Background: Theranostic oncology combines therapy and diagnosis and is a new field of medicine that specifically targets the disease by using targeted molecules to destroy the cancer-ous cells without damaging the surrounding healthy tissues. Objective: We aimed to develop a tool that exploits enzymatic TQ release from glucuronide (G) for the imaging and treatment of lung cancer. We added magnetic nanoparticles (MNP) to enable magnetic hyperthermia and MRI, as well as 131I to enable SPECT imaging and radionuclide thera-py. Methods: A glucuronide derivative of thymoquinone (TQG) was enzymatically synthesized and conjugated with the synthesized MNP and then radioiodinated with 131I. New Zealand white rab-bits were used in SPECT and MRI studies, while tumor modeling studies were performed on 6–7-week-old nude mice utilized with bioluminescence imaging. Results: Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) spectra confirmed the expected structures of TQG. The dimensions of nanoparticles were below 10 nm and they had rather polyhedral shapes. Nanoparticles were radioiodinated with 131I with over 95% yield. In imaging studies, in xenograft models, tumor volume was significantly reduced in TQGMNP-treated mice but not in non-treated mice. Among mice treated intravenously with TQGMNP, xenograft tumor models disappeared after 10 and 15 days, respectively. Conclusion: Our findings suggest that TQGMNP in solid, semi-solid and liquid formulations can be developed using different radiolabeling nuclides for applications in multimodality imaging (SPECT and MRI). By altering the characteristics of radionuclides, TQGMNP may ultimately be used not only for diagnosis but also for the treatment of various cancers as an in vitro diagnostic kit for the diagnosis of beta glucuronidase-rich cancers. © 2021 Bentham Science Publishers.