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1.
Emonds KM Swinnen JV van Weerden WM Vanderhoydonc F Nuyts J Mortelmans L Mottaghy FM 《European journal of nuclear medicine and molecular imaging》2011,38(10):1842-1853
Purpose
The aim of this study was to evaluate the impact of androgen ablation therapy in different prostate cancer (PCa) cell lines—reflecting different stages of the disease—on 18F-fluorodeoxyglucose (FDG), 11C-choline and 11C-acetate uptake. 相似文献2.
Decristoforo C Hernandez Gonzalez I Carlsen J Rupprich M Huisman M Virgolini I Wester HJ Haubner R 《European journal of nuclear medicine and molecular imaging》2008,35(8):1507-1515
PURPOSE: alphavbeta3 integrins are important cell adhesion receptors involved in angiogenic processes. Recently, we demonstrated using [(18)F]Galacto-RGD that monitoring of alphavbeta3 expression is feasible. Here, we introduce (68)Ga- and (111)In-labelled derivatives and compare them with [(18)F]Galacto-RGD. METHODS: For radiolabelling, cyclo(RGDfK(DOTA)) was synthesised using SPPS. For in vitro characterisation determination of partition coefficients, protein binding, metabolic stability, alphavbeta3 affinity and cell uptake and for in vivo characterization, biodistribution studies and micro positron emission tomography (PET) imaging were carried out. For in vivo and in vitro studies, human melanoma M21 (alphavbeta3 positive) and M21-L (alphavbeta3 negative) cells were used. RESULTS: Both tracers can be synthesised straightforward. The compounds showed hydrophilic properties and high metabolic stability. Up to 23% protein-bound activity for [(68)Ga]DOTA-RGD and only up to 1.4% for [(111)In]DOTA-RGD was found. Cell uptake studies indicate receptor-specific accumulation. This is confirmed by the biodistribution data. One hour p.i. accumulation in alphavbeta3-positive tumours was 2.9 +/- 0.3%ID/g and in alphavbeta3-negative tumours 0.8 +/- 0.1%ID/g for [(68)Ga]DOTA-RGD ([(111)In]DOTA-RGD: 1.9 +/- 0.3%ID/g and 0.5 +/- 0.2%ID/g; [(18)F]Galacto-RGD: 1.6 +/- 0.2%ID/g and 0.4 +/- 0.1%ID/g). Thus, tumour uptake ratios were comparable. Due to approx. 3-fold higher blood pool activities for [(68)Ga]DOTA-RGD, tumour/blood ratios were higher for [(111)In]DOTA-RGD and [(18)F]Galacto-RGD. However, microPET studies demonstrated that visualisation of alphavbeta3-positive tumours using [(68)Ga]DOTA-RGD is possible. CONCLUSIONS: Our data indicate that [(68)Ga]DOTA-RGD allows monitoring of alphavbeta3 expression. Especially, the much easier radiosynthesis compared to [(18)F]Galacto-RGD would make it an attractive alternative. However, due to higher blood pool activity, [(18)F]Galacto-RGD remains superior for imaging alphavbeta3 expression. Introduction of alternative chelator systems may overcome the disadvantages. 相似文献
3.
Nanni C Castellucci P Farsad M Rubello D Fanti S 《European journal of nuclear medicine and molecular imaging》2007,34(10):1704-1705
4.
Zettinig G Mitterhauser M Wadsak W Becherer A Pirich C Vierhapper H Niederle B Dudczak R Kletter K 《European journal of nuclear medicine and molecular imaging》2004,31(9):1224-1230
Purpose 11C-metomidate (MTO), a marker of 11-hydroxylase, has been suggested as a novel positron emission tomography (PET) tracer for adrenocortical imaging. Up to now, experience with this very new tracer is limited. The aims of this study were (1) to evaluate this novel tracer, (2) to point out possible advantages in comparison with 18F-fluorodeoxyglucose (FDG) and (3) to investigate in vivo the expression of 11-hydroxylase in patients with primary aldosteronism.Methods Sixteen patients with adrenal masses were investigated using both MTO and FDG PET imaging. All patients except one were operated on. Five patients had non-functioning adrenal masses, while 11 had functioning tumours(Cushings syndrome, n=4; Conns syndrome, n=5; phaeochromocytoma, n=2). Thirteen patients had benign disease, whereas in three cases the adrenal mass was malignant (adrenocortical cancer, n=1; malignant phaeochromocytoma, n=1; adrenal metastasis of renal cancer, n=1).Results MTO imaging clearly distinguished cortical from non-cortical adrenal masses (median standardised uptake values of 18.6 and 1.9, respectively, p<0.01). MTO uptake was slightly lower in patients with Cushings syndrome than in those with Conns syndrome, but the difference did not reach statistical significance. The expression of 11-hydroxylase was not suppressed in the contralateral gland of patients with Conns syndrome, whereas in Cushings syndrome this was clearly the case. The single patient with adrenocortical carcinoma had MTO uptake in the lower range.Conclusion MTO could not definitely distinguish between benign and malignant disease. FDG PET, however, identified clearly all three study patients with malignant adrenal lesions. We conclude: (1) MTO is an excellent imaging tool to distinguish adrenocortical and non-cortical lesions; (2) the in vivo expression of 11-hydroxylase is lower in Cushings syndrome than in Conns syndrome, and there is no suppression of the contralateral gland in primary aldosteronism; (3) for the purpose of discriminating between benign and malignant lesions, FDG is the tracer of choice. 相似文献
5.
Kunikowska J Królicki L Hubalewska-Dydejczyk A Mikołajczak R Sowa-Staszczak A Pawlak D 《European journal of nuclear medicine and molecular imaging》2011,38(10):1788-1797
Purpose
Peptide receptor radionuclide therapy (PRRT) using radiolabelled somatostatin analogues is a treatment option for patients with disseminated neuroendocrine tumours (NET). A combination treatment using the high-energy 90Y beta emitter for larger lesions and the lower energy 177Lu for smaller lesions has been postulated in the literature.The aim of the study was to evaluate combined 90Y/177Lu-DOTATATE therapy in comparison to 90Y-DOTATATE alone. 相似文献6.
7.
Caruso PA Poussaint TY Tzika AA Zurakowski D Astrakas LG Elias ER Bay C Irons MB 《Neuroradiology》2004,46(1):3-14
Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder characterized by a defect in cholesterol biosynthesis, associated with mental retardation and multisystem structural abnormalities. This study investigated the prevalence of congenital CNS abnormalities by MRI in a large series of patients with SLOS and the correlation of the clinical and biochemical findings with the results of MRI and 1H MRS. Eighteen patients were studied; all underwent MRI of the brain, and 16 had 1H MRS of the cerebral white matter. The ratios choline:NAA, lipid:NAA, and lipid:choline metabolite were found to be correlated with the clinical degree of disease severity, serum total sterol ratios (cholesterol/cholesterol + 7-dehydrocholesterol + 8-dehydrocholesterol) and in two cases with the effect of cholesterol therapy. Abnormal CNS findings were noted in five patients, including callosal abnormalities (n=4), Dandy-Walker variant (n=1), and arachnoid cyst (n=1). Holoprosencephaly was noted in one patient with a prevalence of 6%. Choline:NAA was elevated in seven patients. There was a statistically significant positive correlation between the lipid:choline ratio and the serum cholesterol precursor, 8-dehydrocholesterol. In two patients 1H MRS demonstrated abnormally elevated lipids prior to cholesterol therapy, which improved on therapy. The use of MRI and 1H MRS is an effective way to demonstrate brain structural abnormalities in patients with SLOS and may prove to be an effective method for the assessment of the effects of cholesterol replacement therapy in the brain. 相似文献
8.
Objective
201Thallium (TL), 99mTc-tetrofosmin (TF), and 99mTc-sestamibi (MIBI) are extensively used as myocardial perfusion agents. The objective of the present study was to evaluate
their kinetics under acute ischemia–reperfusion.
Methods Isolated rat hearts, perfused by the Langendorff method at a constant flow rate of 10 ml/min, were allotted to normal control,
mild ischemia, and severe ischemia groups, in which 20-min tracer wash-in was conducted followed by a 25-min tracer washout.
No-flow ischemia (15 min for mild ischemia groups; 30 min for severe ischemia groups) was induced before conducting wash-in
and washout in the ischemia groups. Whole-heart radioactivity was determined with an external gamma detector. Myocardial flow
rate (K
1, ml/min) and clearance rate (k
2, min−1) were calculated.
Results
K
1TL, K
1TF, and K
1MIBI decreased according to the severity of ischemia (K
1TL 5.32 ± 0.53, 4.76 ± 0.70, and 1.44 ± 0.59; K
1TF 3.80 ± 0.70, 2.73 ± 0.99, and 1.09 ± 0.45; and K
1MIBI 3.45 ± 1.10, 2.15 ± 0.82, and 1.05 ± 0.13, in the normal control, mild, and severe ischemia groups, respectively). K
1 was significantly higher for TL than for the 99mTc tracers (P < 0.05), but the 99mTc tracers had equivalent K
1 values. k
2TL increased significantly (P < 0.05) in the ischemia groups (k
2TL 0.062 ± 0.013, 0.11 ± 0.045, and 0.12 ± 0.035), but showed no significant difference between the ischemia groups. k
2MIBI and k
2TF were significantly (P < 0.05) lower than k
2TL and increased significantly (P < 0.05) in the severe ischemia group (k
2TF 0.0056 ± 0.0022, 0.0037 ± 0.0015, and 0.024 ± 0.015; and k
2MIBI 0.00072 ± 0.0011, 0.00038 ± 0.00076, and 0.042 ± 0.034). k
2MIBI was significantly (P < 0.05) lower than k
2TF in the normal control and mild ischemia groups.
Conclusions Tracer extraction was higher for TL than for the 99mTc tracers and all tracers decreased according to the severity of ischemia–reperfusion in the three tracer groups. The clearance
kinetics of not only MIBI but also TF is possibly useful for the evaluation of the severity of ischemia, and the Langendorff
method and a methodological approach by continuous determinations of radioactivity may serve for the quantitative analysis
of tracer kinetic profiles. 相似文献
9.
10.
Rizvi SN Visser OJ Vosjan MJ van Lingen A Hoekstra OS Zijlstra JM Huijgens PC van Dongen GA Lubberink M 《European journal of nuclear medicine and molecular imaging》2012,39(3):512-520
Purpose
Positron emission tomography (PET) with 89Zr-ibritumomab tiuxetan can be used to monitor biodistribution of 90Y-ibritumomab tiuxetan as shown in mice. The aim of this study was to assess biodistribution and radiation dosimetry of 90Y-ibritumomab tiuxetan in humans on the basis of 89Zr-ibritumomab tiuxetan imaging, to evaluate whether co-injection of a therapeutic amount of 90Y-ibritumomab tiuxetan influences biodistribution of 89Zr-ibritumomab tiuxetan and whether pre-therapy scout scans with 89Zr-ibritumomab tiuxetan can be used to predict biodistribution of 90Y-ibritumomab tiuxetan and the dose-limiting organ during therapy. 相似文献11.
Sun A Sörensen J Karlsson M Turesson I Langström B Nilsson P Cederblad L Bertling J Riklund K Johansson S 《European journal of nuclear medicine and molecular imaging》2007,34(5):651-657
Purpose The aim of this study was to evaluate the feasibility of using 1-[11C]-acetate positron emission tomography (ACE-PET) to detect and delineate the gross tumour volume of head and neck cancer
before radiotherapy, and to compare the results with those obtained using 18F-fluoro-2-deoxy-D-glucose (FDG) PET.
Methods Ten patients with histologically verified squamous cell carcinoma were investigated by FDG-PET and dynamic ACE-PET prior to
radiotherapy. The two scans were performed on the same day or on consecutive days, except in one patient in whom they were
done 5 days apart. Diagnostic CT or MRI was performed in all patients. The image data sets were analysed both visually and
semi-quantitatively. All primary tumours and metastases were delineated automatically by using the 50% threshold of maximum
radioactivity corrected for background. The mean standardised uptake value (SUV) and the tumour volumes were evaluated and
compared.
Results All ten primary tumours were detected by ACE-PET, while nine primaries were detected by FDG-PET and CT and/or MRI. The ACE
SUV tended to be lower than the FDG SUV (5.3±2.7 vs 9.6±7.0, p=0.07). The tumour volumes delineated with ACE were on average 51% larger than the FDG volumes (p<0.05). ACE-PET identified 20/21 lymph node metastases, while only 13/21 lesions were detected by FDG-PET and 16/21 lesions
by CT or MRI.
Conclusion ACE-PET appears promising for the staging of head and neck cancer. The biological information provided by both FDG and ACE
must be carefully validated before it can be used in clinical routine for radiation treatment planning. More studies are needed
to evaluate the differences in volumes and to confirm the clinical potential of both FDG and ACE-PET, especially in radiotherapy.
The first two authors contributed equally to this paper. 相似文献
12.
Wu Z Li ZB Cai W He L Chin FT Li F Chen X 《European journal of nuclear medicine and molecular imaging》2007,34(11):1823-1831
Purpose We have previously reported that 18F-FB-E[c(RGDyK)]2 (18F-FRGD2) allows quantitative PET imaging of integrin αvβ3 expression. However, the potential clinical translation was hampered by the relatively low radiochemical yield. The goal
of this study was to improve the radiolabeling yield, without compromising the tumor targeting efficiency and in vivo kinetics,
by incorporating a hydrophilic bifunctional mini-PEG spacer.
Methods
18F-FB-mini-PEG-E[c(RGDyK)]2 (18F-FPRGD2) was synthesized by coupling N-succinimidyl-4-18F-fluorobenzoate (18F-SFB) with NH2-mini-PEG-E[c(RGDyK)]2 (denoted as PRGD2). In vitro receptor binding affinity, metabolic stability, and integrin αvβ3 specificity of the new tracer 18F-FPRGD2 were assessed. The diagnostic value of 18F-FPRGD2 was evaluated in subcutaneous U87MG glioblastoma xenografted mice and in c-neu transgenic mice by quantitative microPET imaging studies.
Results The decay-corrected radiochemical yield based on 18F-SFB was more than 60% with radiochemical purity of >99%. 18F-FPRGD2 had high receptor binding affinity, metabolic stability, and integrin αvβ3-specific tumor uptake in the U87MG glioma xenograft model comparable to those of 18F-FRGD2. The kidney uptake was appreciably lower for 18F-FPRGD2 compared with 18F-FRGD2 [2.0 ± 0.2%ID/g for 18F-FPRGD2 vs 3.0 ± 0.2%ID/g for 18F-FRGD2 at 1 h post injection (p.i.)]. The uptake in all the other organs except the urinary bladder was at background level.
18F-FPRGD2 also exhibited excellent tumor uptake in c-neu oncomice (3.6 ± 0.1%ID/g at 30 min p.i.).
Conclusion Incorporation of a mini-PEG spacer significantly improved the overall radiolabeling yield of 18F-FPRGD2. 18F-FPRGD2 also had reduced renal uptake and similar tumor targeting efficacy as compared with 18F-FRGD2. Further testing and clinical translation of 18F-FPRGD2 are warranted.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Zhanhong Wu and Zi-Bo Li contributed equally to this work. 相似文献
13.
Purpose
The α7 nicotinic acetylcholine receptor (nAChR) is implicated in many neuropsychiatric disorders, making it an important target for positron emission tomography (PET) imaging. The first aim of this work was to compare two α7 nAChRs PET radioligands, [18F]ASEM (3-(1,4-diazabicyclo[3.2.2]nonan-4-yl)-6-([18F]fluorodibenzo[b,d]thiophene 5,5-dioxide) and [18F]DBT-10 (7-(1,4-diazabicyclo[3.2.2]nonan-4-yl)-2-([18F]fluorodibenzo[b,d]thiophene 5,5-dioxide), in nonhuman primates. The second aim was to assess further the quantification and test-retest variability of [18F]ASEM in humans.Methods
PET scans with high specific activity [18F]ASEM or [18F]DBT-10 were acquired in three rhesus monkeys (one male, two female), and the kinetic properties of these radiotracers were compared. Additional [18F]ASEM PET scans with blocking doses of nicotine, varenicline, and cold ASEM were acquired separately in two animals. Next, six human subjects (five male, one female) were imaged with [18F]ASEM PET for 180 min, and arterial sampling was used to measure the parent input function. Different modeling approaches were compared to identify the optimal analysis method and scan duration for quantification of [18F]ASEM distribution volume (V T). In addition, retest scans were acquired in four subjects (three male, one female), and the test-retest variability of V T was assessed.Results
In the rhesus monkey brain [18F]ASEM and [18F]DBT-10 exhibited highly similar kinetic profiles. Dose-dependent blockade of [18F]ASEM binding was observed, while administration of either nicotine or varenicline did not change [18F]ASEM V T. [18F]ASEM was selected for further validation because it has been used in humans. Accurate quantification of [18F]ASEM V T in humans was achieved using multilinear analysis with at least 90 min of data acquisition, resulting in V T values ranging from 19.6?±?2.5 mL/cm3 in cerebellum to 25.9?±?2.9 mL/cm3 in thalamus. Test-retest variability of V T was 11.7?±?9.8%.Conclusions
These results confirm [18F]ASEM as a suitable radiotracer for the imaging and quantification of α7 nAChRs in humans.14.
15.
Hellwig D Romeike BF Ketter R Moringlane JR Kirsch CM Samnick S 《European journal of nuclear medicine and molecular imaging》2008,35(1):24-31
Objectives Radioactive amino-acids accumulate in gliomas even with an intact blood-brain-barrier. L-3-[123I]-iodo-α-methyl-tyrosine (IMT) is well established for SPECT imaging of gliomas. Recently, we introduced p-[123I]-iodo-L-phenylalanine (IPA) for the characterisation of brain lesions. This study compares both tracers in glioma patients.
Methods Eleven patients with gliomas (1 WHO grade 1, 5 grade 2, 1 grade 3, 2 grade 4 gliomas, 1 unconfirmed upgrading and 1 post-therapeutic
non-neoplastic lesion) underwent SPECT imaging with IPA (early and delayed acquisitions at 30 min and 3 h) and IMT (early
only). Maximum tumour-to-brain ratios (TBR) were calculated using region-of-interest analysis to assess uptake of IMT and
IPA. Imaging results were compared to histopathological findings.
Results Early TBRs of IMT and IPA were strongly correlated (r = 0.828, p = 0.002). TBRs were higher for IMT than IPA (1.95±0.50 versus
1.79±0.42; p < 0.05), but independent from tumour cell density (p > 0.1). Visual interpretation by different observers was
more concordant for IMT-SPECT than IPA-SPECT (kappa 1.0 versus 0.774). No differences in early TBRs were observed between
low-grade and high-grade gliomas for IMT (1.97±0.53 versus 2.21±0.44, p > 0.5) or IPA (1.70±0.23 versus 2.21±0.56, p = 0.167)
with a trend to higher TBRs in low-grade tumours for IMT (p = 0.093). In contrast to the known wash-out of IMT, we observed
persistent accumulation of IPA in gliomas.
Conclusions IPA shows lower TBRs than IMT, especially in low-grade tumours, so IMT should be preferred for the delineation of low-grade
gliomas by SPECT imaging. Due to its prolonged retention, however, IPA remains promising for therapeutic use in gliomas after
labelling with I-131.
This work was supported by a grant from the “Deutsche Krebshilfe” (70-3024-He 1). 相似文献
16.
Beheshti M Vali R Waldenberger P Fitz F Nader M Loidl W Broinger G Stoiber F Foglman I Langsteger W 《European journal of nuclear medicine and molecular imaging》2008,35(10):1766-1774
Purpose The aim of this prospective study was to compare the potential value of 18F fluorocholine (FCH) and 18F fluoride positron emission tomography (PET)–CT scanning for the detection of bony metastases from prostate cancer.
Methods Thirty-eight men (mean age, 69 ± 8 years) with biopsy-proven prostate cancer underwent both imaging modalities within a maximum
interval of 2 weeks. Seventeen patients were evaluated preoperatively, and 21 patients were referred for post-operative evaluation
of suspected recurrence or progression based on clinical algorithms. The number, sites and morphological patterns of bone
lesions on 18F FCH and 18F fluoride PET–CT were correlated: Concordant lesions between the two modalities with corresponding changes on CT were considered
to be positive for malignancy; discordant lesions were verified by follow-up examinations. The mean follow-up interval was
9.1 months.
Results Overall, 321 lesions were evaluated in this study. In a lesion-based analysis, a relatively close agreement was found between these two imaging modalities for detection of malignant bone lesions
(kappa = 0.57), as well as in a patient-based analysis (kappa = 0.76). Sixteen malignant sclerotic lesions with a high density were negative in both 18F FCH and 18F fluoride PET–CT [mean Hounsfield unit (HU), 1,148 ± 364]. There was also a significant correlation between tracer intensity
by SUV and density of sclerotic lesions by HU both in 18F FCH PET–CT (r = −0.28, p < 0.006) and 18F fluoride PET–CT (r = −0.20, p < 0.05).
The sensitivity, specificity and accuracy of PET–CT in the detection of bone metastases in prostate cancer was 81%, 93% and
86% for 18F fluoride, and 74% (p = 0.12), 99% (p = 0.01) and 85% for FCH, respectively.
18F FCH PET–CT led to a change in the management in two out of 38 patients due to the early detection of bone marrow metastases.
18F fluoride PET–CT identified more lesions in some patients when compared with 18F FCH PET–CT but did not change patient management.
Conclusion FCH PET–CT may be superior for the early detection (i.e. bone marrow involvement) of metastatic bone disease. In patients
with FCH-negative suspicious sclerotic lesions, a second bone-seeking agent (e.g. 18F fluoride) is recommended. 18F fluoride PET–CT demonstrated a higher sensitivity than 18F FCH PET–CT, but the difference was not statistically significant. Furthermore, 18F fluoride PET could be also negative in highly dense sclerotic lesions, which presumably reflects the effect of treatment.
It will be important to clarify in future studies whether these lesions are clinically relevant when compared with metabolically
active bone metastases. 相似文献
17.
Mohd Fahmi Mohd Yusof Puteri Nor Khatijah Abd Hamid Abd Aziz Tajuddin Rokiah Hashim Sabar Bauk Norriza Mohd Isa Muhammad Jamal Md Isa 《Radiological physics and technology》2017,10(3):331-339
The aim of this study was to determine the suitability of tannin-added Rhizophora spp. particleboards as phantom materials in the application of low- and high-energy photons. The tannin-added Rhizophora spp. particleboards and density plug phantoms were created with a target density of 1.0 g/cm3. The elemental composition and effective atomic number of the particleboards were measured using energy dispersive X-ray analysis. The mass attenuation coefficient of the particleboards for low-energy photons were measured using the attenuation of X-ray fluorescence. The mass attenuation coefficients of high-energy photons were measured using the attenuation of 137Cs and 60Co gamma energies. The results were compared to the calculated value of water using XCOM calculations. The results showed that the effective atomic number and mass attenuation coefficients of tannin-added Rhizophora spp. particleboards were similar to those of water, indicating the suitability of tannin-added Rhizophora spp. particleboards as phantom materials for low- and high-energy photons. 相似文献
18.
<Superscript>99m</Superscript>Tc-tetrofosmin or <Superscript>99m</Superscript>Tc-sestamibi for double-phase parathyroid scintigraphy? 总被引:1,自引:1,他引:0
Fröberg AC Valkema R Bonjer HJ Krenning EP 《European journal of nuclear medicine and molecular imaging》2003,30(2):193-196
Several years ago technetium-99m tetrofosmin was reported to localise parathyroid adenomas. The aim of this study was to compare the sensitivity of this radiopharmaceutical with that of (99m)Tc-sestamibi using a double-phase parathyroid scintigraphy protocol. Scans of 12 patients were evaluated visually and lesion to thyroid ratios were calculated. Nine of the patients were subsequently operated on; a total of eight parathyroid adenomas or hyperplastic glands were histologically confirmed in seven of the patients, while in one patient a parathyroid carcinoma was histologically proven. All of these patients had positive (99m)Tc-sestamibi scintigrams, whereas only two (99m)Tc-tetrofosmin scintigrams were positive. With (99m)Tc-sestamibi there was a significant increase in the lesion to thyroid ratio from 10 min to 90 min and 150 min p.i. which was not seen on scintigraphy with (99m)Tc-tetrofosmin. This makes (99m)Tc-tetrofosmin less suitable for double-phase parathyroid scintigraphy. 相似文献
19.
Purpose
The aim of this study was to evaluate the longitudinal changes in [11C]PIB uptake in mild cognitive impairment (MCI) and Alzheimer’s disease (AD) over a long-term follow-up.Methods
Six AD patients, ten MCI patients and eight healthy subjects underwent a [11C]PIB PET scan at baseline and at 2 and 5 years. The clinical status of the MCI patients was evaluated every 6 months.Results
The MCI group showed a significant increase in [11C]PIB uptake over time (p?<?0.001), with a similar increase from baseline to 2 years (4.7 % per year) and from 2 to 5 years (5.0 % per year). Eight MCI patients (80 %) converted to AD, and two of these patients showed a normal [11C]PIB scan at baseline but increased uptake later. There was an increase in [11C]PIB uptake with time in the AD group (p?=?0.02), but this did not significantly differ from the change in the control group.Conclusion
Our results revealed a significant increase in amyloid load even at the time of AD diagnosis in some of the MCI patients who converted. A positive [11C]PIB scan at baseline in MCI patients strongly predicted future conversion to AD but a negative PIB scan in MCI patients did not exclude future conversion. The results suggest that there is wide individual variation in the brain amyloid load in MCI, and in the course of amyloid accumulation in relation to the clinical diagnosis of AD.20.
Solveig Tiepolt Swen Hesse Marianne Patt Julia Luthardt Matthias L. Schroeter Karl-Titus Hoffmann David Weise Hermann-Josef Gertz Osama Sabri Henryk Barthel 《European journal of nuclear medicine and molecular imaging》2016,43(9):1700-1709