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ABSTRACT: Enhanced expression of integrin αvβ3 is commonly used as a biomarker for angiogenesis, which is one of the key pathophysiologic processes in cerebral infarct. Integrin αvβ3 can be imaged with arginine-glycine-aspartic acid (RGD) peptide agents. In this study, characteristics of positron emission tomography (PET) using a 68Ga-labeled RGD were investigated in pediatric cerebral infarct. Pediatric patients with moyamoya disease underwent 68Ga-RGD PET in a research protocol for neovascularization evaluation. In these patients, 17 cerebral infarct lesions of 10 patients were included in the analysis. On 68Ga-RGD PET, the infarct lesion to contralateral brain ratio (LCR) of the infarct lesion was measured and analyzed with regard to postinfarct time interval (PTI) and perfusion single-photon emission computed tomography (SPECT) findings. An increase in 68Ga-RGD uptake was observed in cerebral infarct, particularly in recent lesions. The LCR was significantly higher in the recent than in the chronic lesions, and a significant correlation existed between the LCR and PTI. Additionally, the LCR was significantly higher in the lesions with hyperperfusion on SPECT. This study, as the first human study using an RGD agent for in vivo cerebral infarct imaging, demonstrated that 68Ga-RGD PET has a potential for molecular imaging of integrin αvβ3 expression in cerebral infarct as a biomarker of angiogenesis.
Molecular Imaging 06/2013; 12(4):213-7. · 3.18 Impact Factor
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Hyung-Jun Im,
Do Won Hwang,
Han Kyu Lee,
Jaeho Jang,
Song Lee,
Hyewon Youn,
Yeona Jin,
Seung U Kim,
E Edmund Kim,
Yong Sik Kim, Dong Soo Lee
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ABSTRACT: Transplantation of neural stem cells (NSCs) has been proposed as a treatment for Parkinson disease (PD). The aim of this study was to monitor the viability of transplanted NSCs expressing the enhanced luciferase gene in a mouse model of PD in vivo. The PD animal model was induced by unilateral injection of 6-hydroxydopamine (6-OHDA). The behavioral test using apomorphine-induced rotation and positron emission tomography with [18F]N-(3-fluoropropyl)-2'-carbomethoxy-3'-(4-iodophenyl)nortropane ([18F]FP-CIT) were conducted. HB1.F3 cells transduced with an enhanced firefly luciferase retroviral vector (F3-effLuc cells) were transplanted into the right striatum. In vivo bioluminescence imaging was repeated for 2 weeks. Four weeks after transplantation, [18F]FP-CIT PET and the rotation test were repeated. All 6-OHDA-injected mice showed markedly decreased [18F]FP-CIT uptake in the right striatum. Transplanted F3-effLuc cells were visualized on the right side of the brain in all mice by bioluminescence imaging. The bioluminescence intensity of the transplanted F3-effLuc cells gradually decreased until it was undetectable by 10 days. The behavioral test showed that stem cell transplantation attenuated the motor symptoms of PD. No significant change was found in [18F]FP-CIT imaging after cell transplantation. We successfully established an in vivo bioluminescence imaging system for the detection of transplanted NSCs in a mouse model of PD. NSC transplantation induced behavioral improvement in PD model mice.
Molecular Imaging 06/2013; 12(4):224-34. · 3.18 Impact Factor
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ABSTRACT: The spatial resolution from Compton cameras suffers from measurement uncertainties in interaction positions and energies. The degree of degradation in spatial resolution is shift-variant (SV) over the field-of-view (FOV) because the imaging principle is based on the conical surface integration. In our study, the shift-variant point spread function (SV-PSF) is derived from point source measurements at various positions in the FOV and is incorporated into the system matrix of a fully three-dimensional, accelerated reconstruction, i.e. the listmode ordered subset expectation maximization (LMOSEM) algorithm, for resolution recovery. Simulation data from point sources were used to estimate SV and asymmetric parameters for Gaussian, Cauchy, and general parametric PSFs. Although little difference in the fitness accuracy between Gaussian and general parametric PSFs was observed, the general parametric model showed greater flexibility over the FOV in shaping the curve between that for Gaussian and Cauchy functions. The estimated asymmetric SV-PSFs were incorporated into the LMOSEM for resolution recovery. For simulation data from a single point source at the origin, all LMOSEM-SV-PSFs improved the spatial resolution by 2.6 times over the standard LMOSEM. For two point-source simulations, reconstructions also gave a two-fold improvement in spatial resolution and resulted in a greater recovered activity ratio at different positions in the FOV.
Physics in Medicine and Biology 04/2013; 58(9):2823-2840. · 2.83 Impact Factor
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ABSTRACT: OBJECTIVE: Ga-NOTA-RGD PET is a newly developed molecular imaging for angiogenesis. In this study, Ga-NOTA-RGD PET was used to investigate imaging characteristics in a rat myocardial infarction (MI) model and to monitor the efficacy of an angiogenesis induction therapy. MATERIALS AND METHODS: Ga-NOTA-RGD PET was performed serially in rats with MI or sham operation, and myocardial uptake was analyzed with respect to time duration and tissue characteristics. Subsequently, Ga-NOTA-RGD PET was serially performed for therapeutic efficacy monitoring in MI-induced rats, which were treated with basic fibroblast growth factor (bFGF) injection or saline injection. Image findings were compared with the final change in MI lesion. RESULTS: Ga-NOTA-RGD uptake was significantly increased in MI lesion and gradually decreased over time. Ga-NOTA-RGD uptake in the infarcted tissue corresponded with vascular endothelial growth factor expression and macrophage accumulation. In monitoring of therapeutic efficacy, the lesion uptake in the bFGF-injected group was significantly higher than that of the saline-injected and sham-operated groups on the first day. However, no significant differences were observed between bFGF and saline-injected groups at subsequent time points, corresponding to the final infarct size change. CONCLUSION: Ga-NOTA-RGD PET would be a useful angiogenesis imaging modality in MI for assessment of pathophysiology or monitoring of therapeutic efficacy.
Coronary artery disease 03/2013; · 1.56 Impact Factor
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ABSTRACT: PURPOSE: Castleman disease (CD) is a benign lymphoproliferative disease, which usually shows hypermetabolism on F-FDG PET/CT. In this study, we investigated metabolic characteristics of CD in consecutive series of patients and analyzed F-FDG uptake with regard to major clinicopathologic factors, to investigate clinical implication of F-FDG uptake in CD. METHODS: Twelve patients (5 men and 7 women; mean age, 52 ± 14 years) with pathologically confirmed CD, who underwent F-FDG PET/CT, were retrospectively enrolled, and their images were analyzed. The cases were composed of 10 first diagnosed and 2 relapsed cases. SUVmax was measured for each lesion. Metabolic characteristics were compared according to clinical and pathologic characteristics. RESULTS: All the F-FDG PET/CT images showed hypermetabolic lesions including small lymph nodes of less than 1 cm. The average SUVmax was 5.8 ± 4.1 with a varying range of 2.4 to 17.1. SUVmax was significantly higher in multicentric than in unicentric disease cases (7.0 ± 4.6 vs 3.3 ± 1.1; P = 0.048) and in the patients with clinical manifestation than the other group (7.1 ± 4.5 and 3.1 ± 0.8, respectively; P = 0.028). CONCLUSIONS: F-FDG PET/CT is an effective diagnostic imaging for diagnosis of CD. Castleman disease shows moderately increased F-FDG uptake. In addition, the uptake is well correlated with disease multicentricity and clinical manifestation, suggesting that it would be a significant imaging marker for severity or prognosis of CD.
Clinical nuclear medicine 02/2013; · 3.92 Impact Factor
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ABSTRACT: Background/Aims: There is increasing evidence that the PI3K/Akt signal pathway plays a crucial role in tumorigenesis and tumor progression. Akt protein modulates the function of numerous substrates related to the regulation of cell proliferation, such as cyclin dependent kinase inhibitors, including p27 and Cks1. The aim of this study was to investigate the immunohistochemical expressions of Akt, p27 and Cks1 proteins according to clinicopathological parameters such as gender, lymph node metastases, tumor invasion depth, the TNM stage and Lauren classification in gastric adenocarcinoma. Methodology: Immunohistochemical staining with monoclonal Akt, p27 and Cks1 antibodies was performed on the paraffin embedded specimens of 43 gastric adenocarcinomas. Results: The expression of Akt was increased more in the adenocarcinomas that showed lymph node involvement (53.5%) than in the adenocarcinomas that did not (9.3%) (p=0.007). The expression of Cks1 was increased more in the adenocarcinomas that showed lymph node involvement (39.5%) than in the adenocarcinomas that did not (7%) (p<0.043). Conclusions: Akt and Cks1 are associated with lymph node metastasis in gastric adenocarcinoma. We suggest that Akt and Cks1 proteins might be related with poor prognosis in gastric adenocarcinoma.
Hepato-gastroenterology 01/2013; 60(127). · 0.66 Impact Factor
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Bong Suk Ko,
Woo Tae Kim,
Su Sun Chang,
Eun Hye Kim,
Seung Woo Lee,
Won Seok Park,
Yeon Soo Kim,
Soon Woo Nam, Dong Soo Lee,
Ji Chang Kim,
Sang Bum Kang
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ABSTRACT: A 38-year-old female with a history of alcoholic liver cirrhosis visited our hospital with a massive hematochezia. An esophagogastroduodenoscopy did not demonstrate any bleeding source, and a colonoscopy showed a massive hemorrhage in the ascending colon but without an obvious focus. The source of the bleeding could not be found with a mesenteric artery angiography. We performed an enhanced abdominal computed tomography, which revealed a distal ascending colonic varix, and assumed that the varix was the source of the bleeding. We performed a venous coil embolization and histoacryl injection to obliterate the colon varix. The intervention appeared to be successful because the vital signs and hemoglobin laboratory data remained stable and because the hematochezia was no longer observed. We report here on a rare case of colonic variceal bleeding that was treated with venous coil embolization.
World Journal of Gastroenterology 01/2013; 19(2):311-5. · 2.47 Impact Factor
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ABSTRACT: The conceptual significance of understanding functional brain alterations and cognitive deficits associated with Alzheimer's disease (AD) process has been widely established. However, the whole-brain functional networks of AD and its prodromal stage, mild cognitive impairment (MCI), are not well clarified yet. In this study, we compared the characteristics of the whole-brain functional networks among cognitively normal (CN), MCI, and AD individuals by applying graph theoretical analyses to [(18)F] fluorodeoxyglucose positron emission tomography (FDG-PET) data. Ninety-four CN elderly, 183 with MCI, and 216 with AD underwent clinical evaluation and FDG-PET scan. The overall small-world property as seen in the CN whole-brain network was preserved in MCI and AD. In contrast, individual parameters of the network were altered with the following patterns of changes: local clustering of networks was lower in both MCI and AD compared to CN, while path length was not different among the three groups. Then, MCI had a lower level of local clustering than AD. Subgroup analyses for AD also revealed that very mild AD had lower local clustering and shorter path length compared to mild AD. Regarding the local properties of the whole-brain networks, MCI and AD had significantly decreased normalized betweenness centrality in several hubs regionally associated with the default mode network compared to CN. Our results suggest that the functional integration in whole-brain network progressively declines due to the AD process. On the other hand, functional relatedness between neighboring brain regions may not gradually decrease, but be the most severely altered in MCI stage and gradually re-increase in clinical AD stages.
PLoS ONE 01/2013; 8(1):e53922. · 4.09 Impact Factor
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ABSTRACT: INTRODUCTION: ALK rearrangement in lung cancer has been identified as a novel molecular target in lung adenocarcinoma. In this study, we evaluated metabolic and metastatic features of lung adenocarcinoma by using FDG PET/CT, with regard to specific genotypes of ALK and EGFR mutation. METHODS: Patients with lung adenocarcinoma initially diagnosed and examined with FDG PET/CT and molecular genotyping with biopsy specimen, from September 2009 to September 2011, were selected retrospectively. ALK fluorescence in situ hybridization and EGFR mutations were tested. Maximum standardized uptake value (SUVmax) and metastatic characteristics on FDG PET/CT were analyzed with regard to ALK and EGFR status. RESULTS: Of the 331 lung adenocarcinoma patients, 18 were ALK positive (ALK(+)), 156 were EGFR mutation positive (EGFR(+)), and 157 were wild type (WT) for both ALK and EGFR mutation. The ALK(+) tumor showed significantly higher SUVmax and more common metastasis to lymph nodes and distant organs than those of other genotypes in overall patients (P<0.01). In a subgroup analysis of advanced stage (stage IIIb and IV), ALK(+) lung cancer showed significantly higher SUVmax (P<0.05) than EGFR(+) tumors. In another subgroup analysis of size matched groups, ALK(+) tumors showed significant difference in SUVmax, lymph node and distant metastasis (P<0.01), particularly in the moderate-sized tumors (1.5-3cm). CONCLUSION: ALK-rearranged lung adenocarcinoma represents higher glucose metabolism and more rapid metastasis to lymph nodes or distant sites compared with those with EGFR mutation and wild type, which suggests more aggressive features of ALK rearrangement.
Lung cancer (Amsterdam, Netherlands) 12/2012; · 3.14 Impact Factor
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Tae Min Kim,
Jin Chul Paeng,
In Kook Chun,
Bhumsuk Keam,
Yoon Kyung Jeon,
Se-Hoon Lee,
Dong-Wan Kim, Dong Soo Lee,
Chul Woo Kim,
June-Key Chung,
Il Han Kim,
Dae Seog Heo
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ABSTRACT: BACKGROUND: This study was undertaken to evaluate the prognostic value of quantitative metabolic parameters in [(18) F]2-fluoro-2-deoxyglucose (FDG)-positron emission tomography (PET) for diffuse large B cell lymphoma (DLBCL). METHODS: A total of 140 DLBCL patients underwent FDG-PET scans before rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) chemotherapy. The maximal standardized uptake value (SUV(max) ) and total lesion glycolysis (TLG) were calculated, with the margin thresholds as 25%, 50%, and 75% of SUV(max) of all lesions. Treatment outcomes were compared between groups according to metabolic parameters and the International Prognostic Index (IPI). RESULTS: After a median follow-up of 28.5 months (range, 5-81 months), the 2-year progression-free survival (PFS) and overall survival (OS) were 83% and 87%, respectively. Among metabolic parameters, TLG at the threshold of 50% (TLG(50) ) was significantly associated with treatment outcomes. High TLG(50) values (>415.5) were associated with reduced survivals compared with low TLG(50) values (≤415.5) (2-year PFS of 73% versus 92%, P = .007; and 2-year OS of 81% versus 93%, P = .031). High IPI score (≥3) significantly reduced OS (2-year OS of 79% versus 90%, P = .049). Ann Arbor stage III/IV adversely affected PFS (P = .013). However, high IPI score and Ann Arbor stage of III/V did not significantly shorten PFS (P = .200) and OS (P = .921), respectively. High TLG(50) values independently predicted survivals by multivariate analysis (hazard ratio = 4.4; 95% confidence interval = 1.5-13.1; P = .008 for PFS and hazard ratio = 3.1; 95% confidence interval = 1.0-9.6; P = .049 for OS). CONCLUSIONS: Combined assessment of volume and metabolism (ie, TLG) is predictive of survivals in DLBCL patients who are treated with R-CHOP. Cancer 2012. © 2012 American Cancer Society.
Cancer 12/2012; · 4.77 Impact Factor
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ABSTRACT: For attenuation correction (AC) in PET/MRI systems, segmentation-based methods are most often used. However, the standardized uptake value (SUV) of lesions in the bone and liver, which have higher attenuation coefficients than other organs, can be underestimated, potentially leading to misinterpretation of clinical cases. Errors in SUV estimation are also dependent on the segmentation schemes used in the segmentation-based AC. In this study, this potential bias in SUV estimation using 4 different segmentation-based AC methods was evaluated for the PET/CT data of cancer patients with bone and liver lesions. METHODS: Forty patients who had spine or liver lesions and underwent (18)F-FDG PET/CT participated (18 women and 22 men; 20 spine lesions and 20 liver lesions; mean age (±SD), 60.5 ± 11.4 y; mean body weight, 57.7 ± 10.4 kg). The patient body region was extracted from the CT image and categorized into 5 tissue groups (air, lungs, fat, water, and bone) using Hounsfield unit thresholds, which were determined from the CT histogram. Four segmentation-based AC methods (SLA [soft-tissue/lung/air], WFLA [water/fat/lung/air], SLAB [soft-tissue/lung/air/bone], and WFLAB [water/fat/lung/air/bone]) were compared with CT-based AC. The mean attenuation coefficient for each group was calculated from 40 CT images and assigned to the attenuation maps. PET sinograms were reconstructed using segmentation- and CT-based AC maps, and mean SUV in the lesions was compared. RESULTS: Mean attenuation coefficients for air, lungs, fat, water, and bone were 0.0058, 0.0349, 0.0895, 0.0987, and 0.1178 cm(-1), respectively. In the spine lesions, the SUVs were underestimated by 16.4% ± 8.5% (SLA AC) and 14.7% ± 7.5% (WFLA AC) but not to a statistically significant extent for SLAB and WFLAB AC relative to CT AC. In the liver lesions, the SUVs were underestimated by 11.1% ± 2.6%, 8.1% ± 3.0%, 6.8% ± 3.8%, and 4.1% ± 3.8% with SLA, SLAB, WFLA, and WFLAB AC, respectively. CONCLUSION: Without bone segmentation, the SUVs of spine lesions were considerably underestimated; however, the bias was acceptable with bone segmentation. In liver lesions, the segmentation-based AC methods yielded a negative bias in SUV; however, inclusion of the bone and fat segments reduced the SUV bias. The results of this study will be useful for understanding organ-dependent bias in SUV between PET/CT and PET/MRI.
Journal of Nuclear Medicine 10/2012; · 6.38 Impact Factor
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ABSTRACT: Sertraline hydrochloride (Zoloft®, Pfizer) is an antidepressant drug of the selective serotonin reuptake inhibitor (SSRI). The aims of this study were evaluating its in vivo distribution and kinetic models in human brain. Also, this study was to determine optimal scan duration of dynamic positron emission tomography (PET) for accurate [(11)C]sertraline kinetic parameters and the feasibility of semi-quantitative approach for assessing distribution volume ratio (DVR). [(11)C]sertraline dynamic PET and magnetic resonance imaging (MRI) scans were performed in 5 healthy males. Blood sampling were collected for the input function. Tissue time-activity curves (TAC) were obtained in 7 brain regions using MRI. Goodness-of-fit for TAC using simple tissue compartment model (2C2P) and 3-compartment models with irreversible (3C3P) and reversible (3C4P) were compared. Total distribution volume (DV) for each region of interest (ROI) and DVR were calculated. Also, ratio between the standard uptake value (SUV) of each ROI and that of cerebellum (SUVr) was computed and correlated with the DVR. Akaike information criteria analysis showed that the 2C2P was the most suitable model. Average values of K (1) (mL/min/g) and k (2) (1/min) were 0.54 and 0.012 in putamen. PET scan time longer than 50 min was required for the accurate estimation of DV. SUVr in 50-90 min was well correlated with DVR.
Archives of Pharmacal Research 09/2012; 35(9):1591-7. · 1.59 Impact Factor
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ABSTRACT: We report herein a novel isothiocyanate active ligand for fluorine-18 labeling prepared by four step synthesis. It can be conjugated to a target molecule containing an amino functional group under weak basic conditions by way of thiourea bond formation. We explored the application of synthesized ligand by conjugating to well known α(v)β(3) integrin targeting peptide, c(RGDyK). The conjugated peptide showed good radiochemical yield and efficiency with an excellent radiochemical purity (97.1±1.2%) in a short reaction time (10min). Labeled peptide showed excellent in vitro and in vivo stability (>95%). α(v)β(3) integrin specific tumor uptake was observed both in biodistribution and small animal microPET studies on α(v)β(3)-positive U87MG (human glioma cells) xenograft bearing mice. In general, successful application of synthesized ligand for labeling of RGD peptide could facilitate the possibility of using this ligand for labeling peptides containing an amino functional group.
Bioorganic & medicinal chemistry 08/2012; 20(19):5941-7. · 2.82 Impact Factor
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ABSTRACT: The attachment of specific ligands to the surfaces of nanoparticles is important for medical and biologic imaging. However, covalent modification of nanoparticles has inherent problems in reproducibility because of many factors such as temperature, pH, concentration, and reaction time. Thus, we developed a method for modifying nanoparticles by encapsulation with specific ligand-conjugated amphiphiles.
We synthesized special amphiphiles with a hydrophilic head and a long single-alkyl chain, such as arginine-glycine-aspartic acid-C(18), mannose-C(18), lactose-C(18), and 2-(p-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid-C(18). And then we produced stable quantum dots (QDs) encapsulated with polysorbate 60 (a branched polyethylene glycol head with a C(18) tail) and the synthesized special amphiphiles. The prepared encapsulated QDs were subject to in vitro and in vivo animal biodistribution studies and small-animal PET studies to confirm their specific binding.
The encapsulated QDs could specifically bind to target cells in vitro and in vivo and could be labeled with (68)Ga (a positron emitter) easily and with high efficiency.
The nanoparticles encapsulated with special amphiphiles could provide a straightforward and novel imaging solution with multimodality and multispecificity.
Journal of Nuclear Medicine 08/2012; 53(9):1462-70. · 6.38 Impact Factor
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ABSTRACT: Paragangliomas are extra-adrenal neuroendocrine tumors that are derived from neural crest cells. Among all the paragangliomas,
those in a pelvic location are extremely rare. In addition, the prevalence of nonfunctioning paragangliomas is underestimated
because of their clinical latency, and they are often underdiagnosed unless they cause symptoms. We report a case of a nonfunctioning
periurethral paraganglioma that was incidentally detected by FDG PET/CT during regular follow-up after excision of a melanoma
on the left thumb.
KeywordsNonfunctioning periurethral paraganglioma–Extra-adrenal pheochromocytoma–FDG PET/CT
04/2012; 45(2):145-148.
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ABSTRACT: PurposeWith the recent increase in incidence of thyroid cancer, non-hospitalized low-dose (NH-LD) radioiodine treatment (RIT) has
also increased rapidly. The radioactivity limit that is allowed to be administered without hospitalization depends on individual
calculation, based partly on patients’ behavior. In this study, Korean patients’ behavior in relation to radiation safety
in NHLD RIT was surveyed.
MethodsA total of 218 patients who underwent NH-LD RIT of 1.1GBq 131I in a single center were surveyed. The patients underwent RIT with a standard protocol and the survey was performed by interview
when they visited subsequently for a whole-body scan. The survey questionnaire included three parts of questions: general
information, behavior relating to isolation during RIT, and awareness of radiation safety.
ResultsAfter administration of radioiodine, 40% of patients who returned home used mass transportation, and another 47% went home
by taxi or in car driven by another person. Isolation at home was generally sufficient. However, 7% of patients did not stay
in a separate room. Among the 218 patients, 34% did not go home and chose self-isolation away from home, mostly due to concerns
about radiation safety of family members. However, the places were mostly public places, including hotels, resorts, and hospitals.
About half of the patients replied that access to radiation safety information was not easy and their awareness of radiation
safety was not satisfactory. As a result, 45% of patients wanted hospitalized RIT.
ConclusionsIn many countries, including Korea, RIT is continuously increasing. Considering the radiation safety of patients’ family members
or the public and the convenience of patients, the pretreatment education of patients should be enhanced. In addition, the
hospitalization of patients having low-dose therapy is recommended to be seriously considered and expanded, with the expansion
of dedicated treatment facilities.
KeywordsThyroid cancer-Radioiodine treatment-Behavior-Radiation safety-Hospitalization
04/2012; 44(4):267-272.
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ABSTRACT: PurposeA coincidence detector is an essential unit to acquire distribution of radioisotopes in positron emission tomography (PET)
systems. The coincidence pairs rapidly increase as the number of detector modules increase. To make this system compact, flexible,
and conveniently controllable, a field programmable gated array (FPGA)-based coincidence detector was developed.
MethodsThe unit targeted PET systems have eight detector modules. The coincidence detector module needs veto function for controlling
the data transfer rate of the output signal because the output is connected to the band-limited ADC and data transfer unit.
The coincidence detector module has eight inputs connected to the detector modules, one coincidence output signal connected
to the trigger input of the ADC, and three control signals for setting system parameters, such as the coincidence window time,
output pulse length, and veto time.
ResultsThe performance of the unit was restricted by system clock frequency. The maximum clock frequency was 250 MHz when the unit
was implemented to XILINX Spartan 3 FPGA. The unit had a minimum 2 ns of coincidence timing window when it runs in the double
data rate (DDR) mode. The unit was also applied to PET image acquisition and the PET/CT and PET/MR images were successfully
acquired.
ConclusionsThe coincidence unit developed in this study was useful for PET image acquisition with PMT- and SiPM-based PET prototypes.
The unit can be easily extended to larger systems that have many more detector modules without extra components.
KeywordsPET–FPGA–Coincidence–Acquisition
04/2012; 1(1):27-31.
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ABSTRACT: PurposeWe evaluated the short-term and mid-term differences in perfusion and function after off-pump and on-pump coronary artery
bypass grafting (CABG) using gated myocardial single photon emission computed tomography.
Materials and MethodsA total of 70 patients with coronary artery disease who underwent CABG were included based on the propensity score matching
results from 165 patients. Thirty-five patients underwent off-pump and 35 patients on-pump CABG. Rest 201Tl/dipyridamole stress 99mTc-methoxyisobutylisonitrile gated single photon emission computed tomographies were performed preoperatively and postoperatively
at short-term (103 ± 23days after surgery) and mid-term follow-up (502 ± 111days after surgery). Changes in left ventricular
ejection fraction, end systolic volume, stress and rest segmental perfusion, and segmental wall thickening were compared between
the two groups. The segments with preoperative rest 201Tl uptake under 60% of maximum uptake were included in the segmental analysis.
ResultsLeft ventricular ejection fraction (P = 0.001) and end systolic volume (P = 0.008) showed significant improvement in both groups. There were no significant short-term and mid-term differences between
the two groups in terms of left ventricular ejection fraction (P = 0.309) and end systolic volume (P = 0.938). Likewise, segmental rest (P = 0.178) and stress perfusion (P = 0.071), and systolic wall thickening (P = 0.241) showed significant improvement in both groups with similar time courses.
ConclusionOff-pump CABG resulted in significant improvements in left ventricular ejection fraction, end systolic volume, and regional
myocardial perfusion and function that are comparable to on-pump CABG at short-term and mid-term. Gated myocardial SPECT successfully
revealed that off-pump CABG is as good as on-pump CABG from the viewpoint of myocardial perfusion and function.
KeywordsGated myocardial single photon emission computed tomography-Off-pump coronary artery bypass grafting-Cardiopulmonary bypass-Coronary artery disease
04/2012; 44(2):110-115.
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ABSTRACT: PurposeThe purpose of this study was to investigate the role of 18F-fluorodeoxyglucose (FDG) PET in detecting high-grade meningioma and predicting the recurrence in patients with meningioma
after surgical resection.
MethodsFifty-nine patients (27 men and 32 women) with intracranial meningioma who underwent preoperative FDG PET and subsequent surgical
resection were enrolled. All patients underwent clinical follow-up for tumor recurrence with a mean duration of 34±20months.
The tumor to gray matter ratio (TGR) of FDG uptake was calculated and a receiver-operating characteristic (ROC) curve of the
TGR was drawn to determine the cutoff value of the TGR for detection of high-grade meningioma. Further, univariate analysis
with the log-rank test was performed to assess the predictive factors of meningioma recurrence.
ResultsThe TGR in high-grade meningioma (WHO grade II and III) was significantly higher than that in low-grade ones (WHO grade I)
(p=0.002) and significantly correlated with the MIB-1 labeling index (r=0.338, p=0.009) and mitotic count of the tumor (r=0.284, p=0.03). The ROC analysis revealed that the TGR of 1.0 was the best cutoff value for detecting high-grade meningioma with a
sensitivity of 43%, specificity of 95%, and accuracy of 81%. Of 59 patients, 5 (9%) had a recurrent event. In the log-rank
test, the TGR, MIB-1 labeling index, presence of brain invasion, and WHO grade were significantly associated with tumor recurrence.
The cumulative recurrence-free survival rate of patients with a TGR of 1.0 or less was significantly higher than that of patients
with a TGR of more than 1.0 (p=0.0003)
ConclusionFDG uptake in meningioma was the significant predictive factor of tumor recurrence and significantly correlated with the proliferative
potential of the tumor.
European journal of nuclear medicine and molecular imaging 04/2012; 36(10):1574-1582. · 4.99 Impact Factor
