Kyeong Min Kim

Korea Institute of Radiological & Medical Sciences, Sŏul, Seoul, South Korea

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Publications (75)162.81 Total impact

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    ABSTRACT: Two new bicyclic arginine-glycine-aspartic acid (RGD) peptides, c(RGD-ACP-K) (1a) and c(RGD-ACH-K) (1b), incorporating the aminocyclopentane (ACP) and aminocyclohexane (ACH) carboxylic acids, respectively, were synthesized by grafting the aminocycloalkane carboxylic acids onto the tetra-peptide RGDK sequence. These peptides and their conjugates with DO3A (1,4,7,10-tetraazacyclododecane-1,4,7-trisacetic acid) (2a-b) exhibit high affinity toward U87MG glioblastoma cells. Their affinity is greater than that exhibited by c(RGDyK). Labeling these conjugates with radiometal (64)Cu resulted in high radiochemical yields (>97%) of the corresponding complexes, abbreviated as c(RGD-ACP-K)-DOTA-(64)Cu (3a) and c(RGD-ACH-K)-DOTA-(64)Cu (3b). Both 3a and 3b are stable for 24 h in human and mouse serums and show high tumor uptake, as observed by positron emission tomography (PET). Blocking experiments with 3a and 3b by preinjection of c(RGDyK) confirmed their target specificity and demonstrated their promise as PET radiotracers for imaging ανβ3-positive tumors.
    ACS Medicinal Chemistry Letters 09/2014; 5(9):979-82. · 3.31 Impact Factor
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    ABSTRACT: Although statistical parametric mapping (SPM) analysis is widely used in neuroimaging studies, to our best knowledge, there was no application to myocardial PET data analysis. In this study, we developed the voxel based statistical analysis method for myocardial PET which provides statistical comparison results between groups in image space. PET Emission data of normal and myocardial infarction rats were acquired For the SPM analysis, a rat heart template was created. In addition, individual PET data was spatially normalized and smoothed. Two sample t-tests were performed to identify the myocardial infarct region. This developed SPM method was compared with conventional ROI methods.
    Journal of Instrumentation 09/2014; 9(09):P09005. · 1.66 Impact Factor
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    ABSTRACT: Purpose To compare the cerebral uptake and binding potential of [(18) F]FCWAY and [(18) F]Mefway in the rodent to assess their potential for imaging serotonin 1A (5-HT1A ) receptors. Materials and methods In vitro liver microsomal studies were performed to evaluate the degree of defluorination. Dynamic positron emission tomography (PET) studies were then conducted for 2 h with or without an anti-defluorination agent. The regions of interest were the hippocampus and frontal cortex (5-HT1A target regions) and the cerebellum (5-HT1A non-target region). The in vivo kinetics of the radioligands were compared based on the brain uptake values and target-to-non-target ratio. We also performed a comparison of binding potential (BPND ) as a steady-state binding parameter. Finally, binding affinities to 5-HT1A receptors were assessed in Chinese hamster ovary cells (CHO-K1) cells expressing human recombinant 5-HT1A receptors. Results The radiochemical yield of [(18) F]Mefway was slightly higher than that of [(18) F]FCWAY (19% vs. 15%). With regard to metabolic stability against defluorination, both compounds exhibited similar stability in rat liver microsomes, but [(18) F]Mefway displayed higher stability in the human microsome (defluorination ratio at 30 min: 32 vs. 29 in rat liver microsomes, 31 vs. 64 in human liver microsomes for [(18) F]Mefway and [(18) F]FCWAY, respectively). There were no significant differences in brain uptake, the target-to-non-target ratios, and the BPND (at hippocampus, peak brain uptakes: 6.9 vs. 8.5, target-to-non-target ratios: 6.9 vs. 8.5, BPND : 5.2 vs. 6.2 for [(18) F]Mefway and [(18) F]FCWAY). The binding affinity of [(18) F]Mefway was considerably higher than that of [(18) F]FCWAY (IC50 : 1.5 nM vs. 2.2 nM). Conclusion [(18) F]Mefway exhibits favorable characteristics compared to [(18) F]FCWAY in rodents, and may be a promising radioligand for use in human subjects. Synapse, 2014. © 2014 Wiley Periodicals, Inc.
    Synapse 07/2014; · 2.31 Impact Factor
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    ABSTRACT: The aim of this study was to investigate the potential of FDG PET/CT and MRI in predicting disease-free survival (DFS) after neoadjuvant chemotherapy (NAC) and surgery in patients with advanced breast cancer.
    European journal of nuclear medicine and molecular imaging 06/2014; · 5.11 Impact Factor
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    ABSTRACT: The Siemens Biograph TruePoint TrueV (B-TPTV) positron emission tomography (PET) scanner performs 3D PET reconstruction using a system matrix with point spread function (PSF) modeling (called the True X reconstruction). PET resolution was dramatically improved with the True X method. In this study, we assessed the spatial resolution and image quality on a B-TPTV PET scanner. In addition, we assessed the feasibility of animal imaging with a B-TPTV PET and compared it with a microPET R4 scanner. Spatial resolution was measured at center and at 8 cm offset from the center in transverse plane with warm background activity. True X, ordered subset expectation maximization (OSEM) without PSF modeling, and filtered back-projection (FBP) reconstruction methods were used. Percent contrast (% contrast) and percent background variability (% BV) were assessed according to NEMA NU2-2007. The recovery coefficient (RC), non-uniformity, spill-over ratio (SOR), and PET imaging of the Micro Deluxe Phantom were assessed to compare image quality of B-TPTV PET with that of the microPET R4. When True X reconstruction was used, spatial resolution was <3.65 mm with warm background activity. % contrast and % BV with True X reconstruction were higher than those with the OSEM reconstruction algorithm without PSF modeling. In addition, the RC with True X reconstruction was higher than that with the FBP method and the OSEM without PSF modeling method on the microPET R4. The non-uniformity with True X reconstruction was higher than that with FBP and OSEM without PSF modeling on microPET R4. SOR with True X reconstruction was better than that with FBP or OSEM without PSF modeling on the microPET R4. This study assessed the performance of the True X reconstruction. Spatial resolution with True X reconstruction was improved by 45 % and its % contrast was significantly improved compared to those with the conventional OSEM without PSF modeling reconstruction algorithm. The noise level was higher than that with the other reconstruction algorithm. Therefore, True X reconstruction should be used with caution when quantifying PET data.
    Annals of Nuclear Medicine 02/2014; · 1.41 Impact Factor
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    ABSTRACT: Positron emission tomography (PET) is widely used for diagnosis and follow up assessment of radiotherapy. However, thoracic and abdominal PET suffers from false staging and incorrect quantification of the radioactive uptake of lesion(s) due to respiratory motion. Furthermore, respiratory motion-induced mismatch between a computed tomography (CT) attenuation map and PET data often leads to significant artifacts in the reconstructed PET image. To solve these problems, we propose a unified framework for respiratory-matched attenuation correction and motion compensation of respiratory-gated PET. For the attenuation correction, the proposed algorithm manipulates a 4D CT image virtually generated from two low-dose inhale and exhale CT images, rather than a real 4D CT image which significantly increases the radiation burden on a patient. It also utilizes CT-driven motion fields for motion compensation. To realize the proposed algorithm, we propose an improved region-based approach for non-rigid registration between body CT images, and we suggest a selection scheme of 3D CT images that are respiratory-matched to each respiratory-gated sinogram. In this work, the proposed algorithm was evaluated qualitatively and quantitatively by using patient datasets including lung and/or liver lesion(s). Experimental results show that the method can provide much clearer organ boundaries and more accurate lesion information than existing algorithms by utilizing two low-dose CT images.
    Physics in Medicine and Biology 09/2013; 58(20):7355-7374. · 2.70 Impact Factor
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    ABSTRACT: The purpose of this study is to evaluate the availability of cone-beam computed tomography(CBCT) for gel dosimetry. The absorbed dose was analyzed by using intensity-modulated radiation therapy(IMRT) to irradiate several tumor shapes with a calculated dose and several tumor acquiring images with CBCT in order to verify the possibility of reading a dose on the polymer gel dosimeter by means of the CBCT image. The results were compared with those obtained using magnetic resonance imaging(MRI) and CT. The linear correlation coefficients at doses less than 10 Gy for the polymer gel dosimeter were 0.967, 0.933 and 0.985 for MRI, CT and CBCT, respectively. The dose profile was symmetric on the basis of the vertical axis in a circular shape, and the uniformity was 2.50% for the MRI and 8.73% for both the CT and the CBCT. In addition, the gradient in the MR image of the gel dosimeter irradiated in an H shape was 109.88 while the gradients of the CT and the CBCT were 71.95 and 14.62, respectively. Based on better image quality, the present study showed that CBCT dosimetry for IMRT could be restrictively performed using a normoxic polymethacrylic-acid gel dosimeter.
    Journal- Korean Physical Society 09/2013; 63(5):1083-1087. · 0.51 Impact Factor
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    ABSTRACT: Positron emission tomography (PET), using 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) as a radioactive tracer, is a useful technique for in vivo brain imaging. However, the anatomical and physiological features of the Harderian gland limit the use of FDG-PET imaging in the mouse brain. In PET studies, this gland shows strong FDG uptake, which in turn results in distorted PET images of the frontal brain region. The purpose of this study was to assess if a simple surgical procedure to remove the Harderian gland could eliminate its influence on FDG uptake, prior to PET imaging of mice brains. Measurement of FDG uptake in unilaterally adenectomized mice showed that the radioactive signal emitted from the intact Harderian gland makes the frontal brain region unclear. Spatial parametric measurement analysis demonstrated that the presence of the Harderian gland could prevent accurate assessment of brain PET imaging. Bilateral Harderian adenectomy efficiently eliminated unwanted radioactive signal spillover into the frontal brain region, beginning at postoperative day 10. Harderian adenectomy did not cause any post operative complications during the experimental period. These findings demonstrate the benefits of performing a Harderian adenectomy prior to PET imaging of mice brains.
    Journal of veterinary science (Suwŏn-si, Korea) 06/2013; · 0.89 Impact Factor
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    ABSTRACT: OBJECTIVE: The aim of this study was to measure the apparent diffusion coefficient (ADC) value at the region with the highest FDG uptake using sequential (18)F-FDG PET and MRI, and to correlate it with the histological grade of invasive ductal carcinoma (IDC) of the breast. METHODS: A retrospective study was conducted on 75 untreated patients with IDC. First, a PET/CT scan and subsequent breast MRI were done and the SUVmax of the each breast tumor was recorded. Then, a PET image and ADC map were co-registered. On the axial slice containing the pixel with SUVmax, we drew multiple circular ROIs within the tumor and measured the mean ADC value of each ROI. The average (ADC-mean) and minimum (ADC-min) of the mean ADC values for all ROIs within the tumor were calculated, respectively. Then, a circular ROI was placed at the corresponding location to the pixel with the highest SUV and the mean ADC value of the ROI was denoted as ADC-PET. We compared the averages of the ADC parameters and assessed the correlations among SUVmax and ADC parameters. ROC curve and logistic regression analyses were performed to assess the utility of ADC and SUVmax for detecting histological grade 3. RESULTS: ADC-min was significantly lower than the ADC-mean or ADC-PET. All of the ADC parameters showed a negative correlation with SUVmax. The area under the ROC curve for identifying histological grade 3 using ADC-PET, ADC-min, ADC-mean and SUVmax was 0.684, 0.660, 0.633 and 0.639, respectively. By multivariate analysis, ADC-PET was a significant, independent predictor of histological grade 3 (p = 0.004). CONCLUSIONS: We estimated the ADC value at the breast tumor region with the highest FDG uptake using sequential (18)F-FDG PET and MRI. This new ADC parameter distinguished high-grade IDC, supporting the feasibility of the combined PET-MRI system in patients with breast cancer.
    Annals of Nuclear Medicine 05/2013; · 1.41 Impact Factor
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    ABSTRACT: I has a complex decay scheme with high gamma energy and low positron abundance. In this study, comparative performance measurements of I were performed in terms of spatial resolution, sensitivity, and image quality. All measurements were performed using both 2D and 3D PET in both brain mode and whole body mode. The transverse and axial spatial resolutions at 1 cm were 5.56 and 6.07 mm for I, and were 4.58 and 4.77 mm and for F, respectively. Sensitivities were 0.5 kcps/MBq (2D) and 3.4 kcps/MBq (3D) for I, and 1.8 kcps/MBq (2D) and 9.8 kcps/MBq (3D) for F. The %contrast of 3D was higher than that of 2D in I. For I PET imaging, 3D acquisition with brain mode was highest achievable imaging acquisition mode with finer spatial res-olution and higher contrast. This result will be useful for I PET imaging Index Terms—Image quality, reconstruction algorithms, spatial resolution, whole-body PET.
    IEEE Transactions on Nuclear Science 04/2013; 60(2):797-801. · 1.22 Impact Factor
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    A. Ram Yu, Jin Su Kim, Kyeong Min Kim, Hee Joung Kim
    IEEE Transactions on Nuclear Science 04/2013; 60(2):817-819. · 1.22 Impact Factor
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    ABSTRACT: Attenuation correction (AC) and scatter correction (SC) are problematic issues for animal positron emission tomography (PET). In this study, the effects of AC and SC were assessed using PET on a phantom and actual rat brain. Transmission (TX) was performed using 57Co for 15 min. After a 15 min TX scan, emission (EM) PET was performed in list mode for 1 h. To assess the effects of AC and SC, the spillover ratio (SOR) was measured using a rat-sized NEMA NU4 image-quality phantom; statistical parametric mapping (SPM) was performed to assess the effects of AC and SC in the rat brain using 18F-FDG (FDG). In addition, the binding potential (BP) was compared for 18F-FP-CIT (FP-CIT) PET. SPM was used to compare PET images to which AC and SC were applied, and BP was used for FP-CIT PET. The SORs of air and water decreased after AC and SC. SPM for FDG PET after AC showed a significant increase in FDG-measured activity in the cerebellum and occipital cortex. After AC/SC, a significant decrease in FDG-measured activity was observed in the frontal and temporal cortices. For FP-CIT PET of the rat brain, the BP decreased by 26% after AC because the FP-CIT uptake increased more in the cerebellum than in the striatum owing to AC. After AC and SC, the mean BP increased by 61%. AC and AC/SC were found to be necessary components of the artifact correction process for both FDG PET and FP-CIT PET of rat brains.
    IEEE Transactions on Nuclear Science 04/2013; 60(2):751-757. · 1.22 Impact Factor
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    IEEE Transactions on Nuclear Science 04/2013; 60(2):820-823. · 1.22 Impact Factor
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    ABSTRACT: Aims: It was the aim of this paper to identify prognostic factors in patients with relapsed or refractory B-cell non-Hodgkin's lymphomas, treated by radioimmunotherapy (RIT) with radioiodinated human/murine chimeric anti-CD20 monoclonal antibody rituximab ((131)I-rituximab). Methods: Twenty-four patients were enrolled prospectively and were treated with unlabeled rituximab 70 mg and a therapeutic activity (median 7.3 GBq) of (131)I-rituximab. Contrast-enhanced (18)F-FDG PET/CT scans were performed before and after 1 month of RIT. Tumor sizes and maximum standardized uptake values (SUVmax) of scans were measured. Results: Four of the 24 patients survived. High SUVmax in a pretreatment scan was found to be related to poorer overall survival (OS) and progression-free survival (p = 0.04 and 0.02, respectively). Furthermore, a large tumor size in a pretreatment scan was associated with poorer OS but not with progression-free survival (p < 0.01 and p = 0.07, respectively). By multivariate analyses, a high SUVmax, a large tumor size in a pretreatment scan and diffuse large B-cell lymphoma histology were significantly associated with poorer OS [p = 0.04/hazard ratio (HR) = 3.54, p < 0.01/HR = 5.52, and p = 0.02/HR = 3.38, respectively). Conclusion: SUVmax and tumor size determined by a pretreatment (18)F-FDG PET/CT result as significant predictors of OS in patients with relapsed or refractory B-cell non-Hodgkin's lymphoma treated by RIT.
    Acta Haematologica 03/2013; 130(2):74-82. · 0.89 Impact Factor
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    ABSTRACT: The work describes the synthesis and in vivo application of [Gd(L)(H2O)]·xH2O, where L is a ((125)I/(127)I-RGD)- DOTA conjugate, as a tumor-targeting SPECT/MR bimodal imaging probe. Here, ((125)I/(127)I-RGD)-DOTA signifies a "cocktail mixture" of radioisotopic (1a, L = (125)I-RGD-DOTA) and natural (1b, L = (127)I-RGD-DOTA) Gd complexes. The two complexes are chemically equivalent as revealed by HPLC, and their cocktail mixture exhibits the integrin-specific tumor enhancement, demonstrating that they constitute essentially a single bimodal imaging probe. Employment of a cocktail mixture thus proves to be a sole and practical approach to overcome the sensitivity difference problem between MRI and SPECT.
    ACS Medicinal Chemistry Letters 02/2013; 4(2):216-9. · 3.31 Impact Factor
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    ABSTRACT: Positron emission tomography (PET) images suffer from low spatial resolution. To improve the spatial resolution, we previously proposed a sinogram-based super-resolution (SR) algorithm for a whole-body PET scanner, by assuming space invariant blur. However, since the spatial resolution of a sinogram varies along the radial direction due to parallax error, this algorithm is not appropriate for providing a high-resolution sinogram with reduction of parallax error. In this paper, we propose a novel and efficient sinogram-based SR algorithm that is suitable even for a small animal PET scanner by using space variant blur matrices. In the algorithm, we estimate the space variant blur matrices through a Monte Carlo simulation and use them for the SR process to obtain a high-resolution sinogram. Using a Derenzo phantom and a line source, we demonstrate in a real PET scanner, microPET R4, that the proposed SR algorithm noticeably improves the spatial resolution while alleviating its space variance. By applying the proposed SR algorithm, the full width at half-maximum (FWHM) value reaches 1.2 mm at the system center and 1.63 mm with a considerable parallax error reduction at a radial position of 4 cm.
    IEEE Transactions on Nuclear Science 02/2013; 60(1):158-165. · 1.22 Impact Factor
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    ABSTRACT: PURPOSE: A single treatment of (131)I-rituximab in patients with B cell non-Hodgkin lymphoma (NHL) showed a modest rate of response (29 %) in a relatively short duration (median 2.9 months). On the basis of this result, we investigated whether repeated treatment with (131)I-rituximab could improve the response. PATIENTS AND METHODS: Thirty-one patients with relapsed or refractory B cell NHL received unlabeled rituximab (70 mg) immediately prior to the administration of a therapeutic dose of (131)I-rituximab. The tumor response was evaluated 1 month later by contrast-enhanced (18)F-fluorodeoxyglucose positron emission tomography/computed tomography. Radioimmunotherapy (RIT) was repeated at 4-week intervals. RESULTS: A total of 87 cycles of RIT were administered. Repeated RIT yielded twofold increases in response rate (68 %) and in median response duration (8.6 months). This protocol also induced a favorable response in patients with an aggressive histology compared to that induced by a single treatment (50 vs. 9 %, respectively, p = 0.063). The toxicities were principally hematologic with grade 4 thrombocytopenia occurring in 12 % and neutropenia occurring in 17 % of the 85 assessable cycles. CONCLUSIONS: Compared to a single treatment, repeated RIT with (131)I-rituximab increased the response rate and duration for patients with relapsed or refractory B cell NHL, including those with an aggressive histology.
    Cancer Chemotherapy and Pharmacology 01/2013; · 2.80 Impact Factor
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    ABSTRACT: Postinjection transmission positron emission tomography (PET) may be useful for shortening the total scan time. In this study, the effect of post-transmission scanning was assessed using PET on a phantom (NU4) and actual rat brain. Transmission was performed using (57)Co for 15 min. After a 15-min pre-transmission scan, emission PET was performed in list mode for 1 h, followed by an additional 15-min post-transmission scan. To compare the pre-transmission and post-transmission results, we measured nonuniformity, the recovery coefficient, and the spillover ratio (SOR) using NU4 and rat phantoms. The authors also assessed cerebral glucose metabolism using (18)F-fluorodeoxyglucose (FDG) PET and the binding potential for (18)F-fluorinated N-3-fluoropropyl-2-β-carboxymethoxy-3-β-(4-iodophenyl)nortropane (FP-CIT) in rat brain for differences between pre-transmission and post-transmission scanning. Nonuniformity and the SORs for air and water were comparable on the pre-transmission and post-transmission scans. With FDG-PET, after attenuation and scatter corrections no differences were observed in the brain regions on the pre-transmission and post-transmission scans. With FP-CIT-PET, the binding potentials were also not significantly different. In the present study, we validated a post-transmission method for PET of the rat brain. Post-transmission PET was reliable, and the results were comparable to those of pre-transmission PET. Post-transmission PET eliminates the early tracer uptake time in the PET imaging, making it possible to determine uptake in the conscious subject, which may provide more realistic, "normal" metabolic measurements. Thus, post-transmission PET may be a useful option for increasing the number of subjects who can be evaluated.
    Medical Physics 09/2012; 39(9):5614-20. · 2.91 Impact Factor
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    ABSTRACT: Introduction: [(18) F]MeFWAY has been developed for imaging the serotonin 1A receptors in the brain. The purpose of this study were to verify the metabolic stability of [(18) F]MeFWAY, to measure the degree of defluorination of [(18) F]MeFWAY in vivo, to investigate methods of inhibition of defluorination of [(18) F]MeFWAY, and to assess the efficacy of [(18) F]MeFWAY in rat brains in vivo. Methods: MicroPET experiments in rats were conducted to confirm the distribution of radioactivity in the brain. Nondisplaceable binding potential (BP(ND) ) in the hippocampus and frontal cortex were also analyzed. Miconazole and fluconazole were tested for the ability to suppress defluorination of [(18) F]MeFWAY. We conducted a blockade and displacement experiment by treating with WAY-100635. Results: In vitro stability tests showed that MeFWAY was very stable in serum for 6 h, but PET revealed that authentic [(18) F]MeFWAY underwent significant defluorination in vivo. In vitro inhibition study against decreasing parent activity in liver microsomes, miconazole and fluconazole suppressed metabolic elimination of MeFWAY. However, in the PET study, fluconazole showed more potent inhibitory activity than miconazole. In the suppression of metabolizing enzymes using fluconazole, radioactivity in skull was dramatically decreased by 81% (compared with 69% with miconazole) and it was coupled with an increase in brain uptake. Moreover, BP(ND) in hippocampus was 5.53 and 2.66 in frontal cortex. The blockade and displacement study showed the specificity of [(18) F]MeFWAY to 5-HT(1A) receptors. Conclusion: In the rat brain, [(18) F]MeFWAY microPET showed skull uptake due to defluorination in vivo. We can effectively overcome this drawback with fluconazole. Synapse, 2012. © 2012 Wiley Periodicals, Inc.
    Synapse 08/2012; 66(12):1015-23. · 2.31 Impact Factor
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    ABSTRACT: The work describes the synthesis and in vivo application of heterotrimetallic complexes of the type {Gd(H2O)[(M(H2O)(CO)3)2(1)]} {1 = DTPA-bis(histidyl-amide); M = Re (3a); (99m)Tc (3b)} for dual modality MR/SPECT imaging. Here, the DTPA-bis(histidylamide) conjugate functions as a trinucleating chelate incorporating Gd in the DTPA core with Re or (99m)Tc in the pair of histidylamide side arms. The two complexes are chemically equivalent as revealed by HPLC, and their "cocktail mixture" (3a + 3b) has demonstrated itself to be essentially a single bimodal imaging probe. The present system has thus overcome the sensitivity difference problem between MRI and SPECT and paved the way for practical applications.
    ACS Medicinal Chemistry Letters 04/2012; 3(4):299-302. · 3.31 Impact Factor

Publication Stats

384 Citations
162.81 Total Impact Points

Institutions

  • 2006–2014
    • Korea Institute of Radiological & Medical Sciences
      Sŏul, Seoul, South Korea
  • 2013
    • National Cancer Center Korea
      Kōyō, Gyeonggi Province, South Korea
  • 2008
    • National Institute of Radiological Sciences
      • Molecular Imagining Center
      Chiba-shi, Chiba-ken, Japan
  • 2001–2008
    • National Cerebral and Cardiovascular Center
      • Department of Cardiovascular Medicine
      Ōsaka, Ōsaka, Japan
  • 2004
    • Yale University
      • Department of Psychiatry
      New Haven, CT, United States
    • Konkuk University
      Sŏul, Seoul, South Korea
  • 2002
    • Kyoto University
      • Department of Systems Science
      Kyoto, Kyoto-fu, Japan
  • 1998
    • Seoul National University
      • Department of Nuclear Medicine
      Seoul, Seoul, South Korea