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Naftalin CM, Leek F, Hallinan JTPD, Khor LK, Totman JJ, Wang J, Wang YT, Paton NI. Comparison of 68Ga-DOTANOC with 18F-FDG using PET/MRI imaging in patients with pulmonary tuberculosis. Sci Rep 2020; 10:14236. [PMID: 32859979 PMCID: PMC7455716 DOI: 10.1038/s41598-020-71127-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 08/05/2020] [Indexed: 11/18/2022] Open
Abstract
We compared the somatostatin analog radioligand, DOTANOC, with FDG, to determine whether there was increased detection of active or sub-clinical lesions in pulmonary tuberculosis (TB) with DOTANOC. Three groups were recruited: (1) active pulmonary TB; (2) IGRA-positive household TB contacts; (3) pneumonia (non-TB). DOTANOC PET/MRI followed by FDG PET/MRI was performed in active TB and pneumonia groups. TB contacts underwent FDG PET/MRI, then DOTANOC PET/MRI if abnormalities were detected. Quantitative and qualitative analyses were performed for total lung and individual lesions. Eight active TB participants, three TB contacts and three pneumonia patients had paired PET/MRI scans. In the active TB group, median SUVmax[FDG] for parenchymal lesions was 7.69 (range 3.00–15.88); median SUVmax[DOTANOC] was 2.59 (1.48–6.40). Regions of tracer uptake were fairly similar for both radioligands, albeit more diffusely distributed in the FDG scans. In TB contacts, two PET/MRIs had parenchymal lesions detected with FDG (SUVmax 5.50 and 1.82), with corresponding DOTANOC uptake < 1. FDG and DOTANOC uptake was similar in pneumonia patients (SUVmax[FDG] 4.17–6.18; SUVmax[DOTANOC] 2.92–4.78). DOTANOC can detect pulmonary TB lesions, but FDG is more sensitive for both active and sub-clinical lesions. FDG remains the preferred ligand for clinical studies, although DOTANOC may provide additional value for pathogenesis studies.
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Affiliation(s)
- Claire M Naftalin
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 10 Medical Drive, Singapore, 117597, Singapore
| | - Francesca Leek
- Clinical Imaging Research Centre, National University of Singapore, Singapore, Singapore
| | - James T P D Hallinan
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 10 Medical Drive, Singapore, 117597, Singapore.,Department of Diagnostic Imaging, National University Health System, Singapore, Singapore
| | - Lih Kin Khor
- Department of Diagnostic Imaging, National University Health System, Singapore, Singapore
| | - John J Totman
- Clinical Imaging Research Centre, National University of Singapore, Singapore, Singapore
| | - Jing Wang
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 10 Medical Drive, Singapore, 117597, Singapore
| | - Yee Tang Wang
- Tuberculosis Control Unit, Tan Tock Seng Hospital, Singapore, Singapore
| | - Nicholas I Paton
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, 10 Medical Drive, Singapore, 117597, Singapore. .,University Medicine Cluster, National University Health System, Singapore, Singapore.
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Ngam PI, Goh CXY, Ng DCE, Tan CJX, Osmany S, Tan AEH, Kannivelu A, Cheng LTJ, Khor LK, Tong AKT, Loke, KSH, Wong WY. COVID-19: Preparedness in Nuclear Medicine Departments in Singapore and
Response to The Global Pandemic. Ann Acad Med Singap 2020. [DOI: 10.47102/annals-acadmedsg.2020185] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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3
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Ngam PI, Goh CX, Ng DC, Tan CJ, Osmany S, Tan AE, Kannivelu A, Cheng LT, Khor LK, Tong AK, Loke KS, Wong WY. COVID-19: Preparedness in Nuclear Medicine Departments in Singapore and Response to The Global Pandemic. Ann Acad Med Singap 2020; 49:496-500. [PMID: 33000113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Affiliation(s)
- Pei Ing Ngam
- Department of Nuclear Medicine and Molecular Imaging, Singapore General Hospital, Singapore
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Molton JS, Thomas BA, Pang Y, Khor LK, Hallinan J, Naftalin CM, Totman JJ, Townsend DW, Lim TK, Chee CBE, Wang YT, Paton NI. Sub-clinical abnormalities detected by PET/MRI in household tuberculosis contacts. BMC Infect Dis 2019; 19:83. [PMID: 30678651 PMCID: PMC6346497 DOI: 10.1186/s12879-019-3705-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 01/10/2019] [Indexed: 11/21/2022] Open
Abstract
Background The understanding of early events following TB exposure is limited by traditional tests that rely on detection of an immune response to infection, which is delayed, or on imaging tests with low sensitivity for early disease. We investigated for evidence of lung abnormalities in heavily exposed TB contacts using PET/MRI. Methods 30 household contacts of 20 index patients underwent clinical assessment, IGRA testing, chest x-ray and PET/MRI scan using 18-F-FDG. MRI images were examined by a radiology/nuclear medicine dual-qualified physician using a standardised report form, while PET/MRI images were examined independently by another radiology/nuclear medicine dual-qualified physician using a similar form. Standardised uptake value (SUV) was quantified for each abnormal lesion. Results IGRA was positive in 40%. PET/MRI scan was abnormal in 30%, predominantly FDG uptake in hilar or mediastinal lymph nodes and lung apices. We did not identify any relationship between PET/MRI findings and degree of exposure or IGRA status. Conclusion PET-based imaging may provide important insights into the natural history following exposure to TB that may not be available from traditional tests of TB immune response or imaging. The clinical significance of the abnormalities is uncertain and merits further investigation in longitudinal studies.
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Affiliation(s)
- James S Molton
- University Medicine Cluster, National University Health System, Singapore, Singapore.,Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | | | - Yan Pang
- University Medicine Cluster, National University Health System, Singapore, Singapore
| | - Lih Kin Khor
- Department of Diagnostic Imaging, National University Health System, Singapore, Singapore
| | - James Hallinan
- Department of Diagnostic Imaging, National University Health System, Singapore, Singapore
| | - Claire M Naftalin
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - John J Totman
- A*STAR-NUS Clinical Imaging Research Centre, Singapore, Singapore
| | - David W Townsend
- A*STAR-NUS Clinical Imaging Research Centre, Singapore, Singapore
| | - Tow Keang Lim
- University Medicine Cluster, National University Health System, Singapore, Singapore.,Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | | | - Yee Tang Wang
- Tuberculosis Control Unit, Tan Tock Seng Hospital, Singapore, Singapore
| | - Nicholas I Paton
- University Medicine Cluster, National University Health System, Singapore, Singapore. .,Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
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Vellayappan B, Tan CL, Yong C, Khor LK, Koh WY, Yeo TT, Detsky J, Lo S, Sahgal A. Diagnosis and Management of Radiation Necrosis in Patients With Brain Metastases. Front Oncol 2018; 8:395. [PMID: 30324090 PMCID: PMC6172328 DOI: 10.3389/fonc.2018.00395] [Citation(s) in RCA: 116] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 08/31/2018] [Indexed: 12/25/2022] Open
Abstract
The use of radiotherapy, either in the form of stereotactic radiosurgery (SRS) or whole-brain radiotherapy (WBRT), remains the cornerstone for the treatment of brain metastases (BM). As the survival of patients with BM is being prolonged, due to improved systemic therapy (i.e., for better extra-cranial control) and increased use of SRS (i.e., for improved intra-cranial control), patients are clinically manifesting late effects of radiotherapy. One of these late effects is radiation necrosis (RN). Unfortunately, symptomatic RN is notoriously hard to diagnose and manage. The features of RN overlap considerably with tumor recurrence, and misdiagnosing RN as tumor recurrence may lead to deleterious treatment which may cause detrimental effects to the patient. In this review, we will explore the pathophysiology of RN, risk factors for its development, and the strategies to evaluate and manage RN.
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Affiliation(s)
- Balamurugan Vellayappan
- Department of Radiation Oncology, National University Cancer Institute, National University Health System, Singapore, Singapore
| | - Char Loo Tan
- Department of Pathology, National University Hospital, Singapore, Singapore
| | - Clement Yong
- Department of Diagnostic Imaging, National University Hospital, Singapore, Singapore
| | - Lih Kin Khor
- Nuclear Medicine, Advanced Medicine Imaging, Singapore Institute of Advanced Medicine Holdings, Singapore, Singapore
| | - Wee Yao Koh
- Department of Radiation Oncology, National University Cancer Institute, National University Health System, Singapore, Singapore
| | - Tseng Tsai Yeo
- Department of Neurosurgery, National University Hospital, Singapore, Singapore
| | - Jay Detsky
- Department of Radiation Oncology, Sunnybrook Health Sciences Center, University of Toronto, Toronto, ON, Canada
| | - Simon Lo
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, WA, United States
| | - Arjun Sahgal
- Department of Radiation Oncology, Sunnybrook Health Sciences Center, University of Toronto, Toronto, ON, Canada
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Chia JY, Loi HY, Khor LK, Joe Lee KC, Seow YH. Primary Lung Adenocarcinoma With 68Gallium Prostate-Specific Membrane Antigen-PET/CT Scan Avidity in a Patient on Surveillance After Prostatectomy. Clin Genitourin Cancer 2018; 16:e525-e527. [PMID: 29716834 DOI: 10.1016/j.clgc.2018.03.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 03/21/2018] [Indexed: 12/26/2022]
Affiliation(s)
- Jun Yang Chia
- Department of Urology, National University Hospital, National University Health System, Singapore.
| | - Hoi Yin Loi
- Department of Diagnostic Imaging, National University Hospital, National University Health System, Singapore
| | - Lih Kin Khor
- Department of Diagnostic Imaging, National University Hospital, National University Health System, Singapore
| | - King Chien Joe Lee
- Department of Urology, National University Hospital, National University Health System, Singapore
| | - Yi Heng Seow
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
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Roy S, Cheong DLH, Yan J, Totman JJ, Ng T, Khor LK, Goh J, Tham IWK. Serial FDG-PET/MR Imaging for Head and Neck Cancer Radiation Therapy: A Pilot Study. IEEE Trans Radiat Plasma Med Sci 2017. [DOI: 10.1109/tns.2016.2616884] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Zhang J, Khor LK, Sinha A, Loi HY. Candida pyelonephritis on 18F-fluorodeoxyglucose positron emission tomography/computed tomography. Int J Infect Dis 2016; 51:107-108. [DOI: 10.1016/j.ijid.2016.09.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 09/03/2016] [Accepted: 09/05/2016] [Indexed: 12/30/2022] Open
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Rodríguez LS, Thang SP, Li H, Khor LK, Tay YS, Myint KO, Tong AKT. A descriptive analysis of remnant activity during (90)Y resin microspheres radioembolization of hepatic tumors: technical factors and dosimetric implications. Ann Nucl Med 2015; 30:255-61. [PMID: 26692012 DOI: 10.1007/s12149-015-1052-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 12/08/2015] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Activity planning for (90)Y radioembolization aims to maximize the effect of the treatment while keeping toxicity acceptably low. Our aim was to describe the amount of residual activity in post-treatment v-vials and tubing and analyze the possible factors affecting it (total activity administered, number of split activity injection(s), previous treatments, administration artery and microcatheter size), as these may influence dosimetric planning and treatment. METHODS This was a retrospective review using case records of patients who received (90)Y-radioembolization for hepatic tumors at a single tertiary center. From August 2013 to September 2015, seventy-seven out of one hundred and fifty patients who received radioembolization with (90)Y resin microspheres due to inoperable Hepatocellular Carcinoma (HCC) or liver metastases were included. The rest were mainly excluded due to incomplete data sets. The number of split activities (injections) for the radioembolization could be: one single injection, two or three. The remnant activity in post-treatment v-vials and tubing were measured for every patient. The administration arteries evaluated were: proper hepatic artery (PHA), right hepatic artery (RHA), middle hepatic artery (MHA), left hepatic artery (LHA) and small caliber branch arteries. The sizes of the microcatheters (2.2 or 2.7 Fr) used to administer the dose were also evaluated. RESULTS In total, 77 out of 150 patients were included in the final analysis. There were 59 men of median age 64.0 years old. The total median dose loss was 0.10 GBq. The total dose loss increased 0.244 GBq [95 % CI = (0.169, 0.318)] when three split activities were given compared to single activity injection. Activity loss for each injection increased 0.0297 GBq [95 % CI = (0.0151, 0.0443)] for every 1.0 GBq increase of split activity injection. There were no significant statistical differences in the rest of patient characteristics. CONCLUSIONS There is significant loss of activity observed during radioembolization, which can have a major dosimetric impact. The total administered activity and the number of split injections during radioembolization are the main influencing factors. Further prospective studies as well as measures of clinical outcome are warranted.
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Affiliation(s)
- Lidia Sancho Rodríguez
- Department of Nuclear Medicine, Clínica Universidad de Navarra, Avenida Pio XII, 36, Pamplona, 31008, Navarra, Spain.
| | - Sue Ping Thang
- Department of Nuclear Medicine and PET, Singapore General Hospital, Outram Road, Singapore, 169608, Singapore
| | - HuiHua Li
- Division of Research, Singapore General Hospital, Outram Road, Singapore, 169608, Singapore
| | - Lih Kin Khor
- Department of Diagnostic Imaging, National University Hospital, Singapore, 5 Lower Kent Ridge Rd, Singapore, 119074, Singapore
| | - Young Soon Tay
- Department of Nuclear Medicine and PET, Singapore General Hospital, Outram Road, Singapore, 169608, Singapore
| | - Khin Ohnmar Myint
- Department of Nuclear Medicine and PET, Singapore General Hospital, Outram Road, Singapore, 169608, Singapore
| | - Aaron Kian Ti Tong
- Department of Nuclear Medicine and PET, Singapore General Hospital, Outram Road, Singapore, 169608, Singapore
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Khor LK, Loi HY, Sinha AK, Tong KT, Goh BC, Loh KS, Lu SJ. (68)Ga-DOTA-peptide: A novel molecular biomarker for nasopharyngeal carcinoma. Head Neck 2015; 38:E76-80. [PMID: 26275126 DOI: 10.1002/hed.24164] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2015] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Increased somatostatin receptor (SSTR) expression in patients with undifferentiated nasopharyngeal carcinoma (NPC) has been demonstrated with receptor autoradiography, (111) In-Octreotide scintigraphy, and (68) Ga-DOTA-TOC positron emission tomography (PET)/CT imaging. We sought to compare and correlate the uptake of fluorodeoxyglucose (FDG) and DOTA-NOC in undifferentiated NPC to ascertain the possible role of (68) Ga-DOTA-NOC PET/CT as a new imaging biomarker and to assess whether targeted peptide receptor radionuclide therapy is a feasible treatment option. METHODS After obtaining approval from our institutional review board, 4 patients with biopsy proven nonkeratinizing undifferentiated NPC who had just undergone routine staging/restaging (18) F-FDG PET/CT imaging were prospectively and consecutively recruited for (68) Ga-DOTA-NOC PET/CT imaging. Of these 4 patients, 3 were newly diagnosed with untreated NPC, whereas 1 patient was diagnosed with a case of recurrent NPC with previous treatment. These patients subsequently underwent (68) Ga-DOTA-NOC PET/CT within 10 days from the (18) F-FDG PET/CT to ensure lesion comparability. Tracer uptake in tumor lesions were assessed visually and semiquantitatively by measuring maximum standardized uptake values (SUVmax). RESULTS There were 12 FDG-avid lesions of which 7 showed avid uptake of DOTA-NOC greater than liver uptake, whereas 5 showed low uptake of DOTA-NOC less than liver uptake. Subset analysis of the FDG-avid lesions at the primary and recurrent sites showed that all the FDG-avid primary tumors in the nasopharynx showed avid uptake of DOTA-NOC. On the contrary, the case of recurrent NPC showed avid FDG uptake but low DOTA-NOC uptake. Subset analysis of the suspicious FDG-avid cervical lymph nodes showed that 50% of them demonstrated avid DOTA-NOC uptake greater than liver uptake, whereas the remaining demonstrated low-grade DOTA-NOC uptake less than liver uptake. The 2 subcentimeter cervical lymph nodes that showed low-grade uptake of FDG lower than mediastinal blood pool activity were deemed to be reactive/inflammatory and showed low-grade uptake of DOTA-NOC. CONCLUSION This study highlights the potential of (68) Ga-DOTA-peptide PET/CT as a new molecular biomarker for newly diagnosed undifferentiated NPC, and less so for recurrent NPC and metastatic nodes. This potentially opens up new diagnostic and therapeutic options in the management of undifferentiated NPC.
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Affiliation(s)
- Lih Kin Khor
- Department of Diagnostic Imaging, National University Hospital, Singapore
| | - Hoi Yin Loi
- Department of Diagnostic Imaging, National University Hospital, Singapore
| | - Arvind Kumar Sinha
- Department of Diagnostic Imaging, National University Hospital, Singapore
| | - Kian Ti Tong
- Department of Nuclear Medicine and PET, Singapore General Hospital, Singapore
| | - Boon Cher Goh
- Department of Hematology and Oncology, National University Hospital, Singapore
| | - Kwok Seng Loh
- Department of Otolaryngology, National University Hospital, Singapore
| | - Suat-Jin Lu
- Nuclear Medicine and PET Centre, Mount Elizabeth Hospital, Singapore
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Yan J, Chu-Shern JL, Loi HY, Khor LK, Sinha AK, Quek ST, Tham IWK, Townsend D. Impact of Image Reconstruction Settings on Texture Features in 18F-FDG PET. J Nucl Med 2015; 56:1667-73. [PMID: 26229145 DOI: 10.2967/jnumed.115.156927] [Citation(s) in RCA: 186] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 07/06/2015] [Indexed: 12/21/2022] Open
Abstract
UNLABELLED Evaluation of tumor heterogeneity based on texture parameters has recently attracted much interest in the PET imaging community. However, the impact of reconstruction settings on texture parameters is unclear, especially relating to time-of-flight and point-spread function modeling. Their effects on 55 texture features (TFs) and 6 features based on first-order statistics (FOS) were investigated. Standardized uptake value (SUV) measures were also evaluated as peak SUV (SUVpeak), maximum SUV, and mean SUV (SUVmean). METHODS This study retrospectively recruited 20 patients with lesions in the lung who underwent whole-body (18)F-FDG PET/CT. The coefficient of variation (COV) of each feature across different reconstructions was calculated. RESULTS SUVpeak, SUVmean, 18 TFs, and 1 FOS were the most robust (COV ≤ 5%) whereas skewness, cluster shade, and zone percentage were the least robust (COV > 20%) with respect to reconstruction algorithms using default settings. Heterogeneity parameters had different sensitivities to iteration number. Twenty-four parameters including SUVpeak and SUVmean exhibited variation with a COV less than 5%; 28 parameters, including maximum SUV, showed variation with a COV in the range of 5%-10%. In addition, skewness, cluster shade, and zone percentage were the most sensitive to iteration number. In terms of sensitivity to full width at half maximum (FWHM), 15 TFs and 1 FOS had the best performance with a COV less than 5%, whereas SUVpeak and SUVmean had a COV between 5% and 10%. Grid size had the largest impact on image features, which was demonstrated by only 11 features, including SUVpeak and SUVmean, having a COV less than 10%. CONCLUSION Different image features have different sensitivities to reconstruction settings. Iteration number and FWHM of the gaussian filter have a similar impact on the image features. Grid size has a larger impact on the features than iteration number and FWHM. The features that exhibited large variations such as skewness in FOS, cluster shade, and zone percentage should be used with caution. The entropy in FOS, difference entropy, inverse difference normalized, inverse difference moment normalized, low gray-level run emphasis, high gray-level run emphasis, and low gray-level zone emphasis are the most robust features.
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Affiliation(s)
- Jianhua Yan
- A*STAR-NUS, Clinical Imaging Research Center, Singapore
| | | | - Hoi Yin Loi
- Department of Diagnostic Radiology, National University Hospital, Singapore; and
| | - Lih Kin Khor
- Department of Diagnostic Radiology, National University Hospital, Singapore; and
| | - Arvind K Sinha
- Department of Diagnostic Radiology, National University Hospital, Singapore; and
| | - Swee Tian Quek
- Department of Diagnostic Radiology, National University Hospital, Singapore; and
| | - Ivan W K Tham
- A*STAR-NUS, Clinical Imaging Research Center, Singapore Department of Radiation Oncology, National University Cancer Institute, Singapore
| | - David Townsend
- A*STAR-NUS, Clinical Imaging Research Center, Singapore Department of Diagnostic Radiology, National University Hospital, Singapore; and
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Khor LK, Loi HY, Sinha AK, Lu SJ. Incidental possible diagnosis by 18F-fluorocholine PET/CT of Meckel's diverticulum and potential pitfalls. Hell J Nucl Med 2015; 18:157-9. [PMID: 26187217 DOI: 10.1967/s002449910212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 05/21/2015] [Indexed: 11/18/2022]
Abstract
UNLABELLED A 61 years old man with a history of prostate cancer Gleason 3+4, treated with radical prostatectomy, underwent fluorine-18-fluorocholine positron emission tomography/computed tomography ((18)F-FCH PET/CT) imaging to investigate rising serum prostate specific antigen (PSA) levels. (18)F-FCH PET/CT showed a focus of linear increased uptake by a possible Meckel's diverticulum in the right hemi-pelvis, which was an incidental finding in this asymptomatic patient. Uptake of (18)F-FCH by Meckel's diverticulum has not been reported before and thus the mechanism of uptake has not been established. Two postulations may explain this uptake. First, since Meckel's diverticulum is a true diverticulum containing all layers of the intestinal wall, the uptake may be related to physiological bowel-related uptake. Second, the uptake may be due to heterotopic pancreatic tissue in Meckel's diverticulum, especially since the intensity of uptake we have noticed was similar to that of physiological pancreatic uptake. As (18)F-FCH PET/CT scan is often used for evaluating prostate cancer, (18)F-FCH uptake by Meckel's diverticulum in the pelvis or lower abdomen may be mistaken for tumor involvement/recurrence. The identification by imaging of Meckel's diverticulum relies on the identification of a blind ending tubular structure, arising from the distal ileum. The identification of this structure may be best appreciated on the axial, coronal or sagittal plane. CONCLUSION In this particular case, we managed to clearly demonstrate the presence of a tubular blind ending structure arising from the distal ileum on the sagittal images. The careful identification of this structure indicated that tracer uptake was in a Meckel's diverticulum and not within a pelvic lymph node or pelvic organ hence excluding recurrent disease.
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Affiliation(s)
- Lih Kin Khor
- Department of Diagnostic Imaging, National University Health System, 5 Lower Kent Ridge Road, 119074, Singapore.
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Ng SJK, Sinha AK, Loi HY, Khor LK. Asymptomatic metastasis to cricoid from prostate carcinoma: an incidental finding detected on 18F-choline PET/CT. Jpn J Radiol 2015; 33:298-301. [DOI: 10.1007/s11604-015-0415-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2015] [Accepted: 03/18/2015] [Indexed: 10/23/2022]
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Khor LK, Loi HY, Sinha AK, Tong KT, Goh BC, Loh KS, Lu SJ. Correlation between 68Ga-DOTA-NOC PET/CT and 18F-FDG PET/CT in EBV-positive undifferentiated nasopharyngeal carcinoma. Eur J Nucl Med Mol Imaging 2015; 42:1162-3. [DOI: 10.1007/s00259-015-3012-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 01/29/2015] [Indexed: 11/24/2022]
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Jen WY, Chee YL, Khor LK, Nga ME, Poon L, De Mel S. Diffuse Intrasinusoidal Hepatic Metastasis From Occult Breast Carcinoma Presenting as Thrombotic Microangiopathy: A Case Report and Literature Review. J Hematol 2015. [DOI: 10.14740/jh230w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Khor LK, Wang S, Lu SJ. Anaplastic large cell lymphoma of the vertebra masquerading as tuberculous spondylitis: potential pitfalls of conventional imaging. Intern Emerg Med 2012; 7:573-7. [PMID: 23054413 DOI: 10.1007/s11739-012-0868-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 09/22/2012] [Indexed: 12/21/2022]
Affiliation(s)
- Lih Kin Khor
- Department of Diagnostic Imaging, National University Hospital, Singapore, Singapore.
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Khor CC, Vannberg FO, Chapman SJ, Walley A, Aucan C, Loke H, White NJ, Peto T, Khor LK, Kwiatkowski D, Day N, Scott A, Berkley JA, Marsh K, Peshu N, Maitland K, Williams TN, Hill AVS. Positive replication and linkage disequilibrium mapping of the chromosome 21q22.1 malaria susceptibility locus. Genes Immun 2007; 8:570-6. [PMID: 17703179 PMCID: PMC2850168 DOI: 10.1038/sj.gene.6364417] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Revised: 07/05/2007] [Accepted: 07/05/2007] [Indexed: 11/09/2022]
Abstract
Four cytokine receptor genes are located on Chr21q22.11, encoding the alpha and beta subunits of the interferon-alpha receptor (IFNAR1 and IFNAR2), the beta subunit of the interleukin 10 receptor (IL10RB) and the second subunit of the interferon-gamma receptor (IFNGR2). We previously reported that two variants in IFNAR1 were associated with susceptibility to malaria in Gambians. We now present an extensive fine-scale mapping of the associated region utilizing 45 additional genetic markers obtained from public databases and by sequencing a 44 kb region in and around the IFNAR1 gene in 24 Gambian children (12 cases/12 controls). Within the IFNAR1 gene, a newly studied C --> G single-nucleotide polymorphism (IFNAR1 272354c-g) at position -576 relative to the transcription start was found to be more strongly associated with susceptibility to severe malaria. Association was observed in three populations: in Gambian (P=0.002), Kenyan (P=0.022) and Vietnamese (P=0.005) case-control studies. When all three studies were combined, using the Mantel-Haenszel test, the presence of IFNAR1 -576G was associated with a substantially elevated risk of severe malaria (N=2444, OR=1.38, 95% CI: 1.17-1.64; P=1.7 x 10(-4)). This study builds on previous work to further highlight the importance of the type-I interferon pathway in malaria susceptibility and illustrates the utility of typing SNPs within regions of high linkage disequilibrium in multiple populations to confirm initial positive associations.
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Affiliation(s)
- C C Khor
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK.
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