Objective:To investigate the prognostic value of radiomics features based on ^(18)F-FDG PET/CT imaging for advanced non-small cell lung cancer(NSCLC)treated with chemotherapy.Methods:A sample of 146 NSCLC patients sta...Objective:To investigate the prognostic value of radiomics features based on ^(18)F-FDG PET/CT imaging for advanced non-small cell lung cancer(NSCLC)treated with chemotherapy.Methods:A sample of 146 NSCLC patients stagedⅢor stageⅣwere included in this retrospective study who received ^(18)F-FDG PET/CT before treatment.All patients were treated with standardized chemotherapy after PET/CT examination and were divided into training group and validation group in an 8:2 ratio randomly.Radiomics features were extracted.In the training group,the minimum absolute contraction and selection operator(LASSO)algorithm and Cox risk proportional regression model were used to screen radiomics and clinical prognostic factors of progression-free survival(PFS).The radiomic model,clinical model and complex model were established respectively.The corresponding scores were calculated,then verified in the validation group.Results:The LASSO algorithm finally screened four radiomics features.ROC results showed that in the training group,the AUC of PFS predicted by the radiomics model was 0.746,and that in the verification group was 0.622.COX multivariate analysis finally included three clinical features related to PFS in NSCLC patients,namely pathological type,clinical stage and MTV30.The AUC for predicting PFS by clinical model,radiomics model and composite model were 0.746,0.753 and 0.716,respectively.The radiomics model had the highest diagnostic efficacy,and its sensitivity and specificity were 0.663 and 0.833,respectively.Delong test verified that there was no statistical difference in the predictive efficacy between the radiomics model and the composite model(Z=1.777,P=0.076)and the clinical imaging model(Z=0.323,P=0.747).Conclusion:The radiomics model based on PET/CT has a good predictive value for the prognosis of advanced NSCLC treated with chemotherapy,but it needs further validation before it can be widely used in clinical practice.展开更多
Background: The PET/CT imaging studies have two doses components the dose from the PET radiopharmaceutical and the other from the low dose CT used for PET images attenuation correction. We have one PET/CT scanner at o...Background: The PET/CT imaging studies have two doses components the dose from the PET radiopharmaceutical and the other from the low dose CT used for PET images attenuation correction. We have one PET/CT scanner at our institution a Philips Time of Flight scanner. Our local patient’s radiation protection rules requires continuous assessment of radiation doses delivered to our patients. Purposes: The objectives of this study are to develop a weight- based facility DRLs for paediatric F-18-FDG PET-CT imaging for oncology in a large tertiary hospital and to determine whether the calculated DRLs compares with internationally published DRLs. Materials & Methods: Radiation dose data and patient demographics of two-hundreds and sixteen paediatric PET-CT oncology patients imaging procedures from one large tertiary hospital were selected and analysed in order to establish a facility paediatric DRLs. Statistical analysis was performed. Results: The PET dose reference levels ranged between [62 - 525] MBq of injected activity for a range of pediatric age groups. The CTDI<sub>vol</sub> values were between 3.5 and 16.5 mGy for all age groups. Comparison with current EANM and SNMMI recommendations of patient’s dose are discussed. Conclusion: Our pediatric PET/CT reference levels are higher than the ones reported internationally with notable variations. .展开更多
Bladder tumor is the most common malignant tumor in urinary system and always com- panied with lymph node metastasis. The accurate staging plays a significant role in treatment for bladder tumor and prognostic evaluat...Bladder tumor is the most common malignant tumor in urinary system and always com- panied with lymph node metastasis. The accurate staging plays a significant role in treatment for bladder tumor and prognostic evaluation, and the distant metastasis predicts worse prognosis. The objective of this study was to assess the clinical significance of 18F-FDG PET/CT imaging in diagnosing bladder tumor metastasis lesions. A retrospective analysis of 60 patients with bladder tumor from October 2008 to May 2010 was done. The patients were stratified based on the imaging technique. Among all 60 cases, besides the primary lesion, 81 suspected lesions were spotted and 73 confirmed as metastasis, including 50 lymph node metastases, 22 distant metastases, and 1 bone metastasis. For PET/CT imaging, its sensitivity was 94.5%, specificity 87.5%, positive predictive value 98.6%, negative predictive value 63.6% and accuracy 93.8% respectively. For CT, its sensitivity was 82.2%, specificity 50%, positive predictive value 93.8%, negative predictive value 23.5% and accuracy 79% respectively. PET/CT im- aging was superior to CT in sensitivity, specificity and accuracy. In conclusion, 18F-FDG PET/CT imaging is more significant in diagnosing bladder tumor metastasis lesions.展开更多
The present study explored the 18-kDa translocator protein radioligand ^(18)F-PBR06 as a PET imaging biomarker for diagnosis of inflammation and compared it with ^(18)F-FDG for differentiation of inflammation and lung...The present study explored the 18-kDa translocator protein radioligand ^(18)F-PBR06 as a PET imaging biomarker for diagnosis of inflammation and compared it with ^(18)F-FDG for differentiation of inflammation and lung tumors in animals.^(18)F-PBR06 was synthesized with an average decay-corrected radiochemical yield of 30–40%(end of synthesis, EOS), and the radiochemical purity was greater than 99%. The inflammation-to-blood ratio of ^(18)FPBR06(3.53 ± 0.26) was higher than the tumor-to-blood ratio(1.77 ± 0.35)(P \ 0.001). The inflammation-tomuscle ratio of ^(18)F-PBR06(2.33 ± 0.64) was also higher than the tumor-to-muscle ratio(1.45 ± 0.14)(P = 0.036).Micro-PET/CT images showed high uptake of ^(18)F-FDG in both inflamed muscles and lung tumor tissues. However,^(18)F-PBR06 uptake in inflamed muscles remained higher than that in the lung tumor tissues, following 90 min of dynamic Micro-PET/CT imaging. Further, macrophages in the inflammatory regions showed a higher fluorescence signal than in lung tumor tissues. Results of the study confirmed that ^(18)F-PBR06 PET/CT imaging allowed for diagnosis of inflammation. Moreover,^(18)F-PBR06 uptake in the inflammatory regions was significantly higher than in lung tumor tissues, suggesting that ^(18)F-PBR06 PET/CT imaging has potential to differentiate between peripheral lung cancer and inflammation nodules.展开更多
The accuracy of attenuation correction in positron emission tomography scanners depends mainly on deriving the reliable 511-keV linear attenuation coefficient distribution in the scanned objects. In the PET/CT system,...The accuracy of attenuation correction in positron emission tomography scanners depends mainly on deriving the reliable 511-keV linear attenuation coefficient distribution in the scanned objects. In the PET/CT system, the linear attenu- ation distribution is usually obtained from the intensities of the CT image. However, the intensities of the CT image relate to the attenuation of photons in an energy range of 40 keV-140 keV. Before implementing PET attenuation correction, the intensities of CT images must be transformed into the PET 511-keV linear attenuation coefficients. However, the CT scan parameters can affect the effective energy of CT X-ray photons and thus affect the intensities of the CT image. Therefore, for PET/CT attenuation correction, it is crucial to determine the conversion curve with a given set of CT scan parameters and convert the CT image into a PET linear attenuation coefficient distribution. A generalized method is proposed for con- verting a CT image into a PET linear attenuation coefficient distribution. Instead of some parameter-dependent phantom calibration experiments, the conversion curve is calculated directly by employing the consistency conditions to yield the most consistent attenuation map with the measured PET data. The method is evaluated with phantom experiments and small animal experiments. In phantom studies, the estimated conversion curve fits the true attenuation coefficients accurately, and accurate PET attenuation maps are obtained by the estimated conversion curves and provide nearly the same correction results as the true attenuation map. In small animal studies, a more complicated attenuation distribution of the mouse is obtained successfully to remove the attenuation artifact and improve the PET image contrast efficiently.展开更多
Lung cancer presents a high prevalence around the world and constitutes the leading cause of death due to cancer in men and women. Proper staging is essential in order to provide the correct treatment and estimate sur...Lung cancer presents a high prevalence around the world and constitutes the leading cause of death due to cancer in men and women. Proper staging is essential in order to provide the correct treatment and estimate survival. PET/CT imaging is the method of choice for the staging of lung cancer patients with a better performance than the traditional imaging methods. It allows defining the primary tumor more clearly, separating it from the atelectasis and neighboring fibrotic changes, thus achieving an improved T evaluation while optimizing the target definition for radiotherapy. It presents greater sensibility and specificity than Computed Tomography (CT) when assessing the extra-thoracic and thoracic lymph nodes, modifying the N stage with regard to the traditional study in up to 25% of patients. PET/CT imaging is the method with the best performance for detecting extra-encephalic metastasis and for detecting unexpected lesions in up to 30% of patients. In order to achieve proper encephalic staging, a Magnetic Resonance Imaging scan must be performed or, a CT scan of the brain concomitant to the PET/CT. One to eight percent of lung cancer patients who are subjected to PET/CT imaging present a synchronous secondary extra pulmonary or pulmonary cancer when being diagnosed, with significant prognostic and therapeutic implications. PET/CT imaging has proven to be a valuable tool for survival prognosis with regard to the initial uptake of the tumor and the early response (interim) or final response to chemotherapy, although it is not routinely used for evaluating therapy. The PET/MRI is an emerging hybrid technique with certain advantages, such as less exposure to radiation in comparison to PET/CT and greater contrast resolution of the MRI images. However, its usefulness has not been validated yet for lung cancer patients.展开更多
A seventy eight years old male patient underwent a whole body 18F- FDG PET/CT imaging to diagnose the lesion which was showed in the right lung by a chest X ray test and CT scan before. Besides the intense 18F- FDG up...A seventy eight years old male patient underwent a whole body 18F- FDG PET/CT imaging to diagnose the lesion which was showed in the right lung by a chest X ray test and CT scan before. Besides the intense 18F- FDG uptake of the lesion in the right lung, a lesion in the left parotid gland also showed intense 18F- FDG uptake. To evaluate the pathology of the lesion in the left parotid gland, a parotid gland scintigraphy imaging with Tc-99m pertechnetate was done and revealed a Warthin's tumor. Later a fine needle aspiration(FNA) confirmed that it was a Warthin's tumor.展开更多
Background: To evaluate whether current dose reduction strategies for the CT component of hybrid Positron Emission Tomography—Computed Tomography (PET/CT) systems could reduce patient dose with maintaining adequate i...Background: To evaluate whether current dose reduction strategies for the CT component of hybrid Positron Emission Tomography—Computed Tomography (PET/CT) systems could reduce patient dose with maintaining adequate image quality for PET/CT studies. Materials and Methods: Literature survey was initially based on the selection of keywords and years of publication to identify potentially relevant articles, then the further search was conducted on the authors and references from these articles. The abstract of each article was first appraised to decide whether the content was relevant to this research question. The articles were classified into five groups: studies on dosimetry, studies on radiation-induced diseases, studies on dose reduction methods for CT-based attenuation correction (CTAC), studies on dose reduction methods for CT localization, and studies on reducing the need for a full-dose diagnostic CT in PET/CT imaging. 58 peer-reviewed articles were selected and appraised and 29 articles were used to compose this literature review. Results: The published nuclear medicine and medical physics literature were reviewed. CT dose contributed 47% - 81% of the total effective dose of a standard PET/CT study and was associated with radiation-induced diseases. The dose reduction techniques were extracted and divided into three categories: reducing the CT dose for attenuation correction (AC) and localization, selectively localizing CT use, and reducing the need for a full-dose diagnostic CT. Conclusion: Three strategies have been demonstrated, with high potential for reducing patient dose while maintaining an adequate CT image quality, used for CTCA localization and diagnosis, respectively.展开更多
Paraneoplastic neurological syndromes(PNS) is a series of rare neurologic disorders which happen with an underlying malignancy. It has various clinical symptoms proceding to the diagnosis of tumors. Although the abnor...Paraneoplastic neurological syndromes(PNS) is a series of rare neurologic disorders which happen with an underlying malignancy. It has various clinical symptoms proceding to the diagnosis of tumors. Although the abnormality of anti-neuronal antibodies is suggestive of PNS and tumors, there exist many false positive and false negative cases. The diagnosis of PNS is usually a challenge in clinic. Positron emission tomography/computed tomography(PET/CT) imaging is an anatomical and functional fusion imaging method, which provides the whole-body information by single scan. Fluorodeoxyglucose(FDG) PET/CT imaging can not only detect potential malignant lesions in the whole body, but also assess functional abnormality in the brain. In this review, the mechanism, clinical manifestation, diagnostic procedure and the recent progress of the utility of FDG PET/CT in PNS are introduced respectively.展开更多
This study was to explore the optimal threshold of thyroid-stimulating hormone(TSH)-stimulated serum thyroglobulin(s-Tg) for patients who were to receive18F-fluorodeoxyglucose(18F-FDG) PET/CT scan owing to clinical su...This study was to explore the optimal threshold of thyroid-stimulating hormone(TSH)-stimulated serum thyroglobulin(s-Tg) for patients who were to receive18F-fluorodeoxyglucose(18F-FDG) PET/CT scan owing to clinical suspicion of differentiated thyroid cancer(DTC) recurrence but negative post-therapeutic 131I whole-body scan(131I-WBS). A total of 60 qualified patients underwent PET/CT scanning from October 2010 to July 2014. The receiver operating characteristic(ROC) curve analyses showed that s-Tg levels over 49 μg/L led to the highest diagnostic accuracy of PET/CT to detect recurrence, with a sensitivity of 89.5% and a specificity of 90.9%. Besides, bivariate correlation analysis showed positive correlation between s-Tg levels and the maximum standardized uptake values(SUVmax) of18F-FDG in patients with positive PET/CT scanning, suggesting a significant influence of TSH both on Tg release and uptake of18F-FDG. So, positive PET/CT imaging is expected when patients have negative 131I-WBS but s-Tg levels over 49 μg/L.展开更多
Globally,carcinoma of lung is the predominant cause of cancer death among both men and women.While hematogenous spread from primary lung cancer to multiple other organs is frequently reported,metastases of malignant t...Globally,carcinoma of lung is the predominant cause of cancer death among both men and women.While hematogenous spread from primary lung cancer to multiple other organs is frequently reported,metastases of malignant tumors to diaphragm and spleen are rare.Nowadays,Positron emission tomography(PET)with 18 F-fluorodeoxyglucose(FDG)has emerged in such a way that it has become an effective imaging technology for the evaluation of different carcinomas,particularly for cancer staging and follow up after therapy.PET scan is able to provide metabolic information.In this case,we present an attractive unified PET/CT scan image in a patient with lung carcinoma having unusual diaphragm and splenic metastases.So,PET/CT imaging could strongly identified rare and unusual metastatic sites of cancer and added more appropriate staging in patient with carcinoma of lung.展开更多
In the current landscape of the COVID-19 pandemic,the utilization of deep learning in medical imaging,especially in chest computed tomography(CT)scan analysis for virus detection,has become increasingly significant.De...In the current landscape of the COVID-19 pandemic,the utilization of deep learning in medical imaging,especially in chest computed tomography(CT)scan analysis for virus detection,has become increasingly significant.Despite its potential,deep learning’s“black box”nature has been a major impediment to its broader acceptance in clinical environments,where transparency in decision-making is imperative.To bridge this gap,our research integrates Explainable AI(XAI)techniques,specifically the Local Interpretable Model-Agnostic Explanations(LIME)method,with advanced deep learning models.This integration forms a sophisticated and transparent framework for COVID-19 identification,enhancing the capability of standard Convolutional Neural Network(CNN)models through transfer learning and data augmentation.Our approach leverages the refined DenseNet201 architecture for superior feature extraction and employs data augmentation strategies to foster robust model generalization.The pivotal element of our methodology is the use of LIME,which demystifies the AI decision-making process,providing clinicians with clear,interpretable insights into the AI’s reasoning.This unique combination of an optimized Deep Neural Network(DNN)with LIME not only elevates the precision in detecting COVID-19 cases but also equips healthcare professionals with a deeper understanding of the diagnostic process.Our method,validated on the SARS-COV-2 CT-Scan dataset,demonstrates exceptional diagnostic accuracy,with performance metrics that reinforce its potential for seamless integration into modern healthcare systems.This innovative approach marks a significant advancement in creating explainable and trustworthy AI tools for medical decisionmaking in the ongoing battle against COVID-19.展开更多
Objective:To analyze the characteristics,dynamic changes,and outcomes of the first imaging manifestations of 3 patients with severe COVID-19 in our hospital.Methods:Computed tomography(CT)findings of 3 patients with s...Objective:To analyze the characteristics,dynamic changes,and outcomes of the first imaging manifestations of 3 patients with severe COVID-19 in our hospital.Methods:Computed tomography(CT)findings of 3 patients with severe COVID-19 who tested positive by the nucleic acid test in our hospital were selected,mainly focusing on the morphology,distribution characteristics,and dynamic changes of the first CT findings.Results:3 patients with severe pneumonia were older,with one aged 80.The first chest CT examination for all 3 patients differed.Imaging showed a leafy distribution of consolidation,primarily affecting the lower lobes of both lungs and extending subpleurally.A grid-like pattern was observed,along with changes in the consolidation and air bronchogram.These changes had slower absorption,especially in patients with underlying diseases.Conclusion:CT manifestations of severe COVID-19 have specific characteristics and the analysis of their characteristics and dynamic changes provide valuable insights for clinical treatment.展开更多
Objective:To analyze the value of multi-slice spiral computed tomography(CT)and magnetic resonance imaging(MRI)in the diagnosis of carpal joint injury.Methods:A total of 130 patients with suspected wrist injuries admi...Objective:To analyze the value of multi-slice spiral computed tomography(CT)and magnetic resonance imaging(MRI)in the diagnosis of carpal joint injury.Methods:A total of 130 patients with suspected wrist injuries admitted to the Department of Orthopedics of our hospital from January 2023 to January 2024 were selected and randomly divided into a single group(n=65)and a joint group(n=65).The single group was diagnosed using multi-slice spiral CT,and the joint group was diagnosed using multi-slice spiral CT and magnetic resonance imaging,with pathological diagnosis as the gold standard.The diagnostic results of both groups were compared to the gold standard,and the diagnostic energy efficiency of both groups was compared.Results:The diagnostic results of the single group compared with the gold standard were significant(P<0.05).The diagnostic results of the joint group compared with the gold standard were not significant(P>0.05).The sensitivity and accuracy of diagnosis in the joint group were significantly higher than that in the single group(P<0.05).The specificity of diagnosis in the joint group was higher as compared to that in the single group(P>0.05).Conclusion:The combination of multi-slice spiral CT and MRI was highly accurate in diagnosing wrist injuries,and the misdiagnosis rate and leakage rate were relatively low.Hence,this diagnostic program is recommended to be popularized.展开更多
We observed several patients presenting 2-[^(18)F]FDG uptake in the reactive axillary lymph node at PET/CT imaging,ipsilateral to the site of the COVID-19 vaccine injection.Analog finding was documented at[^(18)F]Chol...We observed several patients presenting 2-[^(18)F]FDG uptake in the reactive axillary lymph node at PET/CT imaging,ipsilateral to the site of the COVID-19 vaccine injection.Analog finding was documented at[^(18)F]Choline PET/CT.The aim of our study was to describe this source of false positive cases.All patients examined by PET/CT were included in the study.Data concerning patient anamnesis,laterality,and time interval from recent COVID-19 vaccination were recorded.SUVmax was measured in all lymph nodes expressing tracer uptake after vaccination.Among 712 PET/CT scans with 2-[^(18)F]FDG,104 were submitted to vaccination;89/104 patients(85%)presented axillary and/or deltoid tracer uptake,related to recent COVID-19 vaccine administration(median from injection:11 days).The mean SUVmax of these findings was 2.1(range 1.6–3.3).Among 89 patients with false positive axillary uptake,36 subjects had received chemotherapy due to lymph node metastases from somatic cancer or lymphomas,prior to the scan:6/36 patients with lymph node metastases showed no response to therapy or progression disease.The mean SUVmax value of lymph nodal localizations of somatic cancers/lymphomas after chemotherapy was 7.8.Only 1/31 prostate cancer patients examined by[^(18)F]Choline PET/CT showed post-vaccine axillary lymph node uptake.These findings were not recorded at PET/CT scans with[^(18)F]-6-FDOPA,[^(68)Ga]Ga-DOTATOC,and[^(18)F]-fluoride.Following COVID-19 mass vaccination,a significant percentage of patients examined by 2-[^(18)F]FDG PET/CT presents axillary,reactive lymph node uptake.Anamnesis,low-dose CT,and ultrasonography facilitated correct diagnosis.Semi-quantitative assessment supported the visual analysis of PET/CT data;SUVmax values of metastatic lymph nodes were considerably higher than post-vaccine lymph nodes.[^(18)F]Choline uptake in reactive lymph node after vaccination was confirmed.After the COVID-19 pandemic,nuclear physicians need to take these potential false positive cases into account in daily clinical practice.展开更多
基金Research and Cultivation Foundation of Hainan Medical College(HYPY2020022)Hainan Natural Science Foundation Youth fund(822QN482)+1 种基金Doctoral Research Fund project of Hainan Cancer Hospital(2022BS04)Key R&D projects in Hainan Province(ZDYF2021SHFZ244)。
文摘Objective:To investigate the prognostic value of radiomics features based on ^(18)F-FDG PET/CT imaging for advanced non-small cell lung cancer(NSCLC)treated with chemotherapy.Methods:A sample of 146 NSCLC patients stagedⅢor stageⅣwere included in this retrospective study who received ^(18)F-FDG PET/CT before treatment.All patients were treated with standardized chemotherapy after PET/CT examination and were divided into training group and validation group in an 8:2 ratio randomly.Radiomics features were extracted.In the training group,the minimum absolute contraction and selection operator(LASSO)algorithm and Cox risk proportional regression model were used to screen radiomics and clinical prognostic factors of progression-free survival(PFS).The radiomic model,clinical model and complex model were established respectively.The corresponding scores were calculated,then verified in the validation group.Results:The LASSO algorithm finally screened four radiomics features.ROC results showed that in the training group,the AUC of PFS predicted by the radiomics model was 0.746,and that in the verification group was 0.622.COX multivariate analysis finally included three clinical features related to PFS in NSCLC patients,namely pathological type,clinical stage and MTV30.The AUC for predicting PFS by clinical model,radiomics model and composite model were 0.746,0.753 and 0.716,respectively.The radiomics model had the highest diagnostic efficacy,and its sensitivity and specificity were 0.663 and 0.833,respectively.Delong test verified that there was no statistical difference in the predictive efficacy between the radiomics model and the composite model(Z=1.777,P=0.076)and the clinical imaging model(Z=0.323,P=0.747).Conclusion:The radiomics model based on PET/CT has a good predictive value for the prognosis of advanced NSCLC treated with chemotherapy,but it needs further validation before it can be widely used in clinical practice.
文摘Background: The PET/CT imaging studies have two doses components the dose from the PET radiopharmaceutical and the other from the low dose CT used for PET images attenuation correction. We have one PET/CT scanner at our institution a Philips Time of Flight scanner. Our local patient’s radiation protection rules requires continuous assessment of radiation doses delivered to our patients. Purposes: The objectives of this study are to develop a weight- based facility DRLs for paediatric F-18-FDG PET-CT imaging for oncology in a large tertiary hospital and to determine whether the calculated DRLs compares with internationally published DRLs. Materials & Methods: Radiation dose data and patient demographics of two-hundreds and sixteen paediatric PET-CT oncology patients imaging procedures from one large tertiary hospital were selected and analysed in order to establish a facility paediatric DRLs. Statistical analysis was performed. Results: The PET dose reference levels ranged between [62 - 525] MBq of injected activity for a range of pediatric age groups. The CTDI<sub>vol</sub> values were between 3.5 and 16.5 mGy for all age groups. Comparison with current EANM and SNMMI recommendations of patient’s dose are discussed. Conclusion: Our pediatric PET/CT reference levels are higher than the ones reported internationally with notable variations. .
文摘Bladder tumor is the most common malignant tumor in urinary system and always com- panied with lymph node metastasis. The accurate staging plays a significant role in treatment for bladder tumor and prognostic evaluation, and the distant metastasis predicts worse prognosis. The objective of this study was to assess the clinical significance of 18F-FDG PET/CT imaging in diagnosing bladder tumor metastasis lesions. A retrospective analysis of 60 patients with bladder tumor from October 2008 to May 2010 was done. The patients were stratified based on the imaging technique. Among all 60 cases, besides the primary lesion, 81 suspected lesions were spotted and 73 confirmed as metastasis, including 50 lymph node metastases, 22 distant metastases, and 1 bone metastasis. For PET/CT imaging, its sensitivity was 94.5%, specificity 87.5%, positive predictive value 98.6%, negative predictive value 63.6% and accuracy 93.8% respectively. For CT, its sensitivity was 82.2%, specificity 50%, positive predictive value 93.8%, negative predictive value 23.5% and accuracy 79% respectively. PET/CT im- aging was superior to CT in sensitivity, specificity and accuracy. In conclusion, 18F-FDG PET/CT imaging is more significant in diagnosing bladder tumor metastasis lesions.
基金funded in part by the National Natural Science Foundation of China(Nos.11875114,81471706,and 81871407)Science and Technology Commission of Shanghai Municipality(No.16410722700)sponsored by the Shanghai Sailing Program(No.17YF1417400)
文摘The present study explored the 18-kDa translocator protein radioligand ^(18)F-PBR06 as a PET imaging biomarker for diagnosis of inflammation and compared it with ^(18)F-FDG for differentiation of inflammation and lung tumors in animals.^(18)F-PBR06 was synthesized with an average decay-corrected radiochemical yield of 30–40%(end of synthesis, EOS), and the radiochemical purity was greater than 99%. The inflammation-to-blood ratio of ^(18)FPBR06(3.53 ± 0.26) was higher than the tumor-to-blood ratio(1.77 ± 0.35)(P \ 0.001). The inflammation-tomuscle ratio of ^(18)F-PBR06(2.33 ± 0.64) was also higher than the tumor-to-muscle ratio(1.45 ± 0.14)(P = 0.036).Micro-PET/CT images showed high uptake of ^(18)F-FDG in both inflamed muscles and lung tumor tissues. However,^(18)F-PBR06 uptake in inflamed muscles remained higher than that in the lung tumor tissues, following 90 min of dynamic Micro-PET/CT imaging. Further, macrophages in the inflammatory regions showed a higher fluorescence signal than in lung tumor tissues. Results of the study confirmed that ^(18)F-PBR06 PET/CT imaging allowed for diagnosis of inflammation. Moreover,^(18)F-PBR06 uptake in the inflammatory regions was significantly higher than in lung tumor tissues, suggesting that ^(18)F-PBR06 PET/CT imaging has potential to differentiate between peripheral lung cancer and inflammation nodules.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.81101070 and 81101175)
文摘The accuracy of attenuation correction in positron emission tomography scanners depends mainly on deriving the reliable 511-keV linear attenuation coefficient distribution in the scanned objects. In the PET/CT system, the linear attenu- ation distribution is usually obtained from the intensities of the CT image. However, the intensities of the CT image relate to the attenuation of photons in an energy range of 40 keV-140 keV. Before implementing PET attenuation correction, the intensities of CT images must be transformed into the PET 511-keV linear attenuation coefficients. However, the CT scan parameters can affect the effective energy of CT X-ray photons and thus affect the intensities of the CT image. Therefore, for PET/CT attenuation correction, it is crucial to determine the conversion curve with a given set of CT scan parameters and convert the CT image into a PET linear attenuation coefficient distribution. A generalized method is proposed for con- verting a CT image into a PET linear attenuation coefficient distribution. Instead of some parameter-dependent phantom calibration experiments, the conversion curve is calculated directly by employing the consistency conditions to yield the most consistent attenuation map with the measured PET data. The method is evaluated with phantom experiments and small animal experiments. In phantom studies, the estimated conversion curve fits the true attenuation coefficients accurately, and accurate PET attenuation maps are obtained by the estimated conversion curves and provide nearly the same correction results as the true attenuation map. In small animal studies, a more complicated attenuation distribution of the mouse is obtained successfully to remove the attenuation artifact and improve the PET image contrast efficiently.
文摘Lung cancer presents a high prevalence around the world and constitutes the leading cause of death due to cancer in men and women. Proper staging is essential in order to provide the correct treatment and estimate survival. PET/CT imaging is the method of choice for the staging of lung cancer patients with a better performance than the traditional imaging methods. It allows defining the primary tumor more clearly, separating it from the atelectasis and neighboring fibrotic changes, thus achieving an improved T evaluation while optimizing the target definition for radiotherapy. It presents greater sensibility and specificity than Computed Tomography (CT) when assessing the extra-thoracic and thoracic lymph nodes, modifying the N stage with regard to the traditional study in up to 25% of patients. PET/CT imaging is the method with the best performance for detecting extra-encephalic metastasis and for detecting unexpected lesions in up to 30% of patients. In order to achieve proper encephalic staging, a Magnetic Resonance Imaging scan must be performed or, a CT scan of the brain concomitant to the PET/CT. One to eight percent of lung cancer patients who are subjected to PET/CT imaging present a synchronous secondary extra pulmonary or pulmonary cancer when being diagnosed, with significant prognostic and therapeutic implications. PET/CT imaging has proven to be a valuable tool for survival prognosis with regard to the initial uptake of the tumor and the early response (interim) or final response to chemotherapy, although it is not routinely used for evaluating therapy. The PET/MRI is an emerging hybrid technique with certain advantages, such as less exposure to radiation in comparison to PET/CT and greater contrast resolution of the MRI images. However, its usefulness has not been validated yet for lung cancer patients.
文摘A seventy eight years old male patient underwent a whole body 18F- FDG PET/CT imaging to diagnose the lesion which was showed in the right lung by a chest X ray test and CT scan before. Besides the intense 18F- FDG uptake of the lesion in the right lung, a lesion in the left parotid gland also showed intense 18F- FDG uptake. To evaluate the pathology of the lesion in the left parotid gland, a parotid gland scintigraphy imaging with Tc-99m pertechnetate was done and revealed a Warthin's tumor. Later a fine needle aspiration(FNA) confirmed that it was a Warthin's tumor.
文摘Background: To evaluate whether current dose reduction strategies for the CT component of hybrid Positron Emission Tomography—Computed Tomography (PET/CT) systems could reduce patient dose with maintaining adequate image quality for PET/CT studies. Materials and Methods: Literature survey was initially based on the selection of keywords and years of publication to identify potentially relevant articles, then the further search was conducted on the authors and references from these articles. The abstract of each article was first appraised to decide whether the content was relevant to this research question. The articles were classified into five groups: studies on dosimetry, studies on radiation-induced diseases, studies on dose reduction methods for CT-based attenuation correction (CTAC), studies on dose reduction methods for CT localization, and studies on reducing the need for a full-dose diagnostic CT in PET/CT imaging. 58 peer-reviewed articles were selected and appraised and 29 articles were used to compose this literature review. Results: The published nuclear medicine and medical physics literature were reviewed. CT dose contributed 47% - 81% of the total effective dose of a standard PET/CT study and was associated with radiation-induced diseases. The dose reduction techniques were extracted and divided into three categories: reducing the CT dose for attenuation correction (AC) and localization, selectively localizing CT use, and reducing the need for a full-dose diagnostic CT. Conclusion: Three strategies have been demonstrated, with high potential for reducing patient dose while maintaining an adequate CT image quality, used for CTCA localization and diagnosis, respectively.
基金Supported by grants from the National Natural Science Foundation of China(No.81101065,31100604)Higher Education Doctoral Program of China Research Fund for New Teacher(No.20110001120043)+1 种基金National Major Scientific Equipment Special Fund(No.2011YQ03011409)Beijing Capital Special Development Application Program(No.Z141107002514159)
文摘Paraneoplastic neurological syndromes(PNS) is a series of rare neurologic disorders which happen with an underlying malignancy. It has various clinical symptoms proceding to the diagnosis of tumors. Although the abnormality of anti-neuronal antibodies is suggestive of PNS and tumors, there exist many false positive and false negative cases. The diagnosis of PNS is usually a challenge in clinic. Positron emission tomography/computed tomography(PET/CT) imaging is an anatomical and functional fusion imaging method, which provides the whole-body information by single scan. Fluorodeoxyglucose(FDG) PET/CT imaging can not only detect potential malignant lesions in the whole body, but also assess functional abnormality in the brain. In this review, the mechanism, clinical manifestation, diagnostic procedure and the recent progress of the utility of FDG PET/CT in PNS are introduced respectively.
基金supported by Shanghai Municipal Commission of Health and Family Planning of China(No.20134339)
文摘This study was to explore the optimal threshold of thyroid-stimulating hormone(TSH)-stimulated serum thyroglobulin(s-Tg) for patients who were to receive18F-fluorodeoxyglucose(18F-FDG) PET/CT scan owing to clinical suspicion of differentiated thyroid cancer(DTC) recurrence but negative post-therapeutic 131I whole-body scan(131I-WBS). A total of 60 qualified patients underwent PET/CT scanning from October 2010 to July 2014. The receiver operating characteristic(ROC) curve analyses showed that s-Tg levels over 49 μg/L led to the highest diagnostic accuracy of PET/CT to detect recurrence, with a sensitivity of 89.5% and a specificity of 90.9%. Besides, bivariate correlation analysis showed positive correlation between s-Tg levels and the maximum standardized uptake values(SUVmax) of18F-FDG in patients with positive PET/CT scanning, suggesting a significant influence of TSH both on Tg release and uptake of18F-FDG. So, positive PET/CT imaging is expected when patients have negative 131I-WBS but s-Tg levels over 49 μg/L.
文摘Globally,carcinoma of lung is the predominant cause of cancer death among both men and women.While hematogenous spread from primary lung cancer to multiple other organs is frequently reported,metastases of malignant tumors to diaphragm and spleen are rare.Nowadays,Positron emission tomography(PET)with 18 F-fluorodeoxyglucose(FDG)has emerged in such a way that it has become an effective imaging technology for the evaluation of different carcinomas,particularly for cancer staging and follow up after therapy.PET scan is able to provide metabolic information.In this case,we present an attractive unified PET/CT scan image in a patient with lung carcinoma having unusual diaphragm and splenic metastases.So,PET/CT imaging could strongly identified rare and unusual metastatic sites of cancer and added more appropriate staging in patient with carcinoma of lung.
基金the Deanship for Research Innovation,Ministry of Education in Saudi Arabia,for funding this research work through project number IFKSUDR-H122.
文摘In the current landscape of the COVID-19 pandemic,the utilization of deep learning in medical imaging,especially in chest computed tomography(CT)scan analysis for virus detection,has become increasingly significant.Despite its potential,deep learning’s“black box”nature has been a major impediment to its broader acceptance in clinical environments,where transparency in decision-making is imperative.To bridge this gap,our research integrates Explainable AI(XAI)techniques,specifically the Local Interpretable Model-Agnostic Explanations(LIME)method,with advanced deep learning models.This integration forms a sophisticated and transparent framework for COVID-19 identification,enhancing the capability of standard Convolutional Neural Network(CNN)models through transfer learning and data augmentation.Our approach leverages the refined DenseNet201 architecture for superior feature extraction and employs data augmentation strategies to foster robust model generalization.The pivotal element of our methodology is the use of LIME,which demystifies the AI decision-making process,providing clinicians with clear,interpretable insights into the AI’s reasoning.This unique combination of an optimized Deep Neural Network(DNN)with LIME not only elevates the precision in detecting COVID-19 cases but also equips healthcare professionals with a deeper understanding of the diagnostic process.Our method,validated on the SARS-COV-2 CT-Scan dataset,demonstrates exceptional diagnostic accuracy,with performance metrics that reinforce its potential for seamless integration into modern healthcare systems.This innovative approach marks a significant advancement in creating explainable and trustworthy AI tools for medical decisionmaking in the ongoing battle against COVID-19.
基金Qinghai Provincial Health Commission Medical and Health Science and Technology Project Guiding Topics“Analysis of Dynamic Changes in Chest Imaging of New Coronavirus Pneumonia in Qinghai Province”(2022-wjzdx-63)。
文摘Objective:To analyze the characteristics,dynamic changes,and outcomes of the first imaging manifestations of 3 patients with severe COVID-19 in our hospital.Methods:Computed tomography(CT)findings of 3 patients with severe COVID-19 who tested positive by the nucleic acid test in our hospital were selected,mainly focusing on the morphology,distribution characteristics,and dynamic changes of the first CT findings.Results:3 patients with severe pneumonia were older,with one aged 80.The first chest CT examination for all 3 patients differed.Imaging showed a leafy distribution of consolidation,primarily affecting the lower lobes of both lungs and extending subpleurally.A grid-like pattern was observed,along with changes in the consolidation and air bronchogram.These changes had slower absorption,especially in patients with underlying diseases.Conclusion:CT manifestations of severe COVID-19 have specific characteristics and the analysis of their characteristics and dynamic changes provide valuable insights for clinical treatment.
文摘Objective:To analyze the value of multi-slice spiral computed tomography(CT)and magnetic resonance imaging(MRI)in the diagnosis of carpal joint injury.Methods:A total of 130 patients with suspected wrist injuries admitted to the Department of Orthopedics of our hospital from January 2023 to January 2024 were selected and randomly divided into a single group(n=65)and a joint group(n=65).The single group was diagnosed using multi-slice spiral CT,and the joint group was diagnosed using multi-slice spiral CT and magnetic resonance imaging,with pathological diagnosis as the gold standard.The diagnostic results of both groups were compared to the gold standard,and the diagnostic energy efficiency of both groups was compared.Results:The diagnostic results of the single group compared with the gold standard were significant(P<0.05).The diagnostic results of the joint group compared with the gold standard were not significant(P>0.05).The sensitivity and accuracy of diagnosis in the joint group were significantly higher than that in the single group(P<0.05).The specificity of diagnosis in the joint group was higher as compared to that in the single group(P>0.05).Conclusion:The combination of multi-slice spiral CT and MRI was highly accurate in diagnosing wrist injuries,and the misdiagnosis rate and leakage rate were relatively low.Hence,this diagnostic program is recommended to be popularized.
基金This study was approved by the Medical Ethics Committee of the“Mariano Santo”Hospital in Cosenza,Italy(CS391273).
文摘We observed several patients presenting 2-[^(18)F]FDG uptake in the reactive axillary lymph node at PET/CT imaging,ipsilateral to the site of the COVID-19 vaccine injection.Analog finding was documented at[^(18)F]Choline PET/CT.The aim of our study was to describe this source of false positive cases.All patients examined by PET/CT were included in the study.Data concerning patient anamnesis,laterality,and time interval from recent COVID-19 vaccination were recorded.SUVmax was measured in all lymph nodes expressing tracer uptake after vaccination.Among 712 PET/CT scans with 2-[^(18)F]FDG,104 were submitted to vaccination;89/104 patients(85%)presented axillary and/or deltoid tracer uptake,related to recent COVID-19 vaccine administration(median from injection:11 days).The mean SUVmax of these findings was 2.1(range 1.6–3.3).Among 89 patients with false positive axillary uptake,36 subjects had received chemotherapy due to lymph node metastases from somatic cancer or lymphomas,prior to the scan:6/36 patients with lymph node metastases showed no response to therapy or progression disease.The mean SUVmax value of lymph nodal localizations of somatic cancers/lymphomas after chemotherapy was 7.8.Only 1/31 prostate cancer patients examined by[^(18)F]Choline PET/CT showed post-vaccine axillary lymph node uptake.These findings were not recorded at PET/CT scans with[^(18)F]-6-FDOPA,[^(68)Ga]Ga-DOTATOC,and[^(18)F]-fluoride.Following COVID-19 mass vaccination,a significant percentage of patients examined by 2-[^(18)F]FDG PET/CT presents axillary,reactive lymph node uptake.Anamnesis,low-dose CT,and ultrasonography facilitated correct diagnosis.Semi-quantitative assessment supported the visual analysis of PET/CT data;SUVmax values of metastatic lymph nodes were considerably higher than post-vaccine lymph nodes.[^(18)F]Choline uptake in reactive lymph node after vaccination was confirmed.After the COVID-19 pandemic,nuclear physicians need to take these potential false positive cases into account in daily clinical practice.