Image quality in positron emission tomography(PET)is affected by random and scattered coincidences and reconstruction protocols.In this study,we investigated the effects of scattered and random coincidences from outsi...Image quality in positron emission tomography(PET)is affected by random and scattered coincidences and reconstruction protocols.In this study,we investigated the effects of scattered and random coincidences from outside the field of view(FOV)on PET image quality for different reconstruction protocols.Imaging was performed on the Discovery 690 PET/CT scanner,using experimental configurations including the NEMA phantom(a body phantom,with six spheres of different sizes)with a signal background ratio of 4:1.The NEMA phantom(phantom I)was scanned separately in a one-bed position.To simulate the effect of random and scatter coincidences from outside the FOV,six cylindrical phantoms with various diameters were added to the NEMA phantom(phantom II).The 18 emission datasets with mean intervals of 15 min were acquired(3 min/scan).The emission data were reconstructed using different techniques.The image quality parameters were evaluated by both phantoms.Variations in the signal-to-noise ratio(SNR)in a 28-mm(10-mm)sphere of phantom II were 37.9%(86.5%)for ordered-subset expectation maximization(OSEM-only),36.8%(81.5%)for point spread function(PSF),32.7%(80.7%)for time of flight(TOF),and 31.5%(77.8%)for OSEM+PSF+TOF,respectively,indicating that OSEM+PSF+TOF reconstruction had the lowest noise levels and lowest coefficient of variation(COV)values.Random and scatter coincidences from outside the FOV induced lower SNR,lower contrast,and higher COV values,indicating image deterioration and significantly impacting smaller sphere sizes.Amongst reconstruction protocols,OSEM+PSF+TOF and OSEM+PSF showed higher contrast values for sphere sizes of 22,28,and 37 mm and higher contrast recovery coefficient values for smaller sphere sizes of 10 and 13 mm.展开更多
Cancer of the head and neck is often devastating and the morbidity associated with its treatment is substantial. Positron Emission Tomography-Computed Tomography (PET-CT) combines the power of biological / molecular i...Cancer of the head and neck is often devastating and the morbidity associated with its treatment is substantial. Positron Emission Tomography-Computed Tomography (PET-CT) combines the power of biological / molecular imaging with the anatomic detail of CT in order to provide a very sensitive and specific imaging tool for the evaluation of head and neck pathology. PET can aid the clinician in establishing diagnosis, staging, (It has been shown to be more accurate than CT), assessing, prognosis and determining response to therapy. Lymphoma, melanoma, multiple myeloma, leukemia, salivary gland tumors, odontogenic carcinomas, soft tissue sarcomas, thyroid, parathyroid, lacrimal gland and bone / cartilage tumors are some of the entities where PET-CT may be useful. (Tumors of salivary glands and of odontogenic tissue are particularly difficult to diagnose due to the relative infrequency when compared with other tumors and the extremely vast histologic variation).It is important to note that carcinoma metastasis, is the most common malignancy found within the mandibular bone. PET-CT and skeletal scintigraphy are both very sensitive and specific in these types of patients.展开更多
Introduction:Fluorine-18 fluorodeoxyglucose(18F-FDG)positron emission tomography/computed tomography(PET/CT)is a powerful tool for monitoring the response of diffuse large B-cell lymphoma(DLBCL)to therapy,but the crit...Introduction:Fluorine-18 fluorodeoxyglucose(18F-FDG)positron emission tomography/computed tomography(PET/CT)is a powerful tool for monitoring the response of diffuse large B-cell lymphoma(DLBCL)to therapy,but the criteria to interpret PET/CT results remain under debate.We investigated the value of post-treatment PET/CT in predicting the prognosis of DLBCL patients when interpreted according to qualitative visual trichotomous assessment(QVTA)criteria compared with the Deauvil e criteria.Methods:In this retrospective study,final PET/CT scans of DLBCL patients treated with rituximab-based regimens between October 2005 and November 2010 were interpreted using the Deauvil e and QVTA criteria.Survival curves were estimated using Kaplan-Meier analysis and compared using the log-rank test.Results:A total of 253 patients were enrol ed.The interpretation according to the Deauvil e criteria revealed that 181patients had negative PET/CT scan results and 72 had positive results.The 3 year overal survival(OS)rate was significantly higher in patients with negative scan results than in those with positive results(91.6%vs.57.5%,P<0.001).The72 patients with positive scan results according to the Deauville criteria were divided into two groups by the interpretation according to the QVTA criteria:29 had indeterminate results,and 43 had positive results.The 3 year OS rate was significantly higher in patients with indeterminate scan results than in those with positive results(91.2%vs.33.5%,P<0.001)but was similar between patients with negative and indeterminate scan results(91.6%vs.91.2%,P=0.921).Conclusions:Compared with the Deauvil e criteria,using the QVTA criteria for interpreting post-treatment PET/CT scans of DLBCL patients is likely to reduce the number of false positive results.The QVTA criteria are feasible for therapeutic outcome evaluation and can be used to guide risk-adapted therapy.展开更多
目的:探讨^(68)Ga标记的成纤维细胞激活蛋白抑制剂(fibroblast activation protein inhibitor,FAPI)-04正电子发射断层显像/X线计算机体层成像(positron emission tomography and computed tomography,PET/CT)对初诊胰腺癌的诊断价值及...目的:探讨^(68)Ga标记的成纤维细胞激活蛋白抑制剂(fibroblast activation protein inhibitor,FAPI)-04正电子发射断层显像/X线计算机体层成像(positron emission tomography and computed tomography,PET/CT)对初诊胰腺癌的诊断价值及对肿瘤分期的影响。方法:回顾性收集2021年8月至2023年8月于重庆大学附属肿瘤医院就诊的134例因怀疑胰腺占位的患者临床及影像资料。分析^(68)Ga-FAPI-04 PET/CT对胰腺癌原发灶及转移灶的诊断价值;并与传统CT比较,分析^(68)Ga-FAPI-04 PET/CT对胰腺癌肿瘤分期的影响。结果:共计纳入134例患者,其中胰腺癌127例,良性病变7例。^(68)Ga-FAPI-04 PET/CT对胰腺癌原发灶、区域淋巴结及远处转移灶检出率分别为100%(127/127)、68.63%(35/51),95.35%(41/43)。胰腺癌中位最大标准化摄取值(standard uptake value maxium,SUVmax)为14.92,高于胰腺良性病变中位SUVmax(6.1)(Z=−2.921,P=0.003)。与传统CT比较,^(68)Ga-FAPI PET/CT检查后共有32.28%(41/127)胰腺癌患者TNM分期发生改变。3.94%(5/127)患者改变了治疗方案。结论:^(68)Ga-FAPI-04 PET/CT对胰腺癌原发灶诊断具有较高的敏感性,较传统CT可发现更多远处转移病灶,改善患者M分期,有助于全面评估全身肿瘤负荷、制定治疗计划。展开更多
目的探讨多元化护理干预措施在老年肿瘤患者正电子发射型断层(PET)/X线计算机断层(CT)检查中的应用效果,为治疗该病症提供护理方法。方法选取2020年10月—2022年10月于西京医院收治的老年肿瘤患者81例,采用随机摸红蓝球的方式分为多元...目的探讨多元化护理干预措施在老年肿瘤患者正电子发射型断层(PET)/X线计算机断层(CT)检查中的应用效果,为治疗该病症提供护理方法。方法选取2020年10月—2022年10月于西京医院收治的老年肿瘤患者81例,采用随机摸红蓝球的方式分为多元化护理组(n=41,蓝球)和常规护理组(n=40,红球)。常规护理组接受常规护理干预,多元化护理组在常规护理组的基础上采用多元化护理干预,2组均干预2周。比较2组干预前后心理状态[采用综合性医院焦虑抑郁量表(Hospital Anxiety and Depression Scale,HADS)评估]评分;比较2组检查用时、检查中断率和重复检查率、PET/CT显像结果准确性、PET/CT显像优良率(以最终诊断为标准)及检查依从率。结果干预后,2组HADS评分中焦虑、抑郁和总分均较同组干预前降低,且多元化护理组评分低于常规护理组,差异均有统计学意义(P<0.05);检查后,多元化护理组检查用时、检查中断率、重复检查率均低于常规护理组(均P<0.05);多元化护理组检查依从率、PET/CT图像优级率均高于常规护理组(均P<0.05);2组PET/CT图像优良率和显像结果准确性差异无统计学意义(P>0.05)。结论多元化护理干预措施可能有效提高老年肿瘤患者PET/CT检查的依从率,减少外界因素对测量结果的影响,有助于改善患者检查期间的心理状态,具有一定的临床应用价值。展开更多
基金supported by the Tehran University of Medical Sciences under Grant No.36291PET/CT and Cyclotron Center of Masih Daneshvari Hospital at Shahid Beheshti University of Medical Sciences。
文摘Image quality in positron emission tomography(PET)is affected by random and scattered coincidences and reconstruction protocols.In this study,we investigated the effects of scattered and random coincidences from outside the field of view(FOV)on PET image quality for different reconstruction protocols.Imaging was performed on the Discovery 690 PET/CT scanner,using experimental configurations including the NEMA phantom(a body phantom,with six spheres of different sizes)with a signal background ratio of 4:1.The NEMA phantom(phantom I)was scanned separately in a one-bed position.To simulate the effect of random and scatter coincidences from outside the FOV,six cylindrical phantoms with various diameters were added to the NEMA phantom(phantom II).The 18 emission datasets with mean intervals of 15 min were acquired(3 min/scan).The emission data were reconstructed using different techniques.The image quality parameters were evaluated by both phantoms.Variations in the signal-to-noise ratio(SNR)in a 28-mm(10-mm)sphere of phantom II were 37.9%(86.5%)for ordered-subset expectation maximization(OSEM-only),36.8%(81.5%)for point spread function(PSF),32.7%(80.7%)for time of flight(TOF),and 31.5%(77.8%)for OSEM+PSF+TOF,respectively,indicating that OSEM+PSF+TOF reconstruction had the lowest noise levels and lowest coefficient of variation(COV)values.Random and scatter coincidences from outside the FOV induced lower SNR,lower contrast,and higher COV values,indicating image deterioration and significantly impacting smaller sphere sizes.Amongst reconstruction protocols,OSEM+PSF+TOF and OSEM+PSF showed higher contrast values for sphere sizes of 22,28,and 37 mm and higher contrast recovery coefficient values for smaller sphere sizes of 10 and 13 mm.
文摘Cancer of the head and neck is often devastating and the morbidity associated with its treatment is substantial. Positron Emission Tomography-Computed Tomography (PET-CT) combines the power of biological / molecular imaging with the anatomic detail of CT in order to provide a very sensitive and specific imaging tool for the evaluation of head and neck pathology. PET can aid the clinician in establishing diagnosis, staging, (It has been shown to be more accurate than CT), assessing, prognosis and determining response to therapy. Lymphoma, melanoma, multiple myeloma, leukemia, salivary gland tumors, odontogenic carcinomas, soft tissue sarcomas, thyroid, parathyroid, lacrimal gland and bone / cartilage tumors are some of the entities where PET-CT may be useful. (Tumors of salivary glands and of odontogenic tissue are particularly difficult to diagnose due to the relative infrequency when compared with other tumors and the extremely vast histologic variation).It is important to note that carcinoma metastasis, is the most common malignancy found within the mandibular bone. PET-CT and skeletal scintigraphy are both very sensitive and specific in these types of patients.
文摘Introduction:Fluorine-18 fluorodeoxyglucose(18F-FDG)positron emission tomography/computed tomography(PET/CT)is a powerful tool for monitoring the response of diffuse large B-cell lymphoma(DLBCL)to therapy,but the criteria to interpret PET/CT results remain under debate.We investigated the value of post-treatment PET/CT in predicting the prognosis of DLBCL patients when interpreted according to qualitative visual trichotomous assessment(QVTA)criteria compared with the Deauvil e criteria.Methods:In this retrospective study,final PET/CT scans of DLBCL patients treated with rituximab-based regimens between October 2005 and November 2010 were interpreted using the Deauvil e and QVTA criteria.Survival curves were estimated using Kaplan-Meier analysis and compared using the log-rank test.Results:A total of 253 patients were enrol ed.The interpretation according to the Deauvil e criteria revealed that 181patients had negative PET/CT scan results and 72 had positive results.The 3 year overal survival(OS)rate was significantly higher in patients with negative scan results than in those with positive results(91.6%vs.57.5%,P<0.001).The72 patients with positive scan results according to the Deauville criteria were divided into two groups by the interpretation according to the QVTA criteria:29 had indeterminate results,and 43 had positive results.The 3 year OS rate was significantly higher in patients with indeterminate scan results than in those with positive results(91.2%vs.33.5%,P<0.001)but was similar between patients with negative and indeterminate scan results(91.6%vs.91.2%,P=0.921).Conclusions:Compared with the Deauvil e criteria,using the QVTA criteria for interpreting post-treatment PET/CT scans of DLBCL patients is likely to reduce the number of false positive results.The QVTA criteria are feasible for therapeutic outcome evaluation and can be used to guide risk-adapted therapy.
文摘目的探讨多元化护理干预措施在老年肿瘤患者正电子发射型断层(PET)/X线计算机断层(CT)检查中的应用效果,为治疗该病症提供护理方法。方法选取2020年10月—2022年10月于西京医院收治的老年肿瘤患者81例,采用随机摸红蓝球的方式分为多元化护理组(n=41,蓝球)和常规护理组(n=40,红球)。常规护理组接受常规护理干预,多元化护理组在常规护理组的基础上采用多元化护理干预,2组均干预2周。比较2组干预前后心理状态[采用综合性医院焦虑抑郁量表(Hospital Anxiety and Depression Scale,HADS)评估]评分;比较2组检查用时、检查中断率和重复检查率、PET/CT显像结果准确性、PET/CT显像优良率(以最终诊断为标准)及检查依从率。结果干预后,2组HADS评分中焦虑、抑郁和总分均较同组干预前降低,且多元化护理组评分低于常规护理组,差异均有统计学意义(P<0.05);检查后,多元化护理组检查用时、检查中断率、重复检查率均低于常规护理组(均P<0.05);多元化护理组检查依从率、PET/CT图像优级率均高于常规护理组(均P<0.05);2组PET/CT图像优良率和显像结果准确性差异无统计学意义(P>0.05)。结论多元化护理干预措施可能有效提高老年肿瘤患者PET/CT检查的依从率,减少外界因素对测量结果的影响,有助于改善患者检查期间的心理状态,具有一定的临床应用价值。
