基质金属蛋白酶3在类风湿关节炎患者中的临床意义

目的探讨基质金属蛋白酶3(MMP-3)水平在类风湿关节炎(RA)患者中的临床价值。方法选取2018年1月至2020年1月无锡市第九人民医院收治的74例RA患者为RA组,74例骨关节炎(OA)患者为OA组,另选择同期148例体检健康者为对照组。检测并比较3组红细胞沉降率(ESR)及血清C反应蛋白(CRP)、类风湿因子(RF)及MMP-3水平。采用Pearson相关分析RA组MMP-3水平与ESR、CRP、RF、28关节疾病活动度评分(DAS28)、28个关节肿胀关节数、28个关节压痛关节数、滑膜炎评分、骨髓水肿评分以及骨侵蚀评分相关性。根据RA患者DAS28、骨密度、是否器官/组织受累以及病程分为不同亚组,比较不同亚组间的MMP-3水平。采用受试者工作特征(ROC)曲线分析MMP-3在诊断RA中的临床价值。结果相较于OA组及对照组,RA组ESR及血清CRP、RF、MMP-3水平更高(P<0.05)。相较于OA组,RA组DAS28、28个关节肿胀关节数、28个关节压痛关节数、滑膜炎评分、骨髓水肿评分以及骨侵蚀评分更高(P<0.05)。相关性分析结果显示,RA组MMP-3水平与ESR、CRP、RF、DAS28、28个关节肿胀关节、28个关节压痛关节、滑膜炎评分、骨髓水肿评分以及骨侵蚀评分均呈正相关(P<0.05)。不同亚组间比较结果显示,关节疾病活动度高、骨质疏松、存在器官/组织受累、病程<1年及疾病活动期患者MMP-3水平更高(P<0.05)。ROC曲线结果显示,MMP-3诊断RA的曲线下面积为0.826,最佳临界值为41.77 ng/mL。结论RA患者血清MMP-3水平显著上升,其水平升高在诊断RA中具有一定临床价值。     

Efficacy of polyvinylpyrrolidone solutions of various concentrations in patients with rheumatic diseases of the joints

Twenty-six experimental animals, 93 patients with osteoarthrosis (OA) and 30 patients with rheumatoid arthritis (RA) were examined. Intraarticular injection of both 15% and 20% polyvinylpyrrolidone (PVP) solutions suppressed the development of experimental arthrosis in rabbits, which manifested in a decrease of the degenerative changes in the cartilaginous tissue of the joints. The clinical examination has demonstrated that the use of different concentrations of PVP produces an equally marked effect in OA. In the group of RA and OA patients given placebo the time-course of changes in the clinical data was pronounced less powerfully. PVP turned out to be effective in secondary synovitis, to influence the immunologic responses occurring in synovitis, and to exert a beneficial action on the rheological properties of the synovial fluid. The drug is completely eliminated from the articular cavity and the body during 5 days.     

2-Deoxy-2-[F-18]fluoro-<Emphasis Type="SmallCaps">d</Emphasis>-glucose Positron Emission Tomography/Computed Tomography in the Management of Melanoma

Objectives 2-Deoxy-2-[F-18]fluoro-d-glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) is widely available as a powerful imaging modality, combining the ability to detect active metabolic processes and their morphologic features in a single exam. The role of FDG-PET is proven in a variety of cancers, including melanoma, but the estimates of sensitivity and specificity are based in the majority of the published studies on dedicated PET, not PET/CT. Therefore, we were prompted to review our experience with FDG-PET/CT in the management of melanoma. Methods This is a retrospective study on 106 patients with melanoma (20–87 years old; average: 56.8 ± 15.9), who had whole-body FDG-PET/CT at our institution from January 2003 to June 2005. Thirty-eight patients (35.9%) were women and 68 patients (64.1%) were men. Reinterpretation of the imaging studies for accuracy and data analysis from medical records were performed. Results All patients had the study for disease restaging. The primary tumor depth (Breslow’s thickness) at initial diagnosis was available for 76 patients (71.7%) and ranged from 0.4 to 25 mm (average: 3.56 mm). The anatomic level of invasion in the skin (Clark’s level) was determined for 70 patients (66%): 3, level II; 13, level III; 43, level IV; 11, level V. The administered dose of ¹⁸F FDG ranged from 9.8 to 21.6 mCi (average: 15.4 ± 1.8 mCi). FDG-PET/CT had a sensitivity of 89.3% [95% confidence interval (CI): 78.5–95] and a specificity of 88% (95% CI: 76.2–94.4) for melanoma detection. Conclusion This study confirms the good results of FDG-PET/CT for residual/recurrent melanoma detection, as well as for distant metastases localization. PET/CT should be an integral part in evaluation of patients with high-risk melanoma, prior to selection of the most appropriate therapy.     

The Utility of 2-Deoxy-2-[F-18]fluoro-<Emphasis Type="SmallCaps">d</Emphasis>-glucose Positron Emission Tomography in the Investigation of Patients with Disseminated Carcinoma of Unknown Primary Origin

Purpose A retrospective analysis of the use of 2-deoxy-2-[F-18]fluoro-d-glucose (FDG) positron emission tomography (PET) was performed in patients with histologically proven disseminated carcinoma of unknown primary tumor (CUP).Procedures The records of 31 patients with CUP, excluding patients with isolated neck metastases, were reviewed to identify the ability of PET to detect the putative primary site (PPS) and/or to change therapeutic management.Results In eight out of 31 cases (26%), a PPS was confirmed, either definitively (one pathologically, one radiologically) (true positive) or clinically (six cases). For three cases (10%), histological evidence of a primary tumor distant from the PPS was found (false positive). In a further seven cases (23%), the PPS remained unconfirmed, whereas for 13 cases (42%) no PPS was identified. In five out of seven patients in whom the PET suggested a high probability of having identified the primary site, the PPS was confirmed definitively or clinically. PET altered clinical management in at least 12 cases (38%).Conclusions PET contributed to the management of previously extensively investigated patients with CUP. Identification of a PPS and/or change in management was documented in 38% of cases, the majority of which were lung or pancreatic cancer. These findings are worthy of evaluation in a prospective study.     

Merkel Cell Carcinoma: Is there a Role for 2-Deoxy-2-[F-18]fluoro-d-glucose-Positron Emission Tomography/Computed Tomography?

Purpose 2-Deoxy-2-[F-18]fluoro-d-glucose (FDG)–positron emission tomography (PET)/computed tomography (CT) is becoming widely available as a powerful imaging modality, combining the ability to detect active metabolic processes and their morphologic features in a single study. The role of FDG-PET/CT is proven in lymphoma, melanoma, colorectal carcinoma, and other cancers. However, there are rare malignancies such as Merkel cell carcinoma that can potentially be evaluated with PET/CT. We were therefore prompted to review our experience with FDG-PET/CT in the management of patients with Merkel cell carcinoma.Procedures This is a retrospective case series of six patients with Merkel cell carcinoma, 58–81 years old (average 69 ± 8.3), who had whole-body PET/CT at our institution from January 1st, 2003 to August 31st, 2005. Two patients were women and four were men. Reinterpretation of the imaging studies for accuracy and data analysis from medical records were performed.Results Twelve examinations were acquired for the six patients (one patient had six PET/CT, one patient had two PET/CT, and four patients had one PET/CT). The injected FDG doses ranged 381.1–669.7 MBq (average 573.5 ± 70.3). Four patients had the PET/CT as part of initial staging, and two patients had the exam for restaging (after surgery and XRT). A total of six Merkel lesions (pancreas, adrenal, lip, submandibular lymph nodes, cervical lymph nodes, and parapharyngeal soft tissue) were identified in three patients and confirmed on histopathological examination. The FDG uptake in these areas was intense, with maximum standardized uptake value (SUVmax) values of 5–14 (average 10.4 ± 3.8). In one patient, the PET/CT scan identified abnormal focal distal sigmoid uptake that was biopsied and diagnosed as adenocarcinoma. Two patients had negative scans and had no clinical evidence of disease on follow-up office visits (up to one year after PET/CT).Conclusions This case series suggests that FDG-PET/CT may have a promising role in the management of patients with Merkel cell carcinoma.     

The Synthesis of <Superscript>18</Superscript>F-FDS and Its Potential Application in Molecular Imaging

Purpose 2-Deoxy-2-[¹⁸F]fluoro-d-glucose (FDG) is the most commonly used positron emission tomography (PET) tracer for oncological and neurological imaging, but it has limitations on detecting tumor or inflammation in brain gray matter. In this study, we describe the development of 2-deoxy-2-[¹⁸F]fluorosorbitol (¹⁸F-FDS) and its possible application in lesion detection around brain area. Procedures ¹⁸F-FDS was obtained by reduction of FDG using NaBH₄ (81 ± 4% yield in 30 min). Cell uptake/efflux experiments in cell culture and small animal PET imaging on tumor and inflammation models were performed. Results Despite the low accumulation in cell culture, ¹⁸F-FDS had good tumor uptake and contrast in the subcutaneous U87MG tumor model (4.54%ID/g at 30 min post-injection). Minimal uptake in the normal mouse brain facilitated good tumor contrast in both U87MG and GL-26 orthotopic tumor models. ¹⁸F-FDS also had increased uptake in the inflamed foci of the TPA-induced acute inflammation model. Conclusions Because of the ease of synthesis and favorable in vivo kinetics, ¹⁸F-FDS may have potential applications in certain cases where FDG is inadequate (e.g., brain tumor). Zi-Bo Li and Zhanhong Wu contributed equally to this work     

Reduction of Brown Fat 2-Deoxy-2-[F-18]fluoro-d-glucose Uptake by Controlling Environmental Temperature Prior to Positron Emission Tomography Scan

Brown fat uptake of 2-deoxy-2-[F-18]fluoro-d-glucose (FDG) on a positron emission tomography (PET) scan limits the ability to assess for cancer. Drugs such as benzodiazepine, propranolol, and reserpine have been proposed to reduce this uptake, but the studies have been either small clinical or preclinical trials. As an alternative, we evaluated the effect of controlling the patient’s environmental temperature on brown fat uptake of FDG. Method From January 1, 2002 to November 30, 2004, patients were identified who had (1) a pattern of FDG uptake in the neck/paravertebral areas suggestive of brown fat, (2) a repeat FDG-PET scan after control of the patient’s environmental temperature, and (3) no evidence of cancer in the neck/paravertebral areas by other diagnostic methods. For the follow-up PET scan, all patients wore warm clothing and avoided exposure to cold air during their transit to our facility. After arrival, patients were kept in a separate temperature-controlled room (at least 75°F) for 15 minutes to two hours before FDG injection as well as during the uptake phase. Four physicians blindly and retrospectively assessed the FDG uptake in the neck and paravertebral regions on all initial and temperature-controlled PET scans by visually grading the radioactivity on a semiquantitative scale (0 = background, 1+ = background but <liver, 2+ = equal to liver, 3+ >liver). The changes in maximal SUVs were determined in the left and right neck region. Data were evaluated using a two-tail t-test. Results Ten patients met the above criteria. The median age was 32 years with a range of 11–58 years. In comparing the semiquantitative uptake and the SUVs of FDG in the neck and paravertebral areas on the initial PET scan to the temperature-controlled PET scan, the mean decrease and the standard deviation of the decrease demonstrated a statistically significant decrease in with P values range from <0.02 to <0.001. Conclusion Controlling the patient’s environmental temperature prior to the dosing and during the uptake phase can significantly reduce FDG uptake in brown fat in the neck and paravertebral areas. Further studies are warranted to determine the most effective protocol to control the patient’s environmental temperature in order to minimize brown fat uptake.     

A Small Animal Positron Emission Tomography Study of the Effect of Chemotherapy and Hormonal Therapy on the Uptake of 2-Deoxy-2-[F-18]fluoro-<Emphasis Type="SmallCaps">d</Emphasis>-glucose in Murine Models of Breast Cancer

Purpose We used small animal positron emission tomography (PET) imaging to monitor the time-course of tumor metabolic response to hormone and chemotherapy in a murine model of hormone-sensitive breast cancer. Procedures Estrogen receptor positive murine mammary carcinomas were inoculated in Balb/c mice. Small animal PET imaging using 2-deoxy-2-[F-18]fluoro-d-glucose (FDG) was used to assess tumor metabolic activity. Imaging was done before and at days 1, 7, and 14 after the administration of doxorubicin, methotrexate, letrozole, or placebo. The tumor uptake of FDG was calculated from a region-of-interest drawn around the tumor. Results All treatments resulted in a decrease in tumor growth rate and end volume compared to untreated control. FDG uptake was also markedly decreased after treatment although a flare reaction was observed on PET at day 7, the intensity of which varied according to the treatment modality. Conclusion PET imaging is sensitive to detect early changes associated with therapy in murine breast cancer models. A flare reaction was observed 7 days after the initiation of therapy.     

Imaging Uterine Cervical Cancer with FDG-PET/CT: Direct Comparison with PET

Purpose  To compare 2-deoxy-2-[F-18]fluoro-d-glucose–positron emission tomography (FDG-PET) and PET/computed tomography (CT) for certainty of image interpretation and for diagnostic accuracy in patients with primary and metastatic uterine cervical cancer. Materials and Methods  Images of 13 patients with cervical cancer having PET/CT examinations were reviewed retrospectively. PET and PET/CT images of all cases were read blindly and randomly by two readers. Foci of increased FDG uptake on PET or PET/CT were classified using a scoring system regarding lesion localization and characterization. PET and PET/CT findings were assessed with all clinical information available, and diagnostic accuracy was determined on a per-lesion and on a per-patient basis. Results  For both readers, PET/CT provided significantly higher frequencies of definite lesion localization (>30% higher) and definite lesion characterization (>20% higher) compared to the findings on PET alone. The improvement in lesion localization to the definite level by PET/CT provided the definite lesion characterization in at least 50% of cases. PET/CT tended to exhibit higher diagnostic accuracy than PET alone on a lesion-based analysis (92% vs. 78% in reader 1 and 92% vs. 82% in reader 2, respectively). Metastatic disease spread was, however, almost equally evaluated between PET and PET/CT. Conclusion  PET/CT was demonstrated to be useful in the definite localization and characterization of foci of increased FDG uptake, which provided its higher diagnostic accuracy than PET alone. PET/CT appears preferable to PET in the evaluation of cervical cancer, although additional study is needed.     

Imaging of gynecologic malignancies with FDG PET–CT: case examples,physiolocic activity,and pitfalls

The utilization of 2-[fluorine 18] fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) in combination with computed tomography (CT) in the assessment of gynecologic malignancies has been rapidly growing in recent years; however, its role in clinical practice has yet to be established. A number of pitfalls are commonly encountered, including normal physiologic activity in bowel loops and blood vessels, or focal retained activity in ureters and urinary bladder. Increased uptake has also been reported in many benign pelvic processes and in premenopausal patients; endometrial activity changes cyclically, whereas increased ovarian uptake may be functional. FDG PET–CT has an emerging role in staging nodal disease and in the evaluation of local recurrence or peritoneal spread of gynecologic malignancies and is also useful in monitoring response to therapy and in long-term follow-up. FDG PET–CT is most suitable in patients with high tumor markers and negative or uncertain conventional imaging data. Patient preparation, proper scanning protocol, combined assessment of PET and CT data, and the evaluation of conventional imaging findings are essential to define disease and to avoid diagnostic pitfalls.     

High 2-Deoxy-2[F-18]fluoro-<Emphasis Type="SmallCaps">D</Emphasis>-glucose Uptake on Positron Emission Tomography in Hibernoma Originally Thought to be Myxoid Liposarcoma

Purpose The purpose of the study is to describe the rare tumor on 2-deoxy-2[F-18]fluoro-d-glucose (FDG) positron emission tomography (PET).Procedure A 33-year-old male was diagnosed with high uptake lesion on FDG-PET scanning, which was found to be hibernoma on excision.Results Hibernoma, originally confused with liposarcoma based on its PET and computed tomography presentation, was excised and correctly identified by pathology.Conclusion Although found to be benign, radiological and FDG-PET scanning results were indistinguishable from malignancy, and biopsy is required to exclude neoplasm.     

Clinical Value of Combined Positron Emission Tomography/Computed Tomography Imaging in the Interpretation of 2-Deoxy-2-[F-18]fluoro-<Emphasis Type="SmallCaps">d</Emphasis>-glucose–Positron Emission Tomography Studies in Cancer Patients

Background Positron emission tomography (PET)/computed tomography (CT) is a new imaging modality that provides exact coregistration of anatomic and metabolic data. We have investigated to what degree this new technique might affect the interpretation of PET images in a nonselected group of consecutive cancer patients, reflecting routine condition in a busy cancer center.Methods Whole-body 2-deoxy-2-[F-18]fluoro-d-glucose (FDG)–PET and PET/CT fusion image sets were compared in 100 consecutive, nonselected patients: 21 with head and neck cancer, 39 with chest malignancies, and 40 with malignancies of the abdomen and pelvis. All studies were performed for primary staging or evaluation of therapy and were interpreted by two nuclear medicine physicians also trained in radiology. Areas of abnormal FDG uptake were identified on PET and graded as likely benign, equivocal, or likely malignant. Positron emission tomography/computed tomography fusion images were then made available, and the initial findings were amended if necessary.Results One hundred sixty-six areas with abnormal FDG uptake were identified. Based on PET alone, 51 sites were considered equivocal for malignancy. With PET/CT, the number of equivocal lesions decreased to 24. This difference is more marked in the head and neck as well as the abdomen and pelvis. When the equivocal sites were included in the analysis and grouped with the malignant sites, positive predictive value (PPV) of PET/CT was 89% compared with 75% for PET (p = 0.04).Conclusion Combined PET/CT results in increased reader confidence and 53% fewer equivocal readings, as well as improved PPV compared with PET alone.*Contributed equally to this work.     

Findings of 2-fluoro-2-deoxy-<Emphasis Type="SmallCaps">d</Emphasis>-glucose positron emission tomography in hemorrhoids

Background  

Hemorrhoids are very common in adults. The data regarding the incidence of high 2-fluoro-2-deoxy-d-glucose (FDG) uptake in hemorrhoids is incomplete. In this study, we evaluated FDG uptake in hemorrhoids and calculated the rate of high FDG uptake in these lesions.     

中枢神经系统疾病的18F-FDGPET显像--附17例PET与CT、MRI和EEG对照

目的对１８ＦＦＤＧＰＥＴ在中枢神经系统疾病临床诊断中应用的初步体会作一介绍。方法１８ＦＦＤＧＰＥＴ检查共计１７例,所有患者静脉注射１８Ｆ脱氧葡萄糖（ＦＤＧ）１０ｍＣｉ后４０分钟进行脑１８ＦＦＤＧ正电子发射断层显像（ＰＥＴ）,其结果与同期的ＣＴ、ＭＲＩ、ＥＥＧ结果进行比较。结果在１０例癫痫发作间歇期病人中,４０％的病例１８ＦＦＤＧＰＥＴ显示病侧局部脑叶葡萄糖代谢即ＦＤＧ摄取低下（较正常健侧皮层放射性计数降低２０％以上）,５０％的病例脑叶葡萄糖代谢正常;脑梗塞、脑外伤后软化灶１８ＦＦＤＧＰＥＴ均显示为局部脑叶葡萄糖代谢明显下降或缺损,其余多发性硬化、多发小脓肿、蛛网膜囊肿均表现为脑内葡萄糖代谢正常。结论初步的临床应用显示,１８ＦＦＤＧＰＥＴ在中枢神经系统疾病诊断中具有重要的临床价值     

早期类风湿关节炎跖趾关节滑膜炎的临床检查与超声检查比较

目的应用高频彩色多普勒超声检查早期类风湿关节炎(RA)患者的跖趾关节,调查跖趾关节滑膜炎在早期RA中的发病率及病变特点,并与临床检查结果相比较。方法对连续57例病史<1年的RA患者在入院当天进行跖趾关节体格检查,记录关节有无肿胀、触痛,前足挤压试验阳性情况。同日进行跖趾关节的超声检查,记录关节积液、滑膜增生、滑膜血流情况。以超声检查结果作为金标准,对跖趾关节的体格检查及超声检查结果进行一对一比较。结果 29例患者主诉有足趾痛和(或)行走时前脚掌疼痛症状(占50.9%)。体格检查发现85个跖趾关节肿/痛阳性(阳性率14.9%),45只足前足挤压试验阳性(阳性率39.5%)。对照组超声检查未发现有跖趾关节滑膜炎。RA组中有45例患者(占78.9%)超声检查发现87只足至少1个跖趾关节有滑膜炎。全部570个跖趾关节中共287个发现有滑膜炎(阳性率50.4%),以第2跖趾关节滑膜炎阳性率最高,其次为第3跖趾关节。23个关节增生的滑膜内可检测到血流信号(占有滑膜增生关节的9.8%)。查体肿/痛关节阳性诊断跖趾关节滑膜炎与超声检查诊断滑膜炎的Kappa值为0.134,二者一致性较低。以超声检查结果为金标准,关节肿/痛、挤压试验检测跖趾关节滑膜炎的敏感性、特异性、阳性预测值、阴性预测值、阳性似然比、阴性似然比分别为0.22、0.92、0.73、0.54、2.66、0.85和0.51、0.96、0.98、0.38、13.66、0.51。结论跖趾关节是早期RA较易累及的关节,临床检查虽有较高的特异性,但不够敏感,超声在检测跖趾关节滑膜炎中有较高的应用价值。     

Prospective Comparison of FDG and FET PET/CT in Patients with Head and Neck Squamous Cell Carcinoma

Aim  The clinical usefulness of 2-deoxy-2-[F-18]fluoro-D-glucose-positron emission tomography (FDG-PET) in head and neck squamous cell carcinoma (HNSCC) is now well-documented. However, its sensitivity is greater than its specificity due to false-positive results in inflammatory or infectious lesions, which are frequent in this area, in particular after treatment by surgery and/or radiotherapy. O-2-fluoro-(18F)-ethyl-L-thyrosine (FET) has been reported not to be taken up by such lesions, and a preliminary study indicated that this may be clinically useful in HNSCC. We performed a prospective study to compare the diagnostic performances of FDG and FET PET/CT in the different settings of HNSCC. Materials and Methods  Twenty-seven patients (20 men and seven women, aged 48–76, among 30 patients included) and 69 suspected cancer sites are now evaluable on basis of postsurgical histology and/or follow-up greater than 6 months; 15 patients were referred for initial staging and 12 during posttherapy follow-up, a recurrence being suspected in eight of them. FDG and FET PET/CT were performed on two different days, the patient fasting for 6 h, 1 h after injection of 5 MBq/kg of body mass of each radiopharmaceutical. Both PET/CT examinations were blind read more than 6 months after the end of inclusions in a random order for each tracer and with a time interval greater than 1 month between FDG and FET PET/CT blind readings. Results  Overall diagnostic performances, derived from blind reading: FDG PET/CT on a per patient basis: sensitivity 100%, specificity 71%, accuracy 93%; FDG PET/CT on a per site basis: sensitivity 95%, specificity 63%, accuracy 83%; FET PET/CT on a per patient basis: sensitivity 70%, specificity 100%, accuracy 78%; FET PET/CT on a per site basis: sensitivity 64%, specificity 100%, accuracy 78%. At site level, sensitivity was significantly greater with FDG (p < 0.02) and specificity with FET (p < 0.01). The statistical level of significance was not reached at patient level. Conclusion  Although its good specificity was confirmed, FET did not appear to be suited as a first-line PET tracer in HNSCC imaging and cannot replace FDG for staging due to insufficient sensitivity. However, it was useful in a few selected cases to favor a wait and see attitude when a FDG+ FET− focus was discovered in patients referred for systematic FDG PET during follow-up. In contrast, second primary cancers should not be ruled out if FDG was clearly positive in the lungs or the digestive tract.     

Standardized Uptake Value Atlas: Characterization of Physiological 2-Deoxy-2-[<Superscript>18</Superscript>F]fluoro-<Emphasis Type="SmallCaps">d</Emphasis>-glucose Uptake in Normal Tissues

Purpose The purpose of this study was to map the distribution of 2-deoxy-2-[¹⁸F]fluoro-d-glucose (FDG) uptake in organs of patients with no known abnormalities in those tissues. Procedures We measured maximum and mean standardized uptake values (SUV) from FDG-positron emission tomography (PET)/computed tomography (CT) obtained from 98 patients (48 males and 50 females). Results Significant uptake (mean SUV_mean > 2.5) was visualized in the cerebellum (8.0 ± 2.2), soft palate (2.92 ± 0.86), palatine tonsils (3.45 ± 1.4), lingual tonsils (3.08 ± 1.05), sublingual glands (3.3 ± 1.5), and testes (2.57 ± 0.56). Negative correlation for FDG uptake versus age was observed for the palatine tonsils, sublingual glands, and lungs (P < 0.001). Conclusion Better understanding of physiological uptake throughout the body is valuable for improved interpretive accuracy and should be useful for future semi-automated comparisons to a normal SUV database.     

Optimization of Whole-Body Positron Emission Tomography Imaging by Using Delayed 2-Deoxy-2-[F-18]fluoro-d-glucose Injection Following I.V. Insulin in Diabetic Patients

Purpose High blood glucose levels may decrease the sensitivity of 2-deoxy-2-[F-18]fluoro-d-glucose (FDG)-positron emission tomography (PET). The goal of this study was to assess whether intravenous (i.v.) insulin followed by FDG injection 60 minutes later could decrease the blood glucose level of hyperglycemic patients without altering muscular, liver, or lung FDG uptake.Methods We evaluated 53 diabetic patients with a fasting glycemia higher than 7.0 mmol/l. The control group consisted of 53 nondiabetic patients with a normal fasting glycemia. Sixty minutes before FDG injection, all diabetic patients received up to two intravenous bolus of insulin. Regions of interest were drawn over the lungs, heart, liver, skeletal muscles, and over the most active lung nodule, if present, to calculate a standardized uptake value (SUV) normalized to the lean body weight.Results After one or two boluses of insulin (mean 3.4 units), 39 diabetic patients decreased their blood glucose level from 9.4 ± 1.8 to 6.1 ± 1.3 mmol/l. In 14 patients, two doses of insulin (mean 4.5 ± 2.3 units) were not sufficient, but managed to decrease the blood glucose level from 10.6 ± 2.1 to 9.1 ± 2.1 mmol/l. There was no significant difference for the SUV calculated on the lung, liver, heart, and skeletal muscles. No differences were noted in lung tumor uptake in patients who received insulin compared to the control group.Conclusions With a sufficient waiting period between the insulin and FDG injections, an i.v. bolus of insulin makes it possible to effectively decrease glycemia of diabetic patients without increasing muscular FDG uptake.     

Impact of CT attenuation correction on the viability pattern assessed by <Superscript>99m</Superscript>Tc-tetrofosmin SPECT/<Superscript>18</Superscript>F-FDG PET

SPECT myocardial perfusion imaging (MPI) is commonly used for comprehensive interpretation of metabolic PET FDG imaging in ischemic dysfunctional myocardium. We evaluated the difference in scan interpretation introduced by CT attenuation correction (CTAC) of SPECT MPI in patients undergoing viability characterization by ^99mTc SPECT MPI/PET FDG. In 46 consecutive patients (mean age 64, range 36–83 years) with dysfunctional myocardium, we analyzed viability from combined SPECT MPI and PET FDG scanning without attenuation correction (NC) and with CTAC for SPECT MPI. FDG uptake was classified in groups of percent uptake using the segment with maximum tracer in SPECT perfusion uptake as reference. Viability patterns were categorized as normal, mismatch, mild match and scar by relative comparison of SPECT and PET. Applying CTAC introduced a different reference segment for the normalization of PET FDG study in 57% of cases. As a result, the flow-metabolism pattern changed in 28% of segments, yielding a normal, mismatch, mild match and scar pattern in 462, 150, 123, and 47 segments with NC and 553, 86, 108, and 35 with CTAC, respectively (P = 0.001). Thus, by introducing CTAC for SPECT MPI 25% of segments originally classified as scar were reclassified and the number of normal segments increased by 20%. Introducing CTAC decreased by 54% the number of patients with possible indication for revascularization, from 26/46 to 12/46 (P < 0.001). Different interpretation of myocardial viability can be observed when using CTAC instead of NC SPECT MPI as reference for PET FDG scans.     

Comparison of 11C-Methionine PET and 18F-FDG PET in Patients with Primary Central Nervous System Lymphoma

Purpose  

2-deoxy-2-[¹⁸F]fluoro-d-glucose (FDG) positron emission tomography (PET) has been used as a promising tool to diagnose primary central nervous system (CNS) lymphoma because the tumor shows very high FDG accumulation. Although ¹¹C-methionine (MET) PET has been reported to be useful for evaluating various brain tumors, the role of MET PET in CNS lymphoma is unclear. We compared the uptake of MET and FDG in patients with CNS lymphoma.