FDG PET-CT combined with TBNA for the diagnosis of atypical relapsing polychondritis: report of 2 cases and a literature review

Objective

To explore the value of ¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) combined with transbronchial needle aspiration (TBNA) in diagnosing atypical relapsing polychondritis (RP).

Methods

Data from two patients with atypical RP, which had been diagnosed in our hospital using FDG PET-CT combined with TBNA, were retrospectively analyzed. A review of the relevant literature was also performed.

Results

Consistent with the previously reported 20 cases of RP that had been diagnosed using FDG PET-CT, the two patients in the present study showed the involvement of multiple organs, including the nose, throat, trachea, bronchi, costicartilage and joint cartilages, and increased FDG uptake was found in these areas. The mean value of SUVmax was 5.14. PET-CT revealed that 86.4% of the patients with RP had airway involvement. TBNA technique was used for biopsy of the hypermetabolic lesions, and pathologic examinations confirmed the diagnosis of RP. The time to diagnosis in these two patients and the 20 cases reported previously was about 6.9 months, significantly shorter than the average diagnosis time (20 months).

Conclusions

FDG PET-CT has several advantages for diagnosing RP, especially atypical RP. TBNA is a minimally invasive and safe technique for obtaining airway cartilage. Combining PET-CT with TBNA may play an important role in shortening the time to diagnosis in patients with RP involvement of airway.     

Occupant Dynamics in Rollover Crashes: Influence of Roof Deformation and Seat Belt Performance on Probable Spinal Column Injury

Motor vehicle crashes are the leading cause of death in the United States for people ages 3-33, and rollover crashes have a higher fatality rate than any other crash mode. At the request and under the sponsorship of Ford Motor Company, Autoliv conducted a series of dynamic rollover tests on Ford Explorer sport utility vehicles (SUV) during 1998 and 1999. Data from those tests were made available to the public and were analyzed in this study to investigate the magnitude of and the temporal relationship between roof deformation, lap-shoulder seat belt loads, and restrained anthropometric test dummy (ATD) neck loads. During each of the three FMVSS 208 dolly rollover tests of Ford Explorer SUVs, the far-side, passenger ATDs exhibited peak neck compression and flexion loads, which indicated a probable spinal column injury in all three tests. In those same tests, the near-side, driver ATD neck loads never predicted a potential injury. In all three tests, objective roof/pillar deformation occurred prior to the occurrence of peak neck loads (F ( z ), M ( y )) for far-side, passenger ATDs, and peak neck loads were predictive of probable spinal column injury. The production lap and shoulder seat belts in the SUVs, which restrained both driver and passenger ATDs, consistently allowed ATD head contact with the roof while the roof was contacting the ground during this 1000 ms test series. Local peak neck forces and moments were noted each time the far-side, passenger ATD head contacted ("dived into") the roof while the roof was in contact with the ground; however, the magnitude of these local peaks was only 2-13% of peak neck loads in all three tests. "Diving-type" neck loads were not predictive of injury for either driver or passenger ATD in any of the three tests.     

2-Deoxy-2-[F-18]fluoro-<Emphasis Type="SmallCaps">d</Emphasis>-glucose-Positron Emission Tomography Sensitivity to Serum Glucose: A Survey and Diagnostic Applications

OBJECTIVE: The positron emission tomography (PET) clinical utility of the sensitivity (gamma) of uptake (Q) to a change in plasma glucose concentration (C) is investigated. METHODS: Gamma is obtained from data as [ln(Q (2)/Q (1))] / [ln(C(2)/C(1))], using previously published intrapatient studies varying C within a single patient and some interpatient ones. It can be theoretically related to the half-saturation constant in the Michaelis-Menten quantification of competitive uptake. One of its uses is making uptake corrections for desired vs. actual C using Q(2) = Q(1) (C(2)/C(1))(gamma). RESULTS: Intrapatient studies proved to be preferable to interpatient ones, and a 2-deoxy-2-[F-18]fluoro-D-glucose (FDG)-PET survey with analyses for gamma yielded the following result: usually the gamma values of tumors and brain tissues were near -1, whereas those of other noncerebral tissues were near 0. Regarding correcting uptakes for C, instead of a universally assumed and applied gamma = -1, corrections should be for a single tissue using its known gamma. An advantageous use of gamma is predicting how C affects image contrast, including where glucose loading is sometimes preferable to fasting. CONCLUSIONS: A potentially useful quantifier of uptake sensitivity to plasma glucose has been defined and values obtained. Correcting uptakes to some standard C requires special care. gamma can help PET clinicians select fasting or loading to achieve glucose levels for optimum contrast.     

Using positron emission tomography to study human ketone body metabolism: A review

Ketone bodies – 3-hydroxybutyrate and acetoacetate – are important fuel substrates, which can be oxidized by most tissues in the body. They are synthesized in the liver and are derived from fatty acids released from adipose tissue. Intriguingly, under conditions of stress such as fasting, arterio-venous catheterization studies have shown that the brain switches from the use of almost 100% glucose to the use of > 50–60% ketone bodies. A similar adaptive mechanism is observed in the heart, where fasting induces a shift toward ketone body uptake that provides the myocardium with an alternate fuel source and also favorably affects myocardial contractility. Within the past years there has been a renewed interest in ketone bodies and the possible beneficial effects of fasting/semi-fasting/exercising and other “ketogenic” regimens have received much attention. In this perspective, it is promising that positron emission tomography (PET) techniques with isotopically labeled ketone bodies, fatty acids and glucose offer an opportunity to study interactions between ketone body, fatty acid and glucose metabolism in tissues such as the brain and heart. PET scans are non-invasive and thus eliminates the need to place catheters in vascular territories not easily accessible. The short half-life of e.g. 11C-labeled PET tracers even allows multiple scans on the same study day and reduces the total radiation burden associated with the procedure. This short review aims to give an overview of current knowledge on ketone body metabolism obtained by PET studies and discusses the methodological challenges and perspectives involved in PET ketone body research.     

Choroid Plexus as the Best Reference Region for Standardized Uptake Value Analysis on C11-Acetate PET/CT for Grading and Predicting Prognosis in Patients with Cerebral Gliomas

PurposeWe aimed to compare different reference regions and select one with the most clinical relevance on C11-acetate (ACE) positron emission tomography/computed tomography (PET/CT) in patients with cerebral glioma.MethodsWe retrospectively reviewed 51 patients with cerebral glioma who underwent baseline ACE PET/CT at diagnosis. Other than the standardized uptake value (SUV) of the primary tumor, SUVs of the reference regions including the normal gray matter, white matter, choroid plexus, and cerebellum were measured. Then, the SUV ratio (SUV_R = tumor SUV_max/reference region SUV_mean) was calculated. The effect of patient age on the SUV_mean of each reference was examined and the SUV_Rs of each reference region were compared between grades. age, sex, tumor size, histological grades, SUV_R, and the presence of isocitrate dehydrogenase (IDH) mutation were included for survival analyses.ResultsExcept for the cerebellum showing a mild negative correlation, we found no correlations between age and SUV_mean using the gray matter, white matter, and choroid plexus (r = − 0.280, P = 0.047). Only the SUV_R-choroid plexus was able to differentiate between the WHO grades (Grade II vs. III, P = 0.035; grade III vs. IV, P < 0.001; grade II vs. IV, P < 0.001). Multivariate Cox proportional hazards models found that the SUVR-choroid plexus and IDH mutation were statistically significant for predicting OS.ConclusionOf the different reference regions used for grading cerebral gliomas, the choroid plexus was found to be the most optimal. In addition, the SUV ratio is useful to predict the overall survival in the model with the choroid plexus as a reference region.     

沉默SUV39H1基因对急性髓系白血病KG-1细胞凋亡的影响

摘要本研究旨在探讨沉默SUV39H1基因对急性髓系白血病细胞株KG-1增殖和凋亡的影响。将SUV39HIsiRNA经Lipofectamine…2000转染至KG-1细胞,应用MTS法检测细胞增殖率,观察sUV39111siRNA对KG-1细胞增殖的影响;流式细胞术分析细胞凋亡;Westernblot检测SUV39H1siRNA作用后P15和凋亡相关蛋白BCL-2、procaspase-9、procaspase-3、C-MYC的表达。结果表明,沉默SUV39H1基因可抑制细胞增殖,SUV39H1siRNA浓度为30、60、120、240nmol／L作用48h后,KG-1细胞的增殖率分别为（76．43±1．98）％、（51．31±1．84）％、（37．31±1．61）％、（18．94±3．22）％,差异具有统计学显著意义（P〈0．05）;SUV39HIsiRNA可上调P15基因的表达;SUV39H1siRNA可诱导细胞凋亡,30、60、120nmoL／LSUV39H1siRNA作用48h后,KG-1细胞凋亡率分别为（40．2±5．1）％、（56．8±4．8）％、（71．6±5．6）％,差异有统计学显著意义（P〈0．05）;抗凋亡相关蛋白BCL-2、procaspase-9、procaspase-3、C-MYC的表达减少。结论：SUV39H1siRNA能抑制KG-1细胞的增殖并诱导其凋亡,有望成为白血病治疗的-个新的靶点。     

Comparison of whole-body PET/CT and PET/MRI in breast cancer patients: Lesion detection and quantitation of 18F-deoxyglucose uptake in lesions and in normal organ tissues

Purpose

To compare the performance of PET/MRI imaging using MR attenuation correction (MRAC) (DIXON-based 4-segment -map) in breast cancer patients with that of PET/CT using CT-based attenuation correction and to compare the quantification accuracy in lesions and in normal organ tissues.

Methods

A total of 36 patients underwent a whole-body PET/CT scan 1 h after injection and an average of 62 min later a second scan using a hybrid PET/MRI system. PET/MRI and PET/CT were compared visually by rating anatomic allocation and image contrast. Regional tracer uptake in lesions was quantified using volumes of interest, and maximal and mean standardized uptake values (SUVmax and SUVmean, respectively) were calculated. Metabolic tumor volume (MTV) of each lesion was computed on PET/MRI and PET/CT. Tracer uptake in normal organ tissue was assessed as SUVmax and SUVmean in liver, spleen, left ventricular myocardium, lung, and muscle.

Results

Overall 74 FDG positive lesions were visualized by both PET/CT and PET/MRI. No significant differences in anatomic allocation scores were found between PET/CT and PERT/MRI, while contrast score of lesions on PET/MRI was significantly higher. Both SUVmax and SUVmean of lesions were significantly higher on PET/MRI than on PET/CT, with strong correlations between PET/MRI and PET/CT data (ρ = 0.71–0.88). MTVs of all lesions were 4% lower on PET/MRI than on PET/CT, but no statistically significant difference was observed, and an excellent correlation between measurements of MTV with PET/MRI and PET/CT was found (ρ = 0.95–0.97; p < 0.0001). Both SUVmax and SUVmean were significantly lower by PET/MRI than by PET/CT for lung, liver and muscle, no significant difference was observed for spleen, while either SUVmax and SUVmean of myocardium were significantly higher by PET/MRI. High correlations were found between PET/MRI and PET/CT for both SUVmax and SUVmean of the left ventricular myocardium (ρ = 0.91; p < 0.0001), while moderate correlations were found for the other normal organ tissues (ρ = 0.36–0.61; p < 0.05).

Conclusions

PET/MRI showed equivalent performance in terms of qualitative lesion detection to PET/CT. Despite significant differences in tracer uptake quantification, due to either methodological and biological factors, PET/MRI and PET/CT measurements in lesions and normal organ tissues correlated well. This study demonstrates that integrated whole-body PET/MRI is feasible in a clinical setting with high quality and in a short examination time.     

4D PET/CT对肺部结节呼吸伪影纠正及SUV值影响的初步探讨

目的 通过与3D PET/CT的采集方式进行对比,探讨4D采集对肺部结节呼吸伪影纠正的应用价值. 方法 选择在我科进行常规3D PET/CT显像并同意进行呼吸门控4D显像的患者14例,均伴有多个肺部结节.3D PET采集时间2 min/床位,4D PET采集时间6 min/床位,分为6个呼吸时相,平均每时相1 min.SUV值由AW系统全自动分析获得.每个结节在3D PET以及4D PET的6个时相中共测量7次. 结果 所有患者4D和3D胸部PET/CT图像清晰,PET信噪比分别为4.00 ±0.35和3.98 ±0.55,二者之间差异没有统计学意义(Z=-1.109,P=0.267);而4D CT噪声水平较3D CT略增高,在肺结节特性显示中某些时相优于常规CT.14例患者37个肺部结节中,3D PET/CT发现呼吸伪影33个,4D PET/CT纠正伪影31个(93.9％);4D PET显像可以提高病灶的SUV值,3D和4D PET所获得的SUVmax相关性非常好(r=0.971),但4D PET得到的SUV一明显高于3D PET/CT(13.69 ±6.70 vs 12.76 ±6.74,t=3.475,P=0.001). 结论 采用4D PET/CT显像图像质量清晰,呼吸伪影校正良好,能达到诊断的要求,且4D PET/CT所获得的肺部结节SUVmax比3D常规采集明显升高,可以为临床诊断提供更多的临床依据.