Distinct patterns of neuronal inputs and outputs of the juxtaparaventricular and suprafornical regions of the lateral hypothalamic area in the male rat

We have analyzed at high resolution the neuroanatomical connections of the juxtaparaventricular region of the lateral hypothalamic area (LHAjp); as a control and in comparison to this, we also performed a preliminary analysis of a nearby LHA region that is dorsal to the fornix, namely the LHA suprafornical region (LHAs). The connections of these LHA regions were revealed with a coinjection tract-tracing technique involving a retrograde (cholera toxin B subunit) and anterograde (Phaseolus vulgaris leucoagglutinin) tracer. The LHAjp and LHAs together connect with almost every major division of the cerebrum and cerebrospinal trunk, but their connection profiles are markedly different and distinct. In simple terms, the connections of the LHAjp indicate a possible primary role in the modulation of defensive behavior; for the LHAs, a role in the modulation of ingestive behavior is suggested. However, the relation of the LHAjp and LHAs to potential modulation of these behaviors, as indicated by their neuroanatomical connections, appears to be highly integrative as it includes each of the major functional divisions of the nervous system that together determine behavior, i.e., cognitive, state, sensory, and motor. Furthermore, although a primary role is indicated for each region with respect to a particular mode of behavior, intermode modulation of behavior is also indicated. In summary, the extrinsic connections of the LHAjp and LHAs (so far as we have described them) suggest that these regions have a profoundly integrative role in which they may participate in the orchestrated modulation of elaborate behavioral repertoires.     

SPECT/CT定量分析对肿瘤患者脊柱颈胸段骨病变的诊断价值

目的 使用SPECT SUV进行定量评估,客观比较脊柱颈胸段骨关节炎和骨转移之间的99mTc-MDP示踪剂摄取,探讨SUV定量在骨关节炎和骨转移中的诊断价值.方法 回顾性分析在本院诊断为肿瘤的患者57例,用99mTc-MDP对其进行SPECT/CT骨显像.骨显像共发现187个高代谢颈胸椎病变,其中骨转移组143个,骨关...     

FDG PET-CT in Non-small Cell Lung Cancer: Relationship between Primary Tumor FDG Uptake and Extensional or Metastatic Potential

Objective: To explore the relationships between primary tumor 18F-FDG uptake measured as the SUVmaxand local extension, and nodal or distant organ metastasis in patients with NSCLC on pretreatment PET-CT.Methods: 93 patients with NSCLC who underwent 18F-FDG PET-CT scans before the treatment were included inthe study. Primary tumor SUVmax was calculated; clinical stages, presence of local extension, nodal and distantorgan metastases were recorded. The patients with SUVmax≥2.5 were divided into low and high SUVmax groupsby using the median SUVmax. The low SUVmax group consisted of 45 patients with SUVmax<10.5, the highSUVmax group consisted of 46 patients with SUVmax≥10.5. Their data were compared statistically. Results: 91cases with SUVmax≥2.5 were included for analysis. The mean SUVmax in patients without any metastasis was7.42±2.91 and this was significantly lower than that (12.18±4.94) in patients with nodal and/or distant organmetastasis (P=0.000). In the low SUV group, 19 patients had local extension, 22 had nodal metastasis, and 9 haddistant organ metastasis. In the high SUV group, 31 patients had local extension, 37 had nodal metastasis, and18 had distant organ metastases. There was a significant difference in local extension (P =0.016), distant organmetastasis (P =0.046), and most significant difference in nodal metastasis rate (P =0.002) between the two groups.In addition, there was a moderate correlation between SUVmax and tumor size (r = 0.642, P﹤0.001), tumor stage(r = 0.546, P﹤0.001), node stage (r = 0.388, P﹤0.001), and overall stage (r = 0.445, P= 0.000). Conclusion: Higherprimary tumor SUVmax predicts higher extensional or metastatic potential in patients with NSCLC. Patientswith higher SUVmax may need a close follow-up and more reasonable individual treatment because of theirhigher extensional and metastatic potential.     

Variation in background intensity affects PET-based gross tumor volume delineation in non-small-cell lung cancer: The need for individualized information

Purpose

Efficient tumor volume delineation by the combined use of PET/CT scanning is necessary for the proper treatment of non-small cell lung cancer (NSCLC). To understand the effect of variation in background intensity on PET-based gross tumor volume (GTV) delineation, we determined the background standard uptake values (SUVs) in normal lung, aorta (blood pool), and liver tissues and determined GTVs using different methods.

Methods

Thirty-seven previously untreated patients with pathologically confirmed NSCLC underwent PET/CT scanning with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG). To obtain ¹⁸F-FDG uptake values in normal tissues, regions of interest in the lung lobes (left upper, left lower, right upper, right middle, and right lower), aorta, and liver zones (left, intermediate, and right) were measured. The coefficient of variation (CV) of the SUV was measured for each normal structure. The CT-based GTV (GTV_CT) was considered as the standard to which all PET-based GTVs were compared, and the correlation coefficient was analyzed to compare GTV obtained by the various delineation methods. Linear and logarithmic regression analyses were used to determine the relationship between GTV_CT and GTV_PET.

Results

Normal lung tissue showed a significantly lower SUV and less stability than tissue of the aorta or liver. For the lung, aorta, and liver, the maximum SUV (SUV_max) was 0.82 ± 0.32, 2.35 ± 0.37, and 3.24 ± 0.50 (CV: 38.79%, 15.82%, and 15.30%) and average SUV (SUV_ave) was 0.49 ± 0.18, 1.68 ± 0.32, and 2.34 ± 0.36 (CV: 36.38%, 18.92%, and 15.44%), respectively. The SUVs of the lung varied from lobe to lobe. The GTV delineation method using the SUV_ave of the lung lobe in which the tumor was found as background in the source-to-background ratio (SBR) method showed the best correlation with the volume of CT-based GTV (r = 0.81).

Conclusions

Our results show vast variation in the SUV among normal tissues, as well as in the different lung lobes. The tumor volume delineated using the SBR method correlated well with the CT-based tumor volume. We conclude that it is reasonable and precise to contour GTV in patients with NSCLC after taking into account the background intensity of the lung lobe in which the tumor is found.     

18F-FDG PET/CT在胃部疾病诊断中的应用

[目的] 探讨 18F-FDG PET/CT 在胃部良恶性疾病鉴别诊断中的作用.[方法] 回顾性分析49例临床可疑胃部疾病患者行 18F-FDG PET/CT 显像的结果.分析病灶分布特点、厚度及标准化摄取值最大值(SUVmax).[结果] 胃部良、恶性病灶的厚度分别为(13.800±3.489)mm、(18.088±8.575)mm,差异具有统计学意义(t=-2.486,P=0.017);胃部良、恶性病灶的早期相 SUVmax 分别为3.607±2.710、7.277±6.175,差异具有统计学意义(t=-2.891,P=0.006);胃癌组早期相与延迟相 SUVmax 分别为5.131±2.486与6.156±3.126(t=-3.691,P=-0.002);胃淋巴瘤组则分别为9.183±7.770与11.744±10.222(t=--4.095,P=0.001),差异均有统计学意义.[结论] 18F-FDG PET/CT 显像在胃部良恶性疾病鉴别方面具有重要作用.     

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.     

Evaluation of the therapeutic effects and recurrence for head and neck cancer after chemoradiotherapy by FDG-PET

Objective

The purpose of this study was to detect early stage recurrence or a residual tumor after chemoradiotherapy by FDG-PET.

Methods

A total of 51 head and neck cancer lesions in 27 patients were examined—including primary sites and metastatic lymph nodes. The therapeutic effects were evaluated by visual inspection, pre-treatment SUV, post-treatment SUV and % change in SUV.

Results

No local recurrence was observed in 37 of the lesions, while recurrence or a residual tumor was observed in the other 14 lesions after therapy. A significant difference was found between the two groups regarding the post-treatment SUV and the % change in SUV. Taking the post-treatment SUV of 3 and the % change of 60 as a cut-off value, a significant difference was thus found between the recurrence cases and non-recurrence cases. When all lesions were divided into two groups—including the post-treatment SUV > 3 and the % change in the SUV < 60 group, and the post-treatment SUV < 3 or the % change in SUV > 60 group, the overall accuracy was 88.2% (45/51). Therefore, it is more useful to predict the prognosis after chemoradiotherapy by a combined analysis of the post-treatment SUV and the % change in SUV. According to the post-treatment PET period, namely, within 4 weeks and from 5 to 15 weeks after treatment, the accuracy was 85.7% (24/28) and 91.3% (21/23), respectively (p = 0.5385).

Conclusion

The results suggest that it may be possible to predict the recurrence even at 4 weeks after treatment. Therefore, the use of a semi-quantitative analysis of FDG-PET between the pre-treatment and post-treatment findings is thus considered to be helpful in choosing the optimal therapy and for making an accurate prognosis.     

The Netherlands protocol for standardisation and quantification of FDG whole body PET studies in multi-centre trials

Introduction  Several studies have shown the usefulness of positron emission tomography (PET) quantification using standardised uptake values (SUV) for diagnosis and staging, prognosis and response monitoring. Many factors affect SUV, such as patient preparation procedures, scan acquisition, image reconstruction and data analysis settings, and the variability in methodology across centres prohibits exchange of SUV data. Therefore, standardisation of 2-[¹⁸F] fluoro-2-deoxy-D-glucose (FDG) PET whole body procedures is required in multi-centre trials. Methods  A protocol for standardisation of quantitative FDG whole body PET studies in the Netherlands (NL) was defined. This protocol is based on standardisation of: (1) patient preparation; (2) matching of scan statistics by prescribing dosage as function of patient weight, scan time per bed position, percentage of bed overlap and image acquisition mode (2D or 3D); (3) matching of image resolution by prescribing reconstruction settings for each type of scanner; (4) matching of data analysis procedure by defining volume of interest methods and SUV calculations and; (5) finally, a multi-centre QC procedure is defined using a 20-cm diameter phantom for verification of scanner calibration and the NEMA NU 2 2001 Image Quality phantom for verification of activity concentration recoveries (i.e., verification of image resolution and reconstruction convergence). Discussion  This paper describes a protocol for standardization of quantitative FDG whole body multi-centre PET studies. Conclusion  The protocol was successfully implemented in the Netherlands and has been approved by the Netherlands Society of Nuclear Medicine. An erratum to this article can be found at     

Does partial volume corrected maximum SUV based on count recovery coefficient in 3D-PET/CT correlate with clinical aggressiveness of non-Hodgkin’s lymphoma?

Objective There is much controversy about the correlation between the degree of 2-[¹⁸F]fluoro-2-deoxy-d-glucose (FDG) uptake and clinical aggressiveness of non-Hodgkin’s lymphoma (NHL). In this study, we investigated whether partial volume corrected FDG uptake based on count recovery coefficient in 3D-positron emission tomography (PET)/computed tomography (CT) correlates with the clinical aggressiveness of NHL and improves diagnostic accuracy. Methods Forty-two patients with NHL underwent FDG-PET/CT scans (26 aggressive NHLs and 16 indolent ones). Count recovery curve was obtained using NEMA 2001 body phantom. Scan protocol and reconstructive parameters in the phantom study were the same as those in a clinical scan except for emission time. Relative recovery coefficient (RC) was calculated as RC = A/B (A, maximum pixel count of each hot sphere; B, maximum pixel count of greatest sphere). Partial volume corrected maximum count of standardized uptake value (PVC-SUV) was calculated as PVC-SUV = NC-SUV/RC (NC-SUV: non-corrected maximum count of SUV). Three parameters (NC-SUV, PVC-SUV, and size) between aggressive and indolent NHLs were compared. Results Significant differences were shown in all parameters between aggressive and indolent NHLs. Means ± SD of NC-SUV, PVC-SUV, and size was as following: NC-SUV (15.3 ± 6.9, 8.7 ± 7.0; P < 0.01), PVC-SUV (18.2 ± 8.1, 12.7 ± 7.8; P < 0.05), and size (mm, 32.4 ± 18.3, 21.9 ± 10.3; P < 0.05). When an NC-SUV of 9.5 was the cutoff for aggressive NHL, the receiver-operating-characteristic (ROC) analysis correctly identified 21 of 26 aggressive ones. Sensitivity and specificity were 81% each, and the positive and negative predictive values were 88% and 72%, respectively. When a PVCSUV of 11.2 was the cutoff, the ROC analysis revealed 81% sensitivity, 63% specificity, and positive and negative predictive values of 78% and 67%, respectively. At a cutoff for aggressive NHL of a size of 27 mm, the ROC analysis revealed 50% sensitivity, 81% specificity, and positive and negative predictive values of 81% and 50%, respectively. The comparison of area under the curve in ROC analyses indicated that NC-SUV showed the greatest diagnostic accuracy (NC-SUV 0.84, PVC-SUV 0.72, and size 0.69). Conclusions Diagnostic accuracy of PVC-SUV was inferior to that of NC-SUV. These results suggest that NC-SUV, which contains information on both size and FDG density, provides better differentiation between aggressive and indolent NHLs than PVC-SUV.     

Standardized uptake values of uterine leiomyoma with <Superscript>18</Superscript>F-FDG PET/CT: variation with age,size, degeneration,and contrast enhancement on MRI

OBJECTIVE: To assess the effect of age, size, the degree of degeneration, and contrast enhancement on magnetic resonance imaging (MRI) on 18F-fluoro-2-deoxyglucose (18F-FDG) uptake in uterine leiomyomas using quantitative standardized uptake values (SUVs). METHODS: A total of 61 leiomyomas of 41 patients, who underwent combined positron emission tomography/computed tomography (PET/CT) using 18F-FDG and contrast-enhanced MRI were included in this study. Sixty-one leiomyomas were divided into two groups: "non-degenerated" leiomyomas showing distinct low signal intensity on T2-weighted images and intermediate signal intensity on T1-weighted images, and "degenerated" leiomyomas showing other types of signal intensity. Sixty-one leiomyomas were also divided into two groups of "strongly enhancing" leiomyomas and "weakly enhancing" leiomyomas in terms of their degree of contrast enhancement on MRI. RESULTS: The mean values of the maximum and average SUVs for the total of 61 leiomyomas were 2.34 +/- 0.75 (range 1.59-5.15) and 1.74 +/- 0.50 (0.66-3.95), respectively. There was a moderate negative correlation between the maximum and average SUVs and age (r = -0.43 and P = 0.00016, r = -0.31 and P = 0.029, respectively). Although there was a mild positive correlation between maximum SUV and size (r = 0.35 and P = 0.011), there was no significant difference between average SUV and size. Although there was no significant difference in average SUV between "degenerated" and "non-degenerated" leiomyomas, the maximum SUV of "degenerated" leiomyomas was significantly higher than that of "non-degenerated" leiomyomas (P = 0.0012). The degree of contrast enhancement on MRI was not significantly correlated with 18F-FDG uptake. CONCLUSIONS: Mild or moderate uptake of 18F-FDG is often observed in uterine leiomyoma and declines with age, and should not be confused with malignant accumulation.