Analysis of 18F-FDG PET/CT imaging in infectious mononucleosis / 中华核医学与分子影像杂志

Objective:To summarize the characteristics of 18F-fluorodeoxyglucose (FDG) PET/CT imaging in adult patients with infectious mononucleosis (IM). Methods:18F-FDG PET/CT imaging data and clinical data of 5 IM patients (all males, age 18-77 years) detected in the Department of Nuclear Medicine of the East Hospital Affiliated to Tongji University from July 2015 to July 2019 were analyzed retrospectively. Distribution of lymphatic tissues in the lesions (lymph nodes, tonsils, bone marrow, liver, etc) and 18F-FDG radioactive uptake in the lesions were analyzed semiquantitatively. Results:In 5 patients with IM, the volume of superficial lymph nodes (mainly distributed in the neck, axilla, and groin lymph nodes) and deep lymph nodes (mainly distributed in the mediastinum, hilum of lung, abdominal cavity and posterior abdominal cavity) increased to varying degrees, as well as the FDG uptake. Maximum standardized uptake value (SUV max) of superficial lymph nodes were 1.2-7.3, and those of deep lymph nodes were 3.5-9.7. All patients showed diffuse uptake of FDG in bone marrow, with SUV max of 3.0-7.9. All patients had pharyngeal tonsillar enlargement and FDG uptake increasing, with SUV max of 1.7-13.4. Compared with patients with lymphoma, IM patients had more organ involvement and relatively lower radioactive uptake. Conclusion:18F-FDG PET/CT imaging features of IM can help the diagnosis of IM.

Diagnostic Value of Volume-Based Fluorine-18-Fluorodeoxyglucose PET/CT Parameters for Characterizing Thyroid Incidentaloma

OBJECTIVE: To assess clinical value of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) for differentiation of malignant from benign focal thyroid incidentaloma. MATERIALS AND METHODS: This retrospective study included 99 patients with focal thyroid incidentaloma of 5216 non-thyroid cancer patients that had undergone PET/CT. PET/CT semi-quantitative parameters, volume-based functional parameters, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of thyroid incidentaloma were assessed. Receiver-operating characteristic (ROC) analysis was conducted and areas under the curve (AUC) were compared by Hanley and McNeil test to evaluate usefulness of maximum standardized uptake value (SUVmax), MTV and TLG, as markers for differentiating malignant from benign thyroid incidentalomas. RESULTS: Of 99 thyroid incidentalomas, 64 (64.6%) were malignant and 35 (35.4%) were benign. Malignant thyroid incidentalomas were larger (1.8 cm vs. 1.3 cm, p = 0.006), and had higher SUVmax (11.3 vs. 4.8, p 0.05). A threshold TLG 4.0 of 2.475 had 81.3% sensitivity and 94.3% specificity for identifying malignant thyroid incidentalomas. CONCLUSION: Volume-based PET/CT parameters could potentially have clinical value in differential diagnosis of thyroid incidentaloma along with SUVmax.

FDG-PET/CT and diffusion-weighted MRI evaluation of the early therapeutic effect of radiofrequency ablation for VX2 sarcomas in rabbits / 介入放射学杂志

Objective To discuss the value of diffusion-weighted MRI (DWI) and 18F-FDG-PET/CT in assessing the early therapeutic effect of radiofrequency ablation (RFA) for VX2 sarcomas in experimental rabbits. Methods VX2 sarcoma was inoculated at bilateral hind limbs in 14 New Zealand white rabbits to establish the animal models. The implanted VX2 tumor on one hind leg was treated with ultrasound-guided percutaneous RFA (study group), while no RFA was given to the VX2 tumor on the contralateral hind leg (control group). DWI-MRI was performed at 2 days after RFA, and 18F-FDG-PET/CT examination was employed at 3 days after RFA. The mean apparent diffusion coefficient (ADC) values and standard uptake value (SUV) of the untreated tumor and the ablated tumor were separately calculated. Taking the pathologic result as the gold standard, the consistency of DWI-MRI, PET/CT as well as the combination of DWI-MRI and PET/CT with the clinical diagnosis was separately evaluated by Kappa test. Results Before RFA, DWI-MRI demonstrated that the VX2 tumor was characterized by hypo-intensity signal on T1 and hyper-intensity signal on T2 with ring-shaped enhancement on T1-weighted image; PET/CT showed that the tumor had nodular or ring-shaped 18F-FDG accumulation. After RFA, DWI-MRI revealed that the VX2 tumor was manifested as hyper-intensity signal on T1 and slight higher density on T1 with slight enhancement on contrast-enhanced T1-weighted image; PET/CT showed lowered accumulation of 18F-FDG. The mean ADC value of the ablated tumor was (1.52 ± 0.24) × 10-3 mm2/s, which was obviously higher than that of the un-ablated tumor, that was (1.09 ± 0.12) × 10-3 mm2/s, the difference was statistically significant(P0.05). The Kappa value of the consistency between combination of DWI-MRI with PET/CT and pathology was 0.786, which was significantly different from the result by simple DWI-MRI or simple PET/CT evaluation (P< 0.05). Conclusion Both ADC value of DWI-MRI and SUV value of PET/CT are useful indexes for evaluating the early therapeutic effect of RFA. Both DWI-MRI and PET/CT have their respective advantages, nevertheless, combination use of both can effectively improve the evaluation of curative effect for VX2 tumor after RFA in experimental rabbits.

Analysis on genetic polymorphism of 5 STR loci selected from X chromosome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To select short tandem repeats(STR) from X chromosome.</p><p><b>METHODS</b>STR is a universal genetic marker that has changeable polymorphism and stable heredity in human genome. It is a specific DNA segment composed of 2-6 base pairs as its core sequence. It is an ideal DNA marker used in linkage analysis and gene mapping. In this study, 8 short tandem repeats were selected from two genomic clones on X chromosome by using BCM Search Launcher. Primers amplifying the STR loci were designed by using Primer 3.0 according to the unique sequence flanking the STRs. Polymorphisms of the short tandem repeats in Chinese population were evaluated by PCR amplification and PAGE.</p><p><b>RESULTS</b>Five of these STRs were polymorphic. Chi-square test indicated that the distribution of genotypes agreed with Hardy-Weinberg equilibrium (P>0.05).</p><p><b>CONCLUSION</b>Five polymorphic short tandem repeats have been identified on chromosome X and will be useful for linkage analysis and gene mapping.</p>

Fine mapping of Smith-Fineman-Myers syndrome and exclusion of GPC3, GPCR2 MST4 and GLUD2 as candidate genes / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>Smith-Fineman-Myers syndrome (SFMS) is an X-linked mental retardation syndrome. The authors had ascertained a large Chinese family with SFMS from Shandong and had mapped the disease locus to an interval of 19.8 Mb on Xq25 flanked by markers DXS8064 and DXS8050. Further investigation suggested that SFMS exhibited locus heterogeneity. In this study for facilitating the identification of the gene responsible for SFMS, the additional markers were analyzed to narrow down the candidate region, and four candidate genes (GPC3, MST4,GPCR2 and GLUD2) were chosen and screened for disease-causing mutation.</p><p><b>METHODS</b>PCR and denaturing polyacrylamide gel electrophoresis were used to genotype 13 new polymorphic markers distributed within the candidate region. Mutation detection was accomplished by sequencing the exons and intron-exon junctions of the candidate genes.</p><p><b>RESULTS</b>By analyzing 13 additional polymorphic markers, SFMS candidate region can be reduced to an interval of 10.18 Mb bounded by XSTR3 and XSTR4, and no disease-causing mutation was identified in the coding regions of four candidate genes.</p><p><b>CONCLUSION</b>GPCR2 GPC3, MST4 and GLUD2 were excluded as pathogenic genes for SFMS. The refined SFMS locus will assist in the identification and characterization of other candidate genes for SFMS.</p>