Thyroid incidentalomas on fluorine-18-fluorodeoxyglucose positron emission tomography-computed tomography: incidence, malignancy risk, and comparison of standardized uptake values

Introduction

To determine the incidence of fluorine-18-fluorodeoxyglucose (FDG) avid thyroid incidentalomas detected on positron emission tomography (PET) with integrated computed tomography (CT), and correlate the FDG–PET-CT findings to cytology.

Methods

A total of 942 FDG–PET-CT reports were retrospectively reviewed. Patients with FDG-avid thyroid incidentalomas were further reviewed for correlative cytology.

Results

The incidence of FDG-avid thyroid incidentalomas is 2.2%. Thyroid malignancies were identified in 3 of 6 patients who underwent cytologic correlation, with a positive predictive value of 50% (95% confidence interval, 14%-86%). The mean maximum standardized uptake values of benign and malignant FDG-avid thyroid incidentalomas were 5.6 and 6.6, respectively.

Conclusion

A FDG-avid thyroid incidentaloma may predict underlying malignancy. Cytologic assessment should be considered for FDG-avid thyroid incidentalomas.     

Clinical importance of antineutrophil cytoplasmic antibody positivity during propylthiouracil treatment

Background: Propylthiouracil (PTU) is the mainstay of antithyroid drug therapy. Previous studies reported antineutrophil cytoplasmic antibody (ANCA)‐positive vasculitis in patients treated for Graves’ disease. ANCA has been associated with either PTU or to the disease itself. However, this issue has not been investigated in toxic multinodular goitre (TMNG). The aim of this study was to evaluate the frequency of ANCA positivity in both TMNG and Graves’ disease patients treated with PTU, and to investigate the clinical importance of this issue. Patients and methods: We studied the presence of ANCA in 46 patients treated with PTU (30 Graves’ disease, 16 TMNG). Two years after the discontinuation of PTU, ANCA was re‐evaluated in 29 patients (18 Graves’ disease, 11 TMNG). Results: By indirect immunofluorescence, 19 of the 46 patients (41.3%) on PTU treatment were ANCA positive [13 of the 30 patients in Graves disease (43.3%), six of the 16 patients in TMNG (37.5%)]. There was no statistically significant difference between Graves’ disease and TMNG patients for ANCA positivity (p = 0.362). ANCA positivity was not related to gender, thyroid autoantibodies, alanine aminotransferase, aspartate aminotransferase, neutrophil count and PTU dose. Two years after withdrawal of PTU treatment, 10.3% of patients continued to have positive ANCA (p < 0.0001). Signs and symptoms of vasculitis could not be detected in any of the ANCA‐positive patients. Conclusion: Our study suggests that PTU but not Graves’ disease itself is the most important factor for ANCA development. The frequency of ANCA positivity is 41.3% in our country which was not different in Graves’ disease and TMNG patients. The dose of PTU and ethnic factors are not associated with ANCA positivity. After cessation of PTU, vasculitis did not develop during the 2 years of follow‐up despite positive ANCA.     

Pharmacokinetic profile of tigecycline in serum and skin blister fluid of healthy subjects after multiple intravenous administrations

The pharmacokinetics of tigecycline, when given as a 100-mg loading dose followed by 50 mg every 12 h, were determined in serum and blister fluid. The peak tigecycline concentration and half-life in serum were greater than those in blister fluid. Tigecycline penetrates into blister fluid well, with a mean penetration rate of 74%.     

Multiple Genetic Mutations Associated with Polymyxin Resistance in Acinetobacter baumannii

We studied polymyxin B resistance in 10 pairs of clinical Acinetobacter baumannii isolates, two of which had developed polymyxin B resistance in vivo. All polymyxin B-resistant isolates had lower growth rates than and substitution mutations in the lpx or pmrB gene compared to their parent isolates. There were significant differences in terms of antibiotic susceptibility and genetic determinants of resistance in A. baumannii isolates that had developed polymyxin B resistance in vivo compared to isolates that had developed polymyxin B resistance in vitro.     

Do Regular Ultrasound Scans Reduce the Incidence of Stillbirth in Women with Apparently Normal Pregnancies?

ObjectiveTo determine the incidence of stillbirth in women who have regular ante-natal ultrasound compared to those that have infrequent scans in a low risk population.ResultsOur study included 23,519 ‘low-risk’ deliveries spanning 2007-2011. This included 2,088 (9%) patients who had frequent ultrasound surveillance and delivery at term and 21,431 (91%) patients who did not. The overall stillbirth rate was 0.34% and 0.20% respectively which was not statistically different (p=0.31).ConclusionThere is no difference in the rate of stillbirth between patients who have more frequent ante-natal ultrasound surveillance compared with those who do not in a low risk population.     

吸氧对听感觉门控P50的影响

目的研究呼吸纯氧对健康人听感觉门控P50的影响。方法右利手、健康男性大学生志愿者28名,根据随机数字表分为对照组(n=12)和实验组(n=16)。佩戴面罩,对照组呼吸空气,实验组呼吸医用纯氧60 min。应用条件-测试刺激,记录吸氧前(pre0)、吸氧20 min(Oxy20)、吸氧50 min(Oxy50)、吸氧后30 min(post30)的脑电图,计算听觉P50潜伏期和P50感觉门控电位(S1与S2振幅之差)。结果 S1刺激在4个时间点各组P50潜伏期相对稳定(P0.7);吸氧50 min时,实验组比对照组P50潜伏期缩短(P0.05)。S2刺激在4个时间点各组P50潜伏期相对稳定(P0.30),两组间比较无显著性差异(P0.05)。对照组P50门控电位比较稳定(P=0.70),而实验组随吸氧时间逐渐延长,电位越来越高,停止吸氧后,电位迅速回落,Oxy20和post30(P=0.04)、Oxy50和post30(P=0.02)相比均有显著性差异。组间比较,4个时间点均无显著性差异(P0.05)。结论健康人吸60 min纯氧,可能缩短对刺激的反应时间,有增强听觉门控电位的趋势。     

Treatment of Dural Carotid-Cavernous Fistulas via the Medial Ophthalmic Vein

Aim: To present a novel approach to treatment of dural carotid-cavernous fistulas via the medial ophthalmic vein.

Design: Retrospective case series.

Material and Methods: In this retrospective case series, we present 2 patients (3 eyes) with Type C dural CCFs, who had failed cannulation via the conventional transfemoral route and the transorbital superior ophthalmic vein approach. They subsequently underwent CCF occlusion via an anterior orbital approach through the medial ophthalmic veins, at the Department of Ophthalmology, National University Hospital Singapore. CCF occlusion was confirmed intraoperatively using angiography. Both patients were evaluated postoperatively for best-corrected visual acuity and resolution of clinical signs and symptoms.

Results: Successful occlusion of CCFs via the medial ophthalmic veins were achieved in all three orbits, with excellent visual and cosmetic outcomes postoperatively.

Conclusion: Dural CCFs may potentially lead to severe visual dysfunction and should be diagnosed and treated promptly. When all venous routes have been exhausted, the transorbital approach via the medial ophthalmic vein remains an excellent and viable alternative to access the fistula. Close cooperation between the orbital, anesthetic and radiological teams is essential in ensuring success of the operation.