Pioglitazone reduces cold-induced brown fat glucose uptake despite induction of browning in cultured human adipocytes: a randomised, controlled trial in humans.

AIMS/HYPOTHESIS: Increasing brown adipose tissue (BAT) activity is a possible therapeutic strategy to increase energy expenditure and glucose and lipid clearance to ameliorate obesity and associated comorbidities. The thiazolidinedione (TZD) class of glucose-lowering drugs increase BAT browning in preclinical experimental models but whether these actions extend to humans in vivo is unknown. The aim of this study was to determine the effect of pioglitazone treatment on adipocyte browning and adaptive thermogenesis in humans. METHODS: We first examined whether pioglitazone treatment of cultured human primary subacromioclavicular-derived adipocytes induced browning. Then, in a blinded, placebo-controlled, parallel trial, conducted within the Baker Institute clinical research laboratories, 14 lean male participants who were free of cardiometabolic disease were randomised to receive either placebo (lactose; n = 7, age 22 ± 1 years) or pioglitazone (45 mg/day, n = 7, age 21 ± 1 years) for 28 days. Participants were allocated to treatments by Alfred Hospital staff independent from the study via electronic generation of a random number sequence. Researchers conducting trials and analysing data were blind to treatment allocation. The change in cold-stimulated BAT activity, assessed before and after the intervention by [18F]fluorodeoxyglucose uptake via positron emission tomography/computed tomography in upper thoracic and cervical adipose tissue, was the primary outcome measure. Energy expenditure, cardiovascular responses, core temperature, blood metabolites and hormones were measured in response to acute cold exposure along with body composition before and after the intervention. RESULTS: Pioglitazone significantly increased in vitro browning and adipogenesis of adipocytes. In the clinical trial, cold-induced BAT maximum standardised uptake value was significantly reduced after pioglitazone compared with placebo (-57 ± 6% vs -12 ± 18%, respectively; p < 0.05). BAT total glucose uptake followed a similar but non-significant trend (-50 ± 10% vs -6 ± 24%, respectively; p = 0.097). Pioglitazone increased total and lean body mass compared with placebo (p < 0.05). No other changes between groups were detected. CONCLUSIONS/INTERPRETATION: The disparity in the actions of pioglitazone on BAT between preclinical experimental models and our in vivo human trial highlight the imperative to conduct human proof-of-concept studies as early as possible in BAT research programmes aimed at therapeutic development. Our clinical trial findings suggest that reduced BAT activity may contribute to weight gain associated with pioglitazone and other TZDs. TRIAL REGISTRATION: ClinicalTrials.gov NCT02236962 FUNDING: This work was supported by the Diabetes Australia Research Program and OIS scheme from the Victorian State Government.

Correction to: Pioglitazone reduces cold-induced brown fat glucose uptake despite induction of browning in cultured human adipocytes: a randomised, controlled trial in humans.

The baseline insulin data given in Table 1 for the placebo group were incorrectly reported as 51 ± 10 pmol/l instead of 48 ± 10 pmol/l. This mistake also impacts on data reported in Table 4.

The prevalence of thyroglossal tract thyroid tissue on SPECT/CT following (131) I ablation therapy after total thyroidectomy for thyroid cancer.

OBJECTIVE: To determine the prevalence of thyroglossal tract thyroid tissue on SPECT/CT and to assess the contribution of this tissue to total neck radioactive iodine (RAI) activity in patients given (131) I ablation therapy after total thyroidectomy for thyroid cancer. PATIENTS AND METHODS: Eighty-three consecutive patients with thyroid cancer treated with total thyroidectomy underwent whole-body planar and SPECT/CT imaging of the neck following initial RAI ablation. On SPECT/CT, thyroglossal tract thyroid tissue was defined as RAI in the anterior neck, superior to the thyroid bed in close proximity to the midline without evidence of localization to lymph nodes. Quantification was performed using region of interest analysis on planar imaging following localization on SPECT/CT. SPECT/CT, and planar images were classified by two reviewers as positive, negative or equivocal with interobserver agreement quantified using a Kappa score. Disagreement was resolved using a third reviewer. RESULTS: Thyroglossal tract thyroid tissue was present in 39/83 (47%; 95%CI: 36-58%) patients on SPECT/CT. In these 39 patients, this tissue contributed to a significant amount of total neck activity (median = 50%; IQR 19-74%). Interobserver agreement for the presence of thyroglossal tract thyroid tissue was substantial on SPECT/CT (Kappa = 0.73) and fair on planar imaging (Kappa = 0.31). CONCLUSION: Thyroglossal tract thyroid tissue was present in one half of our study population and contributed to a significant amount of total neck RAI activity. Given the high prevalence of this tissue, our results suggest that total neck RAI activity on planar imaging may not be suitable to assess the completeness of thyroid bed surgery.

A survey of gamma camera and SPECT/CT quality control programs across a sample of public hospitals in Australia.

Performance testing of gamma cameras and single photon computed tomography/computed tomography (SPECT/CT) systems is not subject to regulatory requirements across states and territories in Australia. Internationally recognised testing standards from organisations such as the National Electrical Manufacturers Association (NEMA) describe methodologies for recommended tests. However, variations exist in suggested quality control (QC) schedules from professional bodies such as the Australia and New Zealand Society of Nuclear Medicine (ANZSNM). In this study, a survey was conducted to benchmark current QC programs across a selected sample of eight standalone and networked Australian public hospitals. Vendor-specific flood-field uniformity (intrinsic or extrinsic/system) verification without photomultiplier (PMT) tuning and CT QC were performed at all sites. Weekly and monthly PMT tuning followed by intrinsic flood-field verifications were performed at most sites. At least half of the sites performed monthly centre of rotation (COR) offset verifications. SPECT/CT alignment calibrations and verifications were undertaken by service engineers at all sites, and periodic verifications were performed by local staff at varying frequencies. Variations were observed for other periodic QC tests such as spatial resolution and planar sensitivity. Similarly, variations were observed for tests specific to whole-body systems and SPECT systems. Most sites checked daily and periodic QC results against pass/fail criteria set by vendors. Additional analyses of the QC results, including trend analysis and periodic reviews, were not common practice. The lack of regulatory requirements is likely to have led to variations in QC tests that are generally either harder to perform or are more labour intensive.

The Evaluation of Gastric Emptying Using Nuclear Scintigraphy Compared to Three-Dimensional Multi-detector Computed Tomography (3D-MDCT) Gastric Volumetry in the Assessment of Poor Weight Loss Following Sleeve Gastrectomy.

BACKGROUND: Poor weight loss and weight regain are principal challenges following laparoscopic sleeve gastrectomy (LSG). There is a lack of standardised assessments and diagnostic tests to stratify the status post-LSG and determine whether anatomical or physiological problem exists. We aimed to compare nuclear scintigraphy gastric emptying with CT volumetric analysis of sleeve anatomy and determine the impact of anatomy on physiological function and its correlation with weight loss. MATERIALS AND METHODS: Patients greater than 12 months post-LSG were categorised into optimal weight loss (OWL) (n = 29) and poor weight loss groups (PWL) (n = 50). All patients underwent a protocolised nuclear scintigraphy and three-dimensional multi-detector computed tomography (3D-MDCT) gastric volumetry imaging. RESULTS: Post-operative % total weight loss in OWL was 26.2 ± 10.5% vs. 14.2 ± 10.7% in the PWL group (p value < 0.0001). The PWL group had significantly more delayed gastric emptying half-time than OWL (34.1 ± 18.8 vs. 19.5 ± 4.7, p value < 0.0001). Gastric emptying half-time showed statistically significant correlations with weight loss parameters (BMI; r = 0.215, p value 0.048, %EWL; r = - 0.336, p value 0.002 and %TWL; r = - 0.379, p value < 0.001). The median gastric volume on 3D-MDCT did not differ between the OWL (246 (IQR 50) ml) and PWL group (262 (IQR 129.5) ml), p value 0.515. Nuclear scintigraphy gastric emptying half-time was the most highly discriminant measure. A threshold of 21.2 min distinguished OWL from PWL patients with 86.4% sensitivity and 68.4% specificity. CONCLUSION: Nuclear scintigraphy is a potentially highly accurate tool in the functional assessment of sleeve gastrectomy physiology. It appears to perform better as a diagnostic test than volumetric assessment. Gastric volume did not correlate with weight loss outcomes. We have established diagnostic criteria of greater than 21 min to assess sleeve failure, which is linked to suboptimal weight loss outcomes.

Modified One Anastomosis Gastric Bypass Following Sleeve Gastrectomy for Severe Reflux and Delayed Gastric Emptying: A Prospective Trial with Clinical and Physiological Outcome Measures.

BACKGROUND: Gastro-esophageal reflux (GORD) following sleeve gastrectomy (SG) is a central challenge, and precise indications for revisional surgery or the physiology have not been precisely defined. We aimed to determine whether OAGB performed for reflux post-SG (1) accelerates gastric emptying half-time, (2) reduces the frequency and severity of reflux events, and (3) improves reflux symptoms. METHODS: We undertook a prospective trial (ACTRN12616001089426). There were 22 participants who underwent measurement before and after revisional surgery with 29 optimal SG (patients with optimal outcome from their primary surgery) as controls. All participants underwent a protocolized nuclear scintigraphy, 24-h pH monitoring, and gastroscopy and completed objective questionnaires. RESULTS: Trial patients were 90.9% female, age 44.4 years. Conversion from SG to OAGB was at a median of 45.2 ± 19.6 months. Scintigraphy showed an increased rate of gastric emptying post-OAGB 34 (IQR 14) vs 24 (IQR 10.3) min, p-value 0.008, with decreased number of reflux events post-prandially (39 (IQR 13) vs 26 (IQR 7), p-value 0.001). This data correlated with the pH analysis; total acid events substantially reduced post-OAGB 58.5 (IQR 88) vs 12 (IQR 9.4) events, p-value 0.017. Endoscopic findings indicated a reduction in incidence of bile stasis 72.7% vs 40.9% post-OAGB, p-value < 0.00010. Post-OAGB, patients experienced less frequent regurgitation (12 ± 4.1 vs. 5.5 ± 3, p-value 0.012) and reflux (37.1 ± 15.7 vs. 16.8 ± 12.6, p-value 0.003). CONCLUSIONS: We found OAGB is an effective treatment for reflux associated with delayed gastric emptying post-SG. The likely mechanisms is by, an increase in the rate of gastric clearance and reduced reflux events and overall esophageal acid exposure. This suggests that some forms of post-SG reflux are driven by slower emptying of the residual stomach and are amenable to treatment with drainage above the incisura.

Comparison of contemporaneous left ventricular ejection fraction (LVEF) obtained from planar gated cardiac blood pool scans (GCBPS) and Tl-201 gated myocardial perfusion scans (MPS) using a novel solid state dedicated cardiac camera.

BACKGROUND: There is limited data on the concordance of left ventricular ejection fraction (LVEF) obtained via solid state dedicated cardiac cameras (SSD) and gated cardiac blood pool scans (GCBPS). This study aimed to examine the agreement of LVEF measured during GCBPS and Tl-201 myocardial perfusion scans (MPS) using SSD. METHODS: Seventy six patients were enrolled. Following stress MPS with 0.8 Mbq/kg (0.022 mCi/kg) Tl-201 and 8-frame gated rest studies after additional 15 Mbq (0.41 mCi) Tl-201, LVEFs were obtained using ECToolbox (ECT) and quantitative gated SPECT (QGS) software. Same day 16-frame planar GCBPS were performed. Interobserver variability was compared and LVEF results were compared using paired t tests, Pearson's correlation and the differences of the LVEF were plotted against GCBPS values. RESULTS: For GCBPS, ECT and QGS, the mean (±SD) LVEF was 52% ± 14%, 61% ± 18% and 48% ± 19%, respectively. When compared to GCBPS, ECT and QGS, LVEFs had similar R values of 0.85 and 0.83, respectively, and mean differences [95% limits of agreement (LA)] of -8.6% (-27.4% to +10.2%, P < .001) and 4.2% (-17.2% to +25.6%, P = .001), respectively. CONCLUSION: While the LVEF obtained by ECT or QGS demonstrates a statistically significant correlation with GCBPS, they are significantly different and the wide 95% LA suggest that Tl-201 MPS LVEFs derived from either software package are not interchangeable with GCBPS results.

Changes in Oesophageal Transit, Macro-Reflux Events, and Gastric Emptying Correlate with Improvements in Gastro-Intestinal Symptoms and Food Tolerance Early Post Sleeve Gastrectomy.

PURPOSE: There are significant alterations in gastro-intestinal function, food tolerance, and symptoms following sleeve gastrectomy (SG). These substantially change over the first year, but it is unclear what the underlying physiological basis for these changes is. We examined changes in oesophageal transit and gastric emptying and how these correlate with changes in gastro-intestinal symptoms and food tolerance. MATERIAL AND METHODS: Post-SG patients undertook protocolised nuclear scintigraphy imaging along with a clinical questionnaire at 6 weeks, 6 months, and 12 months. RESULTS: Thirteen patients were studied: mean age (44.8 ± 8.5 years), 76.9% females, pre-operative BMI (46.9 ± 6.7 kg/m2). Post-operative %TWL was 11.9 ± 5.1% (6 weeks) and 32.2 ± 10.1% (12 months), p-value < 0.0001. There was a substantial increase of meal within the proximal stomach; 22.3% (IQR 12%) (6 weeks) vs. 34.2% (IQR 19.7%) (12 months), p = 0.038. Hyper-accelerated transit into the small bowel decreased from 6 weeks 49.6% (IQR 10.8%) to 42.7% (IQR 20.5%) 12 months, p = 0.022. Gastric emptying half-time increased from 6 weeks 19 (IQR 8.5) to 12 months 27 (IQR 11.5) min, p = 0.027. The incidence of deglutitive reflux of semi-solids decreased over time; 46.2% (6 weeks) vs. 18.2% (12 months), p-value < 0.0001. Reflux score of 10.6 ± 7.6 at 6 weeks vs. 3.5 ± 4.4 at 12 months, (p = 0.049) and regurgitation score of 9.9 ± 3.3 at 6 weeks vs. 6.5 ± 1.7, p = 0.021 significantly reduced. CONCLUSIONS: These data demonstrate that there is an increase in the capacity of the proximal gastric sleeve to accommodate substrate over the first year. Gastric emptying remains rapid but reduce over time, correlating with improved food tolerance and reduced reflux symptoms. This is likely the physiological basis for the changes in symptoms and food tolerance observed early post-SG.

Optimal reproducibility of gated sestamibi and thallium myocardial perfusion study left ventricular ejection fractions obtained on a solid-state CZT cardiac camera requires operator input.

AIM: To evaluate the reproducibility of serial re-acquisitions of gated Tl-201 and Tc-99m sestamibi left ventricular ejection fraction (LVEF) measurements obtained on a new generation solid-state cardiac camera system during myocardial perfusion imaging and the importance of manual operator optimization of left ventricular wall tracking. METHODS: Resting blinded automated (auto) and manual operator optimized (opt) LVEF measurements were measured using ECT toolbox (ECT) and Cedars-Sinai QGS software in two separate cohorts of 55 Tc-99m sestamibi (MIBI) and 50 thallium (Tl-201) myocardial perfusion studies (MPS) acquired in both supine and prone positions on a cadmium zinc telluride (CZT) solid-state camera system. Resting supine and prone automated LVEF measurements were similarly obtained in a further separate cohort of 52 gated cardiac blood pool scans (GCBPS) for validation of methodology and comparison. Appropriate use of Bland-Altman, chi-squared and Levene's equality of variance tests was used to analyse the resultant data comparisons. RESULTS: For all radiotracer and software combinations, manual checking and optimization of valve planes (+/- centre radius with ECT software) resulted in significant improvement in MPS LVEF reproducibility that approached that of planar GCBPS. No difference was demonstrated between optimized MIBI/Tl-201 QGS and planar GCBPS LVEF reproducibility (P = .17 and P = .48, respectively). ECT required significantly more manual optimization compared to QGS software in both supine and prone positions independent of radiotracer used (P < .02). CONCLUSIONS: Reproducibility of gated sestamibi and Tl-201 LVEF measurements obtained during myocardial perfusion imaging with ECT toolbox or QGS software packages using a new generation solid-state cardiac camera with improved image quality approaches that of planar GCBPS however requires visual quality control and operator optimization of left ventricular wall tracking for best results. Using this superior cardiac technology, Tl-201 reproducibility also appears at least equivalent to sestamibi for measuring LVEF.

18 F-FDG PET/CT features of immune-related adverse events and pitfalls following immunotherapy.

18 F-FDG PET/CT scanning is routinely performed to stage and evaluate the treatment response in many malignancies. Immunotherapy is a rapidly growing treatment option for many cancers, and both clinicians and imaging specialists need to be familiar with 18 F-FDG PET/CT imaging characteristics unique to patients on this type of treatment. In particular, many immune-related adverse events (irAEs) can be detected on 18 F-FDG PET/CT and early accurate identification is critical to reduce treatment related morbidity and incorrect interpretation of malignant disease status. This pictorial essay reviews frequently encountered irAEs in clinical practice and their appearances on 18 F-FDG PET/CT along with a brief discussion on pseudoprogression and hyperprogression.

Noninvasive Assessment of Acute Graft-Versus-Host Disease of the Gastrointestinal Tract After Allogeneic Hemopoietic Stem Cell Transplantation Using 18F-FDG PET.

Acute graft-versus-host disease of the gastrointestinal tract (acute GIT-GVHD) often complicates allogeneic hemopoietic stem cell transplantation (AHSCT). 18F-FDG PET/CT is known to detect active inflammation and may be a useful noninvasive test for acute GIT-GVHD. The objective of this study was to evaluate the diagnostic utility of 18F-FDG PET/CT to noninvasively assess patients with clinically suspected acute GIT-GVHD. Fifty-one AHSCT patients with clinically suspected acute GIT-GVHD prospectively underwent 18F-FDG PET/CT scanning followed by upper and lower GIT endoscopy within 7 d. Endoscopic biopsies of 4 upper GIT and 4 colonic segments were obtained for histology to compare with corresponding quantitative segmental 18F-FDG PET/CT SUVmax Receiver-operating-characteristic curve (ROC) analysis was performed to determine predictive capacity of 18F-FDG PET/CT SUVmax for acute GIT-GVHD. A separate qualitative visual 18F-FDG PET/CT analysis was also performed for comparison. Results: Twenty-three of 51 (45.1%) patients had biopsy-confirmed acute GIT-GVHD, with 19 of 23 (82.6%) having upper GIT and 22 of 22 (100%) colonic involvement. One of 23 patients did not undergo a colonoscopy. GVHD involved the entire colon contiguously in 21 of 22 patients. For quantitative analysis, histology from 4 upper GIT and 4 colonic segments were compared with 18F-FDG PET/CT SUVmax Colonic segments positive for GVHD had a higher SUVmax (4.1 [95% CI, 3.6-4.5]) than did normal colonic segments (2.3 [1.9-2.7], P = 0.006). No difference was demonstrated in upper GIT segments. Quantitative 18F-FDG PET/CT yielded a 69% sensitivity, 57% specificity, 73% negative predictive value, and 59% positive predictive value for the detection of GVHD compared with 70%, 76%, 76%, and 68%, respectively, for qualitative analysis. Conclusion: 18F-FDG PET is a useful noninvasive diagnostic test for acute GIT-GVHD, which when present always involves the colon and usually in its entirety, suggesting colonic biopsy obtained by sigmoidoscopy is adequate for histologic confirmation when acute GIT-GVHD is suspected. Of note, 18F-FDG PET cannot distinguish acute GIT-GVHD from non-GVHD inflammatory changes in the colon.

Clinical utility of stimulated cholescintigraphy using a standardized Ensure-Plus fatty meal protocol in patients with suspected functional gallbladder disorder: a retrospective study of seven-years clinical experience.

BACKGROUND: The clinical utility of fatty meal stimulated cholescintigraphy particularly using a standardized formulation in patients with suspected functional gallbladder disorder has not been extensively studied. We present our seven-year clinical experience using an Ensure plus protocol. METHODS: A retrospective study was performed on patients undergoing stimulated cholescintigraphy using Ensure Plus for evaluation of suspected functional gallbladder disorder. A gallbladder ejection fraction (GBEF) of <33% was considered abnormal. RESULTS: Of the 173 patients evaluated, 57 (33%) had an abnormal GBEF, 112 (65%) had a normal GBEF and 4 (2%) had no gallbladder visualization. Of the 57 patients with an abnormal GBEF, symptom improvement occurred in 30/31 (97%) who underwent cholecystectomy and in 17/26 (65%) who were managed conservatively (p = 0.003). Of the 112 patients with a normal GBEF, symptom improvement occurred in 8/10 (80%) who underwent cholecystectomy and 74/102 (73%) who were managed conservatively (p = 1.000). In the subgroup of 102 patients with a normal GBEF managed conservatively, those without symptomatic improvement had lower GBEFs compared to those with symptomatic improvement (median GBEF 46% versus 57%, p = 0.019). CONCLUSION: Our retrospective results support a clinical role for stimulated cholescintigraphy using Ensure Plus in the evaluation of patients with suspected functional gallbladder disorder. While an abnormal GBEF predicts good surgical outcome, our results suggest that using an absolute GBEF cut off value of <33% may not apply to all patients and hence GBEF results should only be used as an adjunct in the surgical decision-making process.

Delayed Gastric Emptying After Sleeve Gastrectomy Is Associated with Poor Weight Loss.

BACKGROUND: Intermediate to long-term weight regain is a major challenge following sleeve gastrectomy (SG). Physiological changes that mediate the extent of weight loss remain unclear. We aimed to determine if there were specific esophago-gastric transit and emptying alterations associated with weight regain. MATERIAL AND METHODS: Participants greater than 12 months post-SG were categorized into optimal (n = 29) and poor weight loss (PWL) (n = 72). All patients underwent a liquid contrast barium swallow demonstrating normal post-surgical anatomy and a protocolized nuclear scintigraphy designed specifically to characterize gastric emptying following SG. RESULTS: The %total weight loss in the optimal group was 26.2 ± 10.5 vs. 14.3 ± 8.8% in the PWL group (p = 0.001). Scintigraphy showed PWL had relatively increased gastric emptying half-time (GE 1/2t) 35 (IQR 23) min vs 19 (IQR 5.5) min (p = 0.001). The multivariate regressions delineated GE 1/2t as the best diagnostic measure for PWL (OR 1.16; CI 1.04-1.29, p-value 0.021). The probability of PWL increased by 16% for every 1-min increase above 21 min of GE 1/2t. A threshold of 21 min was found to have 88% sensitivity and 69% specificity predicting poor weight loss. CONCLUSION: Gastric emptying half-times greater than 21 min appear to reliably correlate with poor weight loss following SG. Additionally, further elevations above 21 min in emptying half-time increase the risk of poor weight loss. We have shown nuclear scintigraphy represents a simple and accurate diagnostic tool in patients who experience poor weight loss after SG, provided substantially altered reporting references in interpreting nuclear scintigraphy are applied.

Use of a radiopharmaceutical multidose dispenser for positron emission tomography: Risk assessment and mitigation measures for infection prevention.

Positron emission tomography (PET) imaging necessitates the use of multidose vials for radiopharmaceutical delivery to patients. Conventional practices involve manual extraction of radiopharmaceuticals from a multidose vial prior to each PET procedure, which exposes the technologist to increasing levels of radiation and poses a potential infection risk to patients with frequent handling and access of the vial. New technologies for automated dosing and infusion delivery are available, however these incorporate both a multidose vial and a multi-patient infusion set. There is an absence of guidance for infection prevention (IP) units regarding the safety and acceptability of these devices. This paper describes the process of risk assessment and the mitigation measures for training, workflows, and documentation which led to the safe introduction of an automated PET infusion device in a large tertiary public healthcare facility.

Incidence of radiation thyroiditis and thyroid remnant ablation success rates following 1110 MBq (30 mCi) and 3700 MBq (100 mCi) post-surgical 131I ablation therapy for differentiated thyroid carcinoma.

OBJECTIVE: To evaluate the relationships between thyroid remnant (131)I uptake, radiation thyroiditis and remnant ablation success rate between lower (1110 MBq) and higher (3700 MBq) initial ablative (131)I dose for post-surgical ablation therapy for differentiated thyroid cancer. DESIGN: Patients having post-surgical administration of 1110 MBq (68 patients) or 3700 MBq (115 patients) (131)I were retrospectively reviewed. Thyroid remnant (131)I uptake on a 48 h post-administration scan was correlated with neck symptoms experienced. Patients were classified as having insignificant, mild or severe thyroiditis based on symptoms. Absent thyroid bed (131)I uptake on a follow-up 74 MBq (131)I study was considered successful ablation. RESULTS: 183 patients were included. Median (131)I remnant uptake was 37 MBq. 21% (39/183) of patients developed thyroiditis. Incidence and severity of thyroiditis increased with increasing remnant (131)I activity (P 73 MBq. For patients treated with 1110 MBq and 3700 MBq, incidence of thyroiditis was 12% and 27% (P = 0.02) and remnant ablation success rate was 76% and 84% (P = NS), respectively. Occurrence of thyroiditis did not correlate with successful ablation. CONCLUSIONS: Incidence and severity of radiation thyroiditis following (131)I remnant ablation therapy is directly related to thyroid remnant (131)I uptake. As 1110 MBq (131)I is associated with a significantly lower frequency of thyroiditis but similar remnant ablation rate to 3700 MBq, it warrants consideration for thyroid remnant ablation particularly in patients with low risk disease.

Correlation of clinical outcomes with bremsstrahlung and Y-90 PET/CT imaging findings following Y-90 radiosynoviorthesis: a prospective study.

BACKGROUND: It is unclear how to predict which patients will respond to Y-90 radiosynoviorthesis. The aim of this study is to correlate clinical outcomes following Y-90 radiosynoviorthesis with bremsstrahlung and Y-90 PET/CT imaging findings. METHODS: Fifty-one joints underwent bremsstrahlung planar and Y-90 PET/CT imaging following Y-90 radiosynoviorthesis. The Y-90 distribution pattern on bremsstrahlung planar imaging was classified as diffuse or non-diffuse and compared with the intra or extra-articular location of activity on Y-90 PET/CT. Treatment response was assessed by patients and clinicians at 6 months. In patients who underwent bremsstrahlung SPECT, side-by-side comparison with PET was performed with image quality/resolution scored using a five-point-scale. FINDINGS: Bremsstrahlung planar images were classified as diffuse in 33/51 (65 %) and non-diffuse in 18/51 (35 %) scans. There was no association between treatment response and the bremsstrahlung planar imaging pattern. PET/CT confirmed an intra-articular location in all 33/33 (100 %) diffuse scans and an extra-articular location in 3/18 (17 %) non-diffuse scans. Of the three joints with extra-articular activity, none had any treatment response. Excluding these three joints, there remained no association between the bremsstrahlung planar imaging pattern and treatment response. Of the 42 joints imaged with SPECT, PET image quality/resolution was classified as superior in 40 (95 %). In one patient with extra-articular activity on PET/CT, SPECT/CT was unable to definitively localise the activity to the intra or extra-articular space. CONCLUSIONS: The distribution pattern on bremsstrahlung planar imaging did not correlate with clinical outcome following Y-90 radiosynoviorthesis in our study population. However, in patients with non-diffuse planar imaging patterns, Y-90 PET/CT should be considered to exclude extra-articular activity with PET providing superior image quality compared to SPECT.

Ga-68 octreotate PET/CT and Tc-99m heat-denatured red blood cell SPECT/CT imaging of an intrapancreatic accessory spleen.

Intrapancreatic accessory spleens are relatively uncommon and can be difficult to distinguish from neuroendocrine tumours on CT, MRI and somatostatin receptor scintigraphy. We present the case of a 26-year-old woman with an incidentally diagnosed pancreatic lesion confirmed to be an intrapancreatic accessory spleen on Tc-99m heat-denatured red blood cell single photon emission computed tomography/CT.

The great medical imitator: a case of syphilitic osteitis in the setting of HIV infection.

A 44-year-old man with well-controlled HIV presented with low-grade fever, pharyngitis, frontal headache, abdominal and shin pain, and abnormal liver function tests 8 weeks after switching from zidovudine to abacavir (while continuing nevirapine and lamivudine). An abacavir reaction was the working diagnosis and thus his antiretroviral regimen was returned to the previously tolerated combination and he received 10 days of oral penicillin (500mg twice daily) for presumptive tonsillitis with significant improvement. A whole-body bone scan demonstrated multiple foci of increased patchy osteoblastic activity of the long bones and skull. Six months later during routine screening, a syphilis rapid plasma reagin (RPR) titre of 128 was detected. Retrospective testing on stored samples demonstrated a first positive RPR at the time of symptomatic presentation. He received three injections of 1.8g benzathine penicillin on a weekly basis with a subsequent decrease in RPR titre and normalisation of the bone scan. Although syphilitic osteitis is rare, this case re-emphasises the importance of considering syphilis when HIV-infected patients present with unusual symptoms. The use of bone scan in this setting and treatment options are discussed.

Comparison of positron emission tomography/CT and bremsstrahlung imaging following Y-90 radiation synovectomy.

INTRODUCTION: The aim of this study is to compare the results of positron emission tomography (PET)/CT with bremsstrahlung imaging following Y-90 radiation synovectomy. METHODS: All patients referred to our institution for Y-90 radiation synovectomy between July 2011 and February 2012 underwent both PET/CT and bremsstrahlung planar (± single photon emission computed tomography (SPECT) or SPECT/CT) imaging at 4 or 24 h following administration of Y-90 silicate colloid. PET image acquisition was performed for between 15 and 20 min. In patients who underwent SPECT, side-by-side comparison with PET was performed and image quality/resolution scored using a five-point scale. The distribution pattern of Y-90 on PET and bremsstrahlung imaging was compared with the intra- or extra-articular location of Y-90 activity on fused PET/CT. RESULTS: Thirteen joints (11 knees and two ankles) were imaged with both PET/CT and planar bremsstrahlung imaging with 12 joints also imaged with bremsstrahlung SPECT. Of the 12 joints imaged with SPECT, PET image quality/resolution was superior in 11 and inferior in one. PET demonstrated a concordant distribution pattern compared with bremsstrahlung imaging in all scans, with the pattern classified as diffuse in 12 and predominantly focal in one. In all 12 diffuse scans, PET/CT confirmed the Y-90 activity to be located intra-articularly. In the one predominantly focal scan, the fused PET/CT images localised the Y-90 activity to mostly lie in the extra-articular space of the knee. CONCLUSION: PET/CT can provide superior image quality compared with bremsstrahlung imaging and may enable reliable detection of extra-articular Y-90 activity when there are focal patterns on planar bremsstrahlung imaging.