EP.FRI.960 USS appraisal in females of child bearing age presented with possible appendicitis

Aims Appendicitis remains the most common acute surgical condition. No standard guidelines for the use of imaging studies, and there is a discrepancy between the published data regarding accuracy of these modalities and our practical findings. Yet the growing number of USS reported as “appendix not visualized” has led us to rethink about the value of USS in acute appendicitis. Methods A retrospective single centre study for all females (15-45 years) underwent emergency appendectomy for suspected acute appendicitis. Analysis of preoperative clinical, radiographic and postoperative histopathological data was done. Results 632 cases analysed over 18months, out of those 238 (37%) were females (15-45 years). USS was done in 129(54%) cases. 25(10.5) cases had both USS and CTAP. 32(13%) cases had only CTAP. The mean rate of appendix visualization in the USS was 30%(71cases) two thirds reported by radiologist versus one third by sonographers. Our negative appendectomy rate dropped from 25 to 15% after a positive scan. Conclusions Traditional preference for ultrasound in the UK compared to CTAP in young population is mostly due to the potential hazards of irradiation, but USS commonly does not visualise the appendix in our practice (70%), and has low sensitivity and specificity for appendicitis. However, following a positive USS, NAR dropped to 15%. Radiologists had a higher visualization rate of appendix compared to sonographers. Commitment to improve the performance of ultrasonography by allocating adequately timed sessions to the most experienced radiologists and increasing the use of low dose CT scans are possible solutions.

Bone scintigraphy in the diagnosis of transthyretin amyloidosis: a different performance in Portuguese hereditary variant?

Introduction Bone scintigraphy using radioactive technetium-99m and 3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) has been increasingly used to diagnose myocardial involvement of mutated or wild-type transthyretin amyloidosis (ATTR). However, most studies that proved a high sensitivity and specificity of the technique were not in patients with the “Portuguese variant” (Val30Met) mutation in transthyretin (TTR). Other authors had already suggested that in these patients the DPD scan could be less accurate. Methods Observational study of patients referred to Cardiology clinic with suspicion of ATTR cardiomyopathy. We only included patients with data from echocardiogram and DPD scan. For statistical analyses, SPSS was used, p<0.05 for statistical significance. Logistic regressions were used to test an association between DPD result and different covariates. Results Of 273 patients referred with suspicion of cardiac ATTR, we studied 97 patients that did an echocardiogram and a DPD scan. Among the 75 cases with mutated TTR (Val30Met), median age was 36 (IQR 34) and 60% were males. 60 had increased ventricular wall thickness (IVWT) >12 mm, but only 24 had a positive DPD (defined as a visual score >2). Even though a higher wall thickness was associated with a positive DPD (p=0.004), 18 patients with a negative scan had IVWT >14 mm. The DPD results was significantly associated with prior liver transplantation (LT) – p<0.001; 95% CI (7.1; 503.6) – and age at first symptoms – p<0.001; 95% CI (1.036; 1.113); 66.7±10.5 versus 34.8±10.2 years-old for those with and without a positive scan, respectively. Interestingly, fewer patients with a positive scan had neurologic symptoms (74% versus 96%, p=0.009), ophthalmologic, urologic or renal involvement, even though creatinine clearance was on average lower (p=0.01). We did not find a significant association between DPD result and sex, conduction disorders, NT-proBNP, troponin T or treatment with tafamidis. Patients on tafamidis had on average lower IVWT, independent of age (median of 13 versus 14 mm; p=0.020). 4 patients with negative DPD did an endomyocardial biopsy, that was positive for amyloid in 3 cases. In comparison, in the 22 cases with wild-type TTR, there were significantly more males (86%) and patients were older (median age was 81 (IQR 9)). All patients had IVWT (that was significantly higher than in mutated ATTR) and DPD scan was negative in only 2 patients (that had a visual score of 1). Systolic dysfunction was significantly more frequent (59% versus 8%). The occurrence of death or hospitalization for heart failure was significantly higher. Conclusions DPD-scintigraphy seems more sensitive in patients with late onset mutated ATTR or with wild-type ATTR. It is less accurate in early onset patients with Val30Met mutation and particularly if they underwent LT. In those patients, further investigation is needed before excluding myocardial involvement. FUNDunding Acknowledgement Type of funding sources: None.

EP.FRI.511 Optimising Ambulatory Ultrasound in Emergency Surgery

Aims Service provision and assessing the impact of future innovations can best be assessed by accurate reproducible data collection. The traditional model for our ambulatory surgical clinic with ultrasound allowed booking directly from the Emergency Department (ED) without discussion with the Surgical Team. We questioned whether this was the correct model and changed to a model of discussion with the Surgical team before booking in an effort to better utilise resource and reduce unnecessary footfall in the hospital. Methods We reviewed the outcome data of consecutive ambulatory ultrasound clinic referrals before and after implementation of this change in practice (1 month before and after the change) Results Ninety four ambulatory Ultrasound referrals were reviewed. In the first cohort 30 of 50 patients came directly from ED without discussion. A positive USS report was recorded in 8 of the 30 (27% USS positivity rate). After the change in practice to discuss with the surgical team, 11 of 43 patients originated primarily from ED with a positive finding in 4 patients (36%). Conclusions A key aim of service improvement is to optimise / improve utilisation of resource. This must be achieved without missing pathology. In this study we reduced the number of scans performed by ED whilst increasing the likelihood of a positive scan. This change in practice better utilised resource and reduced unnecessary footfall in the hospital.

Amyloid-PET Positive Patient with bvFTD: Wrong Diagnosis, False Positive Scan, or Co-pathology?

A 65-year-old man was referred to a local memory clinic with memory complaints but clinical assessment found no abnormalities. When he presented two years later to our clinic social disinhibition, reduced empathy, poor judgment and hoarding had become obvious. He showed no insight. He had ischemic heart disease and was on preventive treatment. His mother died aged 97 suffering from dementia. Neurological examination was normal. During neuropsychological examination he exhibited verbal and behavioral disinhibition, inattention, emotional blunting and unconcern. He had prominent difficulties in abstraction, set shifting and sequencing with significant impact on memory tests (table1). A clinical diagnosis of behavioral variant FTD (bvFTD) was made. MRI (figure A) showed right more than left-sided temporal atrophy, bilateral frontal and milder parietal atrophy. Fluorodeoxyglucose (FDG)-PET (figure B) demonstrated fronto-temporal hypometabolism. Metabolism in the posterior cingulate was normal. He was homozygous for the APOE ε4 allele and negative for the C9orf72 expansion and mutations in MAPT, GRN, PSEN1, and APP. [18F]-Florbetapir PET (figure C) revealed increased tracer binding in all cortical regions corresponding to a centiloid value of 74%.

Effect of adalimumab on axial manifestations in Japanese patients with psoriatic arthritis: a 24 week prospective, observational study

Objectives PsA is characterized by enthesitis, synovitis and osseous involvement in the peripheral and axial joints. Few studies have examined axial involvement in PsA using imaging techniques. Here we examined axial involvement in PsA patients using MRI. In addition, we determined the efficacy of 24 week adalimumab treatment in improving the MRI findings of spondylitis and sacroiliitis. Methods This was a prospective, open-label, single-arm study in patients with PsA. Adalimumab was administered to patients for a total of 24 weeks. MRI examinations were conducted at baseline and at week 24 of adalimumab treatment. Results Thirty-seven patients with PsA were included in this study. Spondylitis was observed in at least one site of the positive scan in 91% (n = 31) of patients with PsA. The number of arthritic sites in the cervical, thoracic and lumbar regions of the spine was 48, 67 and 53, respectively. All patients had MRI-determined sacroiliitis of grade ≥1 severity while 28 patients (82%) had grade ≥2 sacroiliitis in at least one sacroiliac region. Sacroiliac arthritis was statistically more severe on the right side than on the left side (P < 0.05). In 34 patients with PsA, the thoracic spine was the most common site of spondylitis. In addition, 24 week adalimumab treatment led to an improvement in the mean number of spondylitis sites and the mean grade of sacroiliitis. Conclusion Treatment with adalimumab for 24 weeks resulted in improvement in spondylitis and sacroiliitis.

Impact of the Q.Clear reconstruction algorithm on the interpretation of PET/CT images in patients with lymphoma

Background. Q.Clear is a new Bayesian penalized-likelihood PET reconstruction algorithm. It has been documented that Q.Clear increases the SUVmax values of different malignant lesions. Purpose. As SUVmax values are crucial for interpretation of PET/CT images in patients with lymphoma, particularly when early and final responses to treatment are evaluated. The aim of the study was to systematically analyse the impact of the use of Q.Clear on interpretation of PET/CT in patients with lymphoma.Methods. A total of 280 18F-FDG PET/CT scans in patients with lymphoma were performed for staging (sPET), for early treatment response (iPET), after the end of treatment (ePET) and when a relapse of lymphoma was suspected (rPET). Scans were separately reconstructed with two algorithms, Q.Clear and OSEM, and further compared.Results. The stage of lymphoma was concordantly diagnosed in 69/70 patients with both algorithms on sPET. Discordant assessment of the Deauville score (p<0.001) was found in 11 cases (15.7%) of 70 iPET scans and in 11 cases of 70 ePET scans. An upgrade from a negative to a positive scan by Q.Clear occurred in 3 cases (4.3%) of iPET scans and 7 cases (10.0%) of ePET. The results of all 70 r-PET scans were concordant. The SUVmax values of the target lymphoma lesions measured with Q.Clear were higher than those measured with OSEM in 88.8% of scans. Conclusion. Although the Q.Clear algorithm may alter interpretations of PET/CT in only a small proportion of patients, we recommend using standard OSEM reconstruction for the assessment of treatment response.

Impact of Q.Clear reconstruction algorithm on the interpretation of PET/CT images in patients with lymphoma

Background. Q.Clear is a new Bayesian penalized-likelihood PET reconstruction algorithm. It has been documented that Q.Clear increases SUVmax values of different malignant lesions. Purpose. As SUVmax values are crucial for interpretation of PET/CT images in patients with lymphoma, particularly when early and final response to treatment is evaluated. The aim of the study was to systematically analyze the impact of the use of Q.Clear on interpretation of PET/CT in patients with lymphoma.Methods. 280 18F-FDG PET/CT scans in patients with lymphoma were performed for staging (sPET), for early treatment response (iPET), after the end of treatment (ePET) and when a relapse of the lymphoma was suspected (rPET). Scans were separately reconstructed with two algorithms: Q.Clear and OSEM and further compared.Results. The stage of lymphoma was concordantly diagnosed in 69/70 patients with both algorithms in sPET. Discordant assessment of Deauville score (p<0.001) was found in 11 cases (15.7%) of 70 iPET scans and in 11 cases of 70 ePET scans. An upgrade from negative to positive scan by Q.Clear resulted in 3 cases (4.3%) of iPET scans and 7 (10.0%) of ePET. Results of all 70 r-PET scans were concordant. SUVmax values of the target lymphoma lesions measured with Q.Clear were higher than with OSEM in 88.8% scans. Conclusion. Although the Q.Clear algorithm may alter interpretation of PET/CT only in a small proportion of patients, we recommend to use standard OSEM reconstruction for the assessment of treatment response.

SAT0272 THE VALUE OF CLINICAL AND LABORATORY FEATURES TO PREDICT EXTENT OF LARGE VESSEL VASCULITIS ON PET CT

Background:Giant cell arteritis (GCA) is an idiopathic vasculitis affecting large and medium-sized vessels. The pattern of arterial involvement is heterogeneous with two overlapping categories recognised: classical cranial GCA and extra-cranial GCA (or large vessel vasculitis – LVV) that predominantly affects the aorta and its proximal branches. Although LVV is present in around 80% of patients with cranial GCA, and around one third will develop large vessel complications, there are no guidelines for which patients should be screened for it (1). We sought to investigate whether clinical and laboratory features were a useful guide to the severity of LVV on FDG PET-CT.Objectives:To retrospectively analyse whether baseline patient characteristics are able to predict the extent of large vessel vasculitis on PET-CT.Methods:Clinical data for 65 patients referred for a PET-CT scan by Rheumatology at the Freeman Hospital, Newcastle between January 2015 and May 2018 were retrospectively analysed. The most recent full blood count and inflammatory markers prior to the scan were used. Scans were reviewed by a consultant radiologist and trainee. The arterial network was split in to ten potentially involved territories (aortic arch, thoracic aorta, abdominal aorta, iliac vessels, axillary, brachiocephalic, subclavian, carotid, vertebral and femoral arteries. Both the value of highest standardised uptake value (SUV max) and the territory affected was recorded for each positive scan.Results:In the period analysed 65 PET-CT scans were requested, mostly (77%) as baseline investigations for symptoms with LVV in the differential diagnosis. Of these 22 (34%) were positive for LVV and in that group the majority of patients (64%) were female. In those with a negative scan, 47.5% were on concurrent steroid treatment compared to 9% with a positive scan. Regression analysis suggested that the number of systemic features (weight loss, pyrexia, polymyalgia) was weakly correlated with the number of affected territories (p=0.04). In contrast there was no correlation between laboratory tests ((CRP (p=0.91), ESR (p=0.46), Hb (p=0.44), platelets (p=0.74)) and the number of territories affected. The aortic arch (47%) was most commonly the territory with the highest degree of FDG uptake (SUV max) followed by the abdominal aorta (21%) and thoracic (10%) and femoral arteries (10%). There was no correlation between SUV max and laboratory tests ((CRP (p=0.55), ESR (p=0.89), Hb (p=0.82), platelets (p=0.17)) or the number of systemic features (p=0.7). There was no significant difference in the number of territories affected between those on steroid treatment at the time of the scan and steroid-naïve patients, albeit the number of positive scans in those on steroid treatment was low (n=5).Conclusion:These results suggest that clinical and laboratory features are a poor guide to predicting the maximal severity and extent of disease on FDG PET-CT.References:[1]Koster MJ, Matteson EL, Warrington KJ. Large-vessel giant cell arteritis: diagnosis, monitoring and management. Rheumatology (Oxford). 2018;57(suppl_2):ii32-ii42.Disclosure of Interests:None declared

SAT0557 RESIDUAL DISEASE ACTIVITY IN ADULT-ONSET STILL’S DISEASE: QUALITATIVE AND QUANTITATIVE ANALYSIS OF A SERIES OF 18F FDG-PET/MR

Background:Adult-onset Still’s disease (AOSD) is a systemic autoinflammatory disorder characterized by episodes of spiking fever, the presence of an evanescent pink-salmon rash, arthritis/arthralgias, sore throat and increased inflammatory serum markers. The diagnosis is clinical and needs the exclusion of potential mimickers such as infections and lymphoproliferative disorders. Currently, a specific diagnostic test to assess the disease activity is not available.Objectives:To define the residual disease activity in AOSD and establish a possible response to therapy through18F-FDG PET/MR imaging technique.Methods:23 patients affected by AOSD and 24 controls underwent18F-FDG PET/MR between 2014 and 2018. A total of 5418F-FDG PET/MR were analysed. AOSD patients were diagnosed according to the Yamaguchi’s criteria and were in follow-up at the Rheumatology Unit of Padova University Hospital. The controls were chosen among non-AOSD patients with a previous diagnosis of solid tumors (lymphomas excluded). Aqualitative analysisof PET/RM carried out by a Nuclear Medicine Specialist and asemiquantitative analysiscarried out by measuring SUVs-to-liver (Standardized Uptake Value) for spleen, bone marrow (BM), lymph nodes and pharynx were performed. A SUVmax BM/SUVmean liver higher than 2.09 was set up as significant area of uptake for each organ considered. This threshold was calculated by adding the standard deviation multiplied by 2 at the mean ratio between SUVmax BM and SUVmean liver of the control group. The Pouchot score for disease activity was calculated for each subject. The distribution of the variables was investigated by Shapiro-Wilk test. The analysis of the association between the variables was carried out using the Mann-Whitney U test.Results:AOSD patients present areas of focal18F-FDG uptake mainly in BM, lymph nodes, pharynx, spleen and salivary glands. Sites of uptake in spleen were found in 3.3% of PET/MR, in BM in 23.3%, in lymph nodes in 23.3% and in pharynx in 36.6% of PET/RM respectively. Eleven/thirty (47.8%) patients were defined as “positive” since the uptake was higher than liver, and twelve/thirty (52.2%) were defined as “negative” since the uptake was lower than liver, regardless of SUVs and clinical manifestations. A semi-quantitative analysis assessed whether the values of the SUVmax BM/liver were higher than the cut-off of 2.09 in “positive” PET/MR and lower in the “negative” ones and if the clinical manifestations were present or absent in agreement with the evaluation of SUVs for each patient. BM was found to be active (SUVmax ratio > of 2.09) in 7 out of 11 patients when the PET/MR was defined “positive”, while only in 1 case out of 12 BM SUVmax was >2.09 when the exam was “negative”. Clinical manifestations were present in 10 out of 11 AOSD with a “positive” scan and in 7 out of 11 with both a “positive” scan and a SUV max BM/liver >2.09. Clinical manifestations were present in 1 out of 12 patients with a “negative” scan, while in 10 out of 12 cases with both a negative scan and a SUV max BM/liver <2.09 were absent. Six patients repeated PET/MR during follow-up. The values of the SUVmax BM/liver significantly decreased after anti IL-1β treatment with anakinra. In two cases in which anakinra was deferred, the BM SUVmax values exceeded the cut-off of 2.09 despite the patients did not complain any symptom or inflammation markers increase.Conclusion:18F FGD-PET/MR could be able to evaluate the disease activity in AOSD when clinical manifestations and serum markers are not sufficient to establish it. The uptake on BM seems quite sensitive in pointing out the disease severity and in assessing the response to anti IL-1β therapy.18F PET/MR is an accurate and repeatable method, however further studies are required to validate its applicability in routinary clinical practice.Disclosure of Interests:None declared