A 63-year-old man was admitted to an institution with symptoms and electrocardiogram signs consistent (central chest pain and inferior lead ST segment elevation) with inferior myocardial infarction. He had undergone immediate (paramedic administered) thrombolysis after a brief period of third-degree heart block and seemed to be recovering well. Approximately 24 h after admission (26 h after …

Purpose Transcatheter aortic valve implantation (TAVI) has emerged for treating aortic stenosis in patients who are poor candidates for surgical aortic valve replacement. Although a promising approach for high-risk patients, the indication may be expanded to intermediate- and eventually low-risk patients in the future; however, doing so will require a better understanding of potential complications. In the current presentation, we present our institutional experience of postoperative complications such as myocardial infarction, stroke, bleeding, vascular complications and valve performance. Malpositioning, valve migration/embolisation and conversion to open surgery are other potential complications following TAVI which will be presented. Methods and materials N/A Results N/A Conclusion N/A Transcatheter aortic valve implantation (TAVI) has emerged for treating aortic stenosis in patients who are poor candidates for surgical aortic valve replacement. Although a promising approach for high-risk patients, the indication may be expanded to intermediate- and eventually low-risk patients in the future; however, doing so will require a better understanding of potential complications. In the current presentation, we present our institutional experience of postoperative complications such as myocardial infarction, stroke, bleeding, vascular complications and valve performance. Malpositioning, valve migration/embolisation and conversion to open surgery are other potential complications following TAVI which will be presented. N/A N/A N/A

AIM: To assess the diagnostic accuracy of computed tomography coronary angiography (CTCA) using a combination of high-definition CT (HD-CTCA) and high level of reader experience, with invasive coronary angiography (ICA) as the reference standard, in high-risk patients for the investigation of coronary artery disease (CAD).MATERIALS AND METHODS: Three hundred high-risk patients underwent HD-CTCA and ICA. Independent experts evaluated the images for the presence of significant CAD, defined primarily as the presence of moderate (>= 50%) stenosis and secondarily as the presence of severe (>= 70%) stenosis in at least one coronary segment, in a blinded fashion. HD-CTCA was compared to ICA as the reference standard.RESULTS: No patients were excluded. Two hundred and six patients (69%) had moderate and 178 (59%) had severe stenosis in at least one vessel at ICA. The sensitivity, specificity, positive predictive value, and negative predictive value were 97.1%, 97.9%, 99% and 93.9% for moderate stenosis, and 98.9%, 93.4%, 95.7% and 98.3%, for severe stenosis, on a per-patient basis.CONCLUSION: The combination of HD-CTCA and experienced readers applied to a high-risk population, results in high diagnostic accuracy comparable to ICA. Modern generation CT systems in experienced hands might be considered for an expanded role. (C) 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

AIM: To evaluate the usage, safety, and efficacy of high-dose intravenous metoprolol for heart rate reduction in computer tomographic (CT) coronary angiography.MATERIALS AND METHODS: As this was retrospective analysis of anonymous data, medical ethics committee approval was waived by the regional health research authority. Patients, who had known iodinated contrast medium allergy, contraindications to beta-blockers, atrial fibrillation, and indications other than suspected coronary artery disease, were excluded from analysis. The ultimate study population of 662 were analysed with details of intravenous metoprolol doses, complications, heart rate before administration of intravenous metoprolol (resting heart rate, RHR), heart rate at acquisition of scan (acquisition heart rate, AHR), and usage of low radiation dose protocols.RESULTS: Of the ultimate study population of 662 patients, 183 had no intravenous metoprolol with mean acquisition heart rate (AHR) of 58 beats per minute (bpm), 257 had 1-15 mg intravenous metoprolol with mean AHR of 57 bpm, 114 had 16-29 mg intravenous metoprolol with mean AHR of 62 bpm and 108 had >30 mg intravenous metoprolol with mean AHR of 66 bpm. In the group receiving intravenous metoprolol, average usage was 19 mg (maximum 67 mg) with average reduction in HR of 15 bpm. There were no clinical incidents in relation to the use of high-dose intravenous metoprolol.CONCLUSION: Higher doses of intravenous metoprolol are beneficial in achieving target heart rates to facilitate usage of low radiation dose protocols. With appropriate exclusion criteria, higher doses of intravenous metoprolol, well in excess of 15 mg, can be safely administered when carefully titrated. (C) 2014 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Background Achieving good heart rate control is fundamental to optimal CT coronary angiography (CTCA), to minimise motion artefact and facilitate radiation-reducing techniques. The use of β-blockers is widespread although centres vary in their use of oral or intravenous preparations, or use of alternative agents. At our institution aggressive heart rate control is pursued with intravenous metoprolol tartrate. Standard contraindications are observed but β-blockers are also given cautiously in patients with non-severe asthma or those using diltiazem. Methods We undertook a retrospective analysis of our β-blocker usage to evaluate dosage and safety at our tertiary centre. Results We examined 2219 patients undergoing CTCA over a 28-month period (July 2010–October 2012). In 55 records, use or dosage of β-blockers could not be verified. 758 (34%) did not receive β-blockers due to baseline heart rate or contraindication. 1406 patients received intravenous metoprolol. The dose range was 2.5–67 mg with a mean of 19.8 mg (median 15 mg). 635 (29%) patients received a dose of metoprolol above the licensed dose of 15 mg. Out of 1406 patients there was a solitary serious adverse incident. Transient loss of consciousness (TLOC) occurred (without sequelae) in a patient under investigation for atypical chest pain and TLOC who received 15 mg metoprolol prior to CTCA. No other complications or adverse incidents occurred. 95 patients received intravenous metoprolol despite a resting heart rate within the traditional target range (<65 bpm). The mean dose in this group was 8.9 mg (2.5–35 mg). No complications or adverse incidents were reported in this cohort. Discussion Our data suggest that the use of intravenous β-blockers to facilitate CTCA is safe, when appropriate consideration is taken, which should include those under investigation for TLOC. β-Blockers can be used at doses significantly higher than currently recommended and heart rate targets can be lower.

There have been numerous advances in the field of cardiac imaging. The advent of multidetector computed tomography coronary angiography (MDCT-CA) and in particular electrocardiographic (ECG)-gated acquisition has revolutionized the investigation of the complete spectrum of complications of common cardiothoracic surgical procedures. Generic complications, such as mediastinitis, pericardial effusion, sternal osteomyelitis, and mediastinal fibrosis, are discussed with illustrative examples of multiplanar and volume-rendered three-dimensional reconstructions. Graft-related complications of both coronary artery bypass grafts and aortic root grafts are reviewed. The role of MDCT-CA in the investigation of prosthetic valve endocarditis and root abscesses is outlined. We present a complete illustration of the detailed images that are obtained when investigating a full range of graft-related complications from both aortic and coronary surgery using ECG-gated MDCT-CA. MDCT-CA has the potential to become established as the optimal technique with which to image a multitude of complications post-cardiac surgery.

Background NICE Diagnostics Guidance DG3 recommends ‘new generation’ cardiac CT scanners ‘for first-line evaluation of disease progression, to establish the need for revascularisation, in people with known coronary artery disease in whom imaging with earlier generation CT scanners is difficult’. This has previously been challenging due to artefact from stent metal and heavy calcification in the native vessels of patients who have undergone coronary artery bypass grafting (CABG). High-definition CT coronary angiography (HD-CTCA) aims to address the shortcoming of conventional technology by improving spatial resolution and reducing calcium blooming artefact. We evaluated the accuracy of HD-CTCA in patients presenting with chest pain after previous coronary revascularisation as part of an HD-CTCA accuracy trial. Methods Patients with high pre-test probability and established coronary artery disease were prospectively enrolled into our HD-CTCA accuracy trial. We present the interim results of 64 consecutive, previously revascularised patients (40 PCI, 24 CABG) who underwent HD-CTCA within 30 days following invasive coronary angiography (ICA). Anonymised ICA and HD-CTCA studies were evaluated separately and results compared with ICA as the reference standard. Grafts were not assessed. Results HD-CTCA studies were acquired using prospective gating, 100 kV tube voltage and optimum radiation reduction strategies. The male: female ratio was 3.9:1 and the median age and BMI of patients at the time of scanning were 68 years, 26.4 kg/m2 respectively. The median calcium score of patients without stents was 1715 (53–5389). The median radiation dose was 190 mGy cm (36–350) representing effective doses of 5.3 mSv (1–8.4) using a cardiac specific conversion factor (0.028). Compared to ICA, the per-coronary segment sensitivity and specificity of HD-CTCA for 70% stenosis were 99.0% and 97.7% respectively. The negative predictive value was 99.5% and positive predictive value 95.1%. The κ statistic was 0.95 implying very good agreement between imaging methods. Discussion Interventional cardiologists with direct access to HD-CTCA increasingly use this modality for first-line investigation of patients re-presenting following revascularisation. There has previously been little data to justify this trend although conventional CTCA is well established for the evaluation of coronary bypass grafts. The NICE Guidance supports this trend and this study defines the level of accuracy that can be anticipated with a non-invasive approach to coronary angiography for these patients. Conclusions In expert hands, HD-CTCA is highly accurate with remarkably similar angiographic findings to ICA for the assessment of the native coronary arteries in patients with prior revascularisation. These findings have significant implications for how sophisticated CTCA is integrated into the diagnostic algorithms of those re-presenting with IHD and previous revascularisation.

T.K. Mittal , E.D. Nicol ⁎, S.P. Harden , C.A. Roobottom , S.P. Padley , G. Roditi , C.R. Peebles , A. Taylor , M.C. Hamilton , G.J. Morgan-Hughes , R.W. Bury , on behalf of the British Society of Cardiovascular Imaging a Royal Brompton and Harefield NHS Foundation Trust, London, UK b University Hospital Southampton NHS Foundation Trust, Southampton, UK c Plymouth Hospitals NHS Trust, Plymouth, UK d Glasgow Royal Infirmary, Glasgow, UK e Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science & Great Ormond Street Hospital, London, UK f Bristol Royal Infirmary, Bristol, UK g Blackpool Victoria Infirmary, Blackpool, UK

•. Cardiac CT is a rapidly developing field offering a viable non-invasive alternative to conventional coronary angiography. •. The development of CT technology often outpaces evaluation of its benefit; however 64 slice multidetector CT is now considered as a reference standard for cardiac CT examination. •. Careful selection of patients and optimisation of CT technique is essential to obtain high-quality images and minimise the radiation dose to the patients. •. Although cardiac CT is primarily used for the assessment of coronary artery disease in low- and intermediate-risk patients, it can be used in a range of other indications, including assessment of coronary artery bypass grafts (CABGs), cardiac valves, congenital cardiac anomalies, the left atrium prior to electrophysiology treatment and assessment of suitability for trans-catheter aortic valve implantation. •. The scope of cardiac CT continues to expand and future developments where cardiac CT is likely to be useful include coronary plaque assessment and perfusion imaging. The potential to non-invasively image the heart has led to the rapid development and dissemination of cardiac CT. With the advent of 64 slice systems, cardiac multidetector CT continues to evolve as an essential tool in the investigation of many cardiac conditions. It is now routinely used to provide accurate information about coronary artery disease, cardiac anatomy and congenital anomalies, coronary artery bypass grafts, cardiac valves and pulmonary vein/left atrial anatomy. However, its value in the assessment of coronary stents, ventricular function and coronary plaque morphology remains limited and requires further research. Although cardiac CT is a robust technique, it requires careful patient selection and close interaction between radiologists and cardiologists. It is also considered a radiation-intensive examination and requires careful planning to consistently achieve low levels of radiation exposure to patients. In this review we describe the optimal technique of performing cardiac CT. We also summarise the current indications of cardiac CT and discuss the evidence for various applications.

OBJECTIVES:Radiofrequency ablation of the pulmonary veins is an accepted treatment for atrial fibrillation. An accurate knowledge of pulmonary venous anatomy and dimensions is desirable prior to such a procedure. The objective of this study was to use 64-detector row cardiac CT to investigate the changes in pulmonary venous dimensions during the cardiac cycle. METHODS:Data from 44 consecutive patients with no significant cardiovascular pathology who underwent electrocardiogram (ECG)-gated 64-detector row coronary angiography were retrospectively analysed. Average diameter and cross-sectional area were measured at 5 mm intervals from each pulmonary vein ostium, in ventricular end-diastole and ventricular end-systole, using curved multiplanar reformats. RESULTS:4 (9.1%) patients had pulmonary vein anomalies and were excluded. In the remaining 40 patients, pulmonary vein diameter and area at the ostium were significantly larger in end-systole in all four veins, with the largest differences in the superior pulmonary veins. Dimensional changes for diameter (millimetres) and area (square millimetres) were as follows: left superior pulmonary vein, 2.5 (p<0.001), 65.48 (p<0.001); right superior pulmonary vein, 1.63 (p<0.001), 56.27 (p<0.001); left inferior pulmonary vein, 1.1 (p<0.001), 30.41 (p<0.001); and right inferior pulmonary vein, 0.68 (p=0.005), 30.14 (p=0.005). Less marked changes were seen at measurement sites further from the atrium. Interobserver correlation was high (all but one measurement >0.9). CONCLUSION:Pulmonary vein dimensions change significantly between end-systole and end-diastole, and the ostia of the superior pulmonary veins are potentially the most vulnerable to dimensional inaccuracies. ECG-gated cardiac CT may provide a more precise method of pulmonary venous dimensional measurement than non-gated techniques. Knowledge of change in pulmonary vein diameter offers interesting potential research into the effect of pulmonary vein function.

Background 64-slice Computed Tomographic Coronary Angiography (CTCA) has high negative predictive value in assessment of patients with low-risk of coronary disease (CAD). However, it has a low specificity in assessment of patients with high pre-test probability of or established CAD, due to limited spatial resolution and blooming artefact from coronary artery calcium. Recently published NICE guidelines recommend the use of conventional CTCA for the assessment of patients with low pre-test probability of CAD, but not for patients with high pre-test probability of CAD or those with calcified coronary atheromatous disease (Agatston Calcium score >400). High-definition CT (HDCT) combined with the use of iterative reconstruction (ASIR), aims to address the shortcoming of conventional CT technology by improving spatial resolution and reducing calcium blooming artefact, without increasing ionising radiation exposure. Methods Patients with high pre-test probability of and established CAD, were prospectively enrolled in our HD-CTCA accuracy trial. We present the interim results of our 50 consecutive patients who underwent HD-CTCA following invasive coronary angiography (ICA) for the assessment of coronary disease. HD-CTCA was conducted on all patients within 30 days of ICA. Anonymised ICA and HD-CTCA studies were evaluated separately and results compared with ICA as the reference standard. Results All HD-CTCA studies were acquired using prospective gating, 100 kV tube voltage and optimum radiation dose reduction strategies and images were reconstructed using 50% ASIR. The male: female ratio was 37:13 and the median (IQR) age, BMI and Agatston Calcium Score of patients at the time of scanning were 67.5 (60–76.5) years, 26.5 (24.4–28.6) kg/m2 and 708 (293–1615) respectively. The median (IQR) radiation dose was 151 (131–275) mGy.cm, representing effective doses of 4.2 (3.7–7.7) mSv using a cardiac specific conversion factor (0.028/cm). All coronary segments visualised on ICA were demonstrated on HD-CTCA. Of the 726 coronary segments evaluated on HD-CTCA, 96.4% were of excellent, 2.8% moderate and 0.8% poor diagnostic quality. Compared to ICA, HD-CTCA had sensitivity and specificity of 97% (95% CI 81% to 100%) and 95% (95% CI 72% to 99%) on a per-patient basis and sensitivity and specificity of 94% (95% CI 87% to 980%) and 98% (95% CI 97% to 99%) on a per-coronary segment basis respectively. Conclusion Our interim results demonstrate that HD-CTCA has excellent accuracy compared to ICA in the assessment of patients with high pre-test probability of CAD or with established CAD and can be performed within acceptable radiation dose limits.

Tuesday 11 September Proffered papers 3: Dose managment - Presenting Author: Dr Varut Vardhanabhuti

Illicit drug abuse is a continuing menace of epidemic proportions associated with serious medical and social problems. Drug abuse can have a wide variety of presentations some of which can be life-threatening. The clinical diagnosis can be challenging as the history is usually limited or absent. Radiologists need to be familiar with varied imaging presentations and the related complications of illicit drug abuse to ensure correct diagnosis and appropriate timely treatment. This review will illustrate the imaging spectrum of illicit drug abuse involving several organ systems and also discuss the pathophysiological consequences of drug abuse. (C) 2010 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Multidetector row computed tomography (MDCT) with its high spatial and temporal resolution has now become an established and complementary method for cardiac imaging. It can now be used reliably to exclude significant coronary artery disease and delineate complex coronary artery anomalies, and has become a valuable problem-solving tool. Our experience with MDCT imaging suggests that it is clinically useful for imaging the pericardium. It is important to be aware of the normal anatomy of the pericardium and not mistake normal variations for pathology. The pericardial recesses are visible in up to 44% of non-electrocardiogram (ECG)-gated MDCT images. Abnormalities of the pericardium can now be identified with increasing certainty on 64-detector row CT; they may be the key to diagnosis and therefore must not be overlooked. This educational review of the pericardium will cover different imaging techniques, with a significant emphasis on MDCT. We have a large research and clinical experience of ECG-gated cardiac CT and will demonstrate examples of pericardial recesses, their variations and a wide variety of pericardial abnormalities and systemic conditions affecting the pericardium. We give a brief relevant background of the conditions and reinforce the key imaging features. We aim to provide a pictorial demonstration of the wide variety of abnormalities of the pericardium and the pitfalls in the diagnosis of pericardial disease.

The aim of this study was to determine the prognostic value of coronary multidetector CT angiography (MDCTA) in patients with an intermediate pre-test probability of significant coronary artery disease (CAD). Patients who underwent 64-slice coronary MDCTA and met the selection criteria were identified and assessed for intermediate pre-test probability. Coronary MDCTA scans were preceded by calcium scoring, whereas all MDCTA scans were interrogated for the presence of plaque composition and the distribution and degree of stenosis. Significant stenosis was classified as being >50% of the luminal diameter. All patients were followed up for the occurrence of (i) cardiac death, (ii) non-fatal myocardial infarction, (iii) unstable angina requiring hospital admission and (iv) revascularisation. 138 patients were included (follow-up of 19.9 months); of these, 8 had a cardiac event (all revascularisations) and all had a positive coronary MDCTA. Patients with normal coronary arteries or non-significant stenosis suffered no cardiac events during follow-up. There were significant differences between the two groups regarding the presence of significant stenosis (p<0.001), the presence of plaque (p = 0.011) and a calcium score >10 (p = 0.003); 36.4% of patients with significant stenosis underwent revascularisation. In conclusion, this is the first UK study to investigate survival data in a population of intermediate-risk patients with no prior history of CAD who were investigated with coronary MDCTA. Coronary MDCTA can confidently rule out significant CAD in the intermediate-risk population and guide risk factor modification in patients with demonstrated coronary atheroma.