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C Anagnostopoulos

Publications and source records attributed to C Anagnostopoulos.

At least 19 recordsLinked to original sources
PubMed2006

Syphilitic periostitis in a newly diagnosed HIV-positive man.

A 36-year-old man presented for an HIV test, which answered positive. He gave a six-week history of headache and fever. His syphilis serology was also positive with a Venereal Disease Research Laboratory (VDRL) titre of 1:32, and positive Treponema pallidum particle agglutination (TPPA) assay and fluorescent treponemal antibody (FTA). When he attended for treatment of the syphilis, he had developed severe pain in both lower limbs. Plain radiographs were normal. An isotope bone scan showed multiple areas of increased uptake, consistent with syphilitic periostitis. Some of these lesions were asymptomatic. He was treated with benzathine penicillin and his pain resolved. The bone scan had normalized after six months. We review the previous literature regarding syphilitic bone pain and periostitis. We discuss the importance of considering syphilis in the differential diagnosis of any sexually active adult presenting with bone pain, and highlight the usefulness of isotope bone scans in clarifying the clinical picture.

Adult↗
PubMed2005

EANM/ESC procedural guidelines for myocardial perfusion imaging in nuclear cardiology.

The European procedural guidelines for radionuclide imaging of myocardial perfusion and viability are presented in 13 sections covering patient information, radiopharmaceuticals, injected activities and dosimetry, stress tests, imaging protocols and acquisition, quality control and reconstruction methods, gated studies and attenuation-scatter compensation, data analysis, reports and image display, and positron emission tomography. If the specific recommendations given could not be based on evidence from original, scientific studies, we tried to express this state-of-art. The guidelines are designed to assist in the practice of performing, interpreting and reporting myocardial perfusion SPET. The guidelines do not discuss clinical indications, benefits or drawbacks of radionuclide myocardial imaging compared to non-nuclear techniques, nor do they cover cost benefit or cost effectiveness.

Cardiology↗
PubMed2005

Myocardial perfusion scintigraphy in the UK: insights from the British Nuclear Cardiology Society Survey 2000.

BACKGROUND: The National Institute for Health and Clinical Excellence (NICE) has recently published a very positive technology appraisal of myocardial perfusion scintigraphy (MPS). This has important implications for service provision within the National Health Service, and an accurate knowledge of the current level of MPS activity is necessary. METHODS: A postal questionnaire was sent to 207 nuclear medicine departments in the UK, requesting information about nuclear cardiology facilities, activity, and practice. Non-responding departments were sent a second questionnaire, followed where necessary by a telephone call. RESULTS: A response rate of 61% was achieved; 52% of departments performed MPS, and these tended to have more gamma cameras than those which did not (median (25th-75th centile) 2.0, 1.5-2.5 v 1.0, 0.5-1.5; p = 0.02). The median number of studies performed was 256 (144-460). The estimated rate of MPS in the UK for the year 2000 was 1200 per million population. The median (25th-75th centile) waiting time for MPS was 16 (9-24) weeks. Pharmacological stress was used in 77% of studies, and a technetium-99m based radiopharmaceutical in 60% (two day protocol in 75%). Tomographic rather than planar imaging was performed in 88% of studies, of which 22% were ECG gated. A cardiologist was involved in reporting in 35% of studies. CONCLUSIONS: MPS activity in the UK remains low, and it tends to be provided as a low volume service with unacceptably long waiting times and a lack of involvement by cardiologists. The recent NICE appraisal may provide an impetus for further resourcing and development.

Coronary Disease↗
PubMed2004

Myocardial perfusion scintigraphy: the evidence.

This review summarises the evidence for the role of myocardial perfusion scintigraphy (MPS) in patients with known or suspected coronary artery disease. It is the product of a consensus conference organised by the British Cardiac Society, the British Nuclear Cardiology Society and the British Nuclear Medicine Society and is endorsed by the Royal College of Physicians of London and the Royal College of Radiologists. It was used to inform the UK National Institute of Clinical Excellence in their appraisal of MPS in patients with chest pain and myocardial infarction. MPS is a well-established, non-invasive imaging technique with a large body of evidence to support its effectiveness in the diagnosis and management of angina and myocardial infarction. It is more accurate than the exercise ECG in detecting myocardial ischaemia and it is the single most powerful technique for predicting future coronary events. The high diagnostic accuracy of MPS allows reliable risk stratification and guides the selection of patients for further interventions, such as revascularisation. This in turn allows more appropriate utilisation of resources, with the potential for both improved clinical outcomes and greater cost-effectiveness. Evidence from modelling and observational studies supports the enhanced cost-effectiveness associated with MPS use. In patients presenting with stable or acute chest pain, strategies of investigation involving MPS are more cost-effective than those not using the technique. MPS also has particular advantages over alternative techniques in the management of a number of patient subgroups, including women, the elderly and those with diabetes, and its use will have a favourable impact on cost-effectiveness in these groups. MPS is already an integral part of many clinical guidelines for the investigation and management of angina and myocardial infarction. However, the technique is underutilised in the UK, as judged by the inappropriately long waiting times and by comparison with the numbers of revascularisations and coronary angiograms performed. Furthermore, MPS activity levels in this country fall far short of those in comparable European countries, with about half as many scans being undertaken per year. Currently, the number of MPS studies performed annually in the UK is 1,200/million population/year. We estimate the real need to be 4,000/million/year. The current average waiting time is 20 weeks and we recommend that clinically appropriate upper limits of waiting time are 6 weeks for routine studies and 1 week for urgent studies.

Cardiology↗
PubMed2003

Procedure guidelines for radionuclide myocardial perfusion imaging.

Radionuclide myocardial perfusion imaging (MPI) is an established and non-invasive imaging technique with diagnostic and prognostic efficacy in the investigation of coronary artery disease. It is the only widely available test for assessing myocardial perfusion directly but there are variations in the way it is performed in different centres. Harmonization of practice, at least at a national level, is therefore essential, and clinical governance now makes it mandatory for practice to be based upon evidence whenever possible [ 1]. This is best achieved by expert analysis of the evidence and to this end the British Nuclear Cardiology Society (BNCS) in association with the British Cardiac Society (BCS) and the British Nuclear Medicine Society (BNMS) have developed procedure guidelines for tomographic myocardial perfusion imaging. A systematic literature search was performed and every effort was made to conform with the AGREE recommendations [ 2]. All recommendations are therefore based on either evidence from clinical studies, previous published guidelines or expert consensus of the writing and advisory groups. The guidelines cover the clinical indications of MPI, the methods used for stress testing, the radiopharmaceuticals and the injected activities and also issues related to acquisition, processing and interpretation of images. They do not cover the benefits or drawbacks of the technique in specific circumstances; neither do they address its cost effectiveness in clinical diagnosis and management nor its potential impact on clinical outcomes. The guidelines aim to assist medical practitioners and other health care professionals in recommending, performing, interpreting and reporting single photon emission computed tomography (SPECT) of myocardial perfusion.

Coronary Artery Disease↗
PubMed2001

Non-invasive investigations.

The most commonly used techniques for imaging the effects of coronary artery disease (CAD) on the heart are myocardial perfusion scintigraphy (MPS) and echocardiography. Both tests have been validated during exercise and pharmacological stress and they are valuable for the diagnosis and aiding management decisions in patients with suspected or known CAD. In a proportion of these patients, repetitive episodes of myocardial ischaemia can lead to intracellular and extracellular changes so that myocytes, although viable, have insufficient energy to sustain contraction. This phenomenon is known as myocardial hibernation and it can be detected accurately by both MPS and stress echocardiography. The review that follows highlights the role of these techniques as powerful diagnostic and prognostic tools in clinical cardiology. In order to make the best use of them, attention to detail and planning are required to design the test to suit the clinical problem and to obtain the most accurate data possible.

Adrenergic beta-Agonists↗
PubMed2000

A digital image analysis and neural network based system for identification of third-stage parasitic strongyle larvae from domestic animals.

A competitive learning vector quantization artificial neural network (ANN) was trained to identify third-stage parasitic strongyle larvae from domestic animals on the basis of quantitative data obtained from processed digital images of larvae. For this reason, various quantitative features obtained from processed digital images of larvae were tested as to whether they are variant or invariant to the shape taken by the motile larvae during image recording. A total of 255 images of 57 individual larvae in various shapes belonging to five genera were recorded. Following image processing, 16 features were measured, of which seven were selected as invariant to larva shape. By trial and error, two of those features, 'area' and 'perimeter', along with the quantitative features used in conventional identification, 'overall body length', 'width' and 'extension of sheath' (tip of larva to tip of sheath), were used as an effective training data set for the ANN. This ANN coupled with an image analysis facility and a knowledge relational database became the basis for developing a computer-based larva identification system whose overall identification performance was 91.9%. The advantages of this system are its speed and objectivity. The objectivity of the system is based on the fact that it is not subject to inter- and intra-observer variability arising from the user's profile of competency in interpreting subjective and non-quantifiable descriptions. The limitations of the system are that it cannot handle raw images but only data extracted from images, its performance depends on the reliability of the input vectors used as training data for the ANN, and its use is restricted only to well-equipped laboratories due to its requirement for expensive instrumentation.

Animals↗
PubMed1999

Simultaneous assessment of myocardial viability and function for the detection of hibernating myocardium using ECG-gated 99Tcm-tetrofosmin emission tomography: a comparison with 201Tl emission tomography combined with cine magnetic resonance imaging.

The aims of this study were to evaluate the simultaneous assessment of myocardial viability and function for the detection of hibernating myocardium using ECG-gated 99Tcm-tetrofosmin single photon emission tomography (SPET), and to compare the technique with 201Tl SPET in combination with cine magnetic resonance imaging (MRI). Fifteen patients aged 41-70 years with impaired left ventricular function (mean LVEF 23.4 +/- 8.1%) and three-vessel coronary artery disease were studied before and after coronary artery bypass grafting (CABG). The following investigations were performed within the 3 months before surgery: stress/redistribution and separate-day rest 201Tl SPET with early and late imaging, stress and ECG-gated rest 99Tcm-tetrofosmin SPET, and resting cine MRI. Between 3 and 6 months post-surgery, stress/redistribution 201Tl SPET and cine MRI were repeated. Tracer uptake in nine segments of the left ventricle was graded visually and by quantitative analysis. Myocardial motion and thickening were graded visually from cine MRI and from gated 99Tcm-tetrofosmin SPET images. Segments were defined as hibernating pre-operatively if tracer uptake was moderately reduced or better but myocardial motion was severely hypokinetic or worse. The accuracy of pre-operative assessment was assessed by comparison with post-operative function assessed by MRI. The sensitivity and specificity for the prediction of functional improvement were 69% and 60% for late rest 201Tl uptake combined with MRI; 58% and 62% for rest 99Tcm-tetrofosmin uptake combined with MRI; and 62% and 45% when gated 99Tcm-tetrofosmin SPET was used to assess both tracer uptake and wall motion. In 21 of 135 segments, contractile function could not be assessed by gated 99Tcm-tetrofosmin SPET because of inadequate tracer uptake; function was improved in 5 (25%) of these segments after CABG. In conclusion, the combined assessment of viability and function using ECG-gated 99Tcm-tetrofosmin SPET is feasible and it allows the assessment of hibernating myocardium with similar accuracy to the combination of ungated 99Tcm-tetrofosmin SPET with MRI. Where tracer uptake is too poor for assessment of function, there is a low incidence of myocardial hibernation. However, ECG-gated 99Tcm-tetrofosmin SPET is not superior to 201Tl SPET combined with cine MRI in the identification of hibernation.

Adult↗
PubMed1998

Comparison of 201Tl, 99mTc-tetrofosmin, and dobutamine magnetic resonance imaging for identifying hibernating myocardium.

BACKGROUND: Both radionuclide perfusion tracers and contractile response to dobutamine have been used to identify hibernating myocardium. The aim was to compare 201Tl (thallium) single photon emission CT (SPECT), 99mTc-tetrofosmin (tetrofosmin) SPECT, and dobutamine cine MRI for identifying regions of reversible myocardial dysfunction. METHODS AND RESULTS: Thirty patients with 3-vessel coronary artery disease and impaired left ventricular function (mean LVEF, 24.0%; SD, 8.3%) scheduled for coronary bypass grafting were recruited. All underwent rest/dobutamine stress (5 to 10 microg . kg-1 . min-1) cine MRI, stress/rest tetrofosmin SPECT, and stress/redistribution and separate-day rest/redistribution thallium SPECT before surgery. Stress/redistribution thallium SPECT and resting MRI were repeated after surgery. In a 9-segment model, SPECT images were scored visually for tracer uptake, which was also measured from a polar plot of myocardial counts. MRI was scored visually for endocardial motion, myocardial thickening, and thickness. Five patients died before follow-up, and 2 declined postoperative investigation. In the remaining 23 patients, mean LVEF increased from 24.0% (SD, 8.3%) to 29.7% (SD, 11.1%) (P<0.05). Of 207 segments analyzed, 145 had significantly abnormal wall motion before surgery, and 82 of these improved function after revascularization. The criteria for predicting recovery of severely hypokinetic segments on preoperative imaging were tracer uptake graded "moderately reduced" or better, or positive inotropic response on dobutamine MRI. Late-rest thallium images showed the highest sensitivity (76%), compared with stress-redistribution thallium (68%) and rest tetrofosmin (66%) (P<0.05). All 3 tracer techniques were nonspecific (44%, 51%, and 49%, respectively). Redistribution of thallium after the resting injection was insensitive (18%) but highly specific (83%). Inotropic response to dobutamine was also insensitive (50%) but specific (81%). CONCLUSIONS: Radionuclide uptake is a sensitive but nonspecific predictor of myocardial functional recovery, whereas dobutamine MRI is specific but insensitive.

Adult↗
PubMed1998

A comparison of adenosine and arbutamine for myocardial perfusion imaging.

We have compared our standard stress protocol (adenosine combined with exercise) with the new stress agent arbutamine, for thallium-201 myocardial perfusion imaging (MPI) in order to assess the comparative value of arbutamine. We studied 23 patients referred for MPI, and each patient had two studies (18 males, median age 66 years, five with previous myocardial infarction). Uptake scores were assigned to each of nine segments, and the extent and severity of defects were measured using a polar plot. Haemodynamic changes were greater with arbutamine (rate-pressure product increase 78% vs 51%, P = 0.003). Symptoms were experienced by 21 patients with arbutamine and 16 with adenosine (P = 0.07). Agreement between the techniques for classification of patients as normal or as having reversible, fixed or mixed defects was good (19 of 23 studies, 83%, kappa = 0.76). Agreement for similar classification of segments was also good (82%, kappa = 0.71). Segmental agreement for stress scores was good (86%, kappa = 0.77). However, mean size of stress defect was larger with adenosine (83+/-52 pixels vs 65+/-48 pixels, P<0.05), though severity and reversibility were similar (P = NS). We conclude that arbutamine provides comparable results to those obtained with adenosine and exercise and that the observed differences are not clinically significant.

Adenosine↗
PubMed1998

The effect of angiotensin converting enzyme inhibition on myocardial function and blood pressure after coronary artery bypass surgery--a randomised study.

OBJECTIVE: To investigate the effect of 6 weeks' pre-operative treatment with the angiotensin converting enzyme inhibitor, quinapril, on left ventricular function when measured 3 months after coronary artery bypass graft surgery and to examine the safety of such treatment. PATIENTS AND METHODS: Patients (96) [86 males, 10 females; mean age 61 years] with chronic stable angina, on the waiting list for coronary artery bypass graft surgery, underwent measurement of left ventricular function by resting radionuclide ventriculography. Patients were then randomised to quinapril 20 mg once daily or placebo in a double-blind fashion, in addition to existing anti-anginal therapy and this regimen was continued for up to 6 weeks prior to operation. Measurement of left ventricular function was repeated 3 months following surgery, after recommencement of pre-surgery anti-anginal therapy for 1 week. Effects on systemic vascular resistance (SVR) during bypass were calculated from perfusion records and vasoconstrictor use during operation was documented. The safety of the addition of quinapril to the anti-anginal regimen was assessed by measurement of systemic blood pressure (BP) after the first dose of study medication, measurement of intra-operative BP, administration of inotropes and any intra-operative complications. RESULTS: There was no difference between treatment groups in the pre-study left ventricular ejection fraction (mean (S.D.); 54.9 (13.8)% versus 55.6 (13.2)%, quinapril versus placebo, respectively), or 3 months after surgery (58.1 (13.6)%, versus 56.9 (12.6)%, quinapril versus placebo, respectively). Left ventricular ejection fraction 3 months after surgery did not change significantly from pre-treatment in either group (2.8 (10.7)% and 1.5 (10.1)%; quinapril and placebo, respectively). There was no first-dose hypotension (systolic BP < 100 mmHg). The intra-operative BP and the SVR during bypass in the two treatment groups were not significantly different. The ischaemic time (mean = 56 min) and the use of inotropes were the same in both groups and there was no mortality. CONCLUSIONS: Angiotensin converting enzyme inhibitor treatment before coronary artery bypass graft surgery does not have a significant beneficial effect on left ventricular function following coronary artery bypass graft surgery. Angiotensin converting enzyme inhibition, administered in addition to anti-anginal therapy, does not cause first-dose hypotension or increase morbidity or mortality and can safely be used in patients with coronary heart disease prior to coronary artery bypass graft surgery.

Adult↗
PubMed1998

Simultaneous biplane first-pass radionuclide ventriculography using 99Tcm-tetrofosmin: a comparison with magnetic resonance imaging.

First-pass radionuclide ventriculography (FPRNV) using 99Tcm-labelled myocardial perfusion agents allows the assessment of myocardial function and perfusion simultaneously. We have assessed the feasibility of biplane FPRNV using 99Tcm-tetrofosmin, and have validated global and regional functional measurements by comparison with magnetic resonance imaging (MRI). FPRNV was performed at rest in 18 patients referred for assessment of known or suspected coronary artery disease (5 with previous myocardial infarction). A dual-headed camera was used to acquire RAO and LAO projections simultaneously. Left ventricular ejection fraction (LVEF) was calculated using standard methods and regional wall motion was evaluated visually in five myocardial segments using a 4-point scale and also by Fourier analysis. Cine MRI was performed in four oblique planes, LVEF was calculated using a biplane area-length method and regional motion was assessed visually in a similar fashion to FPRNV. Agreement between the techniques for LVEF was good using RAO FPRNV (mean +/- S.D. difference = 0.7 +/- 4.7%), but less good in the LAO projection (difference = 10.5 +/- 7.1%). Wall motion was normal by both FPRNV and MRI in 5 patients without CAD and 3 of the 13 patients with CAD. In the remaining 10 patients, wall motion by MRI was abnormal in 20 segments; FPRNV with visual analysis was abnormal in 8 patients (80%) and 16 (80%) segments. Fourier analysis showed regional abnormalities in 7 patients (70%) and 13 (65%) segments. There was good agreement (kappa = 0.68) between FPRNV (visual analysis) and MRI for wall motion scores, but moderate agreement (kappa = 0.55) between Fourier analysis and MRI. Thus, LVEF measured by FPRNV in the RAO projection agrees well with MRI. Normal regional wall motion is accurately identified, but regional abnormalities are better assessed with MRI.

Adult↗