Michael R. Rees

Hybrid cardiac imaging: SPECT/CT and PET/CT. A joint position statement by the European Association of Nuclear Medicine (EANM), the European Society of Cardiac Radiology (ESCR) and the European Council of Nuclear Cardiology (ECNC)

Improvements in software and hardware have enabled the integration of dual imaging modalities into hybrid systems, which allow combined acquisition of the different data sets. Integration of positron emission tomography (PET) and computed tomography (CT) scanners into PET/CT systems has shown improvement in the management of patients with cancer over stand-alone acquired CT and PET images. Hybrid cardiac imaging either with single photon emission computed tomography (SPECT) or PET combined with CT depicts cardiac and vascular anatomical abnormalities and their physiologic consequences in a single setting and appears to offer superior information compared with either stand-alone or side-by-side interpretation of the data sets in patients with known or suspected coronary artery disease (CAD). Hybrid systems are also advantageous for the patient because of the single short dual data acquisition. However, hybrid cardiac imaging has also generated controversy with regard to which patients should undergo such integrated examination for clinical effectiveness and minimization of costs and radiation dose, and if software-based fusion of images obtained separately would be a useful alternative. The European Association of Nuclear Medicine (EANM), the European Society of Cardiac Radiology (ESCR) and the European Council of Nuclear Cardiology (ECNC) in this paper want to present a position statement of the institutions on the current roles of SPECT/CT and PET/CT hybrid cardiac imaging in patients with known or suspected CAD.

Use of multidetector computed tomography for the assessment of acute chest pain : a consensus statement of the North American Society of Cardiac Imaging and the European Society of Cardiac Radiology

The diagnosis of patients with acute chest pain remains a challenging problem. There are approximately 6 million chest pain related emergency department (ED) visits annually in the US alone [1]. Approximately 5.3% of all ED patients are seen because of chest pain and reported admission rates are between 30% and 72% for these patients [2]. Only 15–25% of patients presenting with acute chest pain are ultimately diagnosed as having an acute coronary syndrome (ACS). Of those patients who were admitted to the chest pain unit, 44% ultimately had

Assessment of acute myocardial infarction: current status and recommendations from the North American society for cardiovascular imaging and the European society of cardiac radiology

There are a number of imaging tests that are used in the setting of acute myocardial infarction and acute coronary syndrome. Each has their strengths and limitations. Experts from the European Society of Cardiac Radiology and the North American Society for Cardiovascular Imaging together with other prominent imagers reviewed the literature. It is clear that there is a definite role for imaging in these patients. While comparative accuracy, convenience and cost have largely guided test decisions in the past, the introduction of newer tests is being held to a higher standard which compares patient outcomes. Multicenter randomized comparative effectiveness trials with outcome measures are required.

Vibrational angioplasty in the treatment of chronic infrapopliteal arterial occlusions: preliminary experience.

PURPOSE To evaluate the safety and efficacy of vibrational angioplasty in chronic infrapopliteal arterial occlusions. METHODS Twelve patients (9 men, aged 54 to 90 years) with 13 below-knee arterial chronic total occlusions were treated percutaneously using vibrational angioplasty. The occlusions were located in the anterior tibial artery (n=5), the tibioperoneal trunk (n=4), the peroneal artery (n=1), the posterior tibial artery (n=1), and in both the tibioperoneal trunk and peroneal artery (n=2). The length of the lesions ranged from 5 to 14 cm. RESULTS Recanalization was successful in 12 (92.3%) lesions. In 1 case, the wire perforated the arterial wall; the procedure was abandoned without clinical sequelae. The time to cross the occlusions with the wire ranged from 6 to 19 minutes. No other complications were observed. Clinical follow-up ranged to 18 months. Ten patients with ulceration or gangrene demonstrated good wound healing, and pain was alleviated in all successfully treated patients. CONCLUSIONS Vibrational angioplasty appears feasible as a means of safely recanalizing chronic total occlusions of the infrapopliteal arteries. Further experience should be acquired to assess its short- and long-term effects on this vascular territory.

Use of vibrational angioplasty for the treatment of chronic total coronary occlusions: Preliminary results

The aim of the study was to investigate the feasibility and clinical safety of vibrational angioplasty in the treatment of chronic total coronary occlusions and evaluate the clinical and angiographic factors that are predictive of the procedural success and complications of the procedure. Seventy‐eight patients with chronic total occlusions (>3 months) resistant to conventional techniques were treated by vibrational angioplasty using a variety of conventional guidewires. Lesions were successfully crossed in 67 (85.9%) cases and antegrade flow was achieved in 59 (75.5%). Major complications (myocardial infarction and tamponade) occurred in two (2.5%) patients, but no fatalities ensued. Angiographically detectable dissections were seen in 23 (29.5%) patients but only resulted in vessel compromise and reclosure in 5 cases. Multiple stepwise logistic regression analysis identified the duration (<6 months, P = 0.008) and the length of the occlusion (<15 mm, P = 0.03) as independent predictors of final success and the age of the patient (<55 years, P = 0.006) as the only independent predictor of procedural complications. Vibrational angioplasty is a safe technique useful in the treatment of chronic coronary occlusive disease. Patients in whom the procedure is likely to prove most successful may be easily identified by clinical and angiographic features (duration and length of occlusion).Cathet. Cardiovasc. Intervent. 46:98–104, 1999.

Vibrational Angioplasty and Hydrophilic Guidewires in the Treatment of Chronic Total Coronary Occlusions

Purpose: To study the efficacy and safety of vibrational angioplasty versus hydrophilic guidewires for recanalizing chronic total occlusions (CTOs) of the coronary arteries. Methods: In a retrospective study, 99 patients with old (>3 months) CTOs resistant to conventional techniques were treated either with vibrational angioplasty (group A, n = 72) or 0.014-inch hydrophilic guidewires (group B, n = 27). The selection of the technique (vibrational angioplasty or hydrophylic guidewires) was dependent only upon device availability. A variety of guidewires were employed in conjunction with vibrational angioplasty. Results: The crossing success rates in groups A and B were 86.1% (62/72) and 55.5% (15/27) (p < 0.05), with final procedural success rates of 75% (54/72) and 44.4% (12/27) (p < 0.01), respectively. The main reasons for failure were inability to cross the lesion with a guidewire (10/18 in group A and 12/15 in group B) and large dissections resulting in vessel closure (2/18 in group A and 2/15 in group B). Three major complications were seen, 2 in group A and 1 in group B. Three vessel perforations were reported in group A. Both techniques needed prolonged fluoroscopy times. Conclusions: Vibrational angioplasty was more successful in treating CTOs compared to hydrophilic guidewires and had similar complication rates (most without clinical sequelae).

Can rotational atherectomy cause thermal tissue damage? A study of the potential heating and thermal tissue effects of a rotational atherectomy device

Purpose: Thermal tissue damage (TTD) is customarily associated with some lasers. The thermal potential of rotational atherectomy (RA) devices is unknown. We investigated the temperature profile and potential TTD as well as the value of fluid flushing of an RA device.Methods: We used a high-resolution infrared imaging system that can detect changes as small as 0.1 °C to measure the temperature changes at the tip of a fast RA device with and without fluid flushing. To assess TTD, segments of porcine aorta were subjected to the rotating tip under controlled conditions, stained by a special histochemical stain (picrisirius red) and examined under normal and polarized light microscopy.Results: There was significant heating of the rotating cam. The mean “peak” temperature rise was 52.8 ± 16.9°C. This was related to rotational speed; thus the “peak” temperature rise was 88.3 ± 12.6°C at 80,000 rpm and 17.3 ± 3.8°C at 20,000 rpm (p<0.001, t-test). Fluid flushing at 18 ml/min reduced, but did not abolish, heating of the device (11.8 ± 2.9°C). A crater was observed in all segments exposed to the rotating tip. The following features were most notable: (i) A zone of “thermal” tissue damage extended radially from the crater reaching adventitia in some sections, especially at high speeds. This zone showed markedly reduced or absent birefringence, (ii) Fluid flushing of the catheter reduced the above changes but increased the incidence and extent of dissections in the media, especially when combined with high atherectomy speeds, (iii) These changes were observed in five of six specimens exposed to RA without flushing, but in only one of six with flushing (p<0.05). (iv) None of the above changes was seen in control segments.Conclusion: RA is capable of generating significant heat and potential TTD. Fluid flushing reduced heating and TTD. These findings warrant further studies in vivo, and may influence the design of atherectomy devices.

Who wants a career in academic medicine

“Clinical medicine and dentistry are very popular and rewarding professions; biomedical research is one of the most exciting, challenging and productive areas of research today. One might expect the combination of the two, namely clinical academic medicine and dentistry, would be among the most desirable of all professions, but all is not well.” So begins Sir Rex Richardss recently published report on clinical academic careers.1 Why was there a need for such a report? The answer can be found in the disturbing statistics of poor recruitment and retention of Britains medical academic staff, with 56 vacant chairs and 192 other vacant academic posts in 1995-6, and a steady exodus of senior lecturers out of academic medicine into NHS posts. It can also be found wherever medical academics gather to discuss their careers, as at the recent conference of the BMAs Medical Academic Staff Committee (MASC). Instead of optimistic …

Does the Kensey catheter keep a coaxial position inside the arterial lumen?: An in-vitro angioscopic study

Angioscopy was used to evaluate the “self-centering” ability of three Kensey catheters (KC) with different flexibility: one 8Fr “peripheral” and two 5Fr “coronary” (I & II). Angioscopic observations were made inside arteries. 5–18 mm in diameter. There was a good correlation between flexibility and self-centering of the KC [r=0.83, p<0.05]. Increasing the flow rate of rinsing solution from 18 to 60 ml/min prolonged coaxial position from 8.9±3.3 to 36±2.2 sec/min of activation [p<0.001]. A smaller effect on coaxial position was exerted by increasing cam speed from 5.2±0.7 to 19.2±1.6 sec/min (p<0.001). In conclusion, angioscopy showed that the KC has a limited ability to maintain a coaxial position inside the arterial lumen and operators cannot rely on its self-centering property.

Ultrasound and Fluoroscopic-Guided Angioplasty over the Aortic Bifurcation in a Patient with Previous Severe Reaction to Contrast Medium

Purpose: To describe a case of ultrasound and fluoroscopic-guided angioplasty necessitated by a patient history of allergic reaction to contrast medium. Case Report: A 60-year-old man with intermittent right leg claudication had a focal >70% stenosis in the right external iliac artery that was amenable to balloon dilation; however, the patient reported a severe reaction to radiographic contrast medium 10 years previously. Angioplasty was begun with transaortic access to the iliac artery lesion under fluoroscopic guidance only. On-table duplex imaging confirmed the lesion site and reference diameters for balloon selection. The balloon was filled with contrast medium to provide rapid positioning under fluoroscopy. An on-table postangioplasty duplex scan showed improvement in the lumen contour and confirmed a reduction in the peak systolic velocity. At the 1-year follow-up, the patient reports no symptoms referable to the treated segment. Conclusions: The combination of ultrasound and fluoroscopy facilitated quick and efficient balloon dilation of an isolated iliac lesion without the use of any contrast medium.