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The first long-term follow-up of the use of the Antheor inferior vena cava (IVC) filter is presented. Between December 1994 and December 1996, 20 Antheor IVC filters were inserted. Seven patients subsequently died and of the 13 patients remaining alive, 11 were available for long-term follow-up. One death was due to migration of the filter to the main pulmonary artery 6 weeks after insertion and because of this case, and other similar reports, the filter has now been withdrawn from clinical use. Of the 11 filters assessed at follow-up, three were fractured. One filter contained thrombus and one IVC was occluded. Our experience highlights the problem of central migration, but also shows a high incidence of filter fracture which has not previously been described with this design of filter.

We present the case of an adult female patient with a giant coronary artery aneurysm secondary to Kawasaki disease diagnosed for the first time, as far as the authors are aware, on multi-detector row computed tomography (MDCT). The long-term complications relate to the persistence of these aneurysms with giant coronary aneurysms having the lowest regression rate, the highest risk of stenosis and strongest association with myocardial infarction. MDCT coronary angiography represents an ideal, alternative non-invasive imaging modality for the diagnosis and follow-up of the coronary arterial complications of Kawasaki disease, thereby avoiding invasive coronary imaging, and its use in the management algorithm should be considered. We also aim to contribute to the expanding clinical role of MDCT coronary imaging.

The quality of the imaging of the main coronary arteries and side branches provided by multidetector row computed tomography (MDCT) may have importance when assessing congenital coronary artery anomalies. This review discusses the rationale for using MDCT for this indication and examines the advantages and disadvantages of the technique. Examples of MDCT imaging of congenital coronary artery anomalies are presented. These images provide persuasive evidence to support clinical use of MDCT cardiac imaging in the context of suspected congenital coronary artery anomalies as a first line investigation.

A 17-year-old male presented with right knee pain following mild trauma whilst playing badminton. He subsequently developed a popliteal pseudoaneurysm secondary to trauma from a tibial osteochondroma. This is a recognised though very rare occurrence. Its appearance is reported for the first time using multi-detector row computed tomographic angiography (MDCTA). The clinical presentation and management of the popliteal pseudoaneurysm are outlined and the imaging findings are illustrated. There is increasing usefulness of MDCTA as an accessible, accurate, non-invasive clinical tool in the emergency diagnostic setting. Its use in the management of this unusual condition is demonstrated with emphasis on 3D, multi-planar reconstruction post-processing techniques.

EDITOR—Prasad et al do not discuss the recent developments in cardiac computed tomography.1 Coronary angiography using multidetector computed tomography is one of the most impressive advances in non-invasive cardiology for many years.2–4 The authors' judgment on the relative merits of the currently available non-invasive cardiac imaging …

Aim Although arterial closure devices are in use for over a decade, there have been no specific study to assess the use of the same in antegrade puncture. Material and method Consecutive patients undergoing antegrade puncture for peripheral vascular disease in a single centre performed by a single operator were included in this study. The notes and the angiograms were reviewed retrospectively for possible complications and the severity of disease. Result Over a 25-month period, 21 patients with antegrade puncture had Angioseal deployed for haemostasis. Post-procedure complications recorded from the case notes showed one episode of haematoma formation and one case of worsening ischaemia. The severity of the disease at the puncture site did not influence the outcome. Conclusion Use of Angioseal is safe and effective in antegrade punctures for peripheral vascular disease. The result is independent of the severity of disease at the puncture site.

Objective: To assess a new multislice computed tomography (CT) technique for three dimensional quantification of aortic valve calcification volume (3D AVCV) and to study the relation between stenosis and calcification of the aortic valve. Methods: 50 patients with echocardiographic calcification of the aortic valve underwent two separate ECG triggered multislice CT for quantification of 3D AVCV. The agreement between the two 3D AVCV scores was assessed and 3D AVCV was compared with echocardiographic markers of severity of aortic stenosis. Results: Overall the level of agreement between the two 3D AVCV scores was excellent (median interscan variability 7.9% (interquartile range 10.1); correlation coefficient, r = 0.99; repeatability coefficient 237.8 mm3 (limits of agreement −393 to 559 mm3)). However, the magnitude of the 3D AVCV did influence the interscan variability. The 3D AVCV correlated closely with the maximal predicted transvalvar gradient (r2 = 0.77) and aortic valve area (r2 = 0.73). Conclusions: Multislice CT provides a technique for quantifying 3D AVCV that has good reproducibility. There is a close non-linear relation between echocardiographic parameters of severity of valve stenosis and 3D AVCV scores.

OBJECTIVE. Noninvasive imaging of a persistently patent ductus arteriosus in adults remains a challenge. Bearing in mind the excellent spatial resolution provided by multidetector CT (MDCT), we postulated that MDCT might be used to evaluate this anatomic defect. We sought to show that MDCT can depict in detail patent ductus arteriosus in adults and allow determination of the size of the duct, degree of calcification, and morphologic classification.CONCLUSION. MDCT represents a novel method of noninvasively assessing patent ductus arteriosus in adults that provides detailed anatomic information. Comparison with invasive angiographic findings is needed to validate the technique of sizing of ducts using MDCT.

A 72 year old man attended for follow up computed tomography (CT) of a chronic type A aortic dissection, three years on from his original presentation. The contrast enhanced multislice CT was acquired using retrospective ECG gating. Subsequent reconstruction of the CT images was …

There have been a number of advances in helical computed tomography (CT) in recent years, which have had a beneficial impact on the quality of imaging of the thoracic aorta. These advances include sub-second gantry rotation, multislice acquisition, and the use of electrocardiographic (ECG) assistance. We examine these techniques with emphasis on the principles behind ECG assistance and its use to reduce aortic motion artefact. We highlight examples of ECG-assisted multislice CT in a spectrum of pathologies of the thoracic aorta.

A 71-year-old woman underwent aortic valve replacement for severe, symptomatic aortic stenosis. The left ventricle filled rapidly when the left ventricular vent was switched off and postoperatively she was slow to recover with bilateral pleural effusions. These findings prompted early reinvestigation, initially with echocardiography and subsequently with multi-detector row computed tomography. Using a retrospectively electrocardiographic-gated acquisition, adapted from a noninvasive coronary angiography protocol, a calcified, persistently patent ductus arteriosus was identified as the cause for her perioperative and postoperative condition. The defect has since been closed successfully using a transcatheter technique.

The authors assessed motion artifact of the thoracic aorta in 25 patients who underwent multi–detector row computed tomography (CT) with retrospective electrocardiographic (ECG) gating. CT reconstructions centered at four phases of diastole were compared for five different levels of the thoracic aorta. A significant positive correlation was observed between heart rate and motion artifact (r = 0.72, P < .001). The optimal reconstruction phase varied between patients, and this was directly related to heart rate. For patients with a heart rate of 70 beats per minute, the reconstruction phase centered at 75% of the R-R interval had the significantly least motion artifact (P = .004). Conversely, the optimal reconstruction phase for patients with heart rates above 70 beats per minute was centered at 50% of the R-R interval (P = .09). © RSNA, 2003

AIM: To evaluate the technique of coronary angiography with retrospectively electrocardiogram (ECG)-gated four-slice helical computed tomography (CT). MATERIALS AND METHODS: Within 1 month of undergoing routine day-case diagnostic coronary angiography, 30 consecutive patients also underwent retrospectively ECG-gated multislice CT coronary angiography. This enabled direct comparison of seven segments of proximal and mid-coronary artery for each patient by two blinded assessors. Each segment of coronary artery from the multislice CT image was evaluated initially for “assessability” and those segments deemed assessable were subsequently investigated for the presence or absence of a significantly (n=70%) stenotic lesion. RESULTS: Overall 68% of proximal and mid-coronary artery segments were assessable. The sensitivity and specificity of four-slice CT coronary angiography in assessable segments for detecting the presence or absence (n=70%) of stenoses were 72 and 86%, respectively. These results correspond to a positive predictive value of 53% and a 93% negative predictive value. If the 32% of non-assessable segments are added into the calculation then the sensitivity and specificity fall to 49 and 66%, respectively. CONCLUSION: Although multislice CT coronary angiography is a promising technique, the overall assessability and diagnostic accuracy of four-slice CT acquisition is not sufficient to justify routine clinical use. Further, evaluation should investigate the benefit of the reduction in temporal and spatial resolution offered by 16 and 32 slice acquisition.

A 72 year old woman, who presented with severe interscapular pain suggestive of aortic dissection, underwent further evaluation with multislice computed tomography. The contrast enhanced axial images showed extensive intraluminal haematoma within both the descending thoracic aorta and an anomalous, aneurysmal, right subclavian artery (fig 1). Three dimensional reconstruction of the aortic arch was …

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

Two recent deaths from massive air embolism occurring while scuba diving off the South coast of Britain are reported. In each case the circumstances of death were uncertain. In both instances the cause of death, that is massive gas embolism, was determined by plain radiography and findings were confirmed at post-mortem. These cases illustrate that in unexplained deaths that occur after exposure to, or change in hyper- or hypobaric conditions, investigation should include pain radiographs of the chest, abdomen and skull.

Bowel infarction commonly presents as an acute abdomen that rapidly progresses to severe shock. The diagnosis is often not clinically suspected. Three cases are described where the diagnosis was made during dynamic contrast enhanced computed tomography (CT), when gas was demonstrated in the portal venous system and liver. Two patients died during surgery, the third survived because of the prompt diagnosis made on CT, and subsequent surgical treatment. The radiological findings are reviewed.

Background CT coronary angiography CTCA now has an established role in the investigation of patients with chest pain. Under the IRMER regulations radiation doses to patients should be kept as low as reasonably practical (ALARP). Previous publications have used a chest conversion factor to calculate the effective dose (mSv) from CTCA. We have previously demonstrated that chest conversion factors significantly under-estimate the effective dose to the patient when applied to CTCA and have calculated a cardiac specific conversion factor of 0.028 mSv (mGy.cm)-1. Our department follows the ALARP ethos and has implemented new technologies together with physician training to reduce the radiation dose from CTCA. We aimed to investigate what impact the implementation of new technologies has had on the radiation dose of CTCA. Method All patients who were coded as attending for a cardiac CT scan on the PACS and CRIS systems were included in the analysis. Scan indication included: rule out coronary artery disease, CABG assessment, pre-EP studies and problem solving. CT scanning between September 2007 and August 2010 was included; the total dose for the whole examination is used including the scout and non-enhanced scan (calcium score). Scans were performed on a Lightspeed VCT or HD750 (GE Healthcare). To calculate the effective dose a conversion factor was applied to the dose length product of each examination. The DLP is the radiation dose in one CT slice multiplied by the length of the scan. A cardiac specific conversion factor was used rather than a chest conversion factor (0.014) which significantly underestimates the effective dose from CTCA. Data was transformed and expressed as a geometric mean with 99% CI. For each analysis period all scans were included; retrospective, prospective, low kV and zero padding. Results In the 3-year period 1736 scans were performed. The mean radiation dose in the first 6 months of the study (retrospective gating) was 29.6 mSv; using the accepted conversion factor at the time the mean dose was 14.9 mSv. In March 2008 prospective ECG gating was installed; this resulted in a halving of the mean radiation dose to 13.6 mSv. In March 2009 the scanner parameters was set to zero padding and 100 KV reducing the dose to 7.4 mSv. For the final 6 months the mean radiation dose for a cardiac scan was 5.9 mSv; this Abstract 114 figure 1 incorporates scans performed with standard filtered back projection, iterative reconstruction, high definition scanning and retrospective ECG gating for a variety of differing clinical scenarios. Conclusion The introduction of dose saving strategies and appropriate physician training has lead to a significant reduction in the radiation dose from cardiac CT. As CTCA programmes become established in hospitals around the UK it is important that clinicians have the appropriate training and experience to keep the radiation dose to the patients as low as reasonably practical.

Cryoprostatectomy, the use of subzero temperatures to ablate prostate tissue gained favour in the 1960s because of its speed and lack of haemodynamic effects. It fell from use because the freezing process could not be monitored and this led to a high incidence of local complications. We have performed transrectal real time ultrasound in 12 patients undergoing cryoprostatectomy. In all the freezing process was easily visualized as an advancing hyperechoic 'iceball' with distal acoustic shadowing. Monitoring allowed maximum prostate ablation without breaching the prostatic capsule. There were no significant complications and all but one patient gained symptomatic relief. Ultrasound at 1 month showed a heterogeneous echo pattern with very little cavity formation but by 3 months a significant cavity was seen. This study demonstrates that it is possible to monitor the freezing process during transurethral cryoprostatectomy. This, theoretically, should significantly reduce the local complications encountered in previous studies.

The effects of radiographic contrast media (RCM) on leucocyte orientation in vitro were studied using a Zigmond chamber. Leucocyte orientation was assessed following exposure of the leucocytes to iotrolan, iohexol, ioxaglate and diatrizoate. The RCM used were diluted to a concentration similar to that obtained in vivo during routine angiography. At this concentration there was a significant reduction in leucocyte orientation for all RCM investigated but the effect was more pronounced in the monomeric than the dimeric RCM. The results may have significance when deciding which radiographic contrast medium to use in selected patients, particularly those who are immunosuppressed or septicaemic.

We read with interest the article by Ho et al. ([1][1]) in the recent edition of iJACC . Computed tomography (CT) myocardial perfusion imaging (MPI) offers a new, noninvasive functional assessment of myocardial ischemia. When combined with CT coronary angiography, it may offer the strong negative

Coronary arterial microfistulae are abnormal connections between one or multiple coronary arteries and any cardiac chamber, vein, or thoracic vessel. They comprise a subsection of coronary fistulas where the abnormal connections are diffuse, as opposed to the larger, more common single vessel varieties. Most of these anomalies are detected incidentally on catheter angiography; however, we present this anomaly as a case report from the perspective of CT coronary angiography.

Background Subintimal angioplasty may be more successful than conventional (intraluminal) angioplasty for treatment of long femoropopliteal occlusions. This study assessed the clinical and haemodynamic outcome of subintimal angioplasty. Methods All patients with femoropopliteal occlusions treated by subintimal angioplasty over a 3-year period at two centres were reviewed. Clinical assessment and colour duplex imaging were carried out. Results Sixty-nine procedures were performed in 33 men and 33 women of median age 74 (range 47–92) years. Indications for treatment were intermittent claudication in 26 (38 per cent) and critical limb ischaemia in 43 (62 per cent). Median occlusion length was 10 (range 2–50) cm. Primary technical success was achieved in 51 occlusions (74 per cent). There were 11 complications (16 per cent); the majority were minor but surgical intervention was required in two patients (3 per cent). At 6 months the cumulative symptomatic and haemodynamic primary patency rates were 60 and 51 per cent respectively, analysed on an intention-to-treat basis. The symptomatic and haemodynamic patency rates for technically successful procedures were 80 and 77 per cent respectively. Conclusion In this series the short-term clinical success of subintimal angioplasty was poor because of a high incidence of reocclusion and restenosis, despite a relatively high initial technical success rate.

Gastric rupture is an uncommon surgical problem which normally presents with an acute abdomen and peritonism. An unusual case following underwater ascent and its conservative management is presented.

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 ( 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.

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/m 2 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.

Figure 1. (a) Contrast enhanced CT of the chest demonstrating asymmetrically sized breast prosthesis, and bilateral ‘‘Linguini’’ sign. Contrast enhanced CT of (b) the upper and (c) lower abdomen demonstrating a right sided non-enhancing subcutaneous soft tissue mass (siliconoma) with localized inflammatory change. The British Journal of Radiology, 77 (2004), 790–791 E 2004 The British Institute of Radiology DOI: 10.1259/bjr/98330730

In order to ascertain the national variation in practice and workloads amongst interventional radiologists a questionnaire was sent to all members of the British Society of Interventional Radiologists of three or more years standing. The questionnaire was designed to assess changes in workload and angiographic practice amongst members at the various institutions. Results indicate that, over the last five years, there has been a dramatic increase in both diagnostic and therapeutic procedures performed, with an overall doubling of workload. There are, however, wide variations in angiographic practice and technique and referral pattern.

Inverting papilloma of the sinonasal cavity is of importance because of its association with squamous cell carcinoma and its tendency to local recurrence. Appearances of inverting papilloma have only been reported infrequently, and never in recurrent cases. We present the magnetic resonance imaging (MRI) appearances of four cases of inverting papilloma, three of which are recurrent.

A survey of the radiological reduction of intussusception in a selection of British hospitals was performed using a questionnaire. Replies were received from radiologists working in 51 district general hospitals and 25 teaching hospitals or specialist paediatric institutions. Most district general hospitals still use barium as the sole method of reduction of intussusception. Most teaching hospitals and specialist paediatric units have changed to a pneumatic method. The contra-indications, details of patient preparation and technical details of each method varied considerably.

A subgroup of hypertensive patients, with preserved left ventricular function, are susceptible to recurrent episodes of sudden non-ischaemic pulmonary oedema caused by severe (usually bilateral) renal artery stenosis. Renal revascularisation may prevent the occurrence of “flash” pulmonary oedema. More than 70% of patients treated with percutaneous renal revascularisation are free from pulmonary oedema at 12 month follow up.1,2 Although patient selection for renal revascularisation remains controversial, it is generally accepted that patients with recurrent flash pulmonary oedema should at least be considered for intervention.3 Diagnosis requires non-invasive imaging of the renal arteries and this may be achieved with Doppler ultrasonography. However the failure rate is high and it is not therefore a reliable clinical technique.4 Magnetic resonance or computed tomography (CT) angiography are possible alternatives, and both provide additional imaging of the abdominal aorta and three dimensional visualisation. Magnetic resonance imaging is generally the less available of the two options. Helical, single slice, CT has been evaluated in comparison to invasive renal angiography, and the sensitivity and specificity for the detection of ⩾ 70% stenoses, at all sites, has been estimated at up to 92% and 83%, respectively (using maximum intensity projection).5 Multislice CT, which …

An 83-year-old woman underwent transthoracic echocardiography (TTE) to assess her left ventricular systolic function. The TTE showed a large, round, echo-dense mass with central echo-lucencies resembling a posterior periannular tumor. There was no associated mitral valvular dysfunction, and left ventricular function was good. Further assessment was performed using electrocardiographic-gated cardiac multislice computed tomography. This demonstrated that the mass seen on TTE was due to gross calcification of the posterior portion of …

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/m 2 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.

The vast majority of glass and metallic foreign bodies can be detected with conventional radiography. The visibility of common woods and plastics is, however, unknown. To assess their radiographic visibility, various woods and plastics of equal size were inserted into fresh porcine tissue. The pork was then radiographed, under identical conditions, using conventional film-screen combination and a FUJI computed radiographic system utilizing its edge-enhancement facility. The visibility of the compounds was scored by four radiologists for both systems at various times post-insertion. Plastics were found to vary widely in visibility. Dried timbers were visible initially but became isodense with time due to absorption of fluid from surrounding tissues. Fresh woods were invisible from the outset. The computed radiographs improved the visibility of objects visible with conventional radiography but did not bring about visualization of those invisible to normal film-screen combinations. In conclusion the visibility of woods and plastics is variable. Some improvement in visibility can be brought about by the use of digitally edge-enhanced computed radiographs.

Studies describing the effects of radiographic contrast media (RCM) in leukocyte chemotaxis have been contradictory. No studies have been performed after in-vivo exposure. The authors assess the effect of RCM on leukocytes following in-vivo exposure.Seventeen patients were studied after intraarterial bolus injection of 75 mL of iohexol (300 mg/mL) or iotrolan (300 mg/mL), 30 minutes and 24 hours postinjection; chemotaxis was assessed using an ex-vivo whole-blood under-agarose method.With iohexol, there was a profound reduction in chemotaxis compared with the preinjection state (P = .001) at 30 minutes. No effect, however, was seen at 24 hours. With iotrolan, no significant reduction in chemotaxis was seen at 30 minutes or at 24 hours.Radiographic contrast media have differing effects on leukocyte chemotaxis. This may be of significance in the selection of appropriate RCM in certain patients.

The Editor, It appears to be common practice and almost customary for clinicians to request a chest radiograph following diagnostic or therapeutic thoracocentesis. Understandably, this is done to exclude complications that can occur as a result of the procedure; however, a critical look into this reveals a range of unresolved issues. Firstly, routine chest radiographs are usually requested to exclude the most likely complication following thoracocentesis i.e. pneumothorax. It had a 6% incidence following thoracocentesis in a recently published systematic review and meta-analysis [1] and an incidence of between 3% and 20% in a previous study [2]. 1.7% of all patients following thoracocentesis and 34.1% of those with demonstrated pneumothorax require chest tube insertion [1]. A retrospective audit conducted in our institution (Derriford Hospital, Plymouth, UK) yielded similar results whereby the incidence of post-thoracocentesis pneumothorax was 5% with none requiring tube drainage. The indication for a chest radiograph was to exclude pneumothorax in all cases (Table 1). Pneumothorax is a much feared complication; however, it does not occur in the majority of patients and, when it does occur, about two-thirds of patients will not require further intervention. Important factors that should be taken into consideration as possible predictors of pneumothorax include symptoms such as pleuritic chest pain, cough and shortness of breath during or after thoracocentesis, aspiration of air during the procedure and patients undergoing mechanical ventilation. Table 1 Results of a retrospective audit of post-thoracocentesis chest radiographs at Derriford Hospital, Plymouth, UK Secondly, thoracocentesis under ultrasound guidance has been shown to be associated with lower occurrence of pneumothorax and is identified as the “most important strategy to reduce pneumothorax rates” [1]. Although it is safer to perform thoracocentesis under image guidance, the feasibility and impact on service delivery cannot be ignored, leading to wider unresolved issues. If radiologists are expected to perform all ultrasound-guided thoracocentesis, the pros and cons need to be carefully thought through. Apart from lowering the occurrence of pneumothoraces, there is also the opportunity for trainee radiologists to acquire generic skills such as familiarity with ultrasound scanning and image interpretation applicable to a career in general or interventional radiology. However, it will increase the current workload and will probably require service expansion. The possibility of delay before a diagnosis is made has to be entertained if this becomes a planned procedure, which might not be acceptable, especially for urgent cases such as cases of suspected malignancy where prompt diagnosis is crucial. If non-radiologists embrace this to reduce pneumothorax rates, adequate training of the use of ultrasound guidance has to be taken more seriously. There are currently no clinical guidelines, which has led to varying practices across various institutions. Recognition of patients who will benefit from routine chest radiographs will not only avoid unnecessary exposure to radiation but also foster a more efficient and cost-effective use of limited resources. On balance, routine chest radiographs is clearly not indicated in all patients following diagnostic or therapeutic thoracocentesis. Results from various studies over the past decade do not support routine chest radiographs following all thoracocentesis [3-5]. Ultrasound-guided thoracocentesis is undoubtedly beneficial and needs to be incorporated into well designed clinical guidelines, which are long overdue to maintain efficient service provision.

Simpson et al 's splendid evaluation of direct access concluded that direct access computerised tomography (CT) is now the preferred choice for patients with chronic daily headache in primary care.1 They decided this after a rigorous identification of abnormal findings in the study, plus an economic analysis comparing CT scanning with other investigative options. We believe there is a third option – of no investigation and no referral. The first reason …

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 onset of chest pain) his condition …

This article explores the radiological investigations for identifying the cause of severe interscapular pain, focusing on how to exclude acute myocardial infarction, aortic dissection, and pulmonary embolism