Anatomically accurate 3D modelling and printing in a case of obstetric brachial plexus injury.

Obstetric brachial plexus injury is reported in 0.42 per 1000 births in UK and Ireland and are associated with a reduction in quality of life for the patient and their carers. In this report we describe the first use of a patient specific, anatomically accurate 3D model as a communication tool in the treatment of a complex case of posterior shoulder subluxation secondary to glenohumeral deformity resulting from obstetric brachial plexus injury. The use of 3D models for surgical planning is associated with decreased operating time and reduction of intra-operative blood loss, whilst their use in patient education increases patient understanding. In this case all surgeons surveyed agreed that it was useful and will use 3D modelling to improve consent processes and to conceptualise novel techniques for complex cases in future. This highly reproducible, low cost technique may be adapted to a variety of upper limb reconstructive surgeries, and as the resolution of image acquisition and additive manufacturing capabilities increase so too do the potential applications of this precise 3D printed surgical adjunct.

T1 Signal Measurements in Pediatric Brain: Findings after Multiple Exposures to Gadobenate Dimeglumine for Imaging of Nonneurologic Disease.

BACKGROUND AND PURPOSE: Signal intensity increases possibly suggestive of gadolinium retention have recently been reported on unenhanced T1-weighted images of the pediatric brain following multiple exposures to gadolinium-based MR contrast agents. Our aim was to determine whether T1 signal changes suggestive of gadolinium deposition occur in the brains of pediatric nonneurologic patients after multiple exposures to gadobenate dimeglumine. MATERIALS AND METHODS: Thirty-four nonneurologic patients (group 1; 17 males/17 females; mean age, 7.18 years) who received between 5 and 15 injections (mean, 7.8 injections) of 0.05 mmol/kg of gadobenate during a mean of 2.24 years were compared with 24 control patients (group 2; 16 males/8 females; mean age, 8.78 years) who had never received gadolinium-based contrast agents. Exposure to gadobenate was for diagnosis and therapy monitoring. Five blinded readers independently determined the signal intensity at ROIs in the dentate nucleus, globus pallidus, pons, and thalamus on unenhanced T1-weighted spin-echo images from both groups. Unpaired t tests were used to compare signal-intensity values and dentate nucleus-pons and globus pallidus-thalamus signal-intensity ratios between groups 1 and 2. RESULTS: Mean signal-intensity values in the dentate nucleus, globus pallidus, pons, and thalamus of gadobenate-exposed patients ranged from 366.4 to 389.2, 360.5 to 392.9, 370.5 to 374.9, and 356.9 to 371.0, respectively. Corresponding values in gadolinium-based contrast agent-naïve subjects were not significantly different (P > .05). Similarly, no significant differences were noted by any reader for comparisons of the dentate nucleus-pons signal-intensity ratios. One reader noted a difference in the mean globus pallidus-thalamus signal-intensity ratios (1.06 ± 0.006 versus 1.02 ± 0.009, P = .002), but this reflected nonsignificantly higher T1 signal in the thalamus of control subjects. The number of exposures and the interval between the first and last exposures did not influence signal-intensity values. CONCLUSIONS: Signal-intensity increases potentially indicative of gadolinium deposition are not seen in pediatric nonneurologic patients after multiple exposures to low-dose gadobenate.

Lower-limb magnetic resonance angiography: performance of extracellular contrast agents versus blood pool contrast agent for both dynamic and high spatial resolution imaging in extended phase.

AIM: To prospectively compare the performance of extracellular space contrast agents (ECSCAs) versus a blood-pool contrast agent (BPCA) for a comprehensive lower-limb magnetic resonance angiography (MRA) protocol in patients with either claudication or critical ischaemia. MATERIALS AND METHODS: Thirty patients with claudication underwent lower-limb magnetic resonance angiography (MRA) (dynamic crural, three-station bolus chase, and infra-inguinal high resolution) using a triphasic injection method with both a ECSCA and BPCA to allow intra-individual comparison, and 30 patients with critical ischaemia were scanned with either a ECSCA or BPCA. The dynamic, bolus chase, and high-resolution images were scored for quality on a Likert scale (from 1-5). Signal- and contrast-to-noise ratios were analysed and statistical analysis performed. RESULTS: Overall, there was no statistically significant difference between the ECSCAs and BPCA for arteriographic dynamic imaging, bolus chase MRA, or the high spatial resolution imaging. Venous image quality was rated higher quality for BPCA scans than for ECSCA images for calf veins (not significantly for thigh veins). Venous imaging signal intensity measures were higher for BPCA imaging. CONCLUSION: Extended-phase imaging using an ECSCA with this protocol provides arteriographic image quality equal to imaging with a BPCA. Venous depiction is good using ECSCAs with this approach, although better with BPCA.

The safe practice of CT coronary angiography in adult patients in UK imaging departments.

Computed tomography coronary angiography is increasingly used in imaging departments in the investigation of patients with chest pain and suspected coronary artery disease. Due to the routine use of heart rate controlling medication and the potential for very high radiation doses during these scans, there is a need for guidance on best practice for departments performing this examination, so the patient can be assured of a good quality scan and outcome in a safe environment. This article is a summary of the document on 'Standards of practice of computed tomography coronary angiography (CTCA) in adult patients' published by the Royal College of Radiologists (RCR) in December 2014.

Comprehensive MRA of the lower limbs including high-resolution extended-phase infra-inguinal imaging with gadobenate dimeglumine: initial experience with inter-individual comparison to the blood-pool contrast agent gadofosveset trisodium.

AIM: To compare extended-phase imaging using an extracellular space contrast agent, gadobenate dimeglumine, to imaging with a blood-pool contrast agent, gadofosveset, for magnetic resonance angiography. MATERIALS AND METHODS: A lower-limb magnetic resonance angiography (MRA) protocol (dynamic crural, three-station bolus chase, and infra-inguinal high resolution) designed for blood-pool agent imaging was adapted for use with the extracellular agent, gadobenate dimeglumine, primarily by using a triphasic injection protocol. Ten patients scanned with gadofosveset were compared to 10 patients scanned with gadobenate. The dynamic, bolus chase, and high-resolution images were scored for quality on a Likert scale (from 1-5). Signal- and contrast-to-noise ratios were analysed, and Mann-Whitney U statistical analysis performed. RESULTS: There was no significant difference for the dynamic imaging or the aorto-iliac station of the bolus chase. Infra-inguinal bolus chase images were higher quality (p < 0.05 Mann-Whitney U test) with gadobenate. Signal analysis confirmed lower signal and contrast for venous imaging on the high spatial resolution acquisitions with gadobenate; however, this allowed improved arterial conspicuity. CONCLUSION: Extended-phase imaging using an extracellular space contrast agent is feasible and provides image quality to equal imaging with a blood-pool contrast agent.

Right-sided bronchial isomerism diagnosed in adulthood.

This case report describes a diagnosis of right-sided isomerism and specifically right-sided bronchial isomerism in a patient who was being investigated for deteriorating bronchiectasis. Right-sided bronchial isomerism is a variation of the normal bronchial anatomy (situs solitus) consisting of a left lung that is identically configured at the bronchial and lobar level to the right. It is sometimes referred to as bilateral right lung and is usually associated with congenital asplenia and therefore impaired immunity with susceptibility to pneumococcal sepsis and cardiac abnormalities which may be severe and result in a high mortality in infancy. Ivemark syndrome (also known as right atrial isomerism) combines these associations with malrotation of the gut and a midline liver.2 Interestingly, left-sided isomerism is associated with polysplenia as well as midline liver, malrotation of the gut, partially anomalous pulmonary venous drainage and cardiac septal defects.3 To the best of our knowledge cases of right-sided isomerism are sufficiently rare in adulthood that there are only two other reports in the literature and only one of the patients had bronchial isomerism.4,5.

Peripheral arterial disease: the evolving role of non-invasive imaging.

Peripheral arterial disease is usually secondary to stenotic or occlusive atherosclerosis and is both common and increasing in western society. The majority of symptomatic patients have intermittent claudication and only a minority (<2% and typically those with diabetes mellitus or renal failure) progress to critical limb ischaemia, heralded by the onset of rest pain and/or tissue loss. Imaging is largely reserved for patients with disabling symptoms in whom revascularisation is planned. In these patients, accurate depiction of the vascular anatomy is critical for clinical decision making as the distribution and severity of disease are key factors determining whether revascularisation should be by endovascular techniques or open surgery. Driven by advances in technology, non-invasive vascular imaging has recently undergone significant refinement and has replaced conventional digital subtraction angiography for many clinical indications. In this review, the relative merits and limitations of duplex ultrasound, CT angiography, and magnetic resonance angiography are discussed, emerging imaging techniques are described, and complications relating to the use of intravascular contrast agents are highlighted.

An S-shaped sinoatrial nodal artery coronary artery fistula demonstrated by multidetector CT.

The presented case and discussion illustrate the use of CT coronary angiography to depict coronary artery fistulae. A 41-year-old man presented with an acute myocardial infarction. Invasive angiography revealed an incidental coronary artery fistula but was unable to depict its course. CT coronary angiography was undertaken to define the course and termination of the fistula. This confirmed a fistulous connection between the left circumflex artery and the superior vena cava that followed the typical course of an S-shaped sinoatrial nodal artery. Even in such an unusual anomaly this case highlights the ability of CT coronary angiography to accurately depict the coronary artery anatomy.

Elevated troponin levels are associated with sympathoadrenal activation in acute ischaemic stroke.

BACKGROUND: It has been hypothesised that elevated serum troponin levels in acute stroke are due to myocardial damage caused by sympathoadrenal activation, which, in turn, may be due particularly to insular damage. We aimed to determine the factors associated with troponin elevation in ischaemic stroke and the prognostic value of this finding. METHODS: We studied 222 consecutive acute ischaemic stroke admissions. Serum troponin I and catecholamines were measured. Ischaemic damage on brain computed tomography (CT) scan was graded using the Alberta Stroke Program Early CT Score (ASPECTS). Electrocardiograms were classified using the Minnesota Code and the European Society of Cardiology/American College of Cardiology criteria for acute myocardial infarction. The Rankin scale was recorded at 30 days. RESULTS: Forty-five patients (20%) had troponin I >0.2 microg/l. These troponin-positive patients had higher epinephrine levels (median 0.27 vs. 0.17 nmol/l; p = 0.0002) and were more likely to have electrocardiograms coded as definite or possible acute myocardial infarction (odds ratio 3.35; 95% CI 1.26-8.93), compared with those with troponin < or = 0.2 microg/l, in univariate analysis. There were no significant associations between troponin I score and ASPECTS or insular damage on brain CT. In logistic regression analyses, elevated troponin was significantly associated with age, elevated serum creatinine and epinephrine; however, increased troponin was not an independent predictor of death or dependency (Rankin >2) at 30 days. CONCLUSIONS: Raised troponin I is associated with elevation of circulating epinephrine in acute ischaemic stroke. Activation of the sympathoadrenal system may be an important contributor to myocardial damage in these patients. Increased troponin is not associated with insular damage and does not independently predict poor outcome.

Acute renal cortical necrosis in a series of young men with severe acute pancreatitis.

Diffuse renal cortical necrosis from any cause is rare in the Western World. Over the last 5 decades, there have been isolated case reports of acute cortical necrosis as a consequence of acute pancreatitis, but the long-term outcome of these patients has not previously been reported. Here, we report 3 young men, aged 16-21 years, who have presented over the past 19 years with severe acute pancreatitis associated with oliguric acute renal failure. They were all found to have diffuse renal cortical necrosis and consequently made no renal recovery. Despite the appreciable mortality associated with acute pancreatitis complicated by acute renal failure, they all survived the initial illness and all have successfully undergone renal transplantation. We present a detailed account of each patient including diagnostic strategies and discuss the possible factors contributing to a favorable outcome in these patients.

Accurate, practical and cost-effective assessment of carotid stenosis in the UK.

OBJECTIVES: To determine whether less invasive imaging tests [ultrasound (US), magnetic resonance angiography (MRA), computed tomographic angiography (CTA) and contrast-enhanced MRA (CEMRA)], alone or combined, could replace intra-arterial angiography (IAA), what effect this would have on strokes and deaths, endarterectomies performed and costs, and whether less invasive tests were cost-effective. DATA SOURCES: Electronic databases covering the years 1980-2003 inclusive, updated to April 2004. Key journals from 1990 to the end of 2002. REVIEW METHODS: The authors constituted a panel of experts in stroke, imaging, vascular surgery, statistics and health economic modelling. The accuracy of less invasive carotid imaging was systematically reviewed using Standards for Reporting of Diagnostic Accuracy (STARD) methodology, supplemented by individual patient data from UK primary research and audit studies. A systematic review of the costs of less invasive tests, outpatient clinics, endarterectomy and stroke was performed, along with a microcosting exercise. A model of the process of care following a transient ischaemic attack (TIA)/minor stroke was developed, populated with data from stroke epidemiology studies in the UK, effects of medical and surgical interventions, outcomes, quality of life and costs. A survey of UK stroke prevention clinics provided typical timings. Twenty-two different carotid imaging strategies were evaluated for short- and long-term outcomes, quality-adjusted life-years (QALYs) and net benefit. RESULTS: In 41 included studies (2404 patients, median age 60-65 years), most data were available on 70-99% stenosis. CEMRA was the most accurate [sensitivity 0.94, 95% confidence interval (CI) 0.88 to 0.97; specificity 0.93, 95% CI 0.89 to 0.96], compared with US, MRA and CTA, which were all similar (e.g. for US: sensitivity 0.89, 95% CI 0.85 to 0.92; specificity 0.84, 95% CI 0.77 to 0.89). Data for 50-69% stenoses and on combinations of tests were too sparse to be reliable. There was heterogeneity between studies for all imaging modalities except for CTA. The individual patient data (2416 patients) showed that the literature overestimated test accuracy in routine practice and that, in general, tests perform with higher sensitivity and specificity in asymptomatic than in symptomatic arteries. In the cost-effectiveness model, on current UK timings, strategies allowed more patients to reach endarterectomy very quickly, and where those with 50-69% stenosis would be offered surgery in addition to those with 70-99%, prevented most strokes and produced greatest net benefit. This included most strategies with US as first or repeat test, and not those with IAA. However, the model was sensitive to less invasive test accuracy, cost and timing of endarterectomy. In patients investigated late after TIA, test accuracy is crucial and CEMRA should be used before surgery. CONCLUSIONS: In the UK, less invasive tests can be used in place of IAA if radiologists trained in carotid imaging are available. Imaging should be carefully audited. Stroke prevention clinics should reduce waiting times at all stages to improve speed of access to endarterectomy. In patients presenting late after TIA, test accuracy is very important and US results should be confirmed by CEMRA, as patients with 50-69% stenosis are less likely to benefit. More data are required to define the accuracy of the less invasive tests, with improvements made in the data collection methods used and how data are presented. Consideration should also be given to the use of new technologies and randomised trials.