1. Introducing our
Aquilion ONE...
ESC acquires a
640 slice CT scanner 2
Imaging the Heart -
Current Status of
CT Angiography 4
...a view
of the future
Toshiba and ESC sign
Research Partnership
Agreement 8
The European Scanning Centre Newsletter
Special Edition
2. Welcome to this special
edition of Vision.
ESC acquires a 640 slice CT scanner
It has been an exciting
In order to continue to provide a first 7 years to develop and at a cost of more CTA from Aquilion ONE
summer for the ESC with class imaging service, the ESC has than £500 million. With its 16cm detector, a demonstrating (a)
vulnerable soft
several major developments, recently acquired the world’s most five times the size of traditional 64-slice
cholesterol rich plaque
powerful CT scanner, the Toshiba CT scanners, and its innovative in RCA (arrow) and (b)
the most important of which is Aquilion ONE™ 640 slice scanner, reconstruction algorithm, ConeExact, it its extent and degree of
which has been installed alongside can reconstruct 640 slices per rotation, stenosis as analysed by
the installation of a new CT
its EBCT scanner. giving unprecedented accuracy and the software (green =
scanner, the Toshiba Aquilion detail. Its unique area of coverage normal patent lumen,
blue/red = soft plaque.
enables scanning of most organs within
ONE 640 slice CT scanner. Dr Sarah Howling, one rotation, eliminating the need for
Far right panels show
the cross-section
Despite the challenging ESC’s Director of Imaging helical scanning, which in turn, lowers the through the artery.
comments: radiation dose dramatically (0.8 mSv for
economic climate, we remain “I am seldom allowed to shop with such a CT angiogram compared to 2-3 for
latitude! To create a dream list and then other scanners and 6-10 mSv for
convinced that medical succeed in securing the top CT scanner conventional angiograms).
practitioners continue to need available in the world is more than I
hoped for when I joined the ESC in 2005. The new scanner is likely to offer
high quality diagnostic We selected the Toshiba scanner after numerous applications but in particular
imaging. The Aquilion One is detailed evaluation of all the CT systems has significant advantages in cardiac,
on the market. The Aquilion ONE is the neurological, musculoskeletal, oncology
the world’s most powerful top of the CT premier league and a huge and gastroenterology imaging.
advance in technology. Our referring
and advanced scanner and b
doctors are going to be amazed by the Cardiac Imaging – CT angiography
provides images of unrivalled images and applications this will offer.” Coronary CT angiography (CTA) is
sensitivity and spatial gaining increasing acceptance as a
The Aquilion ONE is the world’s first viable alternative to invasive coronary
differentiation. In addition to dynamic volume CT system, taking over angiography for selected patient groups.
Its advantages are speed, minimal risk of
the installation, the centre complications, and low morbidity.
has undergone major However, its more widespread use is
presently limited by concerns about the
refurbishment with the long- spatial definition of current scanners,
needed creation of a waiting including the EBCT scanner, and also the
radiation dose to patients. The Aquilion
room. These developments ONE scanner overcomes these
limitations and in particular its high
will ensure the ESC remains a
temporal and spatial resolution allows
leading independent imaging detailed imaging of all of the coronary
arteries, including the distal branches, as
centre and we look forward to well as clearly differentiating between soft
exploring the capabilities of and calcified plaque. This goal has been
unachievable by conventional angiography.
this remarkable machine. The proprietary software of the Aquilion
2 The European Scanning Centre Newsletter
3. Feature Aquilion ONE 64 slice
scanner scanners
(including
dual-source
scanners) ‘a major role in
Image acquisition per rotation 16 cm volume 3.2 cm cerebral blood
acquisition
flow imaging in
Spatial resolution (mm) 0.3 0.5
patients at risk
No. of rotations to image heart 1 8-10
of stroke’
Radiation dose for CT angiogram (mSv) 0.8 ≈2-3
Accurate imaging and quantification of Yes No Representative
soft plaque images from
dynamic
Need for beta blockade No Yes Cerebral perfusion study in patient with
imaging of a
previous occipital infarct demonstrating
wrist and knee ‘The Aquilion
Able to scan patients with arrhythmias Yes No decreased perfusion (blue)
during joint
Dynamic imaging Yes No movement, ONE...allows
allowing
Perfusion studies Yes No elucidation of detailed imaging
symptom
Ability to image moving joints Yes No aetiology. of all of the
coronary arteries,
ONE also quantifies the extent of soft plaque data. Current studies are exploring the use
burden as well as accurately assessing the of adenosine-induced tachycardia in the including the
degree of stenosis. Such imaging capabilities functional assessment of any stenosis
are likely to transform the management of observed during the CT angiogram.
distal branches,
CHD by enabling practitioners to follow up joint symptoms which may be due to bone
impingement, this is potentially an important
as well as clearly
the progression of soft and calcified Neurology
atheromatous plaque and assess the response The ability of the Aquilion ONE to acquire application for sports injuries. differentiating
to aggressive preventive management. 16cm volumetric scans enables perfusion
studies to be performed. The ESC has Cerebral CT angiogram demonstrating a
Summary between soft and
Apart from its dramatic dose reduction, established close links with neurologists and In summary, the Aquilion ONE 640 slice CT
large arteriovenous malformation (arrow)
scanner represents a major advance in calcified plaque.
another important aspect is the fact that neuroradiologists from the National Hospital
cardiac arrhythmia or heart rates up to 130 for Neurology and Neurosurgery and sees a scanning technology with unrivalled This goal has been
“This scanner should provide high quality
bpm are no longer an issue as is frequently major role for the new scanner in cerebral sensitivity and spatial resolution. As such, it
cerebral CT angiography, an imaging modality
the case with helical 64 slice scanning, blood flow imaging in patients at risk of which is likely to supersede MRI angiography
promises to offer both patients and unachievable
including dual-source scanners. This is stroke. Its ability to perform high quality practitioners a viable non-invasive alternative
and provide an alternative to invasive by conventional
because of the very fast speed of the image cerebral CT angiography will be clinically to many invasive diagnostic procedures, and
angiography for many patients.”
acquisition and the online assessment of the useful in the diagnosis and follow-up of with the added advantage of also being angiography.’
imaged RR-interval by the new system’s carotid stenosis, arteriovenous malformations quicker and cheaper. However, we feel this is
Musculoskeletal
software which ensures that image and aneurysms. just the start and with our talented
The new scanner will for the first time also
reconstruction can proceed as planned. radiography and radiologist team we are only
allow imaging of joint kinematics,
An exciting development of the Aquilion One Dr Paul Jarman, just beginning to consider its dynamic
demonstrating moving joints in real time
is its unique ability to acquire volumetric consultant neurologist at the possibilities. It is an exciting time for all of us!
(bone, ligaments and tendons by viewing in
analysis of the entire heart in one rotation National Hospital for Neurology different window width/levels). As static
which allows the acquisition of perfusion and Neurosurgery says: imaging often fails to elucidate the cause of
3
4. Imaging the Heart - Current Status of CT Angiography
Dr Simon PG Padley The consequent reduction in scan times
and Dr Nevin T Wijesekera renders images less susceptible to cardiac
‘an oral or Department of Radiology, dysrhythmias.
Royal Brompton Hospital, London
intravenous beta Spatial resolution
blocker is usually CT scanning has evolved hugely in the The coronary arteries measure from 4-5mm
administered, past two decades. Improvements in in the left main stem to 1mm in the distal left
speed and resolution have been so anterior descending artery. Sub-millimetre
although not significant that it is now possible to spatial resolution with isotropic imaging (i.e. Prospective gating with Aquilion ONE CT angiogram scan. Image
required with 640 image structures as small and as rapidly equal resolution in all three planes) is acquisition occurs during single heart beat in late diastole,
thereby significantly reducing radiation exposure
slice scanners’ moving as the coronary arteries with desirable to delineate sub-millimetre
temporal and spatial resolution coronary artery branches. In order to Only 180° of rotation is required for image In prospective
approaching that of invasive coronary differentiate a 10-20% stenosis, isotropic generation, so temporal resolution is equal to gating, the
angiography. spatial resolution of 0.3mm is considered half the gantry rotation speed. Current scan is
‘the experience necessary only achieved by the most up to technology has reduced a complete rotation triggered at a
date scanners such as the Aquilion ONE. to 250ms. Ideally, a temporal resolution of specified point
of both the
50ms is needed for coronary CT along the R-R
radiographer Temporal resolution angiography (CTA) to cover all heart rates. interval, a short
acquiring the The temporal resolution of a multi-detector However, with new reconstruction algorithms pulse of x-ray is delivered and then stops, to
CT scanner is determined by the speed of and dual source scanners, a temporal recur at a similar time during the next cycle.
images and the
rotation of the gantry around the patient. resolution of 75ms is achievable.
radiologist in In retrospective gating, data is acquired
reporting them ECG gating continuously throughout the cardiac cycle,
is crucial to the Images are typically acquired over a number allowing images to be later reconstructed at
of cardiac cycles at time points when cardiac an appropriate percentage of the R-R
quality of the motion is least, usually in late diastole (65% interval.
images and thus to 85% of the R-R interval). This requires
the final report’ acquisition of data to be synchronised with Radiation dose
the cardiac cycle by reference to a Radiation doses in MDCT coronary
simultaneously recorded ECG. angiography depends on a number of fixed
Technical background and adjustable factors and now range from
Successive generations of MDCT scanners The most commonly used ECG less than 1mSv to 5mSv on state of the art
have rapidly evolved from 2 to 4, 8, 16, 32, synchronisation techniques for cardiac CT scanners, which is lower than invasive
40, 64, 128, 256 and now 320 rows of scanning are prospective ECG triggering coronary angiography (typically 6 – 10mSv).
detectors (such as the Aquilion ONE). and retrospective ECG gating. The radiation exposure is higher when using
4 The European Scanning Centre Newsletter
5. retrospective ECG gating, compared with non-invasive visualisation of coronary
Indications for CT angiography CTA vs conventional angiography
prospective imaging, because of the arteries with simultaneous evaluation of the
continuous x-ray exposure and overlapping • Atypical chest pain pulmonary arteries, thoracic aorta, and other Advantages
data acquisition. • Exclude coronary heart disease intra-thoracic structures that might explain • Non-invasive
• Equivocal exercise stress test signs and symptoms that overlap with an • afer
S ‘Aquilion ONE
• oronary artery bypass graft
C (no risk of local damage or stroke)
acute coronary syndrome.
CT Angiography: evaluation • Quicker - avoids day case admission promises
step by step • Evaluate stent stenosis Plaque imaging • bility to visualise vulnerable soft
A to be the
• ardiac vein imaging to guide
C plaque
A number of studies have evaluated the
ablation therapy • Visualise anomalous anatomy exception
Premedication. If the heart rate is more ability of CT to distinguish between different
than 65 beats/min, an oral or intravenous • Anomalous coronary artery anatomy types of atherosclerotic plaque, with the • omparable spatial resolution
C with a
• Congenital heart disease (0.3mm with 640 slice scanners)
beta-blocker is usually administered, hope that this may help identify patients at
• riple rule out (pulmonary, coronary
T • Lower radiation reported
although not required with 640 slice elevated risk of future coronary events.
scanners. Sublingual nitrates immediately and aortic angiogram) Plaques may be classified as calcified, • Cost - cheaper spatial
before scanning help dilate the coronary mixed or soft, based on density Disadvantages (16-64 slice scanners) resolution
arteries. of haemodynamically relevant coronary measurement. The clinical application of
• nable to scan arrhythmias
U
artery stenoses (50% luminal diameter coronary CTA for risk stratification based on (AF or high heart rate) of 0.3mm’
Intravenous contrast delivery. A high reduction) using 16-slice and 64-slice CT. plaque characterisation is not yet supported • Lower spatial resolution (0.5 mm)
concentration of contrast agent is injected Whilst the positive predictive value of MDCT by convincing scientific evidence but is an • rone to artefact from high coronary
P
intravenously at a high flow rate (4-5mL/s) using 64-slice MDCT is relatively modest at area of much interest particularly with the artery calcium deposition
followed by a 40-50ml saline chaser bolus to only 80-85%, the negative predictive value ability of the latest scanners to accurately • annot proceed to immediate
C
wash out contrast from the right ventricle. approaches 100%, suggesting that CT can visualise and quantify the vulnerable soft therapeutic procedure
reliably rule out the presence of significant cholesterol-rich plaque which may exist in e.g. angioplasty/ stent insertion
Post-processing techniques. Analysis of coronary artery stenoses and makes the absence of calcification.
the resultant enormous dataset is performed coronary CTA useful in symptomatic
on dedicated powerful workstations. As with patients who are considered for invasive Bypass grafts assessment
all radiology, the experience of both the angiography but have a low-to-intermediate CT permits non-invasive assessment of the
radiographer acquiring the images and the pre-test probability of coronary artery state of previous bypass grafts, including
radiologist in reporting them is crucial to the disease. This approach is currently favoured the anastamosis and the distal native
quality of the images and thus final report. in NICE guidelines (due to be published arteries. Several studies performed using
early 2010). Patients whose clinical 16- and 64-slice MDCT have shown that
Clinical applications of CT coronary presentation suggests a high likelihood of occlusion of bypass grafts and stenoses in
angiography having a stenosis remain more likely to the body of the grafts can be detected with
MDCT is now an established alternative to benefit from invasive angiography, which high accuracy. Native coronary arteries are
cardiac catheterisation in the diagnosis of provides the option of immediate more difficult to assess since they may
coronary artery disease (CAD). Studies have intervention. become heavily calcified following bypass
shown sensitivities of up to 97% and “Triple rule-out” coronary CT angiography is surgery making interpretation of stenoses
specificities as high as 94% for the detection a relatively new technique that provides difficult. This limits the clinical usefulness of
5
6. support the role of CT for routine follow-up cardiovascular magnetic resonance (CMR).
of patients after coronary stent implantation, However, due to the relatively high radiation
although more modern scanners have the dose, MDCT is currently not recommended
‘CT can reliably potential to overcome this as they are less for the evaluation of cardiac function alone,
rule out the affected by artefact and can offer clearer but these data are frequently available from
images of the stent lumen. studies acquired for other primary
presence of indications. CT also allows global cardiac
significant Ventricular assessment assessment in patients unsuitable for MRI.
Multiphase studies allow determination of
coronary both end-diastolic and end-systolic volumes Myocardial perfusion
artery using semi-automated software and hence An area of exciting current study is the use
allow accurate calculation of stroke volume, of contrast-enhanced CT to visualise
stenoses ejection fraction and cardiac output as well infarcted myocardium during first-pass and
and makes as regional wall motion. There is good late perfusion imaging. Preliminary studies
correlation between MDCT and cine assessing myocardial enhancement and
coronary CTA of bypass grafts showing atheroma
within the grafts (arrows)
CTA useful in coronary CTA in patients who develop chest
Cardiac function analysis of a patient with an anomalous LAD arising from RCA
demonstrating reduced wall motion in the area from the anterior wall of the left ventricle to
symptomatic pain after bypass surgery, as it usually will the apex (blue is reduced, green to red is normal). Image courtesy of Charité Hospital, Berlin
using an Aquilion ONE scanner.
be necessary to assess the status of both
patients who the bypass grafts and the native coronary
Wall Motion Wall Thickening Proportional Ejection
are considered arteries. When it is necessary to re-operate, Fraction
MDCT can be critical in delineating the
for invasive position of bypass grafts relative to the
angiography sternum.
but have Coronary stents
low to Stent imaging is challenging due to the
small size and high-density of stent material
intermediate with resulting artefacts that can obscure the
CTA of a patent stent in the LAD. Image
pre test lumen. Accurate stent assessment depends
acquired using Aquilion ONE 320 detector
upon several factors, including stent type scanner.
probability and material, stent dimensions (particularly
of coronary the diameter) and the vessel in which the
stent has been implanted. In-stent re-
artery disease’ stenosis can be suggested when the lumen
does not appear to completely enhance but
current studies using 64 slice scanners have
not yet provided conclusive evidence to
6 The European Scanning Centre Newsletter
7. infarct size early after acute myocardial
infarction have shown good correlation
gantry at approximately 90° to each other,
producing faster scanning and temporal Our Radiologists
between MDCT and CMR. resolutions of 75ms, although they are
unable to image the heart in one rotation. In order to further enhance the quality of our reporting
Congenital anomalies of the exceptional images from the new scanner, we have
Whilst echocardiography and CMR imaging Summary recently recruited several additional specialist radiologists,
remain the techniques of choice for the Computed tomography has advanced from many of the top institutions.
assessment of patient with complex rapidly during the past years. Current MDCT
congenital heart disease, MDCT is now technology permits reliable and accurate Our team of radiologists with their NHS base and expertise is:
emerging as a viable alternative to CMR visualisation of the coronary arteries. The
(claustrophobia, pacemakers etc). MDCT technique is firmly established but recent Cardiac
coronary angiography can also be used to technological advances on a number of
Dr Simon Padley, The Royal Brompton Hospital
identify the course of anomalous coronary fronts are likely to improve the accuracy and
Dr Paras Dalal, Harefield Hospital
arteries. reliability of CT for assessing coronary artery
Dr Sujal Desai, King College Hospital
disease and, if the expected reductions in
Defining pulmonary vein anatomy radiation dose are achieved, the spectrum
Chest
Cardiac CT is routinely employed in of accepted clinical indications will
planning of electrophysiological procedures, undoubtedly expand. Dr Sarah Howling, The Whittington Hospital
such as atrial fibrillation ablation since a
three-dimensional CT image of the atria can Neuro
be superimposed on the electro-anatomical Dr Katherine Miszkiel, National Hospital for Neurology Neurosurgery
map, improving the ability to localise the Dr Jane Evanson, Bart’s and The London
pulmonary veins and hence reduce
fluoroscopy times. Abdomen/pelvis
Recent technical developments
Dr Chris Harvey, Hammersmith Hospital
Computed tomography has gone through
Dr Chris Schelvan, St Mary’s Hospital
rapid improvement during the last few years. Dr Niall Power, Bart’s and The London
Scanners with more detector rows allow a
greater volume to be covered in one rotation Musculo-skeletal
of the scanner, significantly reducing Dr Charles House, The Middlesex and UCL Hospital
breath-hold time and amount of contrast. Dr Simon Bleese, full time private
The latest 320-detector (640-slice) scanners
increase coverage and decrease overall Urology
scan time. Dual-source CT (DSCT) also
Dr Jeevan Kumaradevan, The Whittington Hospital
offers improvements in temporal resolution.
These scanners have two sets of X-ray tubes
and detectors, which are mounted onto the
7
8. European
Scanning Centre
Scans
Aquilion ONE 640 slice CT scans
Abdominal
Toshiba and ESC sign ESC completes Angiography (abdominal, carotid
artery, cerebral, coronary,
Research Partnership Agreement its makeover
peripheral pulmonary)
Brain
Lung scan
The building works at the ESC to accommodate the Pelvic
As part of the collaboration between the ESC and Renal tract
new scanner have resulted in a few additional changes.
Toshiba Medical Systems, the two organisations have
Gone is our old neon-lit office and now in its place is a Sinuses
entered into a long-term Partnership Agreement.
stylishly designed new waiting room, a huge Virtual colonoscopy
improvement on the old corridor seating which patients
The main features of this are: Electron Beam Computed
previously had to endure! Top interior designer, Hugh Tomography (EBCT)
• he ESC will become Toshiba’s UK reference site
T Berry, has worked his magic again and given the room
Heart scan (coronary artery
and centre of excellence for CT imaging. a warm elegant feel but adding a hint of cosiness to calcium score)
make clients feel relaxed both before and after their Bone mineral density
• he ESC will be provided with all upgrades for the
T
scans. The lounge photographs on the wall are of
new scanner for the duration of the agreement,
Harley Street architecture and were taken by our Ultrasound
thereby maintaining it at the cutting edge of
consultant radiologist, Dr Sarah Howling whose love Abdomen Pelvis
scanning technology.
of digital imaging also extends to photography. Abdominal aorta
• oshiba will support the ESC as an academic centre
T Breast
by jointly funding a Toshiba Research Fellow for a The refurbishments have also resulted in the creation Carotid Doppler
minimum of 3 years. of a new ultrasound room as well as two large and Chest wall
beautifully appointed consulting rooms. We are
Shown here (left), Dr Paul Jenkins, Medical Gallbladder (static dynamic)
Dr Matthew Stork, Managing Director, Director of ESC shaking hands on the agreement currently looking to occupy these by medical
Echocardiography
Toshiba Medical Systems UK says: with (right), Dr Matthew Stork, Managing Director, practitioners and if this is of potential interest,
Female reproductive
“Toshiba Medical Systems are delighted to Toshiba Medical Systems UK. please contact the centre on 020 7436 5755 for
Finger
have formed a partnership with the European further information.
Leg veins
Scanning Centre to work together on research The results of this research will be published in peer
in this exciting new area. We have just started Neck
reviewed journals and also presented at national and
exploring the benefits of dynamic volume CT. international scientific meetings. Penile Doppler
Whether it is for cardiac, neuro, abdominal, Post micturition bladder
orthopaedic or other examinations, the potential Dr Paul Jenkins, Medical Director of ESC says: Prostate (trans-abdominal
implications of functional CT studies are trans-rectal)
“We are very excited about our partnership with
widespread. The European Scanning Centre is Toshiba and in becoming their UK reference site. Renal artery
an ideal partner for us, working with leading The establishment of a Toshiba Research Fellow Renal tract
academics across many therapeutic areas will allow us to further our aim of becoming an Urinary flow rate measurement
providing a broad scope for research.” academic centre and we look forward to Testes
developing our clinical applications with the new Thyroid Gland
The Research Fellow will be based at the ESC and will scanner, particularly the role of CT angiography
We offer a complete X-ray and
carry out research in a number of agreed areas - for in both cardiac and cerebral studies as well as MRI service
example myocardial and cerebral perfusion. functional perfusion studies.”
European Scanning Centre • 68 Harley Street • London W1G 7HE • Tel: 020 7436 5755 • Fax: 020 7436 5756 • www.europeanscanning.com