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14th Advanced Neuroradiology Course
16 – 17 October 2014
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Dear Colleagues and Friends,
The Organising Committee and I would like to welcome you to this
year’s 14th Advanced Neuroradiology Course which will be held from
16 – 17 October 2014.
The Advanced Neuroradiology Course aims to update, refresh and as
well as highlight advances in the practise of Neuroradiology and Head
& Neck Radiology from a multidisciplinary approach.
The specially invited international and local faculty will share their
expert knowledge and insights with the audience on the newest
developments in their fields.
The course comprising lectures and discussion of diagnostic and
interventional procedures, will be relevant to all doctors and healthcare
professionals in neuroradiology, head & neck radiology, neurology,
neurosurgery, head and neck surgery, oncology, and the other
neuroscience disciplines.
Last two years, we saw the introduction of the hands-on workshop for
residents and trainees. This year we continue the Resident Review
Course as a useful adjunct to our educational efforts.
We hope you will find the Course fun and rewarding.
Dr Mahendran Nadarajah
Course Director
Organising Committee
14 t h
Advanced Neuroradiology Course
16 – 17 October 2014
CCO
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URRSSEE FFAACCU
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Prof David Hackney
Professor & Chief of Neuroradiology
Harvard Medical School Teaching Hospital
Beth Israel Deaconess Medical Centre, USA
Prof Chul-Ho Sohn
Professor & Chief of Neuroradiology, Seoul National University Hospital
Korea
Prof Ann D. King
Professor of Radiology
Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong
Dr Tufail Patankar
Consultant Interventional Neuroradiologist, Leeds General Infirmary
Senior Lecturer, University of Leeds, UK
A/Prof Goh Poh Sun
Dr Tang Phua Hwee
National University Hospital, Singapore
KK Women’s & Children Hospital, Singapore
Dr Jeevendra Kanagalingam
Dr Yu Wai-Yung
Mount Elizabeth Novena Hospital,
Singapore
National Neuroscience Institute, Singapore
Dr Manish Taneja
Dr Shree Kumar Dinesh
Raffles Hospital, Singapore
National Neuroscience Institute, Singapore
Dr Sumeet Kumar
Dr Loi Hoi Yin
National Neuroscience Institute, Singapore
National University Hospital, Singapore
Dr Robert Chen
Dr Bella Purohit
Singapore General Hospital, Singapore
National Neuroscience Institute, Singapore
Dr Daniel Oh
National Neuroscience Institute, Singapore
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Course Director
Dr Mahendran Nadarajah
Course Manager
Mr Tien Sin Leong
Members
Mr Tan Jau Tsair
Mr Hong Tshun Vun
Ms Low Hwee Huang Mr James Tan
Ms Oh Hui Ping
Mr Sahran Ramli
Mr Syed Zain
Ms Cynthia Anne
Ms Ho Jia Lei
14th Advanced Neuroradiology Course
16 – 17 October 2014
D
Daayy O
Onnee
TThhuurrssddaayy,, 1166 O
Occttoobbeerr 22001144
8.00 am
Registration
8.45 am
Welcome Address & Opening Ceremony
Course Contents & Introduction
by Course Director, Dr Mahendran Nadarajah
SSCCIIEEN
NTTIIFFIICC SSEESSSSIIO
ON
N 11
SUBSPECIALITY NEUROIMAGING
Chairperson: Dr Yu Wai-Yung
9.00 am
The Value of Paediatric Neuroimaging
by Dr Tang Phua Hwee
9.30 am
Evolving Concepts in Normal Pressure Hydrocephalus
by Dr Sumeet Kumar
10.00 am
"i-Map”, a Road Map for Orbital Imaging
By A/Prof Goh Poh Sun
10.30 am
Tea Break (Sponsored by O’Connor’s Singapore Pte Ltd )
SPINAL SESSION 1
Chairperson: A/Prof Tchoyoson Lim
11.00 am
Advanced MR Imaging of the Intervertebral Disk
by Prof David Hackney
11.30 am
Spinal Navigation: A “Snapshot”
by Dr Shree Kumar Dinesh
12.00 pm
Evaluation of Traumatic Spinal Ligamentous Injury
by Prof David Hackney
12.30 pm
Lunch (Sponsored by DePuy Synthes)
Value of Paediatric Neuroimaging
Dr Tang Phua Hwee
Senior Consultant Radiologist
KK Women’s and Children’s Hospital
Singapore
A back to basics approach covering the value of standard imaging modalities
such as cranial ultrasound, CT, MRI, PET and what is the expected potential
and limitations of the new technological advances available today.
Evolving Concept of Normal Pressure Hydrocephalus
Dr Sumeet Kumar
Associate Consultant, Neuroradiology
National Neuroscience Institute
Singapore
The classic concept of hydrocephalus dates back to the work of Sir Walter
Dandy
and
traditionally
classifies
it into
non-communicating
and
communicating hydrocephalus. There is a paradigm shift in the concept of
CSF production and absorption at the level of CNS capillaries as opposed to
the traditional teaching of CSF production by choroid plexus and absorption
at the arachnoid granulations.
The bulk theory of CSF explains many radiological features of acute
obstructive
hydrocephalus
but
communicating hydrocephalus.
fails
to
explain
those
of
chronic
The vascular compliance theory better
explains the hydrodynamics of normal pressure hydrocephalus.
The
radiological pattern that suggests idiopathic normal pressure hydrocephalus
will be elucidated.
“I – Map”, a Road Map for Orbital Imaging
A/Prof Goh Poh Sun
Senior Consultant
Diagnostic Radiology, National University Hospital
National University Health System
Singapore
A map is a useful aid to navigate and make sense of a new or unfamiliar
territory. The orbit is included in most neuroimaging cross sectional CT and
MRI studies, yet unfamiliar territory to many novice neuroradiologists.
We will review an approach to orbital imaging, refined over the last 13 years,
through a close working partnership with the clinical ophthalmology and
pathology teams at the National University Hospital, in Singapore, through
the vehicle of monthly clinical radiology pathology sessions, as well as
academic joint symposiums, and review articles that we have published
together; by presenting an “i-Map”, a roadmap for orbital imaging.
http://padlet.com/dnrgohps/iMap
(Lecture presentation and illustration website)
Advanced MR Imaging of the Intervertebral Disk
Prof David B. Hackney, M.D.
Professor of Radiology
Harvard Medical School and Department of Radiology
Beth Israel Deaconess Medical Center, Boston
USA
The intervertebral disk is a critical and complex element of spine structure. It
permits and controls motion in three axes and cushions impact between the
vertebral endplates. When sitting or standing, the disk transduces axial load
on the nucleus pulposus to tensile strain on the annulus fibrosus. When the
disk loses its ability to perform these functions, progressive degenerative
changes occur, leading to osteophyte formation, spinal canal and neural
foraminal encroachment, spinal cord and nerve root compression, pain and
neurological deficits. Although there are many empirical approaches to
describing the changes seen with magnetic resonance, routine clinical
imaging has typically offered little to improve our understanding of the
underlying processes. MR has now advanced to the point that it can address
these more fundamental questions.
A variety of MR techniques including relaxation rate measures, estimates of
disk water content, magnetization transfer, chemical exchange saturation
transfer, diffusion and spectroscopy have been studied to characterize disk
degeneration and the relationships to symptoms. We will review the results
of these investigations and describe promising results from studies of disk
mechanics inferred from MR.
The imaging methods can be roughly divided into those that reveal
properties of the extracellular matrix- T1, T2, T1rho, diffusion, MT and CEST,
those that interrogate fibrous structure-diffusion tensor imaging and a
method to assess the health of the cellular elements- MR spectroscopy.
We will discuss the state of the art of these methods and suggest prospects
for clinical application.
Spinal Navigation: “A Snapshot”
Dr Shree Kumar Dinesh
Consultant, Neurosurgery
National Neuroscience Institute
Singapore
Intraoperative imaging has taken hold in the operating theatres of most
specialized neurosurgical centres. There has been an exponential rise in the
number of cases performed by spine surgeons with the use of advanced
intraoperative imaging which ranges from fluoroscopy to 3D imaging such as
the O-arm (Medtronic Stealth) and iCT (Brainlab Vectorvision).
Through case examples and a review of the literature, I plan to share my
experience utilizing the aforementioned systems in the performance of
complex spinal surgeries. Both the benefits and pitfalls of existing systems
are discussed as well as what the future holds with regards to bringing
advanced imaging modalities into the operating theatre.
Evaluation of Traumatic Spinal Ligamentous Injury
Prof David B. Hackney, M.D.
Professor of Radiology
Harvard Medical School and Department of Radiology
Beth Israel Deaconess Medical Center, Boston
USA
Quadriplegia is a dreaded complication of cervical spine injury. Although most patients
who develop symptomatic spinal cord compression after trauma are immediately
impaired, there is a small subset who survive the initial incident intact, but suffer spinal
instability. In these patients, we seek to protect the spine until fully evaluated, identify
the level and nature of the mechanical defect and guide treatment decisions.
Before the advent of computed tomography, the vast majority of unstable spine injuries
were detected with plain radiographs and delayed instability was a rare occurrence. CT is
clearly more sensitive than plain radiographs, and provides far more detailed anatomic
imaging. The precise location, extent and nature of fractures are displayed and the full
structural deficits caused by fractures can be described. For these reasons, CT has long
been the gold standard for imaging spine trauma. However, CT cannot directly image
spinal ligaments, normal or abnormal, and thus provides only inferential evidence of
ligamentous injury. The superior soft tissue detail provided by MR produces a similar
advance over CT as CT did over plain films.
In contrast to unambiguous findings of fractures on CT, MR findings in ligamentous injury
frequently are less clear. Often ligaments display findings that appear intermediate
between normal and complete disruption. Many of these “edema pattern” injuries appear
to preserve mechanical stability of the spine. This has given MR a reputation for high
sensitivity and a high false positive rate. Some surgeons treat such injuries conservatively,
assuming they are unlikely to represent complete loss of ligamentous tensile strength. The
significance of an individual ligament injury also depends the associated fractures or
ligament tears and which structures are involved.
Several studies have proposed alternatives to the classic Denis 3-column concept of spinal
injury. These appear better founded in theory.
However, perhaps due to their
complexity, they have performed poorly in studies of interobserver variability. For the
purposes of routine clinical image interpretation, the Denis approach appears to maintain
its value.
With the combination of CT and MR, one can determine the details of posterior
ligamentous complex injury. In fact, the ability to image osseous and ligamentous injury
has now advanced past the known criteria for inferring structural competence.
We will review role of CT and MR in suspected ligamentous injury, the risk of missing pure
soft tissue tears in patients with normal CT scans, and imaging strategies for evaluating
these patients.
Advanced Neuroradiology Course
16 – 17 October 2014
14 t h
D
Daayy O
Onnee
TThhuurrssddaayy,, 1166 O
Occttoobbeerr 22001144
SSCCIIEEN
NTTIIFFIICC SSEESSSSIIO
ON
N 22
STROKE SESSION 1
Chairperson: Dr Mahendran Nadarajah
1.30 pm
Endovascular Therapy for Stroke – Utility or Futility ?
by Dr Daniel Oh
2.00 pm
The Role of Imaging in Management of Acute Stroke
by Prof David Hackney
2.30 pm
Practical Aspect of MGH Stroke Algorithm
by Dr Robert Chen
3.00 pm
Tea Break (Sponsored by O’Connor’s Singapore Pte Ltd )
STROKE SESSION 2
Chairperson: Dr Mahendran Nadarajah
3.30 pm
Mechanical Thrombectomy: Suckers or Pluckers? How I do it!
by Dr Tufail Patankar
4.00 pm-
Interactive Session on Stroke:
Case Presentations and Audience Participation
by Prof David Hackney, Dr Tufail Patankar, Dr Daniel Oh &
Dr Robert Chen
4.45 pm
5.00 pm7.00 pm
Radiology Residents Review Session
by Dr YU Wai-Yung
Venue: e-Learning Laboratory, Tan Tock Seng Hospital, Level 3
(for pre-registered residents / trainees only)
Endovascular Therapy for Stroke – Utility or Futility?
Dr Daniel Oh
Consultant Neurologist
Program Director, Stroke Program and Co-director, Neuro ICU.TTSH
National Neuroscience Institute
Singapore
Acute stroke treatment has been revolutionized since the advent of intravenous
thrombolytics almost 2 decades ago. But stroke still remains a terrible disease with
poor outcomes for many patients despite IV TPA. While thrombolysis remains the
mainstay of therapy for acute stroke, tremendous effort in research has been made
to improve therapeutic options by means of advanced endovascular therapy.
We review the current evidence for mechanical thrombectomy for acute stroke and
its impact thus far while anticipating future trials that may provide more insight on
optimal intervention.
The Role of Imaging in Management of Acute Stroke
Prof David B. Hackney, M.D.
Professor of Radiology
Harvard Medical School and Department of Radiology
Beth Israel Deaconess Medical Center, Boston
USA
Neuroimaging is a critical element in evaluation of patients with suspected acute brain
infarction. Using CT and MR we seek to confirm the clinical diagnosis, exclude alternate
causes for the patient’s symptoms and guide therapy.
Non-contrast CT (NCCT) is the mainstay of initial diagnosis. It permits rapid identification
of hemorrhage, masses or other potential causes of acute neurological deterioration.
Hyperdense vessels, if seen, can both confirm the diagnosis and provide estimates of the
likely effects of intravenous and intra-arterial revascularization therapy. Hemorrhage on
the NCCT scan can eliminate either treatment from consideration due the high risk of
hemorrhagic complications. Similarly, identification of a large infarction on the early NCCT
indicates that the risks of bleeding outweigh the potential benefits.
In spite of the value of NCCT, current neuroradiology includes far more information. CT
perfusion (CTP) can confirm the presence of ischemia and estimate its severity. Mean
transit time (MTT) and time to peak (TTP) measures appear to be the best CTP maps for
detecting ischemia. Blood flow or blood volume, when combined with MTT or TTP, may
have a role in predicting bleeding risk and the likelihood of regaining with successful
reperfusion.
CT angiography (CTA) can define the anatomy of stenotic or occluded vessels and estimate
the adequacy of collateral supply to the affected region. CTA is also essential for planning
intra-arterial therapy.
Magnetic resonance currently offers the best definition of infarcted tissue using diffusion
imaging. Although it is well known that diffusion can become abnormal while tissue
remains viable, this pattern is rarely encountered in clinical care and high signal on
diffusion-weighted images usually is taken and conclusive evidence of completed
infarction. Some treatment protocols exclude patients with diffusion abnormalities
exceeding predefined volumes.
MR perfusion (MRP) can be used in the same way as CTP to identify ischemia and confirm
the diagnosis. Similar to CTP, MRP combined with diffusion can help identify ischemic but
salvageable tissue. With either technique the volume of irreversibly injured brain, the
volume of tissue that can be rescued and the risk of bleeding can be estimated. These
predictions will guide the decision of how aggressively to treat acute stroke.
We will review the evidence basis for use of each imaging approach, the successes and
failures of each and describe where current practice may run ahead of proven efficacy.
Practical aspect of MGH Stroke Algorithm
Dr Robert Chen
Consultant, Neuroradiology
Singapore General Hospital
Singapore
Stroke is one of the leading causes of morbidity and mortality in our society
today. We have several tools at our disposal to diagnose and treat this
disease, but there is often confusion as to what is the best ED triage and
neuroimaging approach to rapidly and effectively diagnose and treat these
patients.
In my talk, I wish to touch upon basic ED triage, mostly centered from a
neuroradiologist perspective, as well as talk about a step by step process of
the MGH neuroimaging protocol for stroke within specific time windows for
IV and IA therapy.
The beginning of the talk will include the time goals of key performance
indicators necessary in stroke triage (door to physician, door to CT, door to IV
tpa etc), as well as talk about the various roles of each member of the stroke
team, in particular, the neuroradiologist.
The bulk and latter part of the talk will include a discussion of the various
modalities performed during the MGH neuroimaging protocol, specifically:
CT, CTA, DWI, perfusion imaging, and the NIHSS. In particular, i’d like to focus
on some of the practical aspects of how to interpret each of above entities
during the acute setting during triage of these patients. Specifically, I would
like to touch upon how to objectively interpret infarct volume on head CTs
(using ASPECTSs and ABC/2), how to identify malignant collateral patterns on
CTA (as a poor prognostic indicator and sign of large infarct core), the role of
MRI and DWI in determining core, and use of a clinical penumbra via NIHSS
rather than perfusion diffusion mismatch in selecting those for IA therapy.
Mechanical Thrombectomy: Suckers or Pluckers? How I
do it!
Dr Tufail Patankar
Consultant Interventional Neuroradiologist, Leeds General Infirmary
Senior Lecturer, University of Leeds
UK
Despite recent advances in the understanding, management and treatment
of acute ischaemic stroke (AIS), it continues to represent a significant
challenge, resulting in permanent disability or death. Standard first line
therapy for patients presenting with AIS, within 4.5 hours of symptom onset,
is the administration of intravenous (IV) tissue plasminogen activator (t-PA).
Whilst this is the only proven treatment, recent reports in the literature have
also demonstrated successful recanalisation using endovascular methods, in
particular if there is a large vessel occlusion (LVO) of either the terminal
internal carotid artery (ICA) or proximal middle cerebral artery (MCA). The
safety of these devices is also well established. It is also well recognized that
good outcome is dependent on the experience and skill of the operator.
This presentation will discuss the technique of improving endovascular
approach to clot retrieval, the benefits and problems associated with some of
the devices used in mechanical thrombectomy for AIS.
INTERACTIVE SESSION ON STROKE
DIAGNOSIS MANAGEMENT AND INTERVENTION
Prof David Hackney
Professor & Chief of Neuroradiology
Harvard Medical School Teaching Hospital
Beth Israel Deaconess Medical Centre, USA
Dr Tufail Patankar
Consultant Interventional Neuroradiologist, Leeds General Infirmary
Senior Lecturer, University of Leeds, UK
Dr Daniel Oh
Consultant, Neurology, National Neuroscience Institute, Singapore
Dr Robert Chen
Consultant, Neuroradiology, Singapore General Hospital, Singapore
Outline of Interactive Session on Stroke: Duration 45 mins
The session will allow for the audience to be guided in the approach to stroke
management from the initial assessment of the patient, through imaging choices, to
intervention and further management.
The format is that of a presentation of a scenario by the panel, followed by a multiple
choice type questions to which the audience can vote with the audience participation
system. The panel would then go forward to discuss the correct option and/or discussion
on the reason for best fit answer.
The session is intended to be light hearted and to try and get the audience involved as
much as possible, while imparting key facts and tips.
We suggest that each faculty bring, as a powerpoint presentation, 1-2 full cases for
discussion with clinical history, imaging and outcomes. It would be better if the cases are
either controversial, or complex from an imaging or management point.
The more visual the presentation, the better.
At judicious points in the presentation we can pause for questions. The questions should
be of a multiple type nature labeled with options A, B ,C, D (if more stems are needed
please do inform us early as the audience response system needs to be setup to accept
more responses).
A short discussion will follow until we get to the end of the case.
Please note that given the time constraint we may not be able to cover all the cases that
speakers bring.
We strongly encourage debate among the panel as we aware of the controversies
surrounding this topic and we wish the audience to be able to participate in the
discussion.
Neuroradiology Resident Review Course
Dr Yu Wai-Yung
Senior Consultant, Neuroradiology
National Neuroscience Institute
Singapore
Course Outline
The Resident Review Course is now in its third year. The content will be
targeted at what radiology residents and trainees need to know for the FRCR
2B examinations and beyond.
Cases will focus on general diagnostic Neuroradiology topics with material
ranging from common emergency CT and MR studies of the brain and spine,
to more difficult or uncommon cases, to advanced Neuroimaging.
Using a mixture of long and short cases in DICOM digital image format on
Windows PC computers, the course will be held in the e-Learning Laboratory
in Tan Tock Seng Hospital. Seats will be limited due to small group tutorial
teaching.
14th Advanced Neuroradiology Course
16 – 17 October 2014
D
Daayy 22
F
Frriiddaayy,, 1177 O
Occttoobbeerr 22001144
8.00 am
Registration
SSCCIIEEN
NTTIIFFIICC SSEESSSSIIO
ON
N 33
NPC SESSION
Chairperson: Dr Julian Goh
9.00 am
Nasopharyngeal Carcinoma: MRI for Early Detection of the
Primary Tumour and Locoregional Tumour Recurrence
by Prof Ann King
9.30 am
Nasopharyngeal Carcinoma: What Determines the Surgical
Approach to salvage Persistent or Recurrent disease?
by Dr J Kanagalingam
10.00 am
Nasopharyngeal Carcinoma: MRI of Radiation-induced
Complications and Mimics of Tumour Recurrence
by Prof Ann King
10.30 am
Tea Break (Sponsored by MicroVention Terumo)
SPINAL SESSION 2
Chairperson: Dr Wickly Lee
11.00 am
Diffusion Imaging of the Spinal Cord
by Prof David Hackney
11.30 am
MR Imaging of Spinal Dural Arteriovenous Fistula: Detecting
the Dots by Dr Sumeet Kumar
12.00 pm
Spinal Vascular Diseases: Anatomy, Classification and
Treatment: What you need to know by Dr Tufail Patankar
12.30 pm
Lunch (Sponsored by DKSH/Stryker
Singapore)
Nasopharyngeal Carcinoma: MRI for Early Detection of the
Primary Tumour and Locoregional Tumour Recurrence
Prof Ann D King
Professor of Radiology
Prince of Wales Hospital, The Chinese University of Hong Kong
Hong Kong
Detection of Early Primary Tumours
Nasopharyngeal MRI detects small nasopharyngeal carcinomas (NPC) that cannot be
visualized through the endoscope because they are buried in the pharyngeal recess or lie
beneath the mucosa. MRI can also identify a range of benign hyperplastic changes in the
nasopharynx, including adenoidal hyperplasia, which have features on MRI that help
distinguish them from cancer. For patients with normal endoscopic findings, such as
those subjects with persistently elevated plasma EBV DNA, MRI can identify the site of a
cancer for biopsy, while those subjects without cancer on MRI can be spared sampling
biopsies. MRI also has a role in those patients with abnormal endoscopic findings who
have a negative biopsy for malignancy. A range of early NPCs and benign nasopharyngeal
hyperplasia will be illustrated on MRI.
Detection of Locoregional Tumour Recurrence
Locoregional failure occurs in approximately 10% of primary and 5% of nodal sites. The
vast majority arise within 5 years, especially the first year, but there is a lifelong risk of
disease recurrence. One third of local tumour recurrences are submucosal and cannot be
seen by endoscopic examination, while nodal recurrences may be impalpable. Imaging
therefore plays an important role in the identification of tumour recurrence. Using MRI,
features suggesting tumour recurrence are focal expansile areas of similar signal intensity
to the pre-treatment tumour (intermediate T2 signal and moderate enhancement on T1 +
contrast (non-fat sat)), as compared to inflammation (high T2 and marked contrast
enhancement) and mature scar tissue (low T2 and low/no contrast enhancement).
However, there is overlap in the signal intensity and some recurrences form irregular
shaped infiltrative non-expansile masses. In addition nodal recurrence often shows
extracapsular extension and may consist of small patchy islands of tumour within scar
tissue rather than discrete nodes. Functional MRI, including DWI, and a comparison of
MRI and FDG-PET will be discussed briefly.
The extent of locoregional tumour recurrence on MRI guides surgical management. At the
primary site tumour involvement of the skull base (unless minor), internal carotid artery,
brain and cavernous sinus usually are contraindications to nasopharyngectomy, while the
location of operable tumours guides the surgical approach.
Nasopharyngeal Carcinoma: What determines the surgical
approach to salvage persistent or recurrent disease?
Dr Jeeve Kanagalingam
Consultant ENT / Head and Neck Surgeon, Mt Elizabeth Novena Hospital
Visiting Consultant, Tan Tock Seng Hospital and Johns Hopkins Singapore International
Medical Centre
Singapore
Nasopharyngeal Carcinoma (NPC) is endemic in Southeast Asia.
The endemic form is
histologically undifferentiated and responds well to radiotherapy. Overall survival rates
for all stages have risen from 50% in the 1980s to over 70% today with the introduction of
new radiotherapy techniques and the addition of chemotherapy. Persistent or recurrent
local disease may affect 10% of patients. Recurrent disease (rNPC) is difficult to treat as
the postnasal space sits in the centre of the head. Surgery where possible remains the
treatment of choice.
Surgical approaches to the nasopharynx include the classical
maxillary swing approach described by William Wei, transpalatal approach, infratemporal
fossa approach by Fisch, mid-facial degloving and endoscopic approaches.
Robotic
nasopharyngectomy promises more accurate endoscopic resection of disease. All these
approaches are compared to the conventional maxilllary swing procedure which boasts a
74% locoregional free survival at 5 years.
Selecting the correct approach for each recurrence is critical.
Marginal status of the
resection is the single most important factor that predicts outcome. Disease in certain
areas of the skull base are difficult to clear, and surgeons rely heavily on good radiology to
decide if rNPC is operable and which approach gives best exposure. This presentation
aims to shed light on what is important for a surgeon to know before embarking on
salvage surgery.
Nasopharyngeal Carcinoma: MRI of Radiation-induced
Complications and Mimics of Tumour Recurrence
Prof Ann D King
Professor of Radiology
Prince of Wales Hospital, The Chinese University of Hong Kong
Hong Kong
Complications of radiotherapy treatment for nasopharyngeal carcinoma are
an important cause of morbidity and mortality in cancer survivors. These
complications may be symptomatic or found incidentally during imaging
surveillance.
It is important to be aware of these radiation induced
complications as they may require treatment and also they should not be
mistaken for recurrent tumour.
The head and neck is a complex region and treatment induced complications
involve many different structures 1) Neurological tissues including the cranial nerves and temporal lobes
(white matter injury, necrosis, cysts and brain abscess).
2) Osteoradionecrosis and osteomyelitis of the skull base, mandible and
cervical spine
3) Mucositis involving the pharynx and paranasal sinuses (including polyps
and mucocoeles)
4) Vascular damage to the arteries (including stenoses, pseudo aneurysms
and carotid blow-out)
5) Glandular tissues (salivary and pituitary)
6) Radiation induced neoplasms
This lecture will illustrate and discuss a wide range of these radiotherapy
related complications, including some that mimic tumour recurrence.
Diffusion Imaging of the Spinal Cord
Prof David B. Hackney, M.D.
Professor of Radiology
Harvard Medical School and Department of Radiology
Beth Israel Deaconess Medical Center, Boston
USA
Although diffusion imaging has long been a critical part of the MR evaluation
of the brain, spinal cord applications have lagged behind.
The technical
challenges of the small size of the cord, physiologic motion and susceptibility
artifacts have limited the quality of cord diffusion studies. As imaging
techniques have improved, diffusion is now a routine part of spinal cord
protocols, while remaining less powerful than for the brain. The susceptibility
artifacts have been attacked with reduced field of view approaches. RFOV
has also helped with motion, as has faster imaging. The essential
characteristics of spinal cord anatomy, with most of the function carried
through dense axonal fiber tracks, remains a challenge for diffusion imaging.
High b-value and q-space approaches have permitted inferences of axon
diameter distribution in health and disease and reveal features not seen on
conventional T2-weighted images.
As in the brain, diffusion imaging is particularly useful in suspected infarction.
This is far less common than in the brain, but the diffusion findings are the
same. Diffusion imaging helps estimate the acuity of demyelinating or other
inflammatory processes and can identify regions of axonal loss. We will
review current and emerging approaches to spinal cord diffusion imaging and
their application to common clinical problems.
MR Imaging of Spinal Dural Arteriovenous Fistula:
Detecting the Dots
Dr Sumeet Kumar
Associate Consultant, Neuroradiology
National Neuroscience Institute
Singapore
Spinal Dural Arteriovenous Fistula (SDAVF ) is an uncommon but treatable
cause of myelopathy with nonspecific clinical presentation.
undiagnosed and untreated, it can result in significant morbidity.
If left
It is
important for the neuroradiologist to be familiar with the appearance of
SDAVF and suspect the diagnosis on the initial MRI.
The radiologist should know the normal blood supply of the spinal cord,
types of SDAVFs and imaging appearances.
Spinal angiogram is
considered the gold standard for the diagnosis of SDAVF.
MRI findings of T2 prolongation within the cord along with presence of
flow voids and/or presence of serpigineous vascular enhancement on the
surface of the cord should prompt spinal angiography.
Selective spinal angiogram demonstrates the feeding artery and venous
drainage and may localise the fistula remote from the site of cord signal
abnormality.
Spinal Vascular Diseases: Anatomy, Classification and
Treatment: What you need to know
Dr Tufail Patankar
Consultant Interventional Neuroradiologist, Leeds General Infirmary, UK
Senior Lecturer, University of Leeds, UK
Spinal arteriovenous lesions (SAVLs) are rare.
SAVLs represent only 3% to
4% of all spinal cord lesions, and can be associated with considerable
morbidity and mortality if left untreated.
There has been an evolution in
imaging, endovascular, and surgical techniques.
These technological
advancements and a better understanding of spinal cord pathophysiology
now allow us to manage SAVLs more effectively. However, there is a lack of a
comprehensive understanding of spinal cord pathophysiology and consensus
in the clinical classification of the various types of SAVLs, and ambiguity in
anatomic spinal cord terminology.
This presentation will discuss the anatomy, classification, and endovascular
treatment of the various types of SAVLs in adults and attempt to simplify the
complex management of SAVLs.
14th Advanced Neuroradiology Course
16 – 17 October 2014
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ADVANCED CLINICAL IMAGING
Chairperson: A/Prof Sitoh Yih Yian
1.30 pm
CT and MR Perfusion in CNS
by Prof Chul-Ho Sohn
2.00 pm
Is the Tumour Dead or Alive? Role of Fluorocholine PET
by Dr Loi Hoi Yin
2.30 pm
Diffusion Tensor Imaging and Parcellation of White Matter
Tracts: Concepts and Applications
by Dr Bela Purohit
3.00 pm
Tea Break (Sponsored by MicroVention Terumo)
ADVANCED VASCULAR IMAGING AND FUTURE DEVICES
Chairperson: A/Prof Francis Hui
3.30 pm
Clinical application of 4D CT Angiography in CNS:
by Prof Chul-Ho Sohn
4.00 pm
Endovascular Treatment of the Brain Aneurysm: Past,
Present and the Future by Dr Tufail Patankar
4.30 pm
Intracranial Atherosclerotic Disease: The Road Ahead
by Dr Manish Taneja
5.00 pm
Closing Remarks
By Course Director, Dr Mahendran Nadarajah
CT and MR Perfusion in CNS
Prof Chul-Ho Sohn, MD, PhD
Professor & Chief of Neuroradiology, Seoul National University Hospital
Korea
In physiology, perfusion is the process of nutritive delivery of arterial blood to
a capillary bed in the biologic tissue. Disorders of perfusion are major
sources of medical morbidity and mortality. The best approach for imaging
perfusion is 15O-water PET scanning. But this technique has a huge
limitation to access clinical application. There are two major approaches to
measure cerebral perfusion with imaging technique: 1) Contrast enhanced
techniques which are based on the indicator-dilution-theory using CT and
MRI, 2) Non-enhanced techniques based on blood bolus tagging (arterial
spin labelling) on MRI.
Contrast enhanced technique is to inject a gadolinium chelate or iodine
contrast and acquire images rapidly as the bolus of contrast agent passes
through the blood vessels in the brain. The contrast agent causes a MR signal
or CT density change; this signal or CT density change over time can then be
analyzed to measure cerebral hemodynamics.
Arterial spin labeling technique uses spatially selective inversion of inflowing
arterial blood as a method to label blood flow. The MRI signal from inverted
blood is made negative relative to uninverted blood. When the labeled blood
reaches the tissue, it attenuates the signal from the image of that tissue.
Subtraction of a labeled image from a control image gives a measure of the
amount of label which flowed into the tissue. This quantity is closely related
to the tissue perfusion. Not using of contrast media for imaging provides
profound advantages of noninvasiveness and repeatability in healthy
individuals, CRF patients, pediatric patients and those who need repetitive
follow-ups. Another advantage of ASL, as compared with contrast enhanced
MR perfusion, is that ASL can be quantitative so that permits comparison
between multiple measurements in a longitudinal study.
Recent
refinements in sequence robustness, decreased acquisition time, increased
image resolution and lesser artifacts, as well as advances in post processing
capabilities have made ASL available for routine clinical practice.
Is The Tumour Dead Or Alive? Role of Flurocholine PET
Dr Loi Hoi Yin
Consultant, Nuclear Medicine
National University Hospital
Singapore
Diagnosis of radiation-induced tumour necrosis and tumour progression
remains a challenge to clinicians and radiologists. Anatomical cross-sectional
imaging with CT or MR cannot reliably discriminate these entities. Tumour
necrosis may be managed by a conservative ‘watch and wait’ approach whilst
tumour progression obviously warrants further intervention or change in
treatment strategy in selected patients.
Invasive brain biopsy procedure,
monitoring patients’ clinical course and follow-up imaging are possible
options but devoid the latter group from an appropriate early treatment.
The widely used Fluorine-18 fluorodeoxyglucose (F-18 FDG) in oncological
PET imaging is known for its disadvantage in brain tumour imaging because
of the inherent high FDG uptake within the normal brain. Choline is a
membrane phospholipid precursor for all cells including malignant cells.
Fluorinated choline analogue has been used as an oncological PET probe in a
variety of human cancers.
The role of Fluorine-18 fluorocholine (F-18 FCH) as a functional imaging
probe in the context of differentiating tumour necrosis versus tumour
progression is discussed in this brief presentation.
Diffusion Tensor Imaging and Parcellation of White Matter
Tracts: Concepts and Applications
Dr Bela Purohit
Associate Consultant, Neuroradiology
National Neuroscience Institute
Singapore
Diffusion-based MR neurography using diffusion tensor imaging (DTI) has the
potential to overcome the limitations of anatomic MR imaging due to its
ability to interrogate tissue microarchitecture.
The unique fibrillary structure of neuronal fibres in brain white matter results
in anisotropy in proton movement across its long axis.
This phenomenon
can be mapped to create fibre tracts and calculate DTI parameters like
fractional anisotropy.
Fractional anisotropy values are used to evaluate
microstructural changes.
Fibre tracking is a promising method for the
parcellation of clinically eloquent white matter tracts which are often
damaged or displaced by space occupying lesions of the brain.
The aim of this presentation is to review the basic concepts of DTI, to revise
the normal anatomy of major white matter tracts, and to discuss the
potential applications of fibre tracking, with emphasis on the neurosurgical
mapping of brain tumours.
Clinical Application of 4D CT Angiography in CNS
Prof Chul-Ho Sohn, MD, PhD
Professor & Chief of Neuroradiology, Seoul National University Hospital
Korea
Computed tomography has tremendously developed due to the software and
hardware evolution, especially, multi-detector CT (four to 320 detector-rows)
techniques have allowed 3D CT angiography and cerebral perfusion studies. The
availability of 320-detector CT with 160mm of z-axis coverage has allowed for
whole-brain coverage with a single gantry rotation. Also, this method allows for
combined dynamic CTA [CT digital subtraction angiography (CT DSA), time-resolved
CTA (4D CTA)] and time-resolved quantitative CT perfusion (CTP).
Time-resolved 4D CTA or CTP has been used for several neurovascular disorders
including arterial steno-occlusive disease (acute ischemic stroke, chronic
cerebrovascular disease), arteriovenous shunting disease (dural AVF, AVM), venous
occlusive lesion, and evaluation of arteriovenous anatomy in aneurysm and
cerebrovascular reserve.
Clinical applications
Acute ischemic stroke
Perfusion CT provides a quantitative measurement of regional cerebral blood flow.
A perfusion CT study involves sequential acquisition of CT sections during
intravenous administration of an iodinated contrast agent. Analysis of the results
allows the physician to calculate the regional cerebral blood volume, the blood
mean transit time through the cerebral capillaries, and the regional cerebral blood
flow. Currently, non-contrast computed tomography is used to detect intracerebral
hemorrhage in stroke patients who are being considered for thrombolytic therapy.
Perfusion CT provides the means to distinguish infarct core and tissue at risk
(penumbra). The penumbra manifests as increased MTT (>145% compared to
contralateral normal side).
Unlike diffusion-weighted imaging, CT perfusion has given us confusion with regard
to the definition of infarct core. At first, an absolute cerebral blood volume (CBV)
value of 2.0 ml/100g was adopted to determine infarct core.
Afterward, however, some suggested that a relative cerebral blood flow (rCBF)
<31% threshold determines infarct core best. It may be due to different acquisition
and/or postprocessing techniques.
This issue would not seem to be solved until we have a single best technique for CT
perfusion. Absolute CBV or rCBF has been used to determine infarct core. However,
it has yet to be determined what represents infarct core best.
Arteriovenous malformations and Dural Arteriovenous fistulas
In the diagnosis of these lesions, it is key to demonstrate the acute A-V shunting.
4D CTA was able to demonstrate size of AVM nidus and drainage pattern
(superficial or deep venous system). Several investigators reported although 4D
CTA is limited in temporal and spatial resolution in comparison with DSA, it is an
effective non-invasive tool for the detection and classification of cerebral dural
AVF. In addition to the diagnosis of cranial dural AVF and AVM, 4D CTA might prove
helpful in the follow-u of treated patients to evaluate whether remnant of nidus of
AVM and fistula remained.
Dynamic evaluation of arteriovenous anatomy
Dynamic CT angiography was used to evaluate dynamic blood floor of small vessels
(artery and vein) in the normal circulation that is no A-V shunting. This dynamic
information was able to distinguish the artery from the vein. It is considered to
have a great potential in the clinical field of microvascular surgery, such as minimal
invasive aneurysm surgery.
Radiation dose
Radiologists should be familiar with and aware of the dose indices normally
displayed on the CT scanner console. These indices include the volumetric CT dose
index (CTDIvol) and the dose-length product (DLP). The CTDIvol, which was
introduced to take into account the pitch of helical acquisitions, represents the
average dose delivered within the reconstructed section, and is calculated as the
weighted CTDI divided by the pitch. The DLP is the CTDIvol multiplied by the scan
length expressed in centimeters. It gives an indication of the energy imparted to
organs, and can be used to assess overall radiation burden associated with a CT
study. CT scanners now routinely record the CTDIvol, and the DLP.
4D CT imaging has a main drawback that should be noted. The radiation dose
presents a problem. It is important to underline that the typical exposure from a
single CT perfusion examination is around 2-10 mSv, similar to head CT alone and
much lower than that from a full length CTA.
Endovascular Treatment of the Brain Aneurysm:
Past, Present and the Future
Dr Tufail Patankar
Consultant Interventional Neuroradiologist, Leeds General Infirmary
Senior Lecturer, University of Leeds
UK
Since ISAT there have been a phenomenal change in practice in the western world
particularly Western Europe in the endovascular treatment of brain aneurysms.
We now have not only a better understanding in the management of the brain
aneurysms in terms of what we should and we should not treat but also a number
of new devices at our disposal to treat them better with open surgery reserved for
very selected aneurysm.
This presentation will discuss the endovascular management of brain aneurysms
with special emphasis on flow divertors and flow disruptors.
Intracranial Atherosclerotic Disease: The Road Ahead
Dr Manish Taneja
Consultant, Interventional Radiology & Neuroradiology
Raffles Hospital
Singapore
Intracranial atherosclerotic disease (ICAD) is a common cause of stroke in our
population. The incidence of intracranial atherosclerotic disease is also more
common in our patients compared to the West. There have been recent trails
and studies that have significantly impacted our clinical practice.
We will discuss the recent past, current practice and what lies ahead for
treating this challenging but common clinical condition.
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