Transcript Old is Gold: Role of Conventional Sialography in

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KNOWING WHAT, WHEN AND HOW TO
INTERPRET: GUIDE TO IMAGING SALIVARY
GLAND PATHOLOGY
Umar Chaudhry+, Saba Hamid+, Umber Shafique+, Joan Maley+,
Bruno Polliceni+, Henry Hoffmman*
+ Section of Neuroradiology,
Department of Diagnostic Radiology,
Univeristy of Iowa Hospitals and Clinics.
* Department of Otolaryngology,
University of Iowa Hospitals and Clinics.
OUTLINE
• INTRODUCTION
• MODALITIES AVAILABLE
• INDIVIDUAL MODALITIES
• INDICATIONS
• PROTOCOL
• ADVANTAGES
• DISADVATAGES
• PICTORIAL EXAMPLES
• PEARLS
“ The years teach much which the days never knew ” Ralph Waldo Emerson
INTRODUCTION
•
Salivary gland pathology is one the most variable amongst the organ system
•
Wide variety of imaging modalities used
•
It becomes confusing to determine the most optimum modality when encountered
with a clinical scenario
•
With era of cost effectiveness, ever increasing patient awareness, and extensive
clinician interactions, the expectations from a radiologist have increased
•
This presentation is intended to be a quick reference guide and refresher for various
tools in our arsenal when dealing with such scenarios
MODALITIES
•
Computed Tomography
•
Magnetic resonance imaging
•
Ultrasound
•
Conventional Sialography
•
Nuclear imaging
COMPUTED TOMOGRAPHY (CT)
INDICATIONS:
Optimal:
-
Inflammatory pathologies, infection
Obstructive pathologies: stones
Occasional:
-
CT sialography, ductal pathology
Masses
Post radiation
PROTOCOL
- Multidetector CT (MDCT)
- kVP 80-120 kVP
- Dose reduction techniques:
-
Thyroid bismuth shields
Automated dose reduction
Lower kV
Studies showed no significant diagnostic difference between 80 and
120 kV protocols
- Inflammatory conditions, abscess usually IV contrast
- Stones - Non contrast
ADVANTAGES
- Quick
- Readily available
- Gross anatomical detail of surrounding structuresextent of
inflammation
- High sensitivity for Stones/calcifications
- 3D reconstructions: CT Sialography
DISADVANTAGES
-
Ionizing radiation- pregnant and children
Not ideal for tumors as higher detail from MRI
Perineural spread in malignancies is difficult
Poor ductal anatomical detail with standard CT
Inflammation of left parotid gland
A case of a left parotid gland tumor – pleomorphic adenoma
with spilling, structural details and margins not as clear as
with MRI
RIGHT SUBMANDIBULAR GLAND DUCT STONE
(RECTANGLE) WITH DILATED DUCT (CIRCLE)
PEARLS - CT
-
Acute conditions in adult patients
Inflammation
Stones questioned
With radiation awareness, consider dose modulation
MAGNETIC RESONANCE IMAGING
(MRI)
INDICATIONS
Salivary gland masses
Systemic conditions, usually non acute
Ductal anatomy - Sialography
PROTOCOL
- For masses or major salivary glands, usually gadolinium
based contrast
- Varies from one institution to the other
- Our institution protocol
-
3 plane localizer
Coronal and axial T2
Axial T1
Diffusion
3 plane post -contrast T1 images
EXAMPLE OF SCAN VOLUMES FOR PAROTID
GLAND
MRI SIALOGRAPHY
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Relies on heavily T2 weighted sequences and water property of saliva
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Side of abnormality and duct included in the scan volume for MR Sialography
-
Protocol also varies from institution to institution
-
2D pulse sequences used traditionally - Projection and Maximum Intensity projections
for Sialography
-
2D pulse sequence techniques to increase quality of images include
-
-
Projection technique by using a microscopic coil improving the quality of the
images obtained with larger coils
Recently 3D pulse sequences utilized for more post processing options
ADVANTAGES
-
No radiation
Non invasive
Excellent gland detail
Tumor characterization, using signal intensity, margins,
pattern of spread, diffusion coefficients
Facial nerve characterization in parotid lesions
DISADVANTAGES
-
Time consuming - not ideal for acute settings
Expensive
Limited field of view
More susceptible to artifacts
Ductal detail needs careful optimization, otherwise may be
confounded by vessels etc.
PEARLS
- Non acute
- Ideal for major salivary gland masses and systemic conditions
such as Sjogren characterization
- Spread of malignancies- perineural tumor spread
- New techniques such as dynamic contrast high potential
- After optimization ductal details acquired non invasively
PLEOMORPHIC ADENOMA ON MRI
T2- HIGH
T1- LOW
POST CONTRAST
HOMOGENOUS
MALIGNANT PAROTID TUMOR WITH PERINEURAL
TUMOR SPREAD (CIRCLE)
ULTRASOUND
INDICATIONS:
-
Acute inflammations
Pediatric and pregnant population
Image guided procedures
Initial screening of major salivary gland mass
PROTOCOL
-
High frequency linear probes
7.5-12 MHz
-
Color doppler
-
Real time imaging
Figure: Example of color doppler on a parotid mass
ADVANTAGES
-
No ionizing radiations
Quick
Real time imaging- image guided procedures
Less expensive and more readily available than MRI
DISADVANTAGES
-
-
Operator dependence
Ducts especially Parotid duct not well seen unless largely
dilated
Limited field of view- Deeper pathologies such as
parapharyngeal space lesions and deep lobes of parotid
glands not well see
Less specific characterization of masses as compared to
MRI
PAROTID PLEOMORPHIC ADENOMA
Normal parotid parenchyma is more echogenic and homogenous
PEARLS
-
Children and pregnant patients
Initial screening for acute conditions such as infections
Image guided procedures
One of the most cost effective modalities in cross sectional
imaging
CONVENTIONAL SIALOGRAPHY
INDICATIONS:
-
Obstructive and ductal salivary gland pathology
Preoperative exam before sialendoscopy
PROTOCOL
-
Fluoroscopy- real time imaging
Usually Kv range close to 70 kV
Iodine based contrast directly instilled into major salivary gland ducts
Images in two planes
Ductal and glandular phase
Stimulation for glandular phase - Lime/candy
Sialography- The Procedure
SIALOGRAPHY -TECHNIQUE
•
Basic principle: Instilling radio-opaque contrast directly into the duct opening
Salivary
Gland
Stenson’s duct
Canula
Syringe containing
contrast
Sialography can be performed with or without digital subtraction - digital subtraction
favored, as it removes the confounding bone opacities
ADVANTAGES
-
Resurgence due to preoperative insight before minimally
invasive ENT procedures
Ductal resolution and detail superior to many other
modalities
Lower dose than CT sialography
DISADVANTAGES
-
Invasive
Ionizing radiation
Expertize required
Common pathologies-a sialographic perspective
SIALOGRAPHY IN SIALOLITHIASIS
Filling defects seen in Stenson’s duct, with dilated ducts upstream from the obstruction
PEARLS
-
Not to be overlooked and seeing a resurgence due to new
minimally invasive techniques in ENT
Ductal pathology well seen
Usually requires close collaboration with ENT
NUCLEAR MEDICINE
INDICATIONS:
-
Long term dysfunction/sialadenitis
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Metastatic workup
PROTOCOL
-
Salivary scintigraphy
- Tc-99m Planar and SPECT imaging
- Mainly for long term dysfunction after radioiodine
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PET
- Fluoro-deoxy glucose for metastatic workup and distant lesions
ADVANTAGES
-
Functional information
Distant metastatic lesions
DISADVANTAGES
-
Non-specific for salivary gland tumors
Non acute pathologies only
Limited use
Cost and availabillity
PET-FDG SCAN IN METASTATIC SALIVARY GLAND
TUMOR: NECK NODE AND RIGHT LUNG NODULE
PEARLS
-
Overall limited role
-
Chronic sialadenitis after radioactive iodine- Tc-99m
scintigraphy
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FDG-PET is non specific, can be used for distant metastasis
after tissue diagnosis
REFERENCES
•
Carotti M, Ciapetti A, Jousse-Joulin S, Salaffi F.Ultrasonography of the salivary glands: the role of
grey-scale and colour/power Doppler.Clin Exp Rheumatol. 2014 Jan-Feb;32(1 Suppl 80):S61-70.
Epub 2014 Feb 17.
•
Aghaghazvini L, Salahshour F, Yazdani N, Sharifian H, Kooraki S, Pakravan M, Shakiba M. Dynamic
contrast-enhanced MRI for differentiation of major salivary glands neoplasms, a 3-T MRI
study.Dentomaxillofac Radiol. 2015;44(2):20140166.
•
Burke CJ, Thomas RH, Howlett D. Imaging the major salivary glands. Br J Oral Maxillofac Surg.
2011 Jun;49(4):261-9. Epub 2010 Apr 9.
•
Harrison JD. Causes, natural history, and incidence of salivary stones and obstructions.
Otolaryngol Clin North Am. 2009 Dec;42(6):927-47.
•
Brown JE, Drage NA, Escudier MP, Wilson RF, McGurk M. Minimally invasive radiologically guided
intervention for the treatment of salivary calculi. Cardiovasc Intervent Radiol. 2002 SepOct;25(5):352-5. Epub 2002 Sep 18.
REFERENCES
•
Abdullah A, Rivas FF, Srinivasan A. Imaging of the salivary glands.Semin Roentgenol. 2013
Jan;48(1):65-74.
•
Gonzalez-Beicos A, Nunez D. Imaging of acute head and neck infections.Radiol Clin North Am.
2012 Jan;50(1):73-83.
•
Obinata K, Sato T, Ohmori K, Shindo M, Nakamura M. A comparison of diagnostic tools for Sjögren
syndrome, with emphasis on sialography, histopathology, and ultrasonography. Oral Surg Oral
Med Oral Pathol Oral Radiol Endod. 2010 Jan;109(1):129-34.
•
Nahlieli O, Nakar LH, Nazarian Y, Turner MD. Sialoendoscopy: A new approach to salivary gland
obstructive pathology. J Am Dent Assoc. 2006 Oct;137(10):1394-400.
•
Mosier KM. Diagnostic radiographic imaging for salivary endoscopy. Otolaryngol Clin North Am.
2009 Dec;42(6):949-72.
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