DOI:10.2214/AJR.07.7032
AJR 2007; 189:S46-S48
© American Roentgen Ray Society
Imaging of Chronic and Exotic Sinonasal Disease: Self-Assessment Module
Arash J. Momeni1,
Catherine C. Roberts2 and
Felix S. Chew3
1 Department of Radiology, David Grant Medical Center, Travis Air Force Base,
Fairfield, CA.
2 Department of Radiology, Mayo Clinic College of Medicine, 5777 E Mayo Blvd.,
Phoenix, AZ 85054.
3 Department of Radiology, University of Washington, Seattle, WA.
revised August 3, 2007;
accepted after revision August 29, 2007.
The opinions and assertions contained herein are the private views of the
authors and are not to be construed as official or as reflecting the views of
the Department of the Air Force or the Department of Defense.
Address correspondence to C. C. Roberts
(roberts.catherine{at}mayo.edu).
Abstract
Chronic sinusitis is one of the most commonly diagnosed illnesses in the
United States. This article focuses on the anatomy, pathophysiology,
microbiology, and diagnosis of sinonasal disease, including chronic and fungal
sinusitis, juvenile nasopharyngeal angiofibroma, inverted papilloma, and
chondrosarcoma.
Keywords: chondrosarcoma • chronic sinusitis • CT • fungal sinusitis • inverted papilloma • juvenile nasopharyngeal angiofibroma • MRI
INTRODUCTION
This self-assessment module on the imaging evaluation of sinonasal disease
has an educational component and a self-assessment component. The educational
component consists of a review article for the participant to read and a Web
lecture. The self-assessment component consists of six multiple-choice
questions with solutions. All of these materials are available on the ARRS Web
site
(www.arrs.org).
To claim CME and SAM credit, each participant must enter his or her responses
to the questions online.
EDUCATIONAL OBJECTIVES
By completing this educational activity, the participant will:
- Exercise, self-assess, and improve his or her understanding of relevant
sinus imaging anatomy.
- Exercise, self-assess, and improve his or her understanding of the imaging
of sinus infection.
- Exercise, self-assess, and improve his or her understanding of sinus
masses.
REQUIRED READING (available at www.arrs.org)
- Momeni AJ, Roberts CC, Chew FS. Imaging of chronic and exotic sinonasal
disease: review. AJR 2007; 189 [suppl]:S35–S45
REQUIRED ACTIVITY (available online at www.arrs.org)
- Smith MM. Imaging of the sinonasal cavities. Neuroradiology Review Course
2003; module
1:www.arrs.org
INSTRUCTIONS
- Read the required article and view the required lecture.
- Visit
www.arrs.org
and select Publications/Journals/SAM articles from the left-hand menu bar.
- Using your member login, order the online SAM as directed.
- Follow the online instructions for entering your responses to the
self-assessment questions and then complete the test by answering the
questions online.
Solution to Question 1
The hiatus semilunaris, situated immediately superior to the uncinate
process, is a slitlike air-filled space anterior and inferior to the largest
ethmoid air cell, the ethmoidal bulla. Mucus is passed through it
posteromedially via the middle meatus into the back of the nasal cavity to the
nasopharynx, where it is subsequently swallowed
[1]. It is clinically
significant because disease located here results in obstruction of the
ipsilateral maxillary antrum, anterior and middle ethmoid air cells, and
frontal sinus. Option B is the best response. Option C is not the best
response because disease localized to the infundibulum would result in
isolated obstruction of the ipsilateral maxillary sinus alone
[2]. Options A, D, and E would
not produce disease in this region.
Solution to Question 2
Benign fungal infections secondary to Aspergillus species, such as
allergic fungal sinusitis, are characterized on CT by increased attenuation in
the sinuses and frequent bilateral involvement. Hyperdense secretions on CT
may be due to four main causes: inspissated secretions, fungal sinusitis,
hemorrhage in the sinus, and calcification
[3]. Options A, C, and D are
not the best responses. The hyperdense sinus may be the only clue to fungal
sinusitis and is an important feature to note. The hyperdense sinus often
corresponds to the hypointense sinus on T2-weighted images. Complete
opacification and expansion, erosion, or remodeling and thinning of the
sinuses are also characteristic features of allergic fungal sinusitis.
Intrasinus calcification on CT is another characteristic of fungal sinusitis,
particularly that due to aspergillosis. Calcification may occur with other
pathologic processes, such as bacterial sinusitis, mucoceles, and neoplasms,
but it is uncommon in nonfungal inflammatory sinonasal disease
[4]. Option B is the best
response given the presence of complete unilateral opacification and
expansion, calcifications, and the patient's clinical history.
Solution to Question 3
A chronic unresolved process is evident in this case given the duration of
the patient's symptoms (6 months) and failure of one round of antibiotics.
Although characteristic findings of sinus disease include air–fluid
levels, mucosal thickening, and opacification of the normally aerated sinus
lumen, the single distinguishing feature of acute sinusitis is the
air–fluid level. Therefore, Option D is the best response because
air–fluid levels as an isolated finding would not be classically seen
after more than 6 months of symptom duration. Option A is not the best
response because the only characteristic finding in chronic sinusitis is
sclerotic, thickened bone of the sinus wall
[5]. Option B is also not the
best response; a mucosal thickening is common to both acute and chronic
sinusitis. Centrally located calcification and osseous destruction of the
lateral sinus wall may be seen in chronic causes. Therefore, Options C and E
are not the best responses.
Solution to Question 4
Juvenile nasopharyngeal angiofibromas are characterized by high vascularity
and a propensity for bleeding. The typical patient is an adolescent boy who
has recurrent epistaxis unrelated to nose-picking. On MRI the distinctive
feature is the abundance of flow voids from its high vascularity, which gives
the lesion a characteristic "salt-and-pepper" (tissue and flow
voids, respectively) appearance that may be seen on T2-weighted and
contrast-enhanced T1-weighted images
[1]. Option C is the best
response. T2-weighted hypointensity, enhancement in a solid fashion, and
fluid–fluid levels are not characteristic of juvenile nasopharyngeal
angiofibromas A convoluted cerebriform enhancement on T2-weighted sequences or
enhanced T1-weighted sequences is typical of inverted papillomas
[6,
7]. Options A, B, D, and E are
not the best responses.
Solution to Question 5
Option D, inverted papilloma, is the best response given the history
and imaging features. Inverted papillomas are benign epithelial neoplasms that
classically arise from the lateral nasal wall or maxillary sinus and have
significant malignant potential. They most often affect patients 40–70
years old and occur two to four times more often in men than in women. The
common symptoms are epistaxis, rhinorrhea, nasal obstruction, anosmia,
sinusitis, facial pain, and frontal headache
[6]. On MRI, the lesion is
isodense to muscle on T1-weighted images and isointense to hypointense on
T2-weighted images. Most other polypoid masses have high, homogeneous signal
intensity on T2-weighted sequences. Options A, B, C, and E are not the best
responses. Inverted papillomas enhance and, in roughly 50% of cases, the
lesions are heterogeneous in both signal intensity and enhancement. A
convoluted cerebriform enhancement on T2-weighted sequences or enhanced
T1-weighted sequences is typical of inverted papillomas
[6,
7].
Solution to Question 6
Nasopharyngeal cancers show density similar to muscle on CT. Because of the
low density difference, subtle carcinomas may be difficult to diagnosis. Thus,
infiltration of the parapharyngeal space is the most reliable and frequent
sign of nasopharyngeal carcinoma
[8]. Therefore, it is critical
to assess the area around Rosenmüller's fossa for any evidence of
infiltration, particularly the loss of planes between the levator and tensor
veli palatine muscles. Incidentally, another important CT finding of
nasopharyngeal carcinoma is widening of the preoccipital soft tissue in the
midline by more than 1.5–2.0 cm. For these reasons, Option A is the
best response. The key to differentiating chondrosarcoma from other
disorders is appreciating whether calcification is present. In fact,
chondrosarcoma should be in the differential diagnosis of calcified enhancing
parasellar masses [9]. Option B
is not the best response. Noncaseating multinucleated giant cell granulomas
and necrotizing vasculitis are histopathologic characteristics of Wegener's
granulomatosis. Option C is not the best response. Option D is not the best
response because the abundance of flow voids is caused by the high vascularity
of nasopharyngeal angiofibromas. Option E is not the best response because
hypodensity on CT is the classic appearance of a Tornwaldt's cyst, although it
may be seen off midline in a small percentage of cases. A Tornwaldt's cyst is
usually hyperintense on T1- and T2-weighted images.
References
- Baroody FM. Nasal and paranasal sinus anatomy and physiology.
Clin Allergy Immunol 2007;19
: 1–21[Medline]
- Brant WE, Helms CA. Fundamentals of diagnostic
radiology, 2nd ed. Philadelphia, PA: Lippincott Williams &
Wilkins, 1999: 211–213
- Gliklich RE, Metson R. The health impact of chronic sinusitis in
patients seeking otolaryngologic care. Otolaryngol Head Neck
Surg 1995; 113:104
–109[CrossRef][Medline]
- Som RM, Lidov M. The significance of sinonasal radiodensities:
ossification, calcification, or residual bone? Am J
Neuroradiol 1994; 15:917
–922[Abstract]
- Zinreich SJ, Abayram S, Benson ML, Oliverio PJ. The ostiomeatal
complex and functional endoscopic surgery. In: Som PM, Curtin HD, eds.
Head and neck imaging, 4th ed. St. Louis, MO: Mosby,2003
: 149–174
- Ojiri H, Ujita M, Tada S, Fukuda K. Potentially distinctive
features of sinonasal inverted papilloma on MR imaging.
AJR 2000; 175:465
–468[Abstract/Free Full Text]
- Gotwald TF, Zinreich SJ, Corl F, Fishman EK. Three-dimensional
volumetric display of the nasal ostiomeatal channels and paranasal sinuses.
AJR 2001; 176:241
–245[Free Full Text]
- Som PM, Brandwein MS. Tumors and tumor-like conditions. In: Som PM,
Curtin HD, eds. Head and neck imaging, 4th ed. St.
Louis, MO: Mosby, 2003:261
–373
- Jones NS. CT of the paranasal sinuses: a review of the correlation
with clinical, surgical, and histopathological findings. Clin
Otolaryngol Allied Sci 2002;27
: 11–17[CrossRef][Medline]
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Abstract
INTRODUCTION
