- Pictorial Review
- Open Access
Imaging findings of the orbital and intracranial complications of acute bacterial rhinosinusitis
© The Author(s) 2015
- Received: 18 March 2015
- Accepted: 17 July 2015
- Published: 8 August 2015
In patients with acute bacterial rhinosinusitis severe orbital and intracranial complications can occur. This review will illustrate the anatomic relationship between the paranasal sinuses and the orbital and intracranial compartments. Subsequently, the spectrum of orbital and intracranial complications of rhinosinusitis and related imaging findings will be discussed and illustrated by case material from daily practice.
• Acute bacterial rhinosinusitis can cause severe orbital and intracranial complications.
• If orbital or intracranial complications are suspected, cross-sectional imaging is mandatory.
• Infection can spread from the ethmoid sinus to the orbit through the lamina papyracea.
• Frontal sinusitis can spread intracranially through dehiscences or osteomyelitis.
• Radiologists must recognize imaging findings of complications of acute bacterial rhinosinusitis.
- Paranasal sinuses
- Acute bacterial rhinosinusitis
Acute bacterial rhinosinusitis frequently evolves from a viral upper respiratory infection (URI). Of all children seeking medical attention for respiratory symptoms, 6 % -7 % have acute bacterial rhinosinusitis . The most common bacterial agents causing this infection are streptococcus pneumoniae, haemophilus influenza and moxarella catarrhalis. Early identification of children with complications of acute bacterial rhinosinusitis is crucial since it can cause life-threatening illness by the spread of infection to the orbits and central nervous system. In clinical practice, orbital complications are encountered most frequently . These typically occur in otherwise healthy young children (age < 5 years) presenting with acute ethmoiditis. If left untreated, orbital complications can result in permanent blindness of the affected side . Clinical symptoms include a swollen eye with or without proptosis or impaired function of the extraocular muscles (i.e. gaze impairment). Intracranial complications are less common but have a higher morbidity and mortality rate . They typically occur in previously healthy adolescent males presenting with rhinosinusitis in combination with severe headache, photophobia, seizures, or other focal neurologic findings . If there is clinical suspicion of orbital or intracranial complications, cross-sectional imaging of the orbit and brain is mandatory .
This review will focus on the complications of acute bacterial rhinosinusitis by firstly reviewing the anatomic relationship of the paranasal sinuses to the orbital and intracranial compartments. Secondly, the various complications and their imaging characteristics will be discussed and illustrated using examples from daily practice.
The roof of the orbit is formed by the frontal bone (i.e. pars orbitalis or orbital plate). Within this bone, the frontal sinus develops. Dorsally, the frontal sinus is directly adjacent to the anterior cranial fossa. Like the lamina papyracea, the frontal sinus may have bony dehiscences that can form a direct route for the spread of infection. Three common sites of congenital dehiscence are: 1) behind the trochlear fossa, 2) behind the supraorbital notch, and 3) at the junction of the middle and outer thirds of the sinus floor (Fig. 2). In addition, acquired dehiscences can exist, for example due to trauma .
Besides the spread of infection through the described dehiscences and canals there are two other mechanisms of spread that play an important role in the complications of bacterial rhinosinusitis. Firstly, there can be a bacterial thrombophlebitis through valveless veins causing spread of infection to the cavernous sinus [8, 12]. Secondly, there can be direct extension of infection through osteomyelitis .
The transition from uncomplicated URI to acute bacterial rhinosinusitis is not straightforward. There is considerable overlap between the symptoms and clinical findings of both entities. Imaging has not been shown to be helpful in distinguishing acute bacterial rhinosinusitis from viral URI. In children younger than 3 years with untreated, uncomplicated, rhinosinusitis or in patients of any age who have an uncomplicated cold for less than 10 days, imaging is not indicated [1, 5]. Especially in the paediatric population soft tissue swelling of the paranasal sinuses on CT and MRI is very common. Extensive mucosal thickening is present in up to 68 % of cases [13, 14]. Generally, rhinosinusitis is a diagnosis based on clinical symptoms. However, distinguishing self-limiting infection from rhinosinusitis with orbital or intracranial complications can be challenging. If complications are clinically suspected contrast-enhanced CT (ceCT) and/or MRI (ceMRI) of the paranasal sinuses should be obtained . To date, there are no head-to-head comparisons of the diagnostic accuracy of ceCT to ceMRI in evaluation of complicated rhinosinusitis in children. Since bony sinus anatomy can be best depicted by CT, CT is often the imaging modality of first choice . In addition CT is widely available, fast, and provides high spatial resolution images. Because of the speed of the acquisition, sedation is usually not required. An important disadvantage of ceCT is the use of ionizing radiation. Especially in children, exposure to radiation should be kept at a minimum. An important disadvantage of ceMRI is that it requires patient sedation in young children. In addition, MRI may not be available around the clock in all hospitals. However, some reports have illustrated that abnormalities responsible for the clinical symptoms are better seen on ceMRI. This seems to be especially true for intracranial complications [16, 17]. In patients that do not require sedation, ceMRI may be preferred over ceCT. If ceCT shows no abnormalities, but the patient has persisting symptoms suspicious for orbital or intracranial complications ceMRI should be obtained .
The acquisition of an orbital ceCT at our institution is done with 0.9 mm slice thickness, 0.45 mm increment, 120 kV, 55 mAs, 140 FOV, and a 512 × 512 matrix. The CT is acquired 2 minutes after manual injection of 100 ml of iodinated contrast material. Two mm thick axial and coronal slices are reconstructed using filtered backprojection with a soft tissue kernel. In addition, multiplanar reconstructions can be made in any plane from the thin slice source data.
An MRI protocol of the orbit should comprise at least coronal T2 STIR, axial T1, and axial and coronal T1 SPIR after gadolinium with a slice thickness of 3 mm or less and a pixel size of 1 mm or less . In addition diffusion-weighted imaging (DWI) has shown to be helpful in the evaluation of orbital infection .
The MRI protocol for intracranial complications should in addition to contrast enhanced T1 weighted (T1w) images comprise DWI, and fluid attenuated inversion recovery (FLAIR) images. DWI is known to be highly sensitive to pus formation and FLAIR can be helpful in detecting oedema and leptomeningitis [20–22].
The orbital complications of rhinosinusitis have been classified by Chandler et al. into five categories: 1) preseptal cellulitis; 2) orbital cellulitis; 3) subperiosteal abscess; 4) orbital abscess; and 5) cavernous sinus thrombosis . Chandler 1 to 3 is primarily treated with intravenous antibiotics. However, if the patient develops loss of vision or shows progressive signs of systemic disease within 24-48 hours, additional functional endoscopic sinus surgery will be performed . Chandler 4 and 5 are directly treated with functional endoscopic sinus surgery and orbital drainage in addition to intravenous antibiotics. In case of cavernous sinus thrombosis anticoagulation therapy can be applied. This is however controversial since intracranial haemorrhage may occur .
On ceMRI, both subperiosteal and orbital abscesses are seen as T1 isointense, T2 hyperintense fluid collections with rim enhancement. In addition, the presence of pus will result in restricted diffusion on DWI .
Besides cavernous sinus thrombosis, intracranial complications that can occur in patients with acute bacterial rhinosinusitis are: subdural empyema, epidural empyema, cerebritis, brain abscess, and meningitis . Patients usually present with severe headache in combination with photophobia, seizures, or other focal neurologic findings . If intracranial complications occur, functional endoscopic sinus surgery is mandatory. In the presence of empyema and brain abscess, neurosurgical intervention is required.
Complications arising from acute bacterial rhinosinusitis can result in life-threatening illness. Knowing the anatomic relationship of the paranasal sinuses to the orbital and intracranial compartment and the mechanisms of infectious spread, is paramount for early diagnosis of these complications. In addition, the radiologist needs to be aware of the specific imaging findings of orbital and intracranial complications of acute bacterial rhinosinusitis, including cavernous sinus thrombosis.
Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
- Wald ER, Applegate KE et al (2013) Clinical practice guideline for the diagnosis and management of acute bacterial sinusitis in children aged 1 to 18 years. Pediatrics. doi:10.1542/peds.2013-1071 Google Scholar
- Oxford LE, McClay J (2005) Complications of acute sinusitis in children. Otolaryngol Head Neck Surg. doi:10.1016/j.otohns.2005.03.020 Google Scholar
- Sultesz M, Csakanyi Z et al (2009) Acute bacterial rhinosinusitis and its complications in our pediatric otolaryngological department between 1997 and 2006. Int J Pediatr Otorhinolaryngol. doi:10.1016/j.ijporl.2009.04.027 Google Scholar
- Kombogiorgas D, Seth R et al (2007) Suppurative intracranial complications of sinusitis in adolescence. Single institute experience and review of literature. Br J Neurosurg. doi:10.1080/02688690701552856 PubMedGoogle Scholar
- Setzen G, Ferguson BJ et al (2012) Clinical consensus statement: appropriate use of computed tomography for paranasal sinus disease. Otolaryngol Head Neck Surg. doi:10.1177/0194599812463848 Google Scholar
- ten Donkelaar HJ (2007) Klinische Anatomie en Embryologie. Reed business. ISBN: 9789035229013Google Scholar
- Weiglein A, Anderhuber W et al (1992) Radiologic anatomy of the paranasal sinuses in the child. Surg Radiol Anat 14:335–339View ArticlePubMedGoogle Scholar
- Jain A, Rubin PA (2001) Orbital cellulitis in children. Int Ophthalmol Clin 41(4):71–86View ArticlePubMedGoogle Scholar
- Soon VT (2011) Pediatric subperiosteal orbital abscess secondary to acute sinusitis: a 5-year review. Am J Otolaryngol. doi:10.1016/j.amjoto.2009.10.002 PubMedGoogle Scholar
- Botting AM, McIntosh D et al (2008) Paediatric pre- and post-septal peri-orbital infections are different diseases. A retrospective review of 262 cases. Int J Pediatr Otorhinolaryngol. doi:10.1016/j.ijporl.2007.11.013 PubMedGoogle Scholar
- Pond F, Berkowitz RG (1999) Superolateral subperiosteal orbital abscess complicating sinusitis in a child. Int J Pediatr Otorhinolaryngol 48(3):255–258View ArticlePubMedGoogle Scholar
- Osborn MK, Steinberg JP (2007) Subdural empyema and other suppurative complications of paranasal sinusitis. Lancet Infect Dis. doi:10.1016/S1473-3099(06)70688-0 PubMedGoogle Scholar
- Kristo A, Uhari M et al (2003) Paranasal sinus findings in children during respiratory infection evaluated with magnetic resonance imaging. Pediatrics 111(5 Pt 1):586–589View ArticleGoogle Scholar
- Manning SC, Biavati MJ et al (1996) Correlation of clinical sinusitis signs and symptoms to imaging findings in pediatric patients. Int J Pediatr Otorhinolaryngol 37(1):65–74View ArticlePubMedGoogle Scholar
- Cornelius RS, Martin J et al (2013) ACR appropriateness criteria sinonasal disease. J Am Coll Radiol. doi:10.1016/j.jacr.2013.01.001 PubMedGoogle Scholar
- McIntosh D, Mahadevan M (2008) Failure of contrast enhanced computed tomography scans to identify an orbital abscess. The benefit of magnetic resonance imaging. J Laryngol Otol. doi:10.1017/S0022215107000102 Google Scholar
- Younis RT, Anand VK et al (2002) The role of computed tomography and magnetic resonance imaging in patients with sinusitis with complications. Laryngoscope. doi:10.1097/00005537-200202000-00005 Google Scholar
- ACR–ASNR–SPR Practice Parameter for the Performance of Magnetic Resonance Imaging (MRI) of the Head and Neck Res. 19 – 2012, Amended 2014 (Res. 39)Google Scholar
- Sepahdari AR, Aakalu VK et al (2009) MRI of orbital cellulitis and orbital abscess: the role of diffusion-weighted imaging. AJR. doi:10.2214/AJR.08.1838 PubMedGoogle Scholar
- Jan W, Zimmerman RA et al (2003) Diffusion-weighted imaging in acute bacterial meningitis in infancy. Neuroradiology. doi:10.1007/s00234-003-1035-8 Google Scholar
- Nickerson JP, Richner B et al (2012) Neuroimaging of pediatric intracranial infection--part 1: techniques and bacterial infections. J Neuroimaging. doi:10.1111/j.1552-6569.2011.00700.x Google Scholar
- Kamran S, Bener AB et al (2004) Role of fluid-attenuated inversion recovery in the diagnosis of meningitis: comparison with contrast-enhanced magnetic resonance imaging. J Comput Assist Tomogr 28(1):68–72View ArticlePubMedGoogle Scholar
- Chandler JR, Langenbrunner DJ et al (1970) Stevens, The pathogenesis of orbital complications in acute sinusitis. Laryngoscope. doi:10.1288/00005537-197009000-00007 Google Scholar
- Coenraad S, Buwalda J (2009) Surgical or medical management of subperiosteal orbital abscess in children: a critical appraisal of the literature. Rhinology 47(1):18–23PubMedGoogle Scholar
- Desa V, Green R (2012) Cavernous sinus thrombosis: current therapy. J Oral Maxillofac Surg. doi:10.1016/j.joms.2011.09.048 PubMedGoogle Scholar
- Kapur R, Sepahdari AR et al (2009) MR imaging of orbital inflammatory syndrome, orbital cellulitis, and orbital lymphoid lesions: the role of diffusion-weighted imaging. AJNR. doi:10.3174/ajnr.A1315 PubMed CentralPubMedGoogle Scholar
- Handler LC, Davey IC et al (1991) The acute orbit: differentiation of orbital cellulitis from subperiosteal abscess by computerized tomography. Neuroradiology 33(1):15–18View ArticlePubMedGoogle Scholar
- LeBedis CA, Sakai O (2008) Nontraumatic orbital conditions: diagnosis with CT and MR imaging in the emergent setting. Radiographics. doi:10.1148/rg.286085515 PubMedGoogle Scholar
- Ebright JR, Pace MT et al (2001) Septic thrombosis of the cavernous sinuses. Arch Intern Med 161(22):2671–2676View ArticlePubMedGoogle Scholar
- Razek AA, Castillo M (2009) Imaging lesions of the cavernous sinus. AJNR Am J Neuroradiol. doi:10.3174/ajnr.A1398 Google Scholar
- Linn J, Michl S et al (2010) Cortical vein thrombosis: the diagnostic value of different imaging modalities. Neuroradiology. doi:10.1007/s00234-010-0654-0 Google Scholar
- Ginat DT, Meyers SP (2012) Intracranial lesions with high signal intensity on T1-weighted MR images: differential diagnosis. Radiographics. doi:10.1148/rg.322105761 PubMedGoogle Scholar
- Yildiz ME, Ozcan UA et al (2014) Diffusion-Weighted MR Imaging Findings of Cortical Vein Thrombosis at 3 T. Clin Neuroradiol. doi:10.1007/s00062-014-0301-y Google Scholar
- Kombogiorgas D, Solanki GA (2006) The Pott puffy tumor revisited: neurosurgical implications of this unforgotten entity. Case report and review of the literature. J Neurosurg. doi:10.3171/ped.2006.105.2.143 PubMedGoogle Scholar
- Foerster BR, Thurnher MM et al (2007) Intracranial infections: clinical and imaging characteristics. Acta Radiol. doi:10.1080/02841850701477728 Google Scholar
- Oliveira CR, Morriss MC et al (2014) Brain magnetic resonance imaging of infants with bacterial meningitis. J Pediatr. doi:10.1016/j.jpeds.2014.02.061 Google Scholar