Vol. 117 No. 6 June 2014

The feasibility of cone beam computed tomographic sialography inthe diagnosis of space-occupying lesions: report of 3 casesShoaleh Shahidi, DDS, MScD,a and Shahram Hamedani, DDS, MScb

School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran

Cone beam computed tomography (CBCT) is being widely used in recent years and has modernized the practice of

oral and maxillofacial radiology by its inherent advantages, such as short scanning time, high resolution, and low dose of

radiation to the patient. Sialography can be considered as the second step of assessment of space-occupying masses after initial

diagnosis with ultrasonography. Sialography is combined with plain radiographs in routine practice. It can also be combined

with advanced modalities such as computed tomography (CT), magnetic resonance imaging (MRI), and CBCT. In this report,

we describe 3 cases to confirm the feasibility and superiority of sialography using CBCT and 3-dimensional (3D) images in

space-occupying lesions of major salivary glands when conventional sialography is not diagnostic or MRI and CTare not easily

available or affordable. CBCT sialography and its 3D images can be helpful in the diagnosis of space-occupying lesions of

major salivary glands. (Oral Surg Oral Med Oral Pathol Oral Radiol 2014;117:e452-e457)

Diagnostic imaging has a crucial role in the assessmentand management of symptomatic major salivary glanddiseases. Such imaging can help in finding the nature,extent, and (probably) the cause of these diseases andcan reveal their possible effects on the adjacentanatomic structures.1

Imaging of the major salivary glands is currentlyperformed with one of the following imaging modal-ities: occlusal intraoral radiographs, conventional sia-lography, ultrasonography (US), computed tomography(CT) with or without contrast media, magnetic reso-nance imaging (MRI) with or without enhancements,magnetic resonance sialography, and nuclear salivaryscintigraphy. Each technique has its own indication orshortcomings considering the primary assessment madeand the availability of these devices.1,2

Currently, US is the preferred imaging modality inthe initial evaluation of salivary glands in many coun-tries. It is widely available, low-cost, patient-friendly,and safe and is valuable for the assessment of superfi-cial lesions of the parotid and submandibular glands. Ithas been reported to be 98% accurate in discriminatingglandular lesions from extraglandular lesions.1 How-ever, US is an operator-dependent technique and islimited in outlining deep parotid masses that areobscured by the mandible. Thus, clinicians should seekfurther imaging modalities to discover large tumor

aBiomaterial Research Centre, Department of Oral and MaxillofacialRadiology, School of Dentistry, Shiraz University of MedicalSciences.bDental Research Development Center, School of Dentistry, ShirazUniversity of Medical Sciences; private practice.Received for publication Sep 2, 2013; returned for revision Dec 11,2013; accepted for publication Feb 19, 2014.� 2014 Elsevier Inc. All rights reserved.2212-4403/$ - see front matterhttp://dx.doi.org/10.1016/j.oooo.2014.02.023

e452

extension or to reach the definitive diagnosis in locallyinvasive lesions.1

Initially performed in 1902, sialography illustratesthe ductal structures of the salivary glands by intro-ducing a contrast agent into the orifice of its duct.3

Traditionally, sialography is performed by using plainradiographs and injection of water-soluble contrastmedia into the major salivary gland ducts to outline theanatomy of the ducts, find strictures, and detect salivarystones (sialoliths).1

Conventional sialography, CT, and MRI can be usedto assess space-occupying lesions of salivary glandswhen US fails.2,3 The main shortcoming of conven-tional sialography is in the diagnosis of space-occu-pying lesions.3

Space-occupying masses of the salivary glands can besubdivided into cystic conditions and neoplastic lesions.Salivary gland tumors are uncommon, and cysts are rare.Fewer than 5% of salivary gland masses are related tocysts, and salivary gland tumors represent fewer than 3%of all tumors in the head and neck region.1-3

With combinations of imaging modalities, 3-dimen-sional (3D) images of ductal structure and gland anat-omy can be obtained by combining sialography withCT or MRI. The high radiation dose of CT and thesophisticated methods of MRI are their primary well-recognized limitations.2,3

Today, the rapid achievement of a 3D image volumeusing cone beam computed tomography (CBCT) hasovercome the limitations of MRI images and spiral(medical) CT scans. CBCT is being widely used inrecent years and has modernized the practice of oral andmaxillofacial radiology by its inherent advantages, suchas short scanning time, high resolution, and low dose ofradiation to the patient.4 The CBCT equipment andprocedures are primarily designed for proper imaging ofbone and some soft tissue.5 Very fine images and 3Dreconstructions can nevertheless be obtained by CBCT,

Fig. 1. Case 1. A, Conventional sialography from right parotid gland. There is no sign of filling defect, space-occupying lesion, orchronic sialoadenitis. B, Cone beam computed tomography sialography of the same gland. An axial section showing the space-occupying lesion in the anterosuperior aspect of the gland. C, Coronal section showing the space-occupying lesion in the ante-rosuperior aspect of the gland.

OOOO CASE REPORT

Volume 117, Number 6 Shahidi and Hamedani e453

and it might be used for the differential diagnosis ofsuspicious radiolucent lesions of the mandible.6

Sialography has been found to be the most successfultechnique to evaluate major salivary gland function andto obtain accurate assessment of the obstructive con-ditions of the salivary glands.7-9 This method can alsobe considered as the second step of assessment ofspace-occupying masses after initial diagnosis with US.Sialography is combined with conventional radiologicprojections in routine practice.

The purpose of this report, which presents 3 clinicalcases, is to verify the feasibility and superiority ofCBCT sialography and its 3D images in the diagnosisof space-occupying lesions of major salivary glands.

CASE REPORTSCase 1A 55-year-old man with a history of 6 to 7 months of painlessswelling of the right parotid gland was referred for sialog-raphy by his otolaryngologist. The clinical evaluation sug-gested a space-occupying lesion, and he was referred forconventional sialography. The sialography procedure wascarried out by an experienced academic maxillofacial radiol-ogist in a private dentomaxillofacial radiology center usingthe hand injection technique. The orifice of the primary ductof the salivary gland under examination was dilated with aseries of gutta percha cones from No. 25 to No. 45. This wasfollowed by cannulation of the main duct through the orificeusing a customized catheter. The catheter was a scalp vein,gauge 19 for parotid glands with blunted needle. Subse-quently, 4 to 5 mL of contrast material (Visipaque; iodixanol,270 mg per 20 mL, Nycomed Amersham, Ireland) was

injected slowly into the duct of the gland. We presumed 1 mLfor the ductal phase and 3 mL for the parenchymal phase(blushing stage).

A unilateral dental panoramic tomography (DPT) image wasthen acquired using the Planmeca system (Planmeca Oy, Hel-sinki, Finland) and a photostimulable phosphor sensor (KonicaCR; Minolta, Japan) to confirm the best possible filling up ofthe ductal structures. All digitally acquired images were viewedunder optimal conditions regarding the monitor and the roomlights. In the conventional sialogram, no filling defects and nosignificant space-occupying lesions were detected, althoughthe Stensen duct was deviated to the inferior. There were alsono signs indicating chronic sialoadenitis. Conventional sia-lography showed no abnormality and was not responsive forexplicit diagnosis in this case (Figure 1, A). Because the plain-film sialogram was not diagnostic, a sialo-CBCT was planned.The patient was then positioned in the CBCT unit (NewTomVGi; QR Srl, Verona, Italy) with a 1-mL boost of contrastmedia, and the scanning of the involved salivary gland wasperformed. The data were examined using the software sup-plied by the manufacturer. CBCT images were compared withthe initial conventional sialography images.

CBCT in axial and cross sections clearly showed a space-occupying lesion in the superomedial aspect of the gland. Thisfinding is compatible with the displacement of the duct infe-riorly in conventional and CBCT sialography. There were nosigns of filling defects (sialodochitis, sialectasia) or any signof ductal deterioration and puddling of the injected contrastmedia. CBCT found a space-occupying lesion, which wasconcurrent with the patient’s condition and the anticipateddiagnosis of the referring physician. Although the diagnosis ofa space-occupying lesion without ductal disease wasconfirmed, the patient refused a fine-needle aspiration (FNA)examination (Figure 1, B).

Fig. 2. Case 2. A, Conventional sialography of the right parotid gland showing multiple calcifications in the periphery of the gland.The image shows no filling defect, space-occupying lesion, or any evidence of chronic sialoadenitis. The width of the major duct isconsistent, although wider than normal. B, Three-dimensional image of the right parotid gland showing the evidence of the space-occupying lesion in the deep portion of the gland. C1, CBCT sialography, axial section. Arrows show the calcifications within thelesion. C2, CBCT sialography, axial section. The image confirms the evidence of space-occupying lesion in the deep portion of thegland. (CBCT, cone beam computed tomography.)

ORAL AND MAXILLOFACIAL RADIOLOGY OOOO

e454 Shahidi and Hamedani June 2014

Case 2A 49-year-old man was referred to the dentomaxillofacialradiology clinic by his general dental practitioner to take aDPT image for routine dental examination. In the DPT im-age, multiple calcifications were detected, being super-imposed on (and lateral to) the right ramus of the mandible.The patient did not present any history of previous diseases.The clinical examination found a slight asymmetry in themasseter muscles. Therefore, US examination was per-formed. The US examination reported a 22 � 26 � 15-mm,irregularly shaped, multilobulated, hypoechoic mass withposterior enhancement in the inferior margin of the rightparotid gland in favor of a multilocular cyst. Multiple smallechogenic foci were detected within the mass, with posteriorattenuation in favor of foci of calcification. There was notany significant vascularity related to the mass. Based onthese findings, the possibility of a multiloculated collectionof lymph nodes or an enlarged lymph node with centralnecrosis and calcification should be considered. The possi-bility of a parotid gland tumor with necrosis and calcificationcould not be ruled out.

Therefore, the conventional sialography was performedusing the same procedure described in the previous case. Thesialogram showed ductal and parenchymal displacement inthe inferomedial aspect of the parotid gland (Figure 2, A).However, the sialogram did not confirm the presence of aspace-occupying lesion, which was revealed in USexamination.

CBCT (NewTom VGi; QR Srl, Verona, Italy) was used toimage the filling phase of the investigation, using 1 mL ofVisipaque (270 mg per 20 mL) contrast media as the boostdose injected by hand. The CBCT system operated at 85kilovolt peak and 3.5 mA with a 15 � 15-cm field of view and10.8 seconds scanning time.

The CBCT sialography, in axial sections, showed a lobu-lated space-occupying lesion in the deep portion of the gland.Multiple calcifications were detected in the lesion. There wasno evidence of ductal involvement, deterioration, or sia-lectasia. A few small round calcifications were detectedoutside the parotid gland (see Figure 2, B, C1, C2). The FNAexamination under US showed some clusters of normal acini,very few ductal cells, and a few inflammatory cells in the

Fig. 3. Case 3. A, Conventional sialography from the right parotid gland showing decreased density of the gland parenchyma inthe inferolateral aspect of the gland. The parenchyma can have similar appearance either in the presence of space-occupying lesionsor because of the pressure of an external mass over the gland. B, Three-dimensional image of the gland confirms the presence of thespace-occupying lesion in the inferolateral aspect of the gland. C, Coronal section of the CBCT sialography showing the presenceof the space-occupying lesion. D, Three-dimensional image of the CBCT sialography showing the space-occupying lesion in thesuperficial aspect of the gland. E, CBCT sialography, axial section, showing the presence of the space-occupying lesion in thesuperficial aspect of the gland. (CBCT, cone beam computed tomography.)

OOOO CASE REPORT

Volume 117, Number 6 Shahidi and Hamedani e455

blood cell background. The FNA result was negative formalignancy.

Case 3This 40-year-old man had a firm, movable swelling on theright side of the face, inferior to the ear. The conventionalsialography showed decreased density of the parenchyma inthe inferolateral aspect of the right parotid gland (Figure 3, A).The CBCT sialography showed a significant space-occupyinglesion (see Figure 3, B-E).

DISCUSSIONCBCT sialography was described initially by Drage andBrown in 2009,10 in a case report of 2 patients with sali-vary gland obstruction. In the first case, a single sialolithwas identified in the right submandibular gland. In thesecond case, a sialolith and a stricture in the right parotidgland were identified and managed with interventionalradiography. The authors could easily identify the sali-varymajor duct, ductal branches, and obstructions in bothcases. Unfortunately, that study did not indicate whetherthe technique was useful for space-occupying lesions.

Drage and Brown10 believed that CBCT sialographywas indicated and justified when conventional

sialography was assumed to be insufficient, or has beenestablished to be insufficient, in complex cases ofsalivary duct obstruction. They also stated that selectioncriteria for CBCT were requisite and that the CBCTsialography would expose patients to higher x-rayradiation and accordingly must be reserved for morecomplicated cases.10

They estimated the radiation doses that were deliv-ered to the patients with CBCT sialography andconstrued that the radiation dose exposure in CBCT(96-134 mSv) was comparable with that of conven-tional fluoroscopic procedures (34-113 mSv).10 How-ever, Jadu et al.8 estimated that the CBCT sialographyprocedure would deliver an effective radiation dose thatranged between 76 mSv (parotid gland) and 170 mSv(submandibular gland). They also estimated that effec-tive radiation doses were similar to effective doses inconventional sialography (parotid, 65 mSv; subman-dibular, 156 mSv).8

Drage and Brown10 concluded that a lower concen-tration of iodine (180 or 240 mg I/mL) might have beenbetter. Jadu et al.11 believed that the lowest concentra-tion of iodine available on the market (140 mg I/mL)would possibly be acceptable for CBCT sialography.

ORAL AND MAXILLOFACIAL RADIOLOGY OOOO

e456 Shahidi and Hamedani June 2014

Adding to other researchers’ studies, in 2011 Liet al.6 reported a case of atypical Stafne bone cavity inwhich CBCT sialography showed detailed informationof the content of the cavity and could help in itsdefinitive diagnosis. They also stated the sialographictechnique could be enhanced by the combination ofsialography with CBCT, particularly with 3D imageconfigurations.6

In 2011, Varoquaux et al.12 reported (in French) aparaclinical examination aiming to find the cause of thenonlithiasic salivary gland obstructions. They studiedthe practicability and efficacy of sialography combinedwith CBCT with flat panel (CPCT). They concludedthat by using 3D CPCT sialography, gland ducts evento their fifth or sixth branches were detectable, and alsosignal- and contrast-to-noise ratio was improved.

Jadu et al.8,11,13,14 conducted a series of studies thatled to the development of a new technique for imagingthe parotid and submandibular salivary glands usingsialography combined with CBCT. In their research in2013,13 they reported the delicate secondary branchesof the ducts and the parenchyma of the salivary glandswere more detectable on CBCT images than plain filmsialography. They also concluded that regarding theimage interpretation, CBCT sialography could be betterthan conventional sialography in detecting the delicatestructures of the parotid and submandibular salivaryglands, finding sialoliths and single ductal strictures, aswell as discriminating the normal salivary glands fromglands involved with changes secondary to inflamma-tion. They believe this achievement was because of theadvantages of CBCT images over 2-dimensional plainradiographs, such as multiplanar viewing of CBCTimages, elimination of overlapping structures, and the3-dimensional nature of images.13 However, CBCTsialography images of our cases showed that 3D imagesobtained from the CBCT sialography images could notreveal the space-occupying lesion. This was differentfrom what is usually seen in filling defects (i.e., sialo-dochitis and sialectasia, where 3D images are veryefficient in diagnosis).

Jadu et al., in their statistically supported study,14

stated that if an abnormal finding was detected onCBCT images, the presence of the disease would bepersuasively indicated. On the other hand, if a stricturewas identified on CBCT images, then an obstructionshould be considered assertively. They explained thatthis finding would probably be due to the fact thatductal obstructions can have secondary causes likespace-occupying masses that may impinge and occludethe ductal structures.13 The detection of strictures onplain radiographs may have the possibility of over-estimation and can be bewildered with areas of ductbranching or bending.13 Ductal obstruction either iscaused by calculi, strictures, or fibromucinous plugs or

is secondary to mass lesions that might affect the ductalstructures and induce their occlusion. They reportedthat the most common cause of obstruction observed onboth CBCT images (46.8%) and plain radiographs(31.9%) was sialoliths.13

In their studies,13 2 cases were interpreted as space-occupying tumors. However, this study also did notpoint to the practicability of CBCT sialography as auseful technique in the diagnosis of space-occupyinglesions.

Current diagnostic imaging provides a relevant diag-nosis and also contributes to the overall management ofpatients. Future studies should grant the accurateassessment of the contribution of this diagnostic imag-ing to the patient management course. Evidence-basedstudies are required to find out whether the informationobtained from this technique will change the clinician’sdiagnostic thinking and whether this technique has anyeffect on the patient management and treatment plan.Moreover, the costs and benefits of this diagnostic im-aging technology should be evaluated.14,15

This study, presenting 3 clinical cases, confirmed thefeasibility and superiority of CBCT sialography and its3D images in the diagnosis of space-occupying lesionsof major salivary glands.

The authors thank Dr Elham Meshksar, oral and maxillofacialradiologist, for her thoughtful consultations and referrals.They also thank Dr Ehsan Bahrampour for his kind help inpreparing the images.

REFERENCES1. Burke CJ, Thomas RH, Howlett D. Imaging the major salivary

glands. Br J Oral Maxillofac Surg. 2011;49:261-269.2. Whaites E. Essentials of Dental Radiography and Radiology. 4th

ed. London, England: Churchill Livingstone; 2007.3. White SC, Pharoah MJ. Oral Radiology: Principles and Inter-

pretation. 6th ed. St Louis, MO: Mosby; 2009.4. Ludlow JB, Ivanovic M. Comparative dosimetry of dental CBCT

devices and 64-slice CT for oral and maxillofacial radiology. OralSurg Oral Med Oral Pathol Oral Radiol Endod. 2008;106:106-114.

5. Miles DA. The future of dental and maxillofacial imaging. DentClin North Am. 2008;52:917-928, viii.

6. Li B, Long X, Cheng Y, Wang S. Cone beam CT sialography ofStafne bone cavity [case reports]. Dentomaxillofac Radiol.2011;40:519-523.

7. Jager L, Menauer F, Holzknecht N, Scholz V, Grevers G,Reiser M. Sialolithiasis: MR sialography of the submandibularductdan alternative to conventional sialography and US? Radi-ology. 2000;216:665-671.

8. Jadu F, Yaffe MJ, Lam EW. A comparative study of the effectiveradiation doses from cone beam computed tomography and plainradiography for sialography. Dentomaxillofac Radiol. 2010;39:257-263.

9. Murdoch-Kinch CA. Salivary gland imaging. J Calif Dent Assoc.2011;39:649-654.

10. Drage NA, Brown JE. Cone beam computed sialography of sia-loliths. Dentomaxillofac Radiol. 2009;38:301-305.

OOOO CASE REPORT

Volume 117, Number 6 Shahidi and Hamedani e457

11. Jadu FM, Hill ML, Yaffe MJ, Lam EW. Optimization of exposureparameters for cone beam computed tomography sialography[research support, non-US-government]. Dentomaxillofac Radiol.2011;40:362-368.

12. Varoquaux A, Larribe M, Chossegros C, Cassagneau P, Salles F,Moulin G. [Cone beam 3D sialography: preliminary study][clinical trial] [in French]. Rev Stomatol Chir Maxillofac.2011;112:293-299.

13. Jadu FM, Lam EW. A comparative study of the diagnostic ca-pabilities of 2D plain radiograph and 3D cone beam CT sialog-raphy. Dentomaxillofac Radiol. 2013;42:20110319.

14. Jadu FM. Development and application of a technique forthree-dimensional sialography using cone beam computed

tomography [doctoral thesis]. Toronto, ON: University ofToronto; 2012.

15. Fryback DG, Thornbury JR. The efficacy of diagnostic imaging.Med Decis Making. 1991;11:88-94.

Reprint requests:

Shahram Hamedani, DDS, MScSchool of DentistryShiraz University of Medical SciencesGhasrodasht AvePO Box 71345-1836, ShirazIranShahram.hamedani@kclalumni.net; Denth_dr@sums.ac.ir

本文献由“学霸图书馆-文献云下载”收集自网络，仅供学习交流使用。

学霸图书馆（www.xuebalib.com）是一个“整合众多图书馆数据库资源，

提供一站式文献检索和下载服务”的24 小时在线不限IP

图书馆。

图书馆致力于便利、促进学习与科研，提供最强文献下载服务。

图书馆导航：

图书馆首页 文献云下载 图书馆入口 外文数据库大全 疑难文献辅助工具