MR sialography. Work in progress

MR sialographic assessment of the masseter muscle and the ductal kinking in patients with recurrent parotitis

Dysfunction of the masseter muscle may cause pathological kinking of the parotid duct leading to parotitis; MR sialography is a non-invasive radiological examination that allows to evaluate dynamically the ductal system of the parotid glands. In the present study we aimed to assess the relationships between Stensen's duct and masseter muscle and their implications in the aetiopathogenesis of recurrent parotitis secondary to masseter muscle dysfunction. Forty-one patients with recurrent unilateral parotitis and nine with bilateral recurrent parotitis, all with a clinical suspicious of masseter muscle hypertrophy due to bruxism were enrolled. They underwent ultrasonography as a first line examination and then MR sialography and sialendoscopy. Different anatomical features were studied. Involved parotid glands had a wider duct compared to contralateral unaffected parotid glands of patients with recurrent parotitis (p = 0.00134); male subjects with parotitis had a longer duct compared to the salivary glands of healthy patients (p = 0.00943 for affected glands and p = 0.00629 for the contralateral). A concordance between the evidence of an acute duct angle during sialendoscopy and a wider duct in patients with parotitis was observed although not statistically significant. These initial findings suggest that the masticatory muscle dysfunction related to bruxism seems to condition alteration of parotid duct course and anatomy thus favouring the occurrence of recurrent parotitis. A specific diagnostic iter based on clinical evaluation, dynamic ultrasonography and MR sialography, is therefore, mandatory to confirm the relationship between masseter muscle anatomy and parotid duct anomalies; this is the premise for an adequate therapeutic approach to underlying masticatory muscle disorder.

Gadolinium as a contrast agent for infusion sialograms in patients with iodine allergy

Objectives

To assess the adequacy of gadolinium in sialography as an alternative contrast agent for patients with iodine allergies. To directly compare images taken with gadolinium versus iodine-based contrast agents using the Iowa Sialography Classification System.

Methods

Retrospective chart review was performed on patients undergoing sialography between February 2008 and July 2022. Patients with sialograms obtained with gadolinium were identified and matched to similar sialograms obtained with iodine-based contrast agent. Patients were matched based on duct location, duct side, and initial radiology findings. Blinded reevaluation of sialograms was performed first independently and then by consensus by two head and neck radiologists to evaluate overall image adequacy and grade using the Iowa Sialography Classification System.

Results

Four patients with six sialograms (one bilateral parotid and one parotid + submandibular) obtained with gadolinium were identified and reevaluated. Five patients with six sialograms (one bilateral parotid) obtained with iodine-based were matched to the gadolinium sialograms. The overall adequacy of images for gadolinium sialograms was graded at an average of 4.25 (4 = good and 5 = excellent); whereas, the overall adequacy of iodine-based sialograms was graded at an average of 5. Inter-observer variability was observed in three sialograms obtained with gadolinium (50%), while no interobserver variability was observed in sialograms obtained with iodine-based contrast agent.

Conclusion

Gadolinium is an adequate alternative to use in sialography for patients with iodine allergies undergoing contemporary digital infusion sialography. Adverse reactions to iodine contrast agents are rare in sialography; however, the precautionary use of gadolinium is acceptable for the diagnostic and therapeutic benefits in sialography.Level of Evidence: IV.

Recommendations from the Brazilian society of rheumatology for the diagnosis of Sjögren's syndrome (Part I): glandular manifestations (systematic review)

BACKGROUND

Primary Sjögren's syndrome (pSS) is a systemic immune-mediated disease whose main characteristic is exocrine gland inflammation and, subsequent reduction in tear and saliva production. A delayed diagnosis is common due to the nonspecific clinical manifestations of disease. The aim of the present study was to develop recommendations for the diagnosis of glandular manifestations of pSS based on evidence and expert opinion. We conducted a systematic literature review to retrieve the best evidence available on the accuracy of diagnostic tests for pSS. We also held two in-person meetings with experts (rheumatologists, pathologists, ophthalmologists and dentists) to establish their level of agreement using the Delphi method. Ultimately, we generated 18 recommendations that aim to facilitate the diagnosis of the glandular manifestations of pSS.

CONCLUSION

The diagnosis of glandular manifestations of pSS is complex and multidisciplinary. It requires specific knowledge in the field of ophthalmology, immunology, pathology and imaging, making it compulsory for the rheumatologist to work with professionals from these different areas in order to improve accuracy and early diagnosis. Glandular dysfunction tests, ANA, RF, Anti-Ro, protein electrophoresis, urinalysis, blood count, C-Reactive protein, complement, testing for syphilis and viruses (HCV, HIV) and SGUS should be investigated when dryness or systemic manifestation are present. Minor salivary gland biopsy is recommended for all anti-Ro negative or incomplete criteria cases.

Unusual giant sialolith of Wharton's duct

Salivary gland calculi account for the most common disease of the salivary glands. Most of the salivary calculi are small in size. Some calculi that reach several centimeters are reported as megaliths or giant calculi in the literature. They may occur in any of the salivary gland ducts but are most common in Wharton's duct and in the submandibular gland. This report presents clinical and radiographical sign of an unusually large sialolith. A patient came with pain in the floor of mouth. There was a swelling on floor of mouth on the left side. Radiographical examination revealed large irregular radio-opaque mass superimposed on left lateral incisor to molar areas. This case report describes a patient presenting with an unusually large submandibular gland duct sialolith, the subsequent patient management, the etiology, diagnosis, and its treatment.

Magnetic resonance sialography of the parotid glands in chronic hepatitis C virus patients with and without vasculitis

AIM

Hepatitis C virus (HCV) is sialotropic. The pathogenesis of sicca manifestations in patients with chronic HCV infection is not fully understood. We aimed to detect changes in magnetic resonance sialography (MRS) of HCV patients with and without vasculitis.

METHOD

We studied 32 HCV patients (19 female, mean age 48.8 ± 10.3 years) and 20 age- and gender-matched healthy controls. Half of the patients had vasculitis. Demographic, clinical and serological data were prospectively evaluated. In patients with vasculitis, the disease activity was assessed by the Birmingham Vasculitis Activity Score (BVAS). MRS was performed on all patients and controls.

RESULTS

Abnormal MRS was found in 25% of patients, (6/16 and 2/16 in patients with and without vasculitis, respectively). Among patients with vasculitis, those with abnormal MRS had longer disease duration, higher leukocytic and lymphocytic counts and more frequent cryoglobulinemia (P < 0.01, P < 0.001, P < 0.001 and P < 0.008, respectively), while BVAS scores were not significantly different.

CONCLUSION

Among HCV patients with vasculitis, longer disease duration and cryoglobulinemia were associated with abnormal findings on MRS. To confirm our results, we propose larger-scale, multicentre studies with longer evaluation periods.

Sonography: the leading diagnostic tool for diseases of the salivary glands

Ultrasound examination is the imaging procedure with the best predictive diagnostic capability for the salivary glands. Due to the salivary glands' relatively superficial anatomical location, clear boundary from surrounding tissue and comparatively typical echogenicity, therefore sonography is ideal for diagnosis. In addition, the technical advances in recent years, including higher resolution, color Doppler sonography, contrast-enhanced ultrasound, elastography, and tissue harmonic have lead to an improvement in diagnostic accuracy of sonography further resulting in an expansion of the range of indications. Sonography allows detection of obstructive salivary gland diseases such as stenosis or sialolithiasis, as well as sialadenosis such as Sjögren syndrome. Ultrasound examination alone is sufficient to diagnose benign tumors. However, in the case of malignant tumors, computer tomography or MRI may be also required, especially to determine the question of infiltration of the skull base.

Magnetic resonance sialography findings of submandibular ducts imaging

PURPOSE

We aimed to assess the problem solving capability of magnetic resonance sialography (MR sialography), a noninvasive method for imaging submandibular gland ducts and determining duct-related pathologies, by comparing diseased and healthy cases.

MATERIALS AND METHODS

We conducted radiological assessment on a total of 60 submandibular glands (mean age 44.7) in 20 cases and 10 volunteers. MR sialography examinations were conducted with single-shot fast spin-echo sequence by using a surface coil placed on the submandibular gland. Each gland was evaluated in terms of the length, width and stricture of the main duct, as well as the difference between the intraparenchymal duct width, and the main duct width. Statistical analysis was performed.

RESULTS

In the MR sialography the primary duct mean length was determined as 51 mm (40-57 mm) in all submandibular glands. On the MR sialography imaging, the visualization ratio of the ductal system of submandibular gland was evaluated in the cases and volunteers.

CONCLUSION

MR sialography is an effective and a noninvasive method in imaging submandibular gland ducts, demonstrating the presence, location and degree of stricture/dilatation, and elucidating the disease etiology.

Giant sialoliths of submandibular gland duct: Report of two cases with unusual shape

Giant sialoliths are classified as those exceeding 15 mm in any one dimension. Although, large sialoliths have been described in the body of salivary glands, they are rarely found in the salivary ducts, particularly when the patients have no painful symptoms. Sialolithiasis is one of the most common diseases of the salivary glands in middle-aged patients and approximately 80% of all reported cases of sialoliths occur in the submandibular gland. Here, we report two cases of giant sialolith of submandibular gland duct. Interestingly, sialolith found in one of our cases had an unusual similarity with the canine tooth and mimicking it in both size and shape. In both cases the calculus was removed surgically via intraoral approach. No recurrence was seen in any of the cases on follow-up.

Modern management of juvenile recurrent parotitis

Aims:

To evaluate modern diagnostic and therapeutic management of juvenile recurrent parotitis, and to show the benefits of operative sialoendoscopy on the basis of our experience in 14 patients and the results of others.

Results:

Ultrasonography is sensitive in detecting the pathological features of juvenile recurrent parotitis. Interventional sialoendoscopy is a safe and effective method of treating the disease. In our case series, after a mean follow-up time of 30 months only 5 patients experienced recurrence of symptoms, with a mean symptom-free period of 20 months.

Conclusion:

The use of modern, minimally invasive diagnostic tools such as colour Doppler ultrasonography, magnetic resonance sialography and sialoendoscopy represents a new frontier in the management of juvenile recurrent parotitis. Operative sialoendoscopy also has the important therapeutic benefit of reducing the number of recurrences of acute episodes of parotitis, thus giving patients a better quality of life until puberty.

[Management of salivary gland diseases with contrast-enhanced ultrasound]

Obstructive diseases of the salivary glands are a common problem in otorhinolaryngology. They are mostly due to sialolithiasis followed by duct stenosis and other rarer causes. Several diagnostic modalities exist which allow classification of the disease; however, in 5-10% of all cases ultrasound and conventional radiological imaging do not provide a clear diagnosis. Ultrasound examination with contrast material injected into the duct (IA-CEUS, intraductal administered contrast-enhanced ultrasound) enables improved evaluation of obstructive diseases of the salivary glands and at the same time an evaluation of the parenchyma of the glands is possible. As a complementary method to conventional investigation techniques IA-CEUS is an economic and rapid method with low side-effects which improves the diagnostic assessment of ultrasound and results in a better treatment for patients.

MR sialography of iatrogenic sialocele: comparison with conventional sialography

OBJECTIVE

The objective of this study was to compare the conventional sialography with MR sialography in a series of patients with iatrogenic sialocele (sialocyst).

METHODS

50 salivary glands in 39 patients with suspected inflammatory disease of the salivary gland underwent conventional sialography and MR sialography. Out of these 39 patients, 6 patients (age range: 16-35 years; 4 males and 2 females; mean age: 23.8 years) had sialoceles and formed our study group. MR sialography findings were compared with conventional sialography findings regarding demonstration of ductal anatomy, the cyst and its communication with the ductal system.

RESULTS

MR sialography demonstrated the site of communication of the sialocyst with the ductal system in all six patients. MR provided additional information over conventional sialography in five cases. In four cases, the ductal system proximal to the cyst was not opacified on digital sialography but was well visualized in all cases by MR sialography. Constructive interference in steady-state (CISS) sequence demonstrated the intraglandular ducts and communication of cysts with ducts better than half-fourier acquisition single-shot turbo-spin echo (HASTE) images.

CONCLUSION

Our preliminary results suggest that MR sialography is a robust, non-invasive method for demonstrating the ductal system up to second-order branches, the site of ductal injury and the focal cystic lesion. MR provided at least the same information as conventional sialography in the evaluation of site of communication but provided additional information about the sialocyst and upstream ductal system in five cases. Being a non-invasive modality, we recommend MR sialography as the investigation of choice in the evaluation of an iatrogenic sialocyst.

Imaging the major salivary glands

Advances in imaging have led to improved sensitivity in the diagnosis of diseases that involve the major salivary glands. Ultrasound (US), plain radiography and sialography, magnetic resonance imaging (MRI), computed tomography (CT), and nuclear scintigraphy/positron emission tomography (PET) all play a part, and imaging often assists in the planning of further management, operative or otherwise. We review the methods used for imaging the major salivary glands, and apply the indications for these methods to the principal pathological processes.

Radiation-induced xerostomia: objective evaluation of salivary gland injury using MR sialography

BACKGROUND AND PURPOSE

Xerostomia (dry mouth) is one of the serious complications of head and neck irradiation and has a strong influence on a patient's activities of daily living. MR sialography with salivary secretion stimulation provides additional functional information (salivary secretion reserve) and may contribute to the evaluation of the severity of xerostomia and predict the risk of developing a radiation-induced xerostomia. This aim of the study was to analyze MR sialography as an objective tool to evaluate radiation-induced salivary injury.

MATERIALS AND METHODS

MR sialography with salivary secretion stimulation was performed in 16 patients with head and neck malignancy before and after irradiation therapy. Multivariate (stepwise multiple regression) analysis was performed to analyze the nonstimulated and stimulated MR sialography findings and the clinical severity of xerostomia.

RESULTS

Multivariate analysis of the preirradiation study revealed no significant independent variables that could predict the clinical severity of xerostomia. In the postirradiation study, following regression with 2 independent variables (secretion response of the submandibular gland [rSG] and parotid gland visualization on stimulated MR sialography [sPG]) could explain 70% of the cases: xerostomia severity grade = 0.681 + 0.871 x rSG - 0.471 x sPG.

CONCLUSIONS

MR sialography is a useful method for visualization of salivary gland radiation injury and estimation of the severity of radiation-induced xerostomia. Insufficiency of secretion reserve at the irradiated submandibular gland has the strongest influence on xerostomia severity. Our investigation suggests that careful submandibular gland protection may lead to prevention and avoidance of radiation-induced xerostomia.

Image interpretation for squamous cell carcinoma of Stensen duct

A case of squamous cell carcinoma presumed to have arisen from the right Stensen duct is reported. The patient, a 62-year-old man, was referred to our hospital with swelling in the right cheek. Magnetic resonance imaging (MRI), including contrast-enhanced MRI, and contrast-enhanced computerized tomography (CECT) enabled diagnosis of a solitary mass in the Stensen duct. Fat-suppressed T(2)-weighted imaging, in particular, demonstrated a mass-like lesion in the dilated Stensen duct and obstructive parotitis where the duct transitions into the parotid gland. Gadolinium-DTPA-enhanced T(1)-weighted imaging demonstrated the mass-like lesion surrounded by signal-hyperintense layer showing continuous transition from the thickened Stensen duct wall, which was also hyperintense. The CECT revealed peripheral annular enhancement surrounding the tumorous mass, with no enhancement of the duct wall itself, reflecting an increase in micro blood vessels in the stroma of the neoplasm. These image findings correlated well with subsequent histopathologic findings. A mass with rim enhancement and dilated Stensen duct accompanied by parotitis and no salivary calculus may suggest a differential diagnosis of malignant tumor of Stensen duct.

MR sialography: the effect of a sialogogue and ductal occlusion in volunteers

MR sialography using heavily T(2) weighted projection techniques relies upon saliva for image contrast, and the visualization of normal ducts is often limited. Methods used to increase the volume of intraductal saliva during imaging in order to improve duct visualization have not been previously evaluated. The effect of a sialogogue and passive ductal occlusion on the ability to visualize the main and intraglandular salivary gland ducts during MR sialography was investigated. Three-dimensional (3D) T(2) weighted MR sialograms were obtained from 12 healthy volunteers with and without the combined use of a sialogogue and passive ductal occlusion pad adjacent to the parotid duct orifice on one side. Two radiologists (in consensus) subjectively evaluated ductal visualization and image artefacts on the resulting blinded maximum intensity projections. The results demonstrate that main duct visualization was significantly improved (p<0.00001) by this technique, with no significant change seen in image artefacts. Although an improvement in intraglandular duct visualization was noted, this was not statistically significant (p = 0.05). Thus, the use of a sialogogue and passive ductal occlusion improves visualization of the main parotid duct in volunteers undergoing MR sialography. Further optimization and evaluation of this approach should lead to improvements in the MR sialography examination of patients.

Comparative Ultrasonographic, Magnetic Resonance Sialographic, and Videoendoscopic Assessment of Salivary Duct Disorders

Objectives:

Salivary duct disorders are the second most common cause of obstruction after calculi. Magnetic resonance sialography has been recently proposed as a means of diagnosing a heterogeneous group of salivary disorders, and so we compared it with sialoendoscopy in evaluating stenoses and sialectasia in 24 patients with obstructive symptoms and ultrasonographic results negative for calculi or masses.

Methods:

All of the patients (19 of whom had recurrent unilateral or bilateral swollen parotid glands and 5 of whom also had recurrent swollen submandibular glands) underwent dynamic color Doppler ultrasonography and dynamic magnetic resonance sialography with lemon juice stimulation of saliva; 18 patients also underwent diagnostic sialoendoscopy.

Results:

Ultrasonography and color Doppler ultrasonography showed duct dilatation in all patients (bilateral in 5 with parotid stenosis). Magnetic resonance sialography confirmed duct dilatation and stenosis in all of the patients, and revealed the simultaneous presence of calculi in 4 cases. A parotid sialocele was found in 4 cases. The magnetic resonance sialographic findings were confirmed in the patients who underwent sialoendoscopy. No side effects were observed.

Conclusions:

Magnetic resonance sialography following prediagnostic ultrasonography allows an adequate diagnosis of salivary duct disorders such as stenosis and sialectasia, as confirmed by objective sialoendoscopic assessment. Magnetic resonance sialography also makes it possible to visualize the salivary duct system up to its tertiary branches and, in this regard, may be considered a valid, noninvasive method for the evaluation of salivary duct disorders.

Giant Sialolith of the Submandibular Salivary Gland

We report the case of a 48-year-old man who had an unusually large submandibular gland sialolith (2.6 cm in greatest dimension), which led to sialadenitis and subsequent abscess formation. We describe the management of this patient and review the literature with emphasis on the various modalities available for diagnostic imaging.

Long-term evaluation of extracorporeal shock wave lithotripsy in the treatment of salivary stones

Extracorporeal shock wave lithotripsy is a rather new therapeutical method in the treatment of sialolithiasis. The objective was to evaluate retrospectively the results of the extracorporeal shock wave lithotripsy therapy performed with a Minilith SL 1 lithotripter on 167 out-patients with symptomatic stones (average size 5.94 mm) of the salivary glands over an observation period of seven years. A successful treatment with total stone disintegration was achieved in 51 (31 per cent) patients. In 92 (55 per cent) patients treatment was partially successful, with disappearance of the symptoms but a sonographically still identifiable stone. Treatment failure occurred in 24 (14 per cent) patients who then underwent surgery. The mean follow-up period was 35.6 months (minimum three, maximum 83), after which 83.2 per cent of the initially successfully treated patients were still free of symptoms.Therefore, extracorporeal shock wave lithotripsy, as a non-invasive treatment alternative with few side effects, is an efficient technique for the therapy of sialolithiasis in selected patients.

3D MR sialography protocol for postradiotherapy follow-up of the salivary duct system

PURPOSE

To develop and evaluate an MR sialography protocol that reproducibly images the parotid and submandibular ducts over time, in 3D. Such a protocol is needed in order to investigate the possible radiation-induced changes to the salivary ducts in patients receiving radiotherapy to the head-and-neck.

MATERIALS AND METHODS

MR sialography was performed on a 1.5-T MR scanner. Sequence parameters were optimized on 11 healthy volunteers. A 3D water-selective turbo spin echo (TSE) pulse sequence (TR/TE = 6000 msec/190 msec), using a two-element circular surface coil was applied twice in one MR session. In order to assess the reproducibility, the same procedure was repeated four to six months later. The quality of the MR sialograms was measured subjectively by developing a visibility scoring system and objectively by the means of contrast-to-noise ratio (CNR) of the ducts vs. fat (CNR(duct-fat)).

RESULTS

High-quality, 3D MR sialographic images were obtained. The quality of the MR sialograms and the subjective visibility score of the salivary ducts were constant over time. The CNR(duct-fat) varied between volunteers (standard deviation, SD 26%) but it was relatively constant per volunteer (SD 5%).

CONCLUSION

The MR sialography protocol presented in this study provides good quality 3D imaging of the major salivary ducts, submandibular duct, and the parotid duct and it can be used for the comparison of the salivary duct system of an individual over time.

Application of Magnetic Resonance Virtual Endoscopy as a Presurgical Procedure Before Sialoendoscopy

OBJECTIVES

The objectives of this study were to investigate the feasibility of clinical application of magnetic resonance (MR) virtual endoscopy as a presurgical procedure before sialoendoscopy and to evaluate its value in the diagnosis of obstructive salivary gland diseases and preoperative visualization of endoluminal views.

STUDY DESIGN

This study presents our initial experience to use MR virtual endoscopy for the presurgical visualization of salivary duct lumen and ductal pathologies in comparison to the sialoendoscopy findings in a feasibility study.

METHODS

Six consecutive patients with suspected obstructive salivary gland diseases underwent MR sialography with a three-dimensional fast imaging using steady-state acquisition. The three-dimensional MR data were transferred to an independent workstation and were postprocessed with navigator software to generate three-dimensional reconstruction and virtual endoscopic images. The fly-through mode was used to imitate the sialoendoscopic exploratory procedure. Then the patients underwent sialoendoscopy and the endoscopic findings were compared with the preoperative virtual endoscopic images.

RESULTS

The MR data acquisition and postprocessing protocol were feasible. The virtual endoscopy created clear endoluminal views of salivary duct and the ductal pathologies. The diagnoses were all confirmed by surgical sialoendoscopy. The virtual endoscopic images showed close resemblance to the sialoendoscopic findings.

CONCLUSIONS

MR virtual endoscopy is an effective and noninvasive diagnostic method for evaluating the endoluminal anatomy and pathologies of the salivary duct. The clinical application of MR virtual endoscopy as a presurgical procedure before sialoendoscopy is a valuable and promising approach, which can provide surgeons useful morphologic and pathologic information.

Fast and high-resolution MR sialography using a small surface coil

PURPOSE

To establish a fast and high-resolution MR sialographic technique that provides fast and high-resolution imaging.

MATERIALS AND METHODS

MR sialography was performed on a 1.5-T MR imager using a small (47-mm) surface coil. We determined appropriate sequence parameters, and then applied the technique to the salivary glands of 143 patients with xerostomia (including those with Sjögren's syndrome or hyperlipidemia) or salivary gland inflammation. We compared the high-resolution MR sialography with conventional x-ray sialography in the patients with xerostomia to evaluate the effectiveness of the MR sialography technique.

RESULTS

We found that a single-shot, single-slice MR sialography (TR/TR/number of signal acquisitions [NSA] = 8000 msec/1000 msec/6) using a small surface coil provides excellent duct images that are clinically feasible with fast (imaging time of 56 seconds) and high-resolution images. An alternative three-dimensional MR sialography technique provided better details of the branches at the expense of imaging time. The MR sialography technique using a small surface coil depicted effectively the ductal changes in the salivary glands in patients with or without Sjögren's syndrome, reflecting the severity of the diseases.

CONCLUSION

We conclude that MR sialography can be performed using a fast and high-resolution sequence.

Mucoepidermoid carcinoma of Stensen's duct: A case report and review of the literature

BACKGROUND

Mucoepidermoid carcinoma of Stensen's duct is a rare neoplasm, with only five cases reported in the literature.

METHODS

We report another case of mucoepidermoid carcinoma of Stensen's duct and review the literature.

RESULTS

Stensen's duct neoplasms tend to be symptomatic at an early stage by causing an obstruction of the parotid duct. New imaging techniques such as MR sialography and sialoendoscopy are very helpful in diagnosis and patient management.

CONCLUSIONS

Although the rarity of this condition prevents definitive conclusions about the optimal treatment, we propose that Stensen's duct neoplasms should be treated like similar neoplasms occurring in the parotid gland tissue, taking into consideration clinical stage, tumor grade, and surgical margins.

Utility of three dimension fast asymmetric spin-echo (3D-FASE) sequences in MR sialographic sequences: model and volunteer studies

OBJECTIVES

To evaluate the utility of 3D-FASE for the visualization of salivary gland ducts for use in MR sialographic sequences.

METHODS

We compared MR sialographic images and virtual endoscopic views from 3D-FASE with those from three kinds of sequences described by previous reports in a 3D parotid gland duct model and volunteer. The four sequences were two-dimension fast spin-echo (2D-FSE), three-dimension fast spin-echo (3D-FSE), two-dimension fast asymmetric spin-echo (2D-FASE), and three-dimension fast asymmetric spin-echo (3D-FASE).

RESULTS

In the 3D parotid gland duct model, image visibility on visual score was clearest with 3D-FSE, followed by 3D-FASE (P = 0.028). In the volunteers, the visualization of images improved in the following order: 3D-FASE > 3D-FSE > 2D-FSE > 2D-FASE.

CONCLUSIONS

The technique of 3D-FASE sequencing is more suitable and useful for MR sialography with an appropriate acquisition time.

MR imaging of salivary glands

Diagnostic imaging of salivary glands has been revolutionized with the advent of cross-sectional imaging modalities like CT and MR imaging. In the era before CT, imaging of the salivary glands was relatively unrewarding and was used uncommonly by ear-nose-throat surgeons. Early diagnostic tests like plain films and sialography evaluated dilated parotid ducts and calculus disease within ducts or glands. Full evaluation of salivary glands, especially deep lobes of parotid gland and masses of minor salivary glands, was not possible by these methods, however. Imaging of the parotid glands has developed significantly since that time. CT and MR imaging greatly compliment physical and endoscopic examinations (and previous favorites like sialography) by direct visualization of previously blind areas of the salivary glands and extension of the disease process in surrounding tissue planes.

MR imaging of salivary glands

In conclusion, if a parotid gland mass is bilateral, it is more likely to be Warthin's tumor, especially if it does not enhance. Less likely, it could be lymphoepithelial cyst or necrotic lymph node. A unilateral, non-enhancing mass with a high T2 signal is more likely to be a Warthin's tumor and less likely a necrotic lymph node or first branchial cleft cyst. If the mass is unilateral, shows postcontrast enhancement, has a high T2 signal, and does not invade surrounding tissue planes, it is more likely to be a pleomorphic adenoma. An intermediate to low T2 signal mass-with or without invasion of surrounding tissue planes--is more likely to be a malignant mass such as adenocystic or mucoepidermoid carcinoma. Biopsy is superior and the gold standard for diagnosis and cannot be replaced by MR imaging, however.

Virtual endoscopic view of salivary gland ducts using MR sialography data from three dimension fast asymmetric spin-echo (3D-FASE) sequences: a preliminary study

OBJECTIVES

We performed magnetic resonance (MR) sialography of parotid gland and/or submandibular gland ducts using three-dimensional fast asymmetric spin-echo (3D-FASE) sequencing. The objective was to make three-dimensional (3D) reconstruction images and virtual endoscopic views of the parotid gland ducts using MR sialography data sets of 3D-FASE sequences.

METHODS

We reviewed the MR sialography data sets with 3D-FASE sequencing of 10 control volunteers and six patients. Three-dimensional reconstruction images and virtual endoscopic views of the parotid gland and/or submandibular gland ducts were generated with maximum intensity projection (MIP), shaded surface display (SSD), and volume rendering techniques (VRT).

RESULTS

The main parotid gland and/or submandibular gland ducts, large branches within the glands, and small branches were fairly well defined in a very short acquisition time on MR sialographic images with 3D-FASE sequencing in nine of the 10 healthy volunteers. The 3D-reconstruction images of the parotid gland ducts and/or submandibular gland ducts showed the entire length of the branch paths and complete images from all angles, and the virtual endoscopic views showed the endoluminal tracts of the main ducts and the large branches in nine. In the patient with Sjogren's syndrome, chronic sialoadenitis, and salivary calculi in the Wharton ducts, the MR sialographic images showed diffuse areas of punctate high signal intensity, dilatation of Stensen's duct, or stones of Wharton's duct, respectively. Furthermore, the 3D-reconstruction images of the salivary gland ducts showed the stenoses and stones in the branch paths and complete images from all angles, and the virtual endoscopic views showed the stenoses and stones in the endoluminal tracts of the main and large branches.

CONCLUSIONS

Our initial experience showed that virtual MR endoscopy could be performed to observe the endoluminal tracts of parotid and submandibular glands. The clinical use of the virtual MR endoscopy for salivary gland ducts has not been established yet. Future applications of the 3D-reconstruction images and virtual endoscopic views using MR sialography data sets of 3D-FASE sequences are very attractive and further expansion of this field is expected.

Salivary glands and lesions: evaluation of apparent diffusion coefficients with split-echo diffusion-weighted MR imaging--initial results

The authors investigated the feasibility of performing diffusion-weighted (DW) magnetic resonance (MR) imaging with split acquisition of fast spin-echo signals (hereafter, split echo) for the assessment of salivary glands and salivary lesions. Eighteen patients without salivary disease and 10 patients with Sjögren syndrome, chronic parotitis, or focal salivary masses underwent split-echo and echo-planar DW MR imaging. DW MR images and apparent diffusion coefficient maps of the salivary gland had higher quality with split-echo rather than with echo-planar DW MR imaging.

Magnetic resonance imaging and magnetic resonance sialography of parotid glands in primary Sjogren's syndrome

OBJECTIVE

To look for structural parotid gland changes on magnetic resonance (MR) imaging and MR sialography of primary Sjögren's syndrome (SS) patients and healthy control subjects and to compare these methods with each other.

METHODS

MR imaging and MR sialography of both parotid glands were performed on 26 patients and 7 healthy controls. Bilateral surface coils were used to obtain high spatial resolution.

RESULTS

Twenty-two of the 26 patients had abnormalities on MR imaging. Twenty-one had a nodular or dendritic parenchymal pattern, 5 had cavities, and 6 had duct dilatations. On MR sialography, 25 of the 26 patients had abnormalities of the ducts, and 16 of them also had cavities. One patient and all 7 controls had normal results with both methods. The structural appearance of the parotid glands on MR images had marginal linear association with the duct system changes but no correlation with the cavitary changes seen on MR sialography. Furthermore, duct system abnormalities did not correlate with cavitary changes. Both parenchymal and sialographic abnormalities were associated with the presence of Ro/SSA antibodies but not with age of the patient, disease duration, salivary flow rate, or the presence of hypergammaglobulinemia or extraglandular manifestations.

CONCLUSION

MR imaging and MR sialography are noninvasive methods that provide definitive information of morphologic changes in parotid glands and can be used as diagnostic indicators of primary SS. Because these methods give information on different aspects of glandular pathology, both should be performed when evaluating parotid glands of SS patients. MR sialography is more sensitive, but conventional MR imaging gives complementary information on the progressive pathologic changes of glandular parenchyma.

A comparative study between MR sialography and salivary gland scintigraphy in the diagnosis of Sjögren syndrome

PURPOSE

The purpose of this work was to compare the diagnostic accuracy of MR sialography with that of salivary gland scintigraphy in Sjögren syndrome.

METHOD

One hundred thirty patients clinically suspected of having Sjögren syndrome were examined by MR sialography and salivary gland scintigraphy. A labial gland biopsy was performed in all patients. Imaging findings of MR sialography and salivary gland scintigraphy were compared with the results of labial gland biopsy.

RESULTS

From the results of labial gland biopsy, the diagnosis of Sjögren syndrome was established in 80 patients. Abnormally high T2 signal intensity areas on MR sialography and decreased uptake and delayed excretion of [(99m)Tc]pertechnetate on salivary gland scintigraphy were well seen in patients with Sjögren syndrome. For the diagnosis of Sjögren syndrome, salivary gland scintigraphy showed higher sensitivity than MR sialography. On the other hand, MR sialography showed higher specificity and positive predictive value (PPV) than salivary gland scintigraphy. Overall diagnostic accuracy was 83% for MR sialography and 72% for salivary gland scintigraphy.

CONCLUSION

The high PPV of MR sialography suggests that MR sialography is the preferred imaging modality in patients suspected of having Sjögren syndrome.

Sialolithiasis and salivary ductal stenosis: diagnostic accuracy of MR sialography with a three-dimensional extended-phase conjugate-symmetry rapid spin-echo sequence

PURPOSE

To evaluate the accuracy of magnetic resonance (MR) sialography in detecting salivary glandular calculi and ductal stenoses.

MATERIALS AND METHODS

In a prospective study, 64 salivary glands in 61 consecutive patients with acute or recurrent parotid or submandibular glandular swelling were examined by using three-dimensional (3D) extended-phase conjugate-symmetry rapid spin-echo (EXPRESS) MR imaging. Transverse and sagittal-oblique source images and maximum intensity projection images were obtained. All MR images were analyzed independently by two radiologists, without knowledge of the final diagnosis. The reference standard was conventional sialography, ultrasonography (US), and sialendoscopy with or without surgery in 31 glands and was conventional sialography and US in 33 glands.

RESULTS

Final diagnoses included sialolithiasis (n = 23), sialolithiasis and stenosis (n = 9), stenosis without lithiasis (n = 11), early Sjögren syndrome without ductal stenosis (n = 2), ductal displacement (n = 3), and normal salivary glands (n = 16). The sensitivity, specificity, and positive and negative predictive values of MR sialography to detect calculi were 91%, 94%-97%, 93%-97%, and 91%, respectively. False-negative readings occurred due to calculi with a diameter of 2-3 mm in nondilated salivary ducts. Ductal stenosis was assessed, with a sensitivity of 100%, specificity of 93%-98%, positive predictive value of 87%-95%, and negative predictive value of 100%. Interobserver agreement was very good (kappa = 0.85-0.97).

CONCLUSION

MR sialography with 3D EXPRESS imaging enables reliable prediction of salivary gland calculi and stenoses.

Sialolithiasis: MR sialography of the submandibular duct--an alternative to conventional sialography and US?

PURPOSE

To determine the value of magnetic resonance (MR) sialography for the diagnosis of sialolithiasis by comparing results prospectively with those of ultrasonography (US) and digital sialography.

MATERIALS AND METHODS

MR sialography was prospectively performed with T2-weighted three-dimensional (3D) constructive interference in steady-state (CISS) and rapid acquisition with relaxation-enhancement (RARE) sequences in 24 patients suspected of having sialolithiasis. Evoked salivation was used as contrast material. T1-weighted spin-echo and T2-weighted turbo spin-echo MR imaging also were performed. The results were then compared with those of US and digital sialography, with the latter as standard of reference.

RESULTS

The 3D CISS images were significantly (P: <.05) superior to RARE images for demonstrating the submandibular ductal system, followed by T2-weighted turbo spin-echo images (P: <.01) and T1-weighted spin-echo images (P: <.001). The sensitivity and specificity were 100% and 80%, respectively, for CISS MR sialography and 80% and 100%, respectively, for RARE MR imaging. The sensitivity and specificity of US were both 80%.

CONCLUSION

MR sialography with evoked salivation is noninvasive and allows delineation of the submandibular ductal system and detection of sialoliths with accuracy that is similar to that of digital sialography and superior to that of US.

Major salivary gland imaging

The algorithm for imaging the salivary glands depends on the clinical scenario with which the patient presents to the clinician. Because of the importance of identifying small calculi in the gland or salivary duct as the cause of the symptom complex, nonenhanced computed tomography is often the best initial study for the evaluation of the painful gland. If an infiltrative neoplasm is highly suspected, nonenhanced and enhanced magnetic resonance (MR) imaging may be superior in demonstrating perineural, meningeal, and skull base invasion. Sialography is reserved for the evaluation of chronic sialadenitides unrelated to sialolithiasis. Thin-section MR techniques for MR sialography may soon replace conventional sialography.

Prospective comparison of magnetic resonance sialography and digital subtraction sialography

We sought to compare the diagnostic utility of magnetic resonance sialography (MRS) and digital subtraction sialography (DSS) in patients with suspected sialolithiasis or sialadenitis. Sixteen consecutive patients (4 female and 12 male, mean age 51+/-16 years) with suspected sialolithiasis or sialadenitis underwent DSS by a standard technique and MRS. MRS was obtained with a T2-weighted single-shot TSE sequence (TR/TE 2800/1100 msec, acquisition time 7 seconds) using a quadrature head (n = 16) and a surface coil (n = 8). Nineteen symptomatic glands were investigated with DSS: eight submandibular glands in 6 patients (two bilateral) and unilateral parotid glands in 11 patients. MRS was always carried out to visualize gland ducts bilaterally. The ductal system was visualized in all glands examined by MRS. DSS depicted the ductal system in all 11 parotid glands, but only 4 of the 8 submandibular glands (50%). Sialolithiasis was diagnosed in three cases (one parotid, two submandibular glands) by MRS and in two cases by DSS. DSS demonstrated tertiary branching ducts and MRS secondary branching ducts. MRS is able to visualize the ductal system of the parotid and submandibular gland noninvasively and is thus not dependent on successful cannulation of the orifice of the ductal system. Our preliminary data indicate that MRS is useful for diagnosing sialolithiasis. MRS allows diagnosis of sialadenitic changes, but DSS achieves a better diagnostic performance due to higher spatial resolution.

Sialolithiasis

Sialolithiasis is one of the most common problems that afflict the salivary glands and is a major cause of salivary gland dysfunction. Sialolithiasis is frequently encountered in clinical practice. The mechanism for stone formation is incompletely understood. The clinical diagnosis and standard management of sialolithiasis are discussed, and new modalities for treatment are also presented in this article.

Magnetic resonance sialography

To evaluate a new noninvasive sialographic technique, we applied a new magnetic resonance technique to 10 healthy volunteers and 21 patients with lesions of the parotid gland. In addition to the usually performed T(1) and T(2) cross-sectional sequences, a heavily T(2)-weighted sequence (TR = 3600 msec, TE = 800 msec) was performed that allowed depiction of the fluid-filled parotid duct system. Twenty-one patients with benign as well as malignant parotid gland pathologies were examined: sialadenitis (n = 6), sicca syndrome (n = 2), pleomorphic adenoma (n = 4), carcinoma of the parotid gland (n = 2), lymphoepithelial carcinoma (n = 1), cystadenolymphoma (n = 3), non-Hodgkin's lymphoma (n = 2), and congenital duct dilatation (n = 1). Stenseńs duct was reliably depicted in all volunteers and patients. The primary branching ducts were reliably depicted in all normal cases. Intraglandular and extraglandular duct dilatations and duct strictures were well depicted in patients with chronic sialadenitis. Sialolithiasis with a calculus obstructing the duct was demonstrated in 2 cases. In conclusion, Initial experience indicates that magnetic resonance sialography can be applied successfully to investigate the duct system of the parotid gland. The usually performed cross-sectional MRI (T(1)- and T(2)-weighted images, gadolinium-DTPA) depicts the internal architecture of the parotid gland with high reliability. Magnetic resonance sialography with heavily T(2)-weighted images adds important information about the ductal system. Because it is completely noninvasive, the only contraindications are the ones generally accepted for MRI.

Unusual elimination of a salivary calculus. A case report

Salivary calculi are frequently formed in the submandibular duct. The most common sites are where the duct turns round the distal edge of the mylohyoid, where the duct crosses the lingual nerve, and just distal to the duct orifice. Untreated calculi can cause obstruction and glandular atrophy, and then may exfoliate through the floor of the mouth. An unusual case of cutaneous exfoliation of a salivary gland stone is presented. The importance of early diagnosis and treatment of sialolithiasis are discussed.

Non-invasive cholangio-pancreatography by breath-hold magnetic resonance imaging: preliminary results

AIMS

A preliminary comparison of a prototype breath-hold magnetic resonance cholangio-pancreatography (MRCP) technique for non-invasive imaging of the pancreatic and biliary ducts with endoscopic retrograde cholangio-pancreatography (ERCP).

METHOD

Twenty ERCP and MRCP examinations were performed in 19 patients referred for routine ERCP with suspected biliary or pancreatic abnormalities. The MRCP technique employed a modified heavily T2-weighted thick slice RARE sequence that allowed up to three images to be obtained in a 16 second breath-hold. The examinations were reported independently and the findings compared.

RESULTS

MRCP accurately discriminated between patients without obstruction (n = 12) and those with (n = 8) and correctly diagnosed the cause of obstruction (three choledocholithiasis, five malignant stricture). In the 12 patients without obstruction the examinations were concordant in eight. In the remaining four patients MRCP provided more information than the corresponding ERCP study, diagnosing a pseudocyst in one patient and visualizing the entire pancreatic duct in three patients in whom this was not possible at ERCP.

CONCLUSIONS

These preliminary results suggest that a breath-hold MRCP technique may allow the selection of those patients with obstructive lesions that require therapeutic ERCP intervention, and may have the potential to reduce the need for diagnostic ERCP examinations.