Clinical ultrasound of the salivary glands

Proposal for standardized ultrasound analysis of the salivary glands: Part 1 submandibular gland

Objectives

The Salivary Gland Committee of the American Academy of Otolaryngology-Head and Neck Surgery seeks to standardize terminology and technique for ultrasonograpy used in the evaluation and treatment of salivary gland disorders.

Methods

Development of expert opinion obtained through interaction with international practitioners representing multiple specialties. This committee work includes a comprehensive literature review with presentation of case examples to propose a standardized protocol for the language used in ultrasound salivary gland assessment.

Results

A multiple segment proposal is initiated with this focus on the submandibular gland. We provide a concise rationale for recommended descriptive language highlighted by a more extensive supplement that includes an extensive literature review with additional case examples.

Conclusion

Recommendations are provided to improve consistency both in performing and reporting submandibular gland ultrasound.

A Novel Prediction Model Based on Quantitative Texture Analysis of Sonographic Images for Malignant Major Salivary Glandular Tumors

Background

The aim of this study was to compare multiple objective ultrasound (US) texture features and develop an objective predictive model for predicting malignant major salivary glandular tumors.

Methods

From August 2007 to May 2018, 144 adult patients who had major salivary gland tumors and subsequently underwent surgery were recruited for this study. Representative brightness mode US pictures were selected for texture analysis and used to develop a prediction model.

Results

We found that the grayscale intensity and standard deviation of the intensity were significantly different between malignant and pleomorphic adenomas. The contrast, inverse difference (INV) movement, entropy, dissimilarity, and INV also differed significantly between benign and malignant tumors. We used stepwise selection of predictors to develop an objective predictive model, as follows: Score = 1.138 × Age - 1.814 × Intensity + 1.416 × Entropy + 1.714 × Contrast. With an optimal cutoff of 0.58, the diagnostic performance of this model had a sensitivity, specificity, overall accuracy, and area under the curve of 83% (95% confidence interval [CI]: 74%-92%), 74% (65%-84%), 78% (72%-85%), and 0.86 (0.80-0.92), respectively.

Conclusion

We have developed a novel computerized diagnostic model based on objective US features to predict malignant major salivary gland tumor. Further improving the computer-aided diagnosis model might change the US examination for major salivary gland tumors in the future.

Assessment of Dimensional Changes in Submandibular Glands in Head-Neck Radiotherapy Patients by Ultrasonography

OBJECTIVES

The present study investigated the dimensional changes in the submandibular glands following radiotherapy using ultrasonography.

METHODS

Twenty-three patients planned to receive head-neck radiotherapy were included in this study. The anteroposterior, superoinferior, mediolateral length, and volumes of 46 submandibular glands were measured by ultrasonography at 3 different time periods (before radiotherapy and in the second and sixth months after the radiotherapy onset) and evaluated in terms of dimensional changes and the effect of the radiation dose on these changes. The data were statistically analyzed using repeated measures analysis of variance (ANOVA) and 2-factor repeated measures ANOVA.

RESULTS

Before radiotherapy and in the second and sixth months after the radiotherapy onset, mean anteroposterior length of the submandibular glands was 32.39 ± 4.55, 30.38 ± 4.80, and 31.50 ± 3.68 mm, respectively; mean superoinferior length was 9.96 ± 1.54, 8.76 ± 1.26, and 9.08 ± 1.01 mm, respectively; mean mediolateral length was 24.66 ± 3.77, 22.03 ± 3.73, and 21.76 ± 4.01 mm, respectively; and mean volume was 4.21 ± 1.01, 3.08 ± 0.77, and 3.32 ± 0.63 cm³ , respectively. Moreover, there were significant differences in the anteroposterior (P < .01), superoinferior (P < .001), and mediolateral lengths (P < .001), as well as the volumes (P < .001) of the submandibular glands measured at the 3 different time periods.

CONCLUSION

In the second and sixth months after the radiotherapy onset, the sizes of the submandibular glands were markedly reduced, but it partially recovered to normal as more time elapsed after radiotherapy.

Imaging of Major Salivary Gland Lesions and Disease

Infectious and inflammatory disorders are the commonest pathologies to affect the major salivary glands however frequently overlap in clinical presentation. Imaging plays an important role in diagnosis, usually initially performed by CT or ultrasound. MRI, with its superior soft-tissue characterization compared with CT, provides a better evaluation of tumors and tumor-like conditions. Imaging features may suggest that a mass is more likely to be benign versus malignant, however, biopsy is often needed to establish a definitive histopathologic diagnosis. Imaging plays a key role in the staging of neoplastic disease.

Clinical Diagnostic Application of Contrast-Enhanced Ultrasound in Focal Lesions of the Salivary Glands

OBJECTIVES

To evaluate the clinical diagnostic value of contrast-enhanced ultrasound (CEUS) for focal benign and malignant lesions of the salivary glands, as well as for common benign lesions.

METHODS

A total of 91 patients with focal lesions of the salivary glands were included in this study. In this study, CEUS was used to study the differential diagnosis of focal benign and malignant lesions of the salivary gland and the most common benign tumors, that is, pleomorphic adenoma (PA) and adenolymphoma.

RESULTS

The differences between focal benign and malignant lesions in the salivary glands were statistically significant (P < .05) in terms of qualitative CEUS indicators, enhancement pattern, enhancement homogeneity, enhancement margin, and enhanced lesion size, whereas the differences were not statistically significant (P > .05) in terms of wash-in and wash-out pattern, enhancement degree. Blurred margins and increased size of the lesion after enhancement are two CEUS features independently associated with focal malignant lesions of the salivary gland. The differences between salivary gland PA and adenolymphoma were statistically significant (P < .05) in terms of wash-in pattern, enhancement degree, enhancement homogeneity, and enhancement pattern, but not in terms of wash-out pattern, enhancement margin, and enhanced lesion size (P > .05).

CONCLUSIONS

As an economical, convenient, and safe imaging method, CEUS has important clinical value in distinguishing benign and malignant salivary glands.

Simultaneous Application of Ultrasound and Sialendoscopy and its Value in the Management of Sialolithiasis

OBJECTIVE

Ultrasound (US) and sialendoscopy (SE) are routinely used in patients presenting with sialolithiasis in the submandibular (SMG) and parotid gland (PG). The objective was to assess the value of the simultaneous application of US and SE in the management of sialolithiasis.

STUDY DESIGN

Retrospective study.

SETTING

Tertiary referral center for salivary gland diseases.

PARTICIPANTS

Patients in whom US and SE as single investigation tools were neither conclusive nor useful in the management of sialolithiasis were investigated using both methods simultaneously (simUS + SE).

MAIN OUTCOME MEASURES

Establishment of the final diagnosis and/or contribution to the planning/performing of treatment in sialolithiasis.

RESULTS

74 patients were examined by simUS + SE (58.1 % SMG and 41.9 % PG). In all patients (unclear) hyperechoic reflexes were assessed and/or localized by SE-controlled US navigation. 68.9 % of the patients were investigated for diagnostic or differential-diagnostic reasons including distinguishing extraductal from intraductal calcifications and/or to exclude residual stones after therapy. In 52.7 % simUS + SE was used to plan and/or perform further treatment, in 20.3 % to enable performing a combined approach (all PG) and in 29.7 % to evaluate and plan the most adequate therapy (mainly intraductal vs. extracorporeal shock wave lithotripsy, 68.2 % of these SMG). In two cases SE-controlled and US-guided stone extraction was performed.

CONCLUSION

SimUS + SE is an innovative approach which proved to be very useful in managing sialolithiasis. It added valuable information regarding the establishment of a diagnosis or differential diagnosis, planning and performing the most adequate treatment, intraoperative control of therapy and postoperative follow-up.

The applicability of ultrasound in the diagnosis of inflammatory and obstructive diseases of the major salivary glands: a scoping review

OBJECTIVES

The purpose of the present scoping review was to determine the contribution of ultrasound images in the diagnosis of inflammatory and obstructive diseases of the major salivary glands (MSGs).

METHODS

A search of studies of ultrasonographic assessments of human samples was performed in several electronic databases and grey literature up to July 2021. The extracted data were the examined MSG; the diagnostic value of ultrasound (sensibility, specificity, positive- and negative predictive value, accuracy); features of lesions, including number, echogenicity, echotexture, form, margins, size, posterior acoustic aspect, and location; and related clinical information, such as swelling, palpation, sensible to pain, salivation, lymph nodes, recurrence, duration, and causes.

RESULTS

After verifying the eligibility criteria, 90 articles focused on detecting inflammatory, and obstructive diseases of the MSG were gathered, with variable study designs and size samples. A wide variety of pathologies were assessed, including sialolitiasis (n = 45), acute sialadenitis (n = 30), chronic sialadenitis (n = 25), granulamatous diseases (n = 15), Kuttner's tumor (n = 11), juvenile recurrent parotitis (n = 9), abscess (n = 7), post-radiotherapy sialadenitis (n = 6), sialadenosis (n = 9), abscess (n = 7), IgG4-related disease sialadenitis (n = 5), HIV-sialadenitis (n = 4), obstructive sialadenitis (n = 3), iodinated contrast-induced sialadenitis (n = 2), and pneumoparotitis (n = 1). Most studies were case reports or series of cases. Few studies exhibited data about the accuracy of ultrasound in detecting MSG diseases.

CONCLUSIONS

The present scoping review concluded that ultrasound aspects of different MSG pathologies are similar but contribute to their differential diagnosis and can be considered as a valuable initial method for assessing the MSG of adults and children.

Contralateral sialadenitis after resection of a right cerebellar metastasis: illustrative case

BACKGROUND

Acute postoperative sialadenitis is a rare and potentially morbid complication of cranial neurosurgery. This rapidly progressive, unilateral neck swelling often presents within hours of extubation. Diagnosis is made by imaging and exclusion of other causes of etiologies, such as neck hematoma, sialolithiasis, and dependent soft tissue edema.

OBSERVATIONS

The authors presented a case of acute postoperative sialadenitis after suboccipital resection of a right cerebellar metastasis. Shortly after extubation, extensive left-sided neck swelling was apparent in the postanesthesia care unit. No central lines were placed during the procedure. Imaging revealed submandibular gland edema and fluid accumulation in the surrounding tissue. The patient was managed conservatively with steroids, antibiotics, and warm compresses, with complete resolution of symptoms 2 weeks after the procedure.

LESSONS

This case emphasizes the broad differential of acute neck swelling after cranial surgery. Physical examination of the neck and airway protection should guide initial treatment. If a patient is stable, bedside ultrasound and computed tomography can be helpful with the differential diagnosis. Here the authors proposed an algorithm for diagnosis and treatment of acute neck swelling after cranial surgery.

Ultrasound in Inflammatory and Obstructive Salivary Gland Diseases: Own Experiences and a Review of the Literature

Background: Ultrasound is established as a diagnostic tool in salivary glands for obstructive diseases such as sialolithiasis and tumors. Concerning inflammatory diseases and in non-sialolithiasis-caused obstruction, much fewer data are available. In recent years, technical development has allowed a better assessment of the gland parenchyma, and knowledge about intraductal pathologies has increased considerably, which has provided new insights and a new interpretation of ultrasound findings. Objectives: To provide a comprehensive review of the literature that includes our own experiences and to point out the state of the art in ultrasound in the diagnostics of inflammatory and obstructive salivary gland diseases, taking adequate techniques and recent technical developments into consideration. Data sources and study eligibility criteria: A systematic literature search was performed in Pubmed using various specific key words. Results: According to the literature results, including our own experiences, ultrasound is of value in up to >90% of cases presenting with inflammatory and/or obstructive diseases. Technical developments (e.g., elastography) and the application of modified ultrasound techniques (e.g., transoral ultrasound) have contributed to these results. Today, ultrasound is considered a first-line diagnostic tool in these diseases. However, in some inflammatory diseases, the final diagnosis can be made only after inclusion of the anamnesis, clinical symptoms, serologic blood tests, or histopathologic investigation. Conclusions: Ultrasound can be considered as a first-line diagnostic tool in obstructive and inflammatory salivary gland diseases. In obstructive diseases, it may be sufficient for diagnostics in >90% of cases. In inflammatory diseases, ultrasound is at least an excellent screening method and can be used to establish the diagnosis in cases of an early suspicion. In all diseases ultrasound can contribute to better management and can be used for monitoring during follow-up.

Narrative review of multiparametric ultrasound in parotid gland evaluation

Disorders affecting parotid gland represent a heterogeneous group comprising congenital, inflammatory and neoplastic diseases which show a focal or diffuse pattern of appearance. The differentiation of neoplastic from non-neoplastic conditions of parotid glands is pivotal for the diagnostic imaging. Frequently there is evidence of overlapping between the clinical and the imaging appearance of the various pathologies. The parotid gland is also often object of study with the combination of different techniques [ultrasound-computed tomography-magnetic resonance imaging (US-CT-MRI), ex.]. Compared to other dominant methods of medical imaging, US has several advantages providing images in real-time at lower cost, and without harmful use of ionizing radiation and of contrast enhancement. B-mode US, and the microvascular pattern color Doppler are usually used as first step evaluation of parotid lesions. Elastography and contrast-enhanced US (CEUS) has opened further possible perspectives to improve the differentiation between benign and malignant parotid lesions. The characterization of the parotid tumors plays a crucial role for their treatment planning and for the prediction of possible surgical complications. We present, here an updated review of the most recurrent pathologies of parotid gland focusing on the diagnostic power of multiparametric US including CEUS and ultrasound elastography (USE); limitations, advantages and the main key-points will be presented.

Parotid gland atrophy after conservative treatment of a post-traumatic parotid fistula in a two-year-old boy

A parotid fistula is a rare complication following parotid gland and duct injury. A two-year-old boy with a previous parotid fistula after parotid injury due to a dog bite was successfully treated with pressure-dressing therapy, which is generally non-invasive and tolerable by young children. During follow-up, ultrasonography revealed atrophy of the parotid gland. This finding is consistent with the healing mechanism previously assumed in adult patients with a parotid fistula. Consideration should be paid to the possibility of oral environmental changes associated with reduced saliva secretion from parotid gland atrophy after conservative treatment of parotid fistula.

Ultrasonographic echogenicity of normal salivary glands in adults: comparison of submandibular and parotid glands

Purpose

The normal submandibular gland (SMG) and parotid gland (PG) are thought to have similar homogeneous ultrasound (US) hyperechogenicity; however, this has not been extensively investigated. The aim of this study was to determine whether the normal SMG and PG have similar US echogenicity.

Methods

We included 969 consecutive adult patients with normal salivary glands. The patients were categorized into three age groups: group 1 (19 to 29 years, n=27), group 2 (30 to 49 years, n=273), and group 3 (≥50 years, n=669). The echogenicities of the SMG and PG were prospectively evaluated by an experienced radiologist. Computed tomography (CT) attenuation in Hounsfield units (HUs) was quantitatively measured for the SMG, PG, and sternocleidomastoid muscle in 140 patients.

Results

Relative to the PG, the echogenicity of the SMG was similar in 706 (73.0%) and homogeneously hypoechoic in 263 patients (27.0%). The frequency of SMG hypoechogenicity decreased with increasing age (group 1, 59.3%; group 2, 36.3%; group 3, 22.1%; P<0.001). The CT attenuation levels (in HUs) of the SMG and PG were significantly higher in patients with hypoechoic SMGs than in patients with SMG echogenicity similar to that of the PG (P<0.001).

Conclusion

Hypoechogenicity of the SMG was observed in more than a quarter of this sample of adults with normal salivary glands. The SMG may be inadequate as a reference standard for evaluating thyroid nodule echogenicity in patients with diffuse thyroid disease with decreased echogenicity.

Salivary gland disease in the era of COVID-19 pandemic

Coronavirus disease 2019 (COVID‐19) pandemic forced significant changes in current approach to outpatient evaluation of common otolaryngology complaints as hospitals around the world are trying to limit the spread of the virus and to preserve health care resources. These changes raise a lot of questions regarding patient triage and treatment decisions in clinical situations when it is unclear if the workup and management can be postponed. In this communication, we present our approach to evaluation and triage of new patients with complaints concerning for salivary gland disease.

Parotitis on Ultrasound: The Pomegranate Sign

The differential diagnosis for facial swelling is broad and can be a diagnostic challenge in the pediatric emergency department. We describe the first pediatric case of acute parotitis with sialolithiasis where the diagnosis was facilitated by point-of-care ultrasound.

Salivary Gland Disorders in Children and Adolescents: A 15-year Experience

Introduction  Diseases of the salivary glands are rare in children and adolescents, with the exception of viral-induced infections.

Objective  To determine the clinical course of the disease, the diagnostic procedures, the treatment and the outcome of all children and adolescents affected with salivary gland diseases at our clinic over a period of 15 years.

Methods  A retrospective chart review including a long-term follow-up was conducted among 146 children and adolescents treated for salivary gland disorders from 2002 to 2016.

Results  Diagnosing acute sialadenitis was easily managed by all doctors regardless of their specialty. The diagnosis of sialolithiasis was rapidly made only by otorhinolaryngologists, whereas diagnosing juvenile recurrent parotitis imposed difficulties to doctors of all specialties – resulting in a significant delay between the first occurrence of symptoms and the correct diagnosis. The severity-adjusted treatment yielded improvements in all cases, and a full recovery of 75% of the cases of sialolithiasis, 73% of the cases of juvenile recurrent parotitis, and 100% of the cases of acute sialadenitis.

Conclusions  Due to their low prevalence and the lack of pathognomonic symptoms, salivary gland diseases in children and adolescents are often misdiagnosed, resulting in an unnecessarily long period of suffering despite a favorable outcome following the correct treatment.

Submandibular sialolithiasis: A series of three case reports with review of literature

One of the most common disorders of the salivary glands is sialolithiasis. A history of pain or/and swelling in the salivary glands, especially during meal suggests this diagnosis. For small and accessible stones conservative therapies like milking of ducts with palliative therapy can produce satisfactory results. Surgical management should be considered when the stone/stones are inaccessible or large in size as conservative therapies turned out to be unsatisfactory. In this paper, we present three cases of sialolithiasis in the submandibular gland along with a review of existing literature. The purpose of this paper is to add three more cases to the literature and review the theories of etiology, clinical features, available diagnostic and treatment procedures.

Applications of 3-Dimensional Ultrasonography in the Neck, Excluding the Thyroid

Ultrasonography (US) of the neck is an accepted, useful imaging modality for many applications beyond its usefulness in thyroid disease. Two-dimensional US has been effectively used for evaluation of many types of neck conditions, and now, 3-dimensional US can be added to the imaging armamentaria. Three-dimensional US is useful in the evaluation of cervical lymph nodes, recurrent/residual thyroid neoplasia, parathyroid glands, parotid and submandibular glands, as well as thyroglossal duct cysts and other assorted palpable and visible abnormalities because of its unique capabilities, including multiplanar reconstruction, accessibility of the coronal view, volume calculation, and regularly spaced incremental slice evaluation.

Evaluation of parotid glands in healthy children and adolescents using shear wave elastography and superb microvascular imaging

OBJECTIVES

We aim to determine parotid gland elasticity values from healthy children and adolescents using shear wave elastography (SWE). We also define the degree of vascularity using superb microvascular imaging (SMI), power Doppler (PD), and color Doppler (CD) and compare SMI with CD and PD.

MATERIALS AND METHODS

A total of 100 cases, comprising 50 girls and 50 boys, with ages ranging from 3 to 17 years were included in this prospective study. SWE, SMI, PD, and CD measurements were taken from both parotid glands, and the relationships with sex, age, and body mass index (BMI) were determined. The SMI was compared with the PD and CD.

RESULTS

The median elasticity values measured with SWE were 8.37 ± 2.09 kPa and 1.68 ± 0.26 m/s on the right and 8.33 ± 2.04 kPa and 1.69 ± 0.26 m/s on the left. There were significant positive correlations present for those aged below and above 10 years and for BMI with elasticity values. The median vascular spot numbers measured using SMI, PD, and CD were 5 ± 1.70, 3.5 ± 1.45, and 2 ± 1.1 on the right and 4 ± 1.7, 4 ± 1.43, and 2 ± 1.05 on the left, respectively. The median values obtained with SMI were significantly higher than the median values obtained with both PD and CD.

CONCLUSION

This study determined the reference SWE, SMI, PD, and CD values for normal parotid glands in healthy children and adolescents. Elasticity values were affected by age and BMI. There was no correlation between vascularity values and age, sex, or BMI. SMI provided more detailed information about vascularity compared with the other methods.

The value of the twinkling artefact for the diagnosis of sialolithiasis of the large salivary glands

Objective:

The imaging of stones in the salivary glands and ducts poses a challenge, even to experienced ultrasound examiners. This study investigated whether the ‘twinkling artefact’, which occurs at internal calcific foci during Doppler ultrasound examinations, is useful for detecting salivary gland stones.

Methods:

In a model test, 20 salivary stones were analysedin vitro, via Doppler ultrasound, with regard to their representability and the triggering of the twinkling artefact. In a follow-up study, 28 patients with sialolithiasis and food-related large salivary gland swellings were examined, using both power and colour Doppler modes, with regard to the twinkling artefact. All ultrasound examinations were performed by an experienced examiner and retrospectively graded by two experienced sonographers.

Results:

All stones could reliably be detected using the twinkling artefact in the model test. Twenty-seven of 28 salivary stones (96 per cent) also showed twinklingin vivo, during patient assessment. The power Doppler mode showed a significantly higher intensity level of twinkling than the colour Doppler mode (p< 0.0001).

Conclusion:

The twinkling artefact is a very reliable sign for the diagnosis of sialolithiasis. Power Doppler is superior to colour Doppler for detection of the twinkling artefact.

Surgeon-Performed Ultrasound for Chronic Obstructive Sialadenitis Helps Predict Sialendoscopic Findings and Outcomes

Objective

To determine the accuracy of surgeon-performed ultrasound (SP-US) features for predicting intraoperative sialendoscopic findings and to correlate ultrasound features with short-term symptomatic outcomes following sialendoscopy-assisted salivary duct surgery (SASDS).

Study Design

Case series with chart review.

Setting

The practices of 2 academic sialendoscopy surgeons.

Subjects and Methods

Between February 2014 and September 2015, 82 patients with 105 symptomatic glands underwent SASDS, of whom 56 patients (75 glands) met inclusion criteria. SP-US and sialendoscopic findings were reviewed for patients with chronic obstructive sialadenitis who underwent SASDS and who had been prospectively evaluated with the University of California–San Francisco Chronic Obstructive Sialadenitis Symptoms (COSS) questionnaire (scored 0-100) administered preoperatively and 3 months postoperatively.

Results

The positive predictive value (PPV) and negative predictive value (NPV) of SP-US for identifying sialoliths intraoperatively were 94% (33/35) and 91% (39/43), respectively. Of glands with sialoliths on SP-US, 97% (34/35) had complete symptom resolution (COSS ≤10) after SASDS. The PPV and NPV of salivary duct dilation on SP-US for finding a corresponding stenosis on sialendoscopy were 93% (14/15) and 50% (14/28), respectively. Nonsialolith SP-US features with the highest PPV for complete or partial symptom resolution (COSS ≤25) following SASDS included distal duct dilation of all glands (86%; 6/7) and dilation of both distal and proximal parotid ducts (75%; 6/8).

Conclusion

SP-US has high accuracy for ruling in and ruling out sialoliths, as well as for ruling in but not for necessarily ruling out stenosis presence and location. Ultrasound is helpful in estimating degree of short-term symptom response following SASDS.

Standards for the assessment of salivary glands - an update

The paper is an update of 2011 Standards for Ultrasound Assessment of Salivary Glands, which were developed by the Polish Ultrasound Society. We have described current ultrasound technical requirements, assessment and measurement techniques as well as guidelines for ultrasound description. We have also discussed an ultrasound image of normal salivary glands as well as the most important pathologies, such as inflammation, sialosis, collagenosis, injuries and proliferative processes, with particular emphasis on lesions indicating high risk of malignancy. In acute bacterial inflammation, the salivary glands appear as hypoechoic, enlarged or normal-sized, with increased parenchymal flow. The echogenicity is significantly increased in viral infections. Degenerative lesions may be seen in chronic inflammations. Hyperechoic deposits with acoustic shadowing can be visualized in lithiasis. Parenchymal fibrosis is a dominant feature of sialosis. Sjögren syndrome produces different pictures of salivary gland parenchymal lesions at different stages of the disease. Pleomorphic adenomas are usually hypoechoic, well-defined and polycyclic in most cases. Warthin tumor usually presents as a hypoechoic, oval-shaped lesion with anechoic cystic spaces. Malignancies are characterized by blurred outlines, irregular shape, usually heterogeneous echogenicity and pathological neovascularization. The accompanying metastatic lesions are another indicator of malignancy, however, final diagnosis should be based on biopsy findings.

Cancers of major salivary glands

Major salivary gland malignancies are a rare but histologically diverse group of entities. Establishing the diagnosis of a malignant salivary neoplasm may be challenging because of the often minimally symptomatic nature of the disease, and limitations of imaging modalities and cytology. Treatment is centered on surgical therapy and adjuvant radiation in selected scenarios. Systemic therapy with chemotherapeutic agents and monoclonal antibodies lacks evidence in support of its routine use.

Ultrasonic Nakagami-parameter characterization of parotid-gland injury following head-and-neck radiotherapy: a feasibility study of late toxicity

PURPOSE

The study aims to investigate whether Nakagami parameters--estimated from the statistical distribution of the backscattered ultrasound radio-frequency (RF) signals--could provide a means for quantitative characterization of parotid-gland injury resulting from head-and-neck radiotherapy.

METHODS

A preliminary clinical study was conducted with 12 postradiotherapy patients and 12 healthy volunteers. Each participant underwent one ultrasound study in which ultrasound scans were performed in the longitudinal, i.e., vertical orientation on the bilateral parotids. For the 12 patients, the mean radiation dose to the parotid glands was 37.7 ± 9.5 Gy, and the mean follow-up time was 16.3 ± 4.8 months. All enrolled patients experienced grade 1 or 2 late salivary-gland toxicity (RTOG/EORTC morbidity scale). The normal parotid glands served as the control group. The Nakagami-scaling and Nakagami-shape parameters were computed from the RF data to quantify radiation-induced parotid-gland changes.

RESULTS

Significant differences in Nakagami parameters were observed between the normal and postradiotherapy parotid glands. Compared with the control group, the Nakagami-scaling parameter of the postradiotherapy group decreased by 25.8% (p < 0.001), and the Nakagami-shape parameter decreased by 31.3% (p < 0.001). The area under the receiver operating characteristic curve was 0.85 for the Nakagami-scaling parameter and was 0.95 for the Nakagami-shape parameter, which further demonstrated the diagnostic efficiency of the Nakagami parameters.

CONCLUSIONS

Nakagami parameters could be used to quantitatively measure parotid-gland injury following head-and-neck radiotherapy. Moreover, the clinical feasibility was demonstrated and this study provides meaningful preliminary data for future clinical investigation.

Shear wave elastography: a new noninvasive tool to assess the intensity of fibrosis of irradiated salivary glands in head and neck cancer patients

The aim of the study was to assess salivary gland parenchyma by means of sonoelastography in patients irradiated for head and neck squamous cell carcinoma (HNSCC). The studied group consisted of 52 patients after radiotherapy (RT) and 54 healthy volunteers. All of the former were treated for advanced larynx (40), oropharynx (9), or maxilla (3) squamous cancers and suffered from chronic dryness. Ultrasonography (US) and elastography (ES) were performed, as well as an assessment of the amount of saliva and Common Terminology Criteria for Adverse Events (CTCAE) scale. There was a statistical difference between ES values in the RT group and in the controls for parotid glands (41.7 kPa versus 26.03 kPa, P = 0.0018) and for submandibular glands (37.6 kPa versus 22.4 kPa; P = 0.005). There was a significant correlation between the CTCAE scores and objective saliva amount (P = 0.0005), and the median amount of saliva in the examined group was lower than in the reference group (1.86 g versus 2.75 g, P = 0.0006). In conclusion sonoelastography adds a new parameter to ultrasonography in “one touch examination” and may be a useful tool for major salivary gland evaluation during the radiotherapy course and follow-up period.

Sonopalpation

Objective

To study the sensitivity and specificity of physical examination, ultrasound (US) alone, and sonopalpation (concurrent US and transoral palpation) for identification of submandibular gland (SMG) calculi.

Study Design

Case series with prospective data collection.

Setting

Tertiary-level academic center.

Subject and Methods

Patients with suspected SMG swelling were examined by physical examination, US alone, and sonopalpation. The presence or absence and location of sialolithiasis was noted in each group. Sialendoscopy, open sialolithotomy, or sialadenectomy was performed as the gold standard for definitive diagnosis. Sensitivity and specificity for each technique was then determined.

Results

Sixty-nine patients were identified with SMG swelling. Physical examination, US, and sonopalpation positively identified sialoliths in 49, 54, and 57 patients, respectively. Fifty-nine patients eventually demonstrated calculi. Sensitivity of physical examination, US alone, and sonopalpation for SMG calculi was 83%, 91%, and 96.6%, respectively. Specificity for physical examination was 60%, 80% for US alone, and 90% for sonopalpation. Of 59 patients with stones, 17 patients underwent purely endoscopic procedures, 36 patients underwent combined or purely transoral approaches, and 6 underwent sialadenectomy. Of the 3 modalities, only sonopalpation was able to both identify and localize pathology and guide treatment management.

Conclusion

US is effective in the diagnosis and management of SMG stones during sialendoscopy or sialolithotomy. Sonopalpation has increased sensitivity and specificity over US alone or physical examination not only for the detection of SMG calculi but also for localization of pathology in the ductal system.

Ultrasound-guided botulinum toxin injections in neurology: technique, indications and future perspectives

Botulinum toxin (BT) therapy is used in neurology to treat muscle hyperactivity disorders including dystonia, spasticity, cerebral palsy, hemifacial spasms and re-innervation synkinesias as well as exocrine gland hyperactivity disorders. To increase its therapeutic effect and to decrease adverse effects in adjacent tissues, exact BT placement is important. Ultrasonography (US) allows non-invasive, real-time imaging of muscular and glandular tissues and their surrounding structures. It can visualize, guide, and standardize the entire procedure of BT application. Small randomized studies suggest that US-guidance can improve therapeutic efficacy and reduce adverse effects of BT therapy when compared to conventional placement. US-guidance should be used in forearm muscles when functionality is important, and in selected leg muscles. It may be used for targeting distinct neck muscles in cervical dystonia. It is helpful for targeting the salivary glands. Here we review the technique, indications and future developments of US-guidance for BT injection in neurological disorders.

Role of ultrasonography in oral and maxillofacial surgery: a review of literature

Maxillofacial surgery, like any other surgical specialty is greatly dependent on the discipline of radiology. This poses a greater challenge because of the complex anatomy of this region. Various investigation modalities have been applied in diagnosing various diseases which are found in the maxillofacial region, including IOPA, PET, USG, CT, MRI and panoramic radiographs. Of these, USG can easily diagnose non invasive and soft tissue diseases. It is very useful in diagnosing the diseases which are not usually evident on a conventional radiograph. However; many of the dentists are not aware of the benefits of USG in diagnosis of oral diseases. In this article, the use of ultrasound in diagnosing the various pathologies of maxillofacial region is elaborated.

Objective and subjective outcome in 42 patients after treatment of sialolithiasis by transoral incision of Warthon's duct: a retrospective middle-term follow-up study

In this retrospective follow-up study, we present the middle-term results of transoral removal of submandibular calculi by incision in the floor of the mouth together with a patient satisfaction survey. These results will be compared with those of international studies. This is an individual retrospective cohort follow-up study. Forty-two patients had salivary calculi removed by incision in the mouth in the period from August 2009 to July 2012 at the Ear-nose-throat department of the North Zealand Hospital, Hillerød, Denmark. A retrospective study was carried out, focusing on the effects of the surgery and on patient satisfaction. The patients completed a questionnaire and underwent an objective physical exam. We found a high success rate (93 %), high patient satisfaction (94 %) and a high number of patients with no symptoms (92 %). In 94 % of the patients the gland was preserved, and there were no infections. One patient (3 %) suffered from damage to the lingual nerve, and 6 % (n = 2) claimed to suffer from continuous tingling of the tongue. Based on the present study and previous studies on transoral removal of calculi by incision in the floor of the mouth, we find this procedure effective, brief and safe for removal of large, immobile calculi from the hilum of the submandibular gland to the papilla.

Interventional sialendoscopy with endoscopic sialolith removal without fragmentation

We performed a retrospective analysis to review the results and complications of sialendoscopy and to identify the overall success rate of mechanical stone retrieval without fragmentation in our patients with sialolithiasis. Between 2009 and 2011, 33 patients with sialolithiasis underwent interventional sialendoscopy. Patients with sialoliths larger than 7 mm in the Wharton's duct and 5 mm in the Stensen's duct or intraparenchymal stones were not included in this study. Grasping forceps, wire baskets and graspers was used for stone removal. The mean age at presentation was 41.7 (range, 29-62) years with a male to female ratio of approximately 1:2. The average size of the stones ranged from 2 to 6 mm. The overall success rate for endoscopic stone retrieval was 78 % (26 of 33) and three patients required a combined approach with intraoral incisions for stone removal. The major complication rate was 3 % (1 of 33) caused by submandibular duct perforation. The endoscopic retrieval of salivary stones is a safe and effective technique in selected cases. As instruments for stone fragmentation are expensive and not available everywhere, selecting patients with small and medium sized stones could lead to successful results in majority of cases.

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.

Ultrasound indicators of persistent obstruction after submandibular sialolithotomy

OBJECTIVE

To identify and describe the ultrasound indicators of persistent obstruction following transoral submandibular sialolithotomy and discuss the utility of ultrasound in the immediate postoperative period.

STUDY DESIGN

We performed a prospective case series with planned data collection of patients who underwent treatment for symptomatic submandibular swelling.

SETTING

A tertiary care center.

SUBJECTS

Thirty-three patients of either sex with known submandibular gland sialoliths who failed endoscopic retrieval of calculi.

METHODS

We performed in-office or operating room-based transoral submandibular gland sialolithotomy followed by immediate postprocedure ultrasound examination for the assessment of residual calculi. All patients underwent mandatory reexploration for suspicious findings.

RESULTS

Only the appearance of hyperechogenic foci with posterior shadowing reliably predicted the presence of residual stones following transoral sialolithotomy (P < .0001). The presence of hyperechogenic foci without posterior shadowing (P = 1.00), ductal dilatation (P = .23), and intraglandular dilatation (P = 1.00) was not indicative of retained calculi.

CONCLUSION

The presence of hyperechogenic foci with posterior shadowing on immediate postprocedure ultrasound is an accurate indicator of residual stones following transoral submandibular sialolithotomy. Ultrasound examination can be reliably used to identify patients at risk of symptomatic recurrence of sialoliths.

Middle-aged man with left neck pain and swelling

BACKGROUND

Disorders of the salivary glands can be evaluated by bedside ultrasonography and should be considered in patients presenting with undifferentiated neck swelling.

OBJECTIVE

Our aim was to describe the sonographic findings present in sialolithiasis and sialadenitis.

CASE REPORT

A 61-year-old man presented to the emergency department with 2 days of neck swelling. Initial evaluation included a bedside ultrasound that demonstrated sialolithiasis, which was later confirmed by computed tomography.

CONCLUSIONS

Bedside ultrasound can be a useful imaging modality in the evaluation of the patient with neck swelling.

Clinical and ultrasonographic characteristics of salivary mucoceles in 13 dogs

Salivary mucocele is one of the causes of submandibular swelling in dogs and is due to a collection of mucoid saliva that has leaked from a damaged salivary gland. The purpose of this case series report was to describe the clinical and ultrasonographic characteristics of confirmed salivary mucoceles in 13 dogs admitted to the Faculty of Veterinary Medicine at Cairo University. The final diagnosis of salivary mucocele was based on aspirate cytology for all dogs and additional surgical excision for seven dogs. For dogs admitted from 2 weeks to 1 month from the onset of clinical signs, the cervical mucocele appeared as a round echogenic structure with a large volume of central anechoic content. The wall was a clearly identified hyperechoic structure surrounding the gland. For dogs admitted between 1 to 2 months from the onset of clinical signs, the volume of anechoic material appeared less than that seen in the acute cases. The overall appearance of the salivary mucocele was heterogenous. For dogs admitted after 2 months from the onset of clinical signs, the salivary mucocele appeared grainy or mottled, with a heterogenous appearance and a further decrease in anechoic content. For one dog that presented after 3 months from the onset of clinical signs, the salivary mucocele was hard on palpation and appeared hyperechoic with distal acoustic shadowing. Findings from this study indicated that ultrasonographic characteristics of salivary mucoceles in dogs vary depending on the chronological stage of the disease.

Ultrasound GLCM texture analysis of radiation-induced parotid-gland injury in head-and-neck cancer radiotherapy: an in vivo study of late toxicity

PURPOSE

Xerostomia (dry mouth), secondary to irradiation of the parotid glands, is one of the most common side effects of head-and-neck cancer radiotherapy. Diagnostic tools able to accurately and efficiently measure parotid gland injury have yet to be introduced into the clinic. This study's purpose is to investigate sonographic textural features as potential imaging signatures for quantitative assessment of parotid-gland injury after head-and-neck radiotherapy.

METHODS

The authors have investigated a series of sonographic features obtained from the gray level co-occurrence matrix (GLCM) - a second order statistical method of texture analysis. These GLCM textural features were selected based on empirical observations that the normal parotid gland exhibits homogeneous echotexture, whereas the postradiotherapy parotid gland often exhibits heterogeneous echotexture. We employed eight sonographic features: (1) angular second moment (ASM), (2) inverse differential moment (IDM), (3) contrast, (4) variance, (5) correlation, (6) entropy, (7) cluster shade, and (8) cluster prominence. Altogether, sonographic properties of the parotid glands were quantified by their degrees of homogeneity (ASM and IDM), heterogeneity (contrast and variance), smoothness (correlation), randomness (entropy), and symmetry (cluster shade and prominence). The sonographic features were tested in a pilot study of 12 postradiotherapy patients and 7 healthy volunteers. The mean follow-up time for the postradiotherapy patients was 17.2 months (range: 12.1-23.9 months) and the mean radiation dose to the parotid glands was 32.3 Gy (range: 11.0-63.4 Gy). Each participant underwent one ultrasound study in which longitudinal (vertical) ultrasound scans were performed on the bilateral parotids - a total of 24 postirradiation and 14 normal parotid glands were examined. The 14 normal parotid glands served as the control group. A radiologist contoured the parotid glands on the B-mode images and the sonographic features were computed from the contoured region-of-interest.

RESULTS

The authors observed significant differences (p < 0.05) in all sonographic features between the normal and postradiotherapy parotid glands. The sonographic findings were consistent with the clinical observations of the ultrasound images: normal parotid glands exhibited homogeneous texture, while the postradiotherapy parotid glands exhibited heterogeneous echotexture (e.g., hyperechoic lines and spots), which likely represents fibrosis.

CONCLUSIONS

The authors have demonstrated the feasibility of ultrasonic texture evaluation of parotid glands; and the sonographic features may serve as imaging signatures to assess radiation-induced parotid injury.

Ultrasound histogram assessment of parotid gland injury following head-and-neck radiotherapy: a feasibility study

Xerostomia (dry mouth), resulting from radiation damage to the parotid glands, is one of the most common and distressing side effects of head-and-neck cancer radiotherapy. A noninvasive, objective imaging method to assess parotid injury is lacking, but much needed in the clinic. Therefore, we investigated echo histograms to quantitatively evaluate the morphologic and microstructural integrity of the parotid glands. Six sonographic features were derived from the echo-intensity histograms to assess the echogenicity, homogeneity and heterogeneity of the parotid gland: (1) peak intensity value (I(peak)), (2) -3-dB intensity width (W(3-dB)), (3) the low (<50% I(peak)) intensity width (W(low)), (4) the high (>50% I(peak)) intensity width (W(high)), (5) the area of low intensity (A(low)) and (6) the area of high intensity (A(high)). In this pilot study, 12 post-radiotherapy patients and seven healthy volunteers were enrolled. Significant differences (p < 0.05) were observed in four sonographic features between 24 irradiated and 14 normal parotid glands. In summary, we developed a family of sonographic features derived from echo histograms and demonstrated the feasibility of quantitative evaluation of radiation-induced parotid-gland injury.

[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.

Emergency physician point-of-care ultrasound in the diagnosis of sialolithiasis

Sialolithiasis is a relatively common diagnosis, with an uncertain etiology, that must be considered in patients presenting with a neck mass. Traditionally, invasive sialography was used to detect salivary stones. Currently, computed tomography has been the test of choice. Ultrasound presents an alternative, rapid, and safe imaging modality for the diagnosis of sialolithiasis. We report a case of sialolithiasis diagnosed by emergency physicians using point-of-care ultrasonography.

Interventional sialendoscopy for parotid ductal calculi: our preliminary experience

With this article we present our initial experience with interventional sialendoscopy of the parotid duct for the parotid calculi. We carried out a prospective study of patients of parotid calculi in a tertiary referral centre. Diagnostic and interventional sialendoscopy was performed in five cases of parotid calculi. The outcome was classified on the basis of clearance of the lumen of the duct and resolution of symptoms. Diagnostic sialendoscopy was able to diagnose the calculus in all cases. Interventional sialendoscopy was done under general anesthesia in all cases and calculus was successfully removed. The average size of sialolith was 8.2 mm. No complications occurred in any of the cases. Check sialendoscopy was done in all cases after a minimum follow up of 6 months, which showed the duct lumen to be free of stone with no stricture of the duct. Sialendoscopy is an optimal technique for removal of intraductal parotid calculi and avoids removal of the gland. In our series there was no associated morbidity and complication.

[Current aspects in ultrasonography of the salivary glands]

Ultrasonography is a basic diagnostic tool in all diseases of the salivary glands. Due to their relatively superficial anatomic location, distinct borders and homogenous echotexture, the salivary glands are ideally positioned for sonographic assessment. The advantages of this technique include its high diagnostic accuracy, non-invasiveness, lack of radiation exposure, as well as high reproducibility and low costs. Progress in ultrasound equipment and ultrasound transducers in recent years, i.e. colour-coded Doppler sonography with and without contrast enhancers, tissue harmonic imaging and elastography have widened the spectrum of indications and diagnostic accuracy. Although unspecific, many diseases of the salivary glands have particular sonographic characteristics. In addition, ultrasound-guided fine-needle biopsy is able to obtain material for cytological analysis in a targeted fashion under visual control. Compared to other imaging techniques such as CT and MRI, ultrasound achieves the highest sensitivity in the identification of neoplasms in the salivary glands.