Salivary Gland Ducts Research Articles

Molecular Identification and Physiological Roles of Parotid Acinar Cell Maxi-K Channels

The physiological success of fluid-secreting tissues relies on a regulated interplay between Ca(2+)-activated Cl(-) and K(+) channels. Parotid acinar cells express two types of Ca(2+)-activated K(+) channels: intermediate conductance IK1 channels and maxi-K channels. The IK1 channel is encoded by the K(Ca)3.1 gene, and the K(Ca)1.1 gene is a likely candidate for the maxi-K channel. To confirm the genetic identity of the maxi-K channel and to probe its specific roles, we studied parotid glands in mice with the K(Ca)1.1 gene ablated. Parotid acinar cells from these animals lacked maxi-K channels, confirming their genetic identity. The stimulated parotid gland fluid secretion rate was normal, but the sodium and potassium content of the secreted fluid was altered. In addition, we found that the regulatory volume decrease in acinar cells was substantially impaired in K(Ca)1.1-null animals. We examined fluid secretion from animals with both K(+) channel genes deleted. The secretion rate was severely reduced, and the ion content of the secreted fluid was significantly changed. We measured the membrane potentials of acinar cells from wild-type mice and from animals with either or both K(+) channel genes ablated. They revealed that the observed functional effects on fluid secretion reflected alterations in cell membrane voltage. Our findings show that the maxi-K channels are critical for the regulatory volume decrease in these cells and that they play an important role in the sodium uptake and potassium secretion process in the ducts of these fluid-secreting salivary glands.

Cellular expression of Noc2, a Rab effector protein, in endocrine and exocrine tissues in the mouse

Noc2 is a Rab effector which participates in regulated exocytosis. It is expressed abundantly in endocrine cells but at low levels in exocrine tissues. Noc2-deficient mice, however, exhibit marked accumulation of secretory granules in exocrine cells rather than endocrine cells. In the present study, we investigated localization of Noc2 immunohistochemically in various endocrine and exocrine tissues in normal mice. Western blotting detected a Noc2-immunoreactive band of 38 kDa in isolated pancreatic islets, the adrenal gland, pituitary gland, and thyroid gland. Immunostaining for Noc2 labeled endocrine cells in the adrenal medulla and adenohypophysis, pancreatic islet cells, thyroid parafollicular cells, and gut endocrine cells, supporting the notion that Noc2 is a Rab effector protein shared by amine/peptide-secreting endocrine cells. Besides endocrine tissues, granular ducts in salivary glands contained Noc2. Although immunostaining failed to detect Noc2 in acinar cells of all exocrine glands examined, reverse transcriptase-polymerase chain reaction analysis detected the mRNA expression in exocrine pancreas. Ultrastructurally, Noc2 immunoreactivity was associated with the limiting membrane of granules in both pancreatic endocrine and salivary duct exocrine cells. The cellular and subcellular localizations of Noc2 should yield key information on its functional significance as well as account for the phenotype in Noc2-deficient mice.

Inverted ductal papilloma of minor salivary gland: Case report with immunohistochemical study and literature review

Inverted ductal papilloma (IDP) is a type of ductal papilloma arising in ducts of minor salivary glands. Very few cases, and no cases in Japan, have been reported. Reported herein is a case of IDP with a review of the literature. The patient was a 49-year-old man presenting with a lump in the right buccal mucosa of the premolar area of the mandible. The tumor was excised en bloc after a biopsy diagnosis of IDP. On the surface of the covering epithelium, an opening was seen to be filled with mucinous material. On cut surface the opening led to the tumor cavity. The major portion of the tumor parenchyma was made up of papillary proliferation of basaloid squamous cells. Some crypts, microcysts, and mucous cells were seen. There were no findings suggestive of a malignant tumor. The patient's postoperative course was uneventful and there has been no recurrence after 1 year's follow up. Immunohistochemical analysis of the present case supports the hypothesis that IDP originates from squamous metaplasia and proliferation of minor salivary gland duct cells.

Surgery in disabled children: General gastroenterological aspects

AbstractCerebral palsy (CP) is a non‐progressive but not unchanging disorder of movement and/or posture, due to an insult to or anomaly of the developing brain. Gastrointestinal surgery can play a role in the treatment of pathologies frequently associated with a condition of neurological impairment such as gastro‐oesophageal reflux disease (antireflux procedure), feeding difficulties (percutaneous endoscopic gastrostomy/jejunostomy) and swallowing difficulties (ligation of salivary gland ducts). Gastro‐oesophageal reflux occurs in up to 70–75% of children with cerebral palsy. Children with gastro‐oesophageal reflux disease (GERD) may present with feeding difficulties, recurrent vomiting and recurrent chest infection associated with poor growth and nutrition, reactive airway disease particularly nocturnal asthma, choking attacks, anaemia, and wheezing. Nutritional deprivation in children with cerebral palsy is the summation of several factors which result in reduced intake. Percutaneous endoscopic gastrostomy (PEG) has radically changed the handling of children with nutritional problems who, before the introduction of this procedure, were force fed parenterally or enterally, by nasogastric tube, conventional surgical gastrostomy or central venous access. In children with CP, PEG is the preferred technique for long‐term enteral feeding. Swallowing dysfunction is the main cause of drooling in cerebral palsy, and medical treatment is often inefficient. Surgical treatment involves neurectomy, translocation of the salivary duct, salivary gland resection or salivary duct (parotid and submandibular) ligation. Conclusion: This review focuses on the role of surgery in managing gastrointestinal aspects in children with CP and, in particular, surgical experience at our department with fundoplication, PEG placement and ligation of salivary ducts.

Surgery in disabled children: General gastroenterological aspects

Cerebral palsy (CP) is a non-progressive but not unchanging disorder of movement and/or posture, due to an insult to or anomaly of the developing brain. Gastrointestinal surgery can play a role in the treatment of pathologies frequently associated with a condition of neurological impairment such as gastro-oesophageal reflux disease (antireflux procedure), feeding difficulties (percutaneous endoscopic gastrostomy/jejunostomy) and swallowing difficulties (ligation of salivary gland ducts). Gastro-oesophageal reflux occurs in up to 70-75% of children with cerebral palsy. Children with gastro-oesophageal reflux disease (GERD) may present with feeding difficulties, recurrent vomiting and recurrent chest infection associated with poor growth and nutrition, reactive airway disease particularly nocturnal asthma, choking attacks, anaemia, and wheezing. Nutritional deprivation in children with cerebral palsy is the summation of several factors which result in reduced intake. Percutaneous endoscopic gastrostomy (PEG) has radically changed the handling of children with nutritional problems who, before the introduction of this procedure, were force fed parenterally or enterally, by nasogastric tube, conventional surgical gastrostomy or central venous access. In children with CP, PEG is the preferred technique for long-term enteral feeding. Swallowing dysfunction is the main cause of drooling in cerebral palsy, and medical treatment is often inefficient. Surgical treatment involves neurectomy, translocation of the salivary duct, salivary gland resection or salivary duct (parotid and submandibular) ligation. This review focuses on the role of surgery in managing gastrointestinal aspects in children with CP and, in particular, surgical experience at our department with fundoplication, PEG placement and ligation of salivary ducts.

The effect of β-bungarotoxin, or geniculate ganglion lesion on taste bud development in the chick embryo

Chick taste bud (gemmal) primordia normally appear on embryonic day (E) 16 and incipient immature, spherical-shaped buds at E17. In ovo injection of beta-bungarotoxin at E12 resulted in a complete absence of taste buds in lower beak and palatal epithelium at developmental ages E17 and E21. However, putative gemmal primordia (solitary clear cells; small, cell groupings) remained, lying adjacent to salivary gland duct openings as seen in normal chick gemmal development. Oral epithelium was immunonegative to neural cell adhesion molecule (NCAM) suggesting gemmal primordia are nerve-independent. Some NCAM immunoreactivity was evident in autonomic ganglion-like cells and nerve fibers in connective tissue. After unilateral geniculate ganglion/otocyst excision on E2.5, at developmental ages E18 and posthatching day 1, approximately 12% of surviving ipsilateral geniculate ganglion cells sustained approximately 54% of the unoperated gemmal counts. After E18, proportional stages of differentiation in surviving developing buds probably reflect their degree of innervation, as well as rate of differentiation. Irrespective of the degree of geniculate ganglion damage, the proportion of surviving buds can be sustained at the same differentiated bud stage as on the unoperated side, or may differentiate to a later bud stage, consistent with the thesis that bud maturation, maintenance, and survival are nerve-dependent.

Biological rhythm of saliva ghrelin in humans

Background: We previously reported that ghrelin in saliva, orexigenic hormone that induces NPY release, was produced and released by salivary glands in humans. The purpose of this study was to investigate a possible circadian rhythm in saliva ghrelin concentration in human subjects as a function of time and meal. Saliva samples were collected at three-hour intervals throughout a 24-h period in 12 healthy volunteer males and ten healthy volunteer females who were provided with meals on a fixed schedule, and saliva collections were made within 15 minutes after each meal. Saliva ghrelin levels were measured by using a commercial radioimmunoassay (RIA) kit that uses 125I-labeled bioactive ghrelin as a tracer and a rabbit polyclonal antibody raised against full-length octanoylated human ghrelin. Immunohistochemical analysis of salivary glands was also performed. The results of this investigation indicated the following. (1) The saliva ghrelin level was slightly higher in female subjects in comparison with male subjects. (2) Saliva ghrelin levels were elevated before each meal and fell to trough levels after eating. (3) Saliva ghrelin levels showed a circadian rhythm that rose throughout the day to a zenith at 0300, then dropped at 0600 – 0900. (4) Saliva ghrelin also weakly correlated with BMI. (5) Immunohistochemical analysis showed that ghrelin was localized in the striated and excretory ducts of salivary glands of human. The present work is the first report of the circadian rhythm of saliva ghrelin level in human subjects as a function of time and meal. Meal plays an important role in lowering saliva ghrelin concentration in humans. However, present data did not exclude whether the circadian changes in saliva ghrelin expression were regulated by the biological clock or by food intake.

Dopamine-induced graded intracellular Ca 2+ elevation via the Na +[sbnd]Ca 2+ exchanger operating in the Ca 2+-entry mode in cockroach salivary ducts

Stimulation with the neurotransmitter dopamine causes an amplitude-modulated increase in the intracellular Ca 2+ concentration ([Ca 2+] i) in epithelial cells of the ducts of cockroach salivary glands. This is completely attributable to a Ca 2+ influx from the extracellular space. Additionally, dopamine induces a massive [Na +] i elevation via the Na + K + 2Cl − cotransporter (NKCC). We have reasoned that Ca 2+-entry is mediated by the Na + Ca 2+ exchanger (NCE) operating in the Ca 2+-entry mode. To test this hypothesis, [Ca 2+] i and [Na +] i were measured by using the fluorescent dyes Fura-2, Fluo-3, and SBFI. Inhibition of Na +-entry from the extracellular space by removal of extracellular Na + or inhibition of the NKCC by 10 μM bumetanide did not influence resting [Ca 2+] i but completely abolished the dopamine-induced [Ca 2+] i elevation. Simultaneous recordings of [Ca 2+] i and [Na +] i revealed that the dopamine-induced [Na +] i elevation preceded the [Ca 2+] i elevation. During dopamine stimulation, the generation of an outward Na + concentration gradient by removal of extracellular Na + boosted the [Ca 2+] i elevation. Furthermore, prolonging the dopamine-induced [Na +] i rise by blocking the Na +/K +-ATPase reduced the recovery from [Ca 2+] i elevation. These results indicate that dopamine induces a massive NKCC-mediated elevation in [Na +] i, which reverses the NCE activity into the reverse mode causing a graded [Ca 2+] i elevation in the duct cells.

Interlobular excretory ducts of mammalian salivary glands: Structural and histochemical review

In the major salivary glands of mammals, excretory ducts (EDs) succeed striated ducts. They are for the most part interlobular in position, although their proximal portions sometimes are on the periphery of a lobule, where they occasionally retain some of the structural features of striated ducts. Based on a survey of a broad range of mammalian species and glands, the predominant tissue type that composes EDs is pseudostratified epithelium. In some species, there is a progression of epithelial types: the proximal EDs are composed of simple cuboidal or columnar epithelium that, in the excurrent direction, usually gives way to the pseudostratified variety. Secretory granules are visible in the apical cytoplasm of the principal cells of the EDs of only a few species, but histochemistry has shown the presence of a variety of glycoproteins in these cells in a spectrum of species. Moreover, the latter methodology has revealed the presence of a variety of oxidative, acid hydrolytic, and transport enzymes in the EDs, showing that, rather than simply acting as a conduit for saliva, these ducts play a metabolically active role in gland function. It is difficult to describe a "typical" mammalian ED because it can vary along its length and interspecific variation does not follow a phylogenetic pattern. Moreover, in contrast to intercalated and striated ducts, ED cellular features do not exhibit a relationship to diet.

下唇に生じた小唾液腺導管内唾石の１例

Sialoliths mainly occur in the major salivary glands and rarely arise in the minor salivary glands. Sialoliths in the lower lip are extremely rare.We report a sialolith occurring in the minor salivary gland duct of the lower lip. An 84-year-old woman was referred to our hospital because of a tumor of the right lower lip. The clinical diagnosis was a benign tumor. We performed tumor excision. There were no adhesions of the surrounding tissue, and the tumor was excised without any problems. Histologically, fragments of calcified material were seen within a dilated duct. The duct epithelium consisted of pseudostratified ciliated columnar epithelium. A minor salivary gland near the duct showed acinar atrophy and fibrosis. The histopathologic diagnosis was a sialolith in the minor salivary gland duct. The patient's postoperative course has been good, with no evidence of recurrence.

Current role of extracorporeal shockwave therapy in surgery.

In urology the introduction of extracorporeal shockwave therapy brought a revolutionary change to the management of urinary calculi. This inspired the introduction of shockwave therapy in several fields of surgery; it has been applied as a potential alternative to several operative procedures but is still experimental. So far, the major application of shockwave therapy has been lithotripsy of stones in the gallbladder, common bile duct, pancreatic duct and salivary gland ducts. Other applications are in the non-operative management of bone healing disturbances and in the inhibition of tumour growth. Steps towards selective thrombus ablation and pretreatment of heavily calcified arteries have also been made. In this review, the applications of extracorporeal shockwave therapy in several areas of surgery are discussed. It is concluded that, for selected patients, shockwave treatment may serve as a useful addition to the surgical armamentarium.

Analysis of in Vivo Role of α-Fodrin Autoantigen in Primary Sjögren's Syndrome

The alpha-fodrin N-terminal portion (AFN) autoantigen mediates in vivo immunoregulation of autoimmune responses in primary Sjögren's syndrome (SS). We further examined this process and found that cleavage products of AFN were frequently detected in the salivary gland duct cells of SS patients. In in vitro studies using human salivary gland HSY cells, anti-Fas-induced apoptosis resulted in specific cleavage of alpha-fodrin into the 120-kd fragment, in association of alpha-fodrin with mu-calpain, and activation of caspase 3. Significant proliferative responses against AlphaFN autoantigen were observed in the peripheral blood mononuclear cells (PBMCs) from SS patients with higher pathological score (grade 4) and with short duration from onset (within 5 years). In vivo roles of AFN peptides were investigated using PBMCs from patients with SS, systemic lupus erythematosus, and rheumatoid arthritis. Significant proliferative T-cell responses of PBMCs to AFN peptide were detected in SS but not in systemic lupus erythematosus or rheumatoid arthritis. AFN peptide induced Th1-immune responses and accelerated down-regulation of Fas-mediated T-cell apoptosis in SS. Our data further elucidate the in vivo role of AFN autoantigen on the development of SS and suggest that the AFN autoantigen is a novel participant in peripheral tolerance.

A CASE OF SIALADENOMA PAPILLIFERUM OF THE ESOPHAGUS

Sialadenoma papilliferum of the esophagus is an extremely rare benign tumor that derives from the submucosal gland duct of the minor salivary gland. A 45‐year‐old man underwent upper gastrointestinal series. A 13 mm diameter esophageal polyp was suspected in the mid esophagus. Endoscopy examination revealed a pedunculated polyp arising from the posterior wall of the esophagus. The head of the polyp was covered with exudate and was slightly nodular but the pedicle had normal mucosa. We performed endoscopic mucosal resection (EMR) and the histological examination of the polyp showed that it was compatible with sialadenoma papilliferum of the esophagus.

The functional evaluation of salivary glands using dynamic MR sialography following citric acid stimulation: A preliminary study

We introduce a new technique for the functional evaluation of the salivary glands using continuous magnetic resonance (MR) sialography before and after citric acid stimulation. In 10 volunteers, the time-dependent changes in the maximum area of the detectable parotid gland ducts on MR sialographic images taken every 30 seconds before and after citric acid stimulation were analyzed. The time period to the occurrence of the maximum duct area poststimulation was noted, and then the time for the area to return to its 50% value pre-citric acid stimulation was also observed. This new technique was clinically applied in 1 patient with an excessive supply impression of saliva and in 1 patient with a short supply impression with saliva. In all volunteers after citric acid stimulation, the maximum area of the detectable salivary gland ducts first increased and then decreased. A strong relationship was found between the maximum area of the detectable salivary gland ducts before citric acid stimulation and total saliva volume (Pearson r = 0.672, P = .031). Compared with all the volunteers, the ratio of change in the detectable ducts was the highest in the patient with an excessive supply impression of saliva, but lowest in the patient with a short supply impression with saliva. This initial study suggests that dynamic MR sialography allows for functional and morphological evaluation of the salivary glands. This technique appears to have many possible applications and further investigation in this field is necessary.

Ultrastructural and EDS Study of Sialoliths of the Salivary Glands

A.P. Alves de Matos*, P. A. Carvalho**, A. Almeida*, L. Duarte***, R. Vilar** and J. Leitao* *Departamento de Biomateriais, Faculdade de Medicina Dentaria, Universidade de Lisboa, 1649-003 Lisbon, Portugal. **Departamento de Engenharia de Materiais, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal. ***Servico de Cirurgia Maxilo-Facial, Hospital de S. Jose, R. Antonio Serrano, 1100 Lisboa, Portugal. Sialoliths, frequently developing in de ducts of salivary glands, are a cause of pain, inflammation and infection of the affected glands. Ultrastructural studies combined with EDS analysis have revealed variable patterns of structural elements with variable calcification levels. However the mechanism of formation of these complex stones and the cause of their formation are still unclear [1,2]. We have studied 8 sialoliths from the parotid, submandibular and submaxilar glands by scanning electron microscopy combined with EDS analysis. Sialoliths were broken approximately through the middle, mounted in carbon supports with carbon painting, and covered with a carbon layer in a rotary vacuum evaporator. Selected samples were embedded in an epoxy resin, grounded with SiC paper and polished using alumina suspensions. Smaller sialoliths usually displayed multiple thin (1-5 µm) concentric layers surrounding an compact core (figs. 1-2), while larger samples displayed multiple cores and in one case lacked the thin layer component (Fig. 3). The layers displayed variable fine structure from homogeneous to needle-like (fig. 4). The outer layers of all samples were thick (> 20µm) and compact (Fig. 1). Polished samples revealed structures that were not clearly identified in fractured ones. Among them, droplet-like structures in different stages of calcification were a prominent feature of some samples (fig 5). The variable structures observed suggest that several growth mechanisms may be present, probably related to the disease process. EDS analysis showed that the central amorphous core were always heavily mineralized and composed of phosphorus and calcium (fig. 6), probably representing hydroxyapatite [2]. Thin layers were heavily mineralized like the core or composed by a sulphur rich substance (fig. 7). Sulphur-containing areas with variable content of calcium and phosphate were also detected in the outer layers of large samples and were darker in backscattered electron images than mineralized areas (fig 3). Mg, Cl, and Si were also detected in variable amounts in the sialoliths. The sulphur-containing areas may represent organic substances with high S content [3], but not all of them seem to be undergoing a calcification process.

The Systemic Impact of Third Molar Periodontal Pathology

used to document successful exploration and instrumentation of the ductal system. The ducts were then harvested, dissected, and any traumatic injuries photographed. Results: All submandibular (n 20) and parotid ducts (n 20) were dilated without complications. The coronary stent was inserted using a guide wire and the balloon inflated to expand the stent. When the balloon was deflated and withdrawn, the stent remained in place, serving as scaffolding for the widened duct. Insertion and handling of a 1mm endoscope, through the stented salivary duct was facile, fast, and effortless in all 20 parotid and 20 submandibular ducts. Insertion of the endoscope was successful in all 10 control parotid and submandibular ducts but with greater difficulty. Results of the clinical and video capture assessment of damage to the ducts will be presented. Conclusion: Intraductal stent placement is feasible and provides easier access for the surgeon with little trauma to the salivary gland duct. Live animal experiments are ongoing.

Immunohistochemical study of autoimmune pancreatitis using anti‐IgG4 antibody and patients' sera

Autoimmune pancreatitis (AIP), characterized by raised serum IgG4 levels, is frequently complicated by disorders of extrapancreatic organs. The aim of the present study was to examine immunohistochemically which extrapancreatic organs are affected, and whether an autoantibody to such organs is present in the serum of AIP patients. Various tissues/organs obtained from AIP patients were studied immunohistochemically with an anti-IgG4 antibody. To examine the presence of an autoantibody in the serum of AIP patients, sera were incubated with various normal organs/tissues extracted for other diseases, followed by detection with an anti-IgG4 antibody. Sera were also examined before and after glucocorticoid therapy. Marked infiltration of IgG4+ plasma cells was observed in the pancreas, liver, bile duct and salivary gland of many of the AIP patients examined. The normal epithelia of the pancreatic ducts, bile ducts, gallbladder and salivary gland ducts reacting with the patients' sera were detectable by the anti-IgG4 antibody. Following glucocorticoid therapy the IgG4 antibody from the patients' sera showed decreased reactivity with these tissues. AIP may also affect extrapancreatic organs, the serum of AIP patients may contain an IgG4 autoantibody to various organs and glucocorticoid therapy may improve such disorders.

Epithelial Sodium Channel Inhibition by AMP-activated Protein Kinase in Oocytes and Polarized Renal Epithelial Cells

The epithelial Na(+) channel (ENaC) regulates epithelial salt and water reabsorption, processes that require significant expenditure of cellular energy. To test whether the ubiquitous metabolic sensor AMP-activated kinase (AMPK) regulates ENaC, we examined the effects of AMPK activation on amiloride-sensitive currents in Xenopus oocytes and polarized mouse collecting duct mpkCCD(c14) cells. Microinjection of oocytes expressing mouse ENaC (mENaC) with either active AMPK protein or an AMPK activator inhibited mENaC currents relative to controls as measured by two-electrode voltage-clamp studies. Similarly, pharmacological AMPK activation or overexpression of an activating AMPK mutant in mpkCCD(c14) cells inhibited amiloride-sensitive short circuit currents. Expression of a degenerin mutant beta-mENaC subunit (S518K) along with wild type alpha and gamma increased the channel open probability (P(o)) to approximately 1. However, AMPK activation inhibited currents similarly with expression of either degenerin mutant or wild type mENaC. Single channel recordings under these conditions demonstrated that neither P(o) nor channel conductance was affected by AMPK activation. Moreover, expression of a Liddle's syndrome-type beta-mENaC mutant (Y618A) greatly enhanced ENaC whole cell currents relative to wild type ENaC controls and prevented AMPK-dependent inhibition. These findings indicate that AMPK-dependent ENaC inhibition is mediated through a decrease in the number of active channels at the plasma membrane (N), presumably through enhanced Nedd4-2-dependent ENaC endocytosis. The AMPK-ENaC interaction appears to be indirect; AMPK did not bind ENaC in cells, as assessed by in vivo pull-down assays, nor did it phosphorylate ENaC in vitro. In summary, these results suggest a novel mechanism for coupling ENaC activity and renal Na(+) handling to cellular metabolic status through AMPK, which may help prevent cellular Na(+) loading under hypoxic or ischemic conditions.

MR-Sialographie: Optimierung und Bewertung ultraschneller Sequenzen mit paralleler Bildgebung und oraler Stimulation

Purpose: To optimise a fast sequence for MR-sialography and to compare a parallel and non-parallel acquisition technique. Additionally, the effect of oral stimulation regarding the image quality was evaluated. Material and Methods: All examinations were performed by using a 1.5-T superconducting system. After developing a sufficient sequence for MR-sialography, a single-shot turbo-spin-echo sequence (ss-TSE) with an acquisition time of 2.8 sec was used in transverse and oblique sagittal orientation in 27 healthy volunteers. All images were performed with and without parallel imaging technique. The assessment of the ductal system of the submandibular and parotid gland was performed using a 1 to 5 visual scale for each side separately. Images were evaluated by four independent experienced radiologists. For statistical evaluation, an ANOVA with post-hoc comparisons was used with an overall two-tailed significance level of P=.05. For evaluation of interobserver variability, an intraclass correlation was computed and correlation >.08 was determined to indicate a high correlation. Results: All parts of salivary excretal ducts could be visualised in all volunteers, with an overall rating for all ducts of 2.26 (SD ′ 1.09). Between the four observers a high correlation could be obtained with an intraclass correlation of 0.9475. A significant influence regarding the slice angulations could not be obtained (p = 0.74). In all healthy volunteers the visibility of excretory ducts improved significantly after oral application of a Sialogogum (p < 0.001; η 2 = 0.049). The use of parallel imaging technique did not lead to an improvement of visualisation, showing a significant loss of image quality compared to an acquisition technique without parallel imaging (p<0.001; η 2 =0.013), Conclusion: The optimised ss-TSE MR-sialography seems to be a fast and sufficient technique for visualisation of excretory ducts of the main salivary glands, with no elaborate post-processing needed. To improve results of MR-sialography, it is reasonable to use an oral Sialogogum.

MR-Sialographie: Optimierung und Bewertung ultraschneller Sequenzen mit paralleler Bildgebung und oraler Stimulation

To optimise a fast sequence for MR-sialography and to compare a parallel and non-parallel acquisition technique. Additionally, the effect of oral stimulation regarding the image quality was evaluated. All examinations were performed by using a 1.5-T superconducting system. After developing a sufficient sequence for MR-sialography, a single-shot turbo-spin-echo sequence (ss-TSE) with an acquisition time of 2.8 sec was used in transverse and oblique sagittal orientation in 27 healthy volunteers. All images were performed with and without parallel imaging technique. The assessment of the ductal system of the submandibular and parotid gland was performed using a 1 to 5 visual scale for each side separately. Images were evaluated by four independent experienced radiologists. For statistical evaluation, an ANOVA with post-hoc comparisons was used with an overall two-tailed significance level of P =.05. For evaluation of interobserver variability, an intraclass correlation was computed and correlation >.08 was determined to indicate a high correlation. All parts of salivary excretal ducts could be visualised in all volunteers, with an overall rating for all ducts of 2.26 (SD +/- 1.09). Between the four observers a high correlation could be obtained with an intraclass correlation of 0.9475. A significant influence regarding the slice angulations could not be obtained (p = 0.74). In all healthy volunteers the visibility of excretory ducts improved significantly after oral application of a Sialogogum (p < 0.001; eta (2) = 0.049). The use of a parallel imaging technique did not lead to an improvement of visualisation, showing a significant loss of image quality compared to an acquisition technique without parallel imaging (p < 0.001; eta (2) = 0.013). The optimised ss-TSE MR-sialography seems to be a fast and sufficient technique for visualisation of excretory ducts of the main salivary glands, with no elaborate post-processing needed. To improve results of MR-sialography, it is reasonable to use an oral Sialogogum.