Evaluation of the Normal Structures of Parotid Duct Using Magnetic Resonance Hydrography / 中国医学科学院学报

To investigate the normal structures of parotid duct by using magnetic resonance(MR)hydrography. MR three-dimensional heavy T2-weighted imaging was performed in 21 normal subjects.After taking 200 mg of vitamin C orally for 3 minutes,the subjects underwent parotid duct coronal hydro-magnetic resonance imaging.The images were transferred to the GE AW4.5 workstation,on which multi-planner reformation was performed using Functool software.The numbers of the parotid duct,accessory parotid duct,segments,and its branches was counted and the length and diameter of the intra-and extra-parotid ducts were measured. Accessory ducts were found in 24 parotid glands(57.1%,24/42),with the average length being(9.54±9.98)mm and the average diameter being(0.87±0.88)mm.The intra-parotid ducts were found to be with 3 segments were in 3 cases(7.14%,3/42),with 2 segments in 19 cases(45.23%,19/42),and with 1 segment in 20 cases(47.62%,20/42).The average number of the branches of the first,second and third segment was 2.38,0.88,and 0.1,respectively.The average length of the intra-parotid duct was(36.97±7.97)mm,with its average diameter being(2.01±0.76)mm.The average length of extra-parotid duct was(34.98±10.25)mm,with its average diameter being(2.13±0.79)mm.The average length of the whole parotid duct was(71.95±11.47)mm,with its average diameter being(2.07±0.68)mm. The parotid duct,the accessory parotid duct,and the segments and their branches of the intra-parotid duct can be accurately displayed by MR hydrography.

Usefulness of Magnetic Resonance Sialography for Diagnosis of Idiopathic Chronic Sialadenitis / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The symptoms of salivary diseasess are often nonspecific, and a variety of investigative methods can be employed. Conventional sialography, which is still widely used for diagnosis of salivary ductal pathologies, has the withdrawback of invasiveness and radiation exposure, and thus ultrasound and magnetic resonance (MR) sialography can replace the conventional tools. This study was performed to evaluate the usefulness of MR sialography for the diagnosis of idiopathic chronic sialadenitis. SUBJECTS AND METHOD: From November 2013 to June 2014, we have retrospectively analyzed 26 patients who have had swelling and pain of salivary glands and undergone MR sialography for further diagnosis of the idiopathic salivary obstructive symptom. We analyzed the symptom scores, salivary flow rate (SFR) and parameters of salivary gland scintigraphy. Then we evaluated correlation among MR sialography findings (duct visualization, grade of stenosis at main duct, degree of sialectasis and glandular volume size). RESULTS: Among the 26 patients, stenosis of salivary duct was observed in 14 patients (53.8%), chronic sialadenitis without stenosis in 6 patients (23.1%), Sjogren's syndrome in 3 patients (11.5%), Juvenile reccutent parotitis in 1 patient (3.8%), and 2 patients were norma (7.7%). The degree of sialectasis was significantly correlated with Tmin (time interval, in minutes, from stimulation to minimum count), maximum secretion (p<0.05), and glandular volume size was also significantly correlated with unstimulated SFR (p<0.05). But others did not show any significant correlations. From these findings, we report three cases that were useful to diagnose the gland disease using MR sialography. CONCLUSION: Resutls show that MR sialogarphy indirectly reflects the salivary gland function. Therefore MR sialography can be helpful when the differential diagnosis of idiopathic chronic sialadenitis is difficult with conventional tools.

The role of Magnetic resonance sialography in evaluating radiation-induced xerostomia for patients with early stage nasopharyngeal carcinoma / 中华放射肿瘤学杂志

Objective To investigate the value of magnetic resonance sialography (MRS) as a noninvasive tool in evaluating major salivary gland function before and after radiotherapy (RT) for nasopharyngeal carcinoma patients.Methods From August 2009 to June 2010,patients with stage Ⅰ and Ⅱa (AJCC/UICC 2002) nasopharyngeal carcinoma were enrolled.All the patients were treated with intensity modulated radiation therapy alone.MRS with salivary stimulation was performed in patients before and after RT on a 3.0T MR scanner.An MRS categorical scoring system was used to compare the visibility of ducts pre-RT and post-RT.The relationship between MRS score and EORTC Core QOL and EORTC Head and Neck QOL was analyzed.Spearman rank correlation test was performed to analyze the non-stimulated and stimulated MRS findings and the clinical severity of xerostomia.Results All 10 enrolled patients completed planned treatment.The mean dose of the parotid glands and submandibular glands were (37.99 + 3.70) Gy and (55.65 + 2.99) Gy,respectively.Good-quality MRS images were obtained.The visibility scores of both the parotid and submandibular ducts were increased after secretion stimulation.Irradiation decreased the visualization of the salivary ducts and attenuated the response to secretion stimulation.There were specific correlations between post-RT secretion response of the parotid gland and EORTC QLQ scales ( global QOL scale in QLQ-C30 ( rs =0.636,P =0.048 ) and xerostomia scale in QLQ H&N35 ( rs =- 0.694,P =0.026) ).Conclusions MRS can be used as a non-invasive way to evaluated of the functional changes of major salivary glands before and after RT and as a promising approach for investigating radiation-induced xerostomia.

Advance in MR imaging for evaluation of postradiotherapy salivary function in patients with head and neck cancer / 中国癌症杂志

Salivary gland damage with subsequent xerostomia has been an unavoidable complication in most head and neck cancer patients after radiotherapy.However,there were many shortcomings of each current detecting technique.Magnetic resonance sialography(MRS) and diffusion-weighted magnetic resonance imaging(DW MRI) ,as two of the most important progresses in the latest MRI techniques,with the virtue of non-invasion and non-ionizing radiation,has been rapidly developed in salivary function assessment in recent years,and it has kept on improving technically.This article mainly reviewed the clinical applications and research advances of these two MRI technologies in post-radiotherapy salivary function assessment in patients with head and neck cancers,so as to provide reference for further study.