Wataru Fukumoto, Presenter: Nothing to Disclose

Toru Higaki PhD, Abstract Co-Author: Nothing to Disclose

Yuko Nakamura MD, Abstract Co-Author: Nothing to Disclose

Yoshiko Iwakado, Abstract Co-Author: Nothing to Disclose

Tatsuya Ohkubo, Abstract Co-Author: Employee, Toshiba Corporation

Kazuo Awai MD, Abstract Co-Author: Research Grant, Toshiba Corporation Research Grant, Hitachi Ltd Research Grant, Bayer AG Research Consultant, DAIICHI SANKYO Group Research Grant, Eisai Co, Ltd

Yoko Kaichi, Abstract Co-Author: Nothing to Disclose

Kenji Kajiwara, Abstract Co-Author: Nothing to Disclose

The time-spatial labeling inversion pulse (Time-SLIP) technique is a new MRI technique based on arterial spin labeling. It can visualize not only the blood flow but also intravital flows such as the cerebrospinal fluid flow and pancreatic secretion. The purpose of this study was to assess the feasibility of the Time-SLIP technique for demonstrating salivary flow in normal volunteers.

Using a 3T-MRI scanner (Vantage Titan 3T; Toshiba), surface coils placed on the parotid gland, and the “flow-in” method of the Time-SLIP technique, we acquired images of salivary flow from the right parotid gland of 16 normal volunteers ranging in age from 24-53 years (median 40.5 years). We applied a spatially selective inversion recovery (IR) pulse to a parotid duct and then determined the black blood inversion time (time from the selective IR pulse to image acquisition) to null the background signal. We scanned the parotid duct 24 times at identical intervals. To stimulate saliva secretion we injected 1 mL of 2% citric acid into the mouth before scans 5, 9, 13, 17, and 21, and scored visualization of the parotid duct on the flow images (grade A= 100% visualization, grade B= 50-99% visualization, grade C= 1-49% visualization, grade D= incomplete visualization).We also measured the mean signal intensity ratio (SIR) of the parotid gland ([mean SI during each stimulation] / [mean unstimulated SI=1]) during each Stimulation (Stimulation1=1st scan, Stimulation2=2nd scan, Stimulation3=3rd scan, Stimulation2=4th scan after stimulation,).

With the Time-SLIP technique salivary flow from the parotid gland could be visualized in 15 of 16 volunteers. The scores were A in 1-, B in 8-, and C in 6 volunteers.Mean SIR during each Stimulation1, 2, 3, 4 were 1.18 (standard deviation 0.28), 1.21 (0.23), 1.14 (0.17), and 1.11 (0.16), respectively. In 9 of 15 volunteers salivary flow could be most clearly visualized on the 2nd scan after each stimulation.

Salivary flow from the parotid gland could be visualized in 15 of 16 volunteers on images acquired with the Time-SLIP technique.

The Time-SLIP MRI technique holds promise for the quantitative and qualitative evaluation of salivary flow. It may be useful in the evaluation of patients with reduced salivary secretion, e.g. patients with Sjogren syndrome and patients undergoing radiation therapy for head and neck tumors.

Fukumoto, W, Higaki, T, Nakamura, Y, Iwakado, Y, Ohkubo, T, Awai, K, Kaichi, Y, Kajiwara, K, Demonstration of Salivary Flow from the Parotid Gland by MRI Using the Time-spatial Labeling Inversion Pulse (Time-SLIP) Technique: Feasibility Study in Normal Volunteers.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14003984.html