Visualization of swallowing using real-time TrueFISP MR fluoroscopy

Abstract

The aim of this study was to evaluate the ability of different real-time true fast imaging with steady precession (TrueFISP) sequences regarding their ability to depict the swallowing process and delineate oropharyngeal pathologies in patients with dysphagia. Real-time TrueFISP visualization of swallowing was performed in 8 volunteers and 6 patients with dysphagia using a 1.5 T scanner (Magnetom Sonata, Siemens, Erlangen Germany) equipped with high-performance gradients (amplitude 40 mT/m). Image quality of four different real-time TrueFISP sequences (TR 2.2-3.0 ms, TE 1.1-1.5 ms, matrix 63 x 128-135 x 256, field of view 250 mm(2), acquisition time per image 139-405 ms) was evaluated. Water, yoghurt, and semolina pudding were assessed as oral contrast agents. Functional exploration of the oropharyngeal apparatus was best possible using the fastest real-time TrueFISP sequence (TR 2.2 ms, TE 1.1 ms, matrix 63 x 128). Increased acquisition time resulted in blurring of anatomical structures. As the image contrast of TrueFISP sequences depends on T2/T1 properties, all tested foodstuff were well suited as oral contrast agents, but image quality was best using semolina pudding. Real-time visualization of swallowing is possible using real-time TrueFISP sequences in conjunction with oral contrast agents. For the functional exploration of swallowing high temporal resolution is more crucial than spatial resolution.

Dynamic imaging of swallowing in a seated position using open‐configuration MRI

“…Anagnostara et al (5) reported that the turbo fast low-angle shot (Turbo-FLASH) sequence achieved 0.15-0.3 seconds/ slice using a 1.5T MRI system (Gyroscan ACS-NT; Philips Medical Systems, Best, The Netherlands). Barkhausen et al (10) reported that the true fast imaging with steady precession (TrueFISP) sequence produced 0.139 -0.405 seconds/image using a 1.5T MRI system (Magnetom Vision, Siemens, Erlangen, Germany). Ajaj et al (11) also used the real-time TrueFISP sequence and reported that it produced 0.5 seconds/ image using a 1.5T MRI system (Virtuosos; Siemens Medical Systems, Erlangen, Germany).…”

Protein‐Stabilised Emulsions and Rheological Aspects of Structure and Mouthfeel

“…The authors have found that swallowing requires a range of coordinated compressive and expansive movements that last in the order of 500 ms. From the obtained images, the strain rates experienced on the tongue have been estimated and found to be both positive and negative with a magnitude of about 0.2 per second. Developing fMRI techniques to study phenomena occurring during eating is an active area of research, but conclusive quantitative results have not been published yet (Barkhausen et al, 2002;Humbert and Robbins, 2007). A technique based on video rate endoscopy has also been developed and used to investigate the interactions between food material and oral surfaces, with an emphasis on food residues remaining in the mouth after swallowing; for example, the same study demonstrated that the material remaining onto the surfaces in the mouth after swallowing increased exponentially with increasing viscosity of the food (Watson et al, 2002;Adams et al, 2007;Pivk et al, 2008).…”

Comparison between Logopedic and MRI Findings in Evaluating Tongue Function

“…FIESTA is one of the high-speed MRI sequences that are combined under the name SSFP (steady-state free precession). The latter have been widely used to investigate the dynamic swallowing act [2,4,7,17]. Imaging with much higher time resolution is hence feasible, as is analysis in three spatial planes.…”