Evaluation of velopharyngeal function using high-speed cine-magnetic resonance imaging based on T2-weighted sequences: a preliminary study

The objective was to introduce a new technique for visualizing the three-dimensional (3D) movements of velopharyngeal-related muscles using high-speed cine-magnetic resonance imaging (MRI) based on T2-weighted sequences. The evaluation of phonation- and water swallowing-related events was performed in 11 healthy subjects. Specifically, whether cine-MRI could precisely visualize normal velopharyngeal function during these two events was examined. The 3D movements of the soft palate, superior pharyngeal constrictor muscles, and levator veli palatini muscles were visualized in all 11 subjects. A noteworthy finding was that the magnetic resonance signals of the superior constrictor pharyngeal muscles and the levator veli palatini muscles were significantly higher during phonation and during water swallowing than at rest. This initial study suggests that the 3D movements of velopharyngeal-related muscles can be successfully and precisely visualized without side effects. The magnetic resonance signal changes seen in the superior pharyngeal constrictor and levator veli palatini muscles using the technique described here should be useful to develop better methods of evaluation of velopharyngeal function.

Alterations in 18F-FDG accumulation into neck-related muscles after neck dissection for patients with oral cancers

BACKGROUND

18F-fluoro-2-deoxy-D-glucose (18F-FDG) accumulations are commonly seen in the neck-related muscles of the surgical and non-surgical sides after surgery with neck dissection (ND) for oral cancers, which leads to radiologists having difficulty in diagnosing the lesions. To examine the alterations in 18F-FDG accumulation in neck-related muscles of patients after ND for oral cancer.

MATERIAL AND METHODS

18F-FDG accumulations on positron emission tomography (PET)-computed tomography (CT) in neck-related muscles were retrospectively analyzed after surgical dissection of cervical lymph nodes in oral cancers.

RESULTS

According to the extent of ND of cervical lymph nodes, the rate of patients with 18F-FDG-PET-positive areas increased in the trapezius, sternocleidomastoid, and posterior neck muscles of the surgical and/or non-surgical sides. In addition, SUVmax of 18F-FDG-PET-positive areas in the trapezius and sternocleidomastoid muscles were increased according to the extent of the ND.

CONCLUSIONS

In evaluating 18F-FDG accumulations after ND for oral cancers, we should pay attention to the 18F-FDG distributions in neck-related muscles including the non-surgical side as false-positive findings.

Variety and complexity of fluorine-18-labelled fluoro-2-deoxy-D-glucose accumulations in the oral cavity of patients with oral cancers

OBJECTIVES

To elucidate the points that require attention when interpreting fluorine-18-labelled fluoro-2-deoxy-d-glucose ((18)F-FDG)/positron emission tomography (PET) images by demonstration of (18)F-FDG accumulation in various areas of the oral cavity other than primary lesions in patients with oral cancers.

METHODS

(18)F-FDG accumulations with a maximal standardized uptake value of over 2.5 in various areas of the oral cavity other than primary lesions were identified in 82 patients with oral cancers.

RESULTS

(18)F-FDG/PET-positive areas, excluding primary tumours, included the front intrinsic muscles of the tongue (89.0%), upper and lower marginal parts of the orbicularis oris muscle (64.6%), sublingual glands, palatine tonsil, pharyngeal tonsil, and lingual tonsil. In addition, some areas in the jaws also showed accumulation.

CONCLUSIONS

In patients with oral cancers, areas of (18)F-FDG accumulation in the oral cavity should be precisely identified and appropriately diagnosed, because accumulations can be seen in areas other than the primary tumour.