Stiffness of salivary gland and tumor measured by new ultrasonic techniques: Virtual touch quantification and IQ.

Objective: To evaluate normal salivary gland stiffness and compare the diagnostic performance of virtual touch quantification (VTQ) and virtual touch imaging quantification (VTIQ) for head and neck tumor.

Methods: A total of 92 measurements were examined, comprising 77 normal salivary glands, 11 benign tumors and four malignant tumors. Examinations were made to evaluate normal salivary gland stiffness and compare the diagnostic performances of new ultrasonic techniques regarding head and neck tumor.

Results: The mean values of VTQ and VTIQ for the normal salivary group (NSG) were 1.92 and 2.06m/s, respectively. The VTQ and VTIQ values were correlative, and there were no statistical differences in each mean value between the normal parotid glands and submandibular glands. For the benign tumor group (BTG), four of the 11 values were non-numeric and were considered above the measurable range. The mean VTIQ value for the BTG was 4.24m/s. For the malignant tumor group (MTG), all four VTQ values were non-numeric. The mean VTIQ value for the MTG was 6.52m/s. For the mean VTIQ values, significant differences were observed among the three groups. The optimum VTQ cutoff value to detect malignant tumors was above the measurable range, and that of VTIQ was 4.83m/s.

Conclusion: The VTQ and VTIQ values were correlative for the salivary glands, and the stiffnesses of normal parotid glands were almost same as those of submandibular glands. VTQ and VTIQ values could be applied for the preoperative diagnosis in salivary gland lesions.