MRI-based volumetric and histogram analysis of parotid and submandibular glands in hypertensive patients: a retrospective study.

BACKGROUND

The aim of this retrospective study is to evaluate the volumetric and histogram-based characteristics of the parotid and submandibular salivary glands in patients with hypertension compared with healthy controls.

METHODS

Magnetic Resonance images of a total of 94 patients, including 42 hypertensive and 52 control subjects, were included in the study. The volumes of the right and left parotid and submandibular glands were manually measured on images obtained using a 1.5 Tesla Magnetic Resonance scanner. For volumetric assessment of the parotid and submandibular glands, T1-weighted MR images were analyzed using the Sectra IDS7 software program on a full HD display. In addition, histogram analysis was performed on manually defined regions of interest to calculate mean, skewness, and kurtosis values.

RESULTS

A total of 94 participants were included. Submandibular gland volumes were significantly higher in hypertensive patients (right: 8.58 ± 2.0; left: 8.61 ± 2.1 ) compared to controls (right: 7.81 ± 2.1; left: 7.73 ± 1.9), while parotid gland volumes showed no significant difference (p < 0.05). Histogram analysis revealed significantly lower mean grayscale values in the parotid glands in the hypertension group (right: 113.73 ± 27.9; left: 113.81 ± 25.6) compared to healthy controls (right: 145.91 ± 31.1; left: 148.89 ± 32.6)(p < 0.001), whereas skewness and kurtosis values were not significantly different (p > 0.05).

CONCLUSION

Hypertension may be associated with gland-specific volumetric changes and diffuse microstructural alterations in salivary glands. Histogram-based analysis provides complementary information beyond volumetric measurements and may improve the detection of subtle tissue changes. MRI is an effective method for quantitative evaluation of salivary glands.