Chikui Toru, Yamashita Yasuo, Kise Yoshitaka, Saito Tomonori, Okamura Kazutoshi, Yoshiura Kazunori
1 Department of Oral and Maxillofacial Radiology, Faculty of Dental Science, Kyushu University , Fukuoka , Japan.
2 Department of Medical Technology, Kyushu University Hospital , Fukuoka , Japan.
Br J Radiol. 2018 May;91(1085):20170671. doi: 10.1259/bjr.20170671. Epub 2018 Feb 6.
Our first objective was to prove the validity of the six-point Dixon method for estimating the proton density fat fraction (PDFF) of the salivary gland. The second objective was to estimate the salivary gland PDFF using Dixon method to evaluate the pathological conditions.
At first, 12 volunteers underwent two types of sequences: single-voxel magnetic resonance spectroscopy and the Dixon method and the PDFFs obtained by the two methods were compared. Next, a total of 67 individuals [normal, n = 46; Sjögren's syndrome (SS), n = 11; and IgG4-related dacryoadenitis and sialadenitis (IgG4-DS), n = 4, parotitis, n = 6] were enrolled to estimate the parotid gland (PG) and submandibular gland (SMG) PDFF using the Dixon method.
This volunteer study demonstrated excellent correlation between two methods (R = 0.964, slope = 1.05). In the normal group, the PG-PDFF was correlated with the weight and body mass index (BMI) (ρ = 0.38, p = 0.0085; and ρ = 0.63, p < 0.0001). The SMG-PDFF was also correlated with the weight, BMI, and serum triglyceride (ρ = 0.37, p = 0.0067; ρ = 0.42, p = 0.0022; and ρ = 0.35, p = 0.024). The PG-PDFF of the SS group (48.2 ± 15.1%) was higher than that of any other groups; however, no significant difference was found due to the wide overlap. The SS group (39.0 ± 26.14%) also had significantly higher SMG-PDFF than the normal group (8.9 ± 5.4%), p < 0.0001) and IgG4-DS group (3.8 ± 2.3%), p = 0.020).
The Dixon method is a feasible method for estimating the PDFF and demonstrates fat accumulation in SMG in the SS group. Advances in knowledge: The PDFF obtained by the Dixon method is helpful for understanding the salivary gland pathological condition.
我们的首要目标是证明六点狄克逊法用于估计唾液腺质子密度脂肪分数（PDFF）的有效性。第二个目标是使用狄克逊法估计唾液腺PDFF以评估病理状况。
首先，12名志愿者接受了两种序列检查：单体素质子磁共振波谱和狄克逊法，并比较了两种方法获得的PDFF。接下来，共纳入67名个体[正常，n = 46；干燥综合征（SS），n = 11；IgG4相关性泪腺炎和涎腺炎（IgG4-DS），n = 4，腮腺炎，n = 6]，使用狄克逊法估计腮腺（PG）和下颌下腺（SMG）的PDFF。
这项志愿者研究表明两种方法之间具有良好的相关性（R = 0.964，斜率 = 1.05）。在正常组中，PG-PDFF与体重和体重指数（BMI）相关（ρ = 0.38，p = 0.0085；ρ = 0.63，p < 0.0001）。SMG-PDFF也与体重、BMI和血清甘油三酯相关（ρ = 0.37，p = 0.0067；ρ = 0.42，p = 0.0022；ρ = 0.35，p = 0.024）。SS组的PG-PDFF（48.2 ± 15.1%）高于其他任何组；然而，由于重叠范围广，未发现显著差异。SS组（39.0 ± 26.14%）的SMG-PDFF也显著高于正常组（8.9 ± 5.4%），p < 0.0001）和IgG4-DS组（3.8 ± 2.3%），p = 0.020）。
狄克逊法是一种估计PDFF的可行方法，并证明了SS组SMG中存在脂肪堆积。知识进展：通过狄克逊法获得的PDFF有助于了解唾液腺病理状况。
