Department of Radiology, Hospital de Pediatría Dr. Juan P. Garrahan, Combate de los Pozos 1881 (C 1245 AAM), Buenos Aires, Argentina.
Department of Research and Development, Hospital de Pediatría Dr. Juan P. Garrahan, Combate de los Pozos 1881 (C 1245 AAM), Buenos Aires, Argentina.
Pediatr Radiol. 2023 Jul;53(8):1618-1628. doi: 10.1007/s00247-023-05601-0. Epub 2023 Mar 4.
Pediatric hepatic steatosis is a global public health concern, as an increasing number of children are affected by this condition. Liver biopsy is the gold standard diagnostic method; however, this procedure is invasive. Magnetic resonance imaging (MRI)-derived proton density fat fraction has been accepted as an alternative to biopsy. However, this method is limited by cost and availability. Ultrasound (US) attenuation imaging is an upcoming tool for noninvasive quantitative assessment of hepatic steatosis in children. A limited number of publications have focused on US attenuation imaging and the stages of hepatic steatosis in children.
To analyze the usefulness of ultrasound attenuation imaging for the diagnosis and quantification of hepatic steatosis in children.
Between July and November 2021, 174 patients were included and divided into two groups: group 1, patients with risk factors for steatosis (n = 147), and group 2, patients without risk factors for steatosis (n = 27). In all cases, age, sex, weight, body mass index (BMI), and BMI percentile were determined. B-mode US (two observers) and US attenuation imaging with attenuation coefficient acquisition (two independent sessions, two different observers) were performed in both groups. Steatosis was classified into four grades (0: absent, 1: mild, 2: moderate and 3: severe) using B-mode US. Attenuation coefficient acquisition was correlated with steatosis score according to Spearman's correlation. Attenuation coefficient acquisition measurements' interobserver agreement was assessed using intraclass correlation coefficients (ICC).
All attenuation coefficient acquisition measurements were satisfactory without technical failures. The median values for group 1 for the first session were 0.64 (0.57-0.69) dB/cm/MHz and 0.64 (0.60-0.70) dB/cm/MHz for the second session. The median values for group 2 for the first session were 0.54 (0.51-0.56) dB/cm/MHz and 0.54 (0.51-0.56) dB/cm/MHz for the second. The average attenuation coefficient acquisition was 0.65 (0.59-0.69) dB/cm/MHz for group 1 and 0.54 (0.52-0.56) dB/cm/MHz for group 2. There was excellent interobserver agreement at 0.94 (95% CI 0.92-0.96). There was substantial agreement between both observers (κ = 0.77, with a P < 0.001). There was a positive correlation between ultrasound attenuation imaging and B-mode scores for both observers (r = 0.87, P < 0.001 for observer 1; r = 0.86, P < 0.001 for observer 2). Attenuation coefficient acquisition median values were significantly different for each steatosis grade (P < 0.001). In the assessment of steatosis by B-mode US, the agreement between the two observers was moderate (κ = 0.49 and κ = 0.55, respectively, with a P < 0.001 in both cases).
US attenuation imaging is a promising tool for the diagnosis and follow-up of pediatric steatosis, which provides a more repeatable form of classification, especially at low levels of steatosis detectable in B-mode US.
小儿肝脂肪变性是一个全球性的公共卫生问题，因为越来越多的儿童受到这种疾病的影响。肝活检是诊断的金标准方法；然而，该程序具有侵入性。磁共振成像（MRI）衍生的质子密度脂肪分数已被接受为活检的替代方法。然而，这种方法受到成本和可用性的限制。超声衰减成像是一种用于非侵入性定量评估儿童肝脂肪变性的新兴工具。有限数量的出版物集中在超声衰减成像和儿童肝脂肪变性的阶段。
分析超声衰减成像在儿童肝脂肪变性的诊断和定量中的作用。
2021 年 7 月至 11 月期间，共纳入 174 例患者，分为两组：组 1，有脂肪变性风险因素的患者（n=147）；组 2，无脂肪变性风险因素的患者（n=27）。所有患者均记录年龄、性别、体重、体重指数（BMI）和 BMI 百分位数。对两组均进行 B 型超声（两名观察者）和超声衰减成像（两名独立的会话，两名不同的观察者）采集衰减系数。使用 B 型超声将脂肪变性分为四级（0：无，1：轻度，2：中度和 3：重度）。根据 Spearman 相关性，将衰减系数采集与脂肪变性评分相关联。使用组内相关系数（ICC）评估衰减系数采集测量的观察者间一致性。
所有衰减系数采集测量均无技术失败，结果令人满意。组 1 第一次会话的中位数为 0.64（0.57-0.69）dB/cm/MHz，第二次会话的中位数为 0.64（0.60-0.70）dB/cm/MHz。组 2 第一次会话的中位数为 0.54（0.51-0.56）dB/cm/MHz，第二次会话的中位数为 0.54（0.51-0.56）dB/cm/MHz。组 1 和组 2 的平均衰减系数采集分别为 0.65（0.59-0.69）dB/cm/MHz 和 0.54（0.52-0.56）dB/cm/MHz。观察者间具有极好的一致性（0.94，95%CI 0.92-0.96）。两名观察者之间存在显著的一致性（κ=0.77，P<0.001）。超声衰减成像与 B 型超声评分之间存在正相关（观察者 1：r=0.87，P<0.001；观察者 2：r=0.86，P<0.001）。各脂肪变性等级的衰减系数采集中位数均有显著差异（P<0.001）。在 B 型超声评估脂肪变性时，两名观察者之间的一致性为中度（κ=0.49 和 κ=0.55，均 P<0.001）。
超声衰减成像是一种很有前途的小儿脂肪变性的诊断和随访工具，它提供了一种更可重复的分类形式，尤其是在 B 型超声可检测到的低水平脂肪变性中。
