Department of Radiology, Academic Medical Center, Meibergdreef 9, Amsterdam 1105 AZ, The Netherlands.
AJR Am J Roentgenol. 2011 Jun;196(6):W736-42. doi: 10.2214/AJR.10.5215.
The purpose of this study was to assess, with histopathologic control, the use of open-system 1-T (1)H MR spectroscopy for the evaluation of hepatic steatosis in morbidly obese patients undergoing gastric bypass surgery.
Patients underwent (1)H MR spectroscopy (MRS) for the assessment of steatosis before and 3 months after surgery. Liver biopsy was performed during surgery. Hepatic steatosis was expressed as the ratio of fat peak area to cumulative water and fat peak areas. Histopathologic percentage of steatosis was graded as none (0-5%), mild (5-33%), moderate (33-66%), or severe (> 66%). The accuracy of (1)H-MRS and Spearman correlation coefficient were calculated. Differences between groups were assessed with the Wilcoxon signed rank and Mann-Whitney tests.
The study included 38 patients (median age, 45.5 years; median body mass index, 47.7). Before surgery, median steatosis measured with (1)H-MRS was 5.8%. The accuracy of (1)H-MRS was 89% (32/36), and the (1)H-MRS findings correlated with the histopathologic assessment of steatosis (r = 0.85, p < 0.001). With (1)H-MRS, no steatosis was discriminated from mild steatosis (p = 0.011), mild was discriminated from moderate steatosis (p < 0.001), and moderate was discriminated from severe steatosis (p = 0.021). Three months after surgery, steatosis had decreased to 3.1% (p < 0.001). The prevalence of hepatic steatosis measured with (1)H-MRS decreased from 53% to 32%.
In the care of morbidly obese patients undergoing assessment of hepatic steatosis and changes in steatosis after gastric bypass surgery, (1)H-MRS with an open 1-T MRI system is feasible. Measurements of hepatic fat with (1)H-MRS are accurate and correlate with clinical and histopathologic results.
本研究旨在通过组织病理学对照，评估开放式 1-T（1）H 磁共振波谱（MRS）在病态肥胖患者行胃旁路手术后评估肝脂肪变性中的应用。
患者在手术前行（1）H MRS 评估肝脂肪变性，并在术后 3 个月进行。术中行肝活检。肝脂肪变性用脂肪峰面积与水和脂肪峰面积总和的比值表示。组织病理学脂肪变性程度评为无（0-5%）、轻度（5-33%）、中度（33-66%）或重度（>66%）。计算（1）H-MRS 的准确性和斯皮尔曼相关系数。采用 Wilcoxon 符号秩和检验和 Mann-Whitney 检验比较组间差异。
研究纳入 38 例患者（中位年龄 45.5 岁；中位体重指数 47.7）。术前（1）H-MRS 测量的肝脂肪变性中位数为 5.8%。（1）H-MRS 的准确率为 89%（32/36），且（1）H-MRS 结果与肝脂肪变性的组织病理学评估相关（r=0.85，p<0.001）。（1）H-MRS 可区分无脂肪变性与轻度脂肪变性（p=0.011）、轻度与中度脂肪变性（p<0.001）以及中度与重度脂肪变性（p=0.021）。术后 3 个月，脂肪变性减少至 3.1%（p<0.001）。（1）H-MRS 测量的肝脂肪变性患病率从 53%降至 32%。
在评估病态肥胖患者的肝脂肪变性和胃旁路手术后脂肪变性变化的过程中，使用开放式 1-T MRI 系统的（1）H-MRS 是可行的。（1）H-MRS 测量肝脂肪含量准确，并与临床和组织病理学结果相关。
