比較不同磁振造影及磁共振波譜技術定量肝組織脂肪堆積之研究

Quantification of Hepatic Steatosis: A Comparison of the Accuracy among Multiple Magnetic Resonance Techniques

吳志宏(Chih-Horng Wu)

指導教授 ： 施庭芳

國立臺灣大學/醫學院/臨床醫學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.01164

摘要

脂肪肝是指可逆性的脂肪堆積在肝臟細胞內，是已開發國家常見的肝臟疾病。飲酒、肥胖、糖尿病及代謝症候群是造成脂肪肝最常見的原因。肝臟切片是脂肪肝診斷的黃金標準但它屬於一種侵襲性的檢查。過去的研究顯示磁振造影及磁共振波譜相較於超音波及電腦斷層有較好的診斷力。但不同的磁振造影方法及磁共振波譜之間精確度的比較仍然不明瞭。本研究是要比較不同的磁振技術與組織切片下脂肪肝的程度及實驗室內肝細胞脂肪油滴萃取的相關性。
我們收集六十位預備接受肝切除手術的病人進行二迴波磁振造影(double-echo magnetic resonance imaging)、三迴波磁振造影(triple-echo magnetic resonance imaging)及磁共振波譜(magnetic resonance spectroscopy)的檢查。病人脂肪肝的程度以外科檢體內組織脂肪肝的百分比(histologic steatosis percentage)及肝細胞內三酸甘油酯密度(intrahepatocellular triglyceride density)當作黃金標準並以皮爾森相關係數(Pearson correlation coefficient)來作為相關性的指標。此外，以林氏一致性相關係數(Lin’s concordance coefficient)，Bland-Altman 95%一致性界限來評估三種磁振技術估計肝細胞內三酸甘油酯密度的準確性。診斷的表現則是以ROC (receiver operating characteristic)曲線來比較及分析。
三種影像方法所測的脂肪訊號與脂肪肝程度都有顯著相關，但三迴波磁振造影及磁共振波譜相較於二迴波磁振造影與組織脂肪肝的百分比及肝細胞內三酸甘油酯密度具有較強的相關性。此外，三迴波磁振造影有最高的林氏一致性相關係數(ρ = 0.881)及最高比例在Bland-Altman 95%一致性界限內(93.3%, 56/60)。最後，以ROC曲線分析大於5%組織脂肪肝，三迴波磁振造影的曲線下面積(0.9783)相較於二迴波磁振造影達到統計上的顯著(P = .0121)。
在三種磁振技術中，三迴波磁振造影是非侵犯性評估脂肪肝較好的方法。

關鍵字

脂肪肝 ； 非酒精性脂肪肝病 ； 肝硬化 ； 磁振造影 ； 磁共振波譜

並列摘要

Hepatic steatosis is reversible presence of fat deposits in hepatocytes. It is a common liver disease in developed country. Alcoholism, obesity, insulin-resistant diabetes mellitus, and metabolic syndrome are the most common causes of fatty liver. Liver biopsy has been the gold standard for hepatic steatosis diagnosis. Previous study shows magnetic resonance imaging and magnetic resonance spectroscopy are better diagnostic tools than ultrasound and computed tomography but their relative accuracy remains uncertain. This study was conducted to compare different magnetic resonance techniques and correlate the techniques with the histological findings and measurement of intracellular lipid density.
Sixty patients scheduled for elective liver resection were included in this study. Liver fat fraction was preoperatively counted from non-tumor liver parenchyma with double-echo, triple-echo magnetic resonance imaging, and magnetic resonance spectroscopy. The hepatic steatosis was defined by histologic steatosis percentage and intrahepatocellular triglyceride density from the surgical specimen as the reference standard. Imaging quantification results were evaluated by using Pearson correlation. Lin’s concordance coefficient and Bland-Altman 95% limits of agreement were used to evaluate the concordance among the 3 magnetic resonance techniques in estimating intrahepatocellular triglyceride density. The diagnostic performance was compared by using receiver operating characteristic curve analysis.
All 3 imaging methods were significantly correlated with the degree of hepatic steatosis. However, triple-echo magnetic resonance imaging, and magnetic resonance spectroscopy measurements of hepatic steatosis had a stronger relationship with histologic steatosis percentage and intrahepatocellular triglyceride density than did double-echo magnetic resonance imaging. The triple-echo magnetic resonance imaging had the highest concordance correlation coefficients (ρ = 0.881) and percentage (93.3%, 56/60) within the Bland-Altman 95% limits of agreement. For receiver operating characteristic curve analysis with diagnosing >5% histologic steatosis percentage, the triple-echo magnetic resonance imaging had larger area under curve (0.9783) than double-echo magnetic resonance imaging with statistical significance (P = .0121).
Among 3 magnetic resonance techniques, triple-echo magnetic resonance imaging may be the preferred imaging examination method for a noninvasive assessment of hepatic steatosis.

並列關鍵字

Fatty liver ； Non-alcoholic fatty liver disease ； Liver cirrhosis ； Magnetic resonance imaging ； Magnetic resonance spectroscopy

參考文獻

1. Browning JD, Szczepaniak LS, Dobbins R, Nuremberg P, Horton JD, Cohen JC, et al. Prevalence of hepatic steatosis in an urban population in the United States: Impact of ethnicity. Hepatology. 2004 Dec;40(6):1387–95.

2. Szczepaniak LS, Nurenberg P, Leonard D, Browning JD, Reingold JS, Grundy S, et al. Magnetic resonance spectroscopy to measure hepatic triglyceride content: prevalence of hepatic steatosis in the general population. Am. J. Physiol.-Endocrinol. Metab. 2005;288(2):E462–E468.

3. Lai S-W, Tan C-K, Ng K-C. Epidemiology of fatty liver in a hospital-based study in Taiwan. South. Med. J. 2002 Nov;95(11):1288–92.

4. Selzner M, Clavien PA, others. Fatty liver in liver transplantation and surgery. Semin. Liver Dis. 2001. p. 105–14.

5. Kim HJ, Kim HJ, Lee KE, Kim DJ, Kim SK, Ahn CW, et al. Metabolic significance of nonalcoholic fatty liver disease in nonobese, nondiabetic adults. Arch. Intern. Med. 2004;164(19):2169.