Comparison of magnetic resonance spectroscopy, proton density fat fraction and histological analysis in the quantification of liver steatosis in children and adolescents

Abstract

AIMTo establish a threshold value for liver fat content between healthy children and those with non-alcoholic fatty liver disease (NAFLD) by using magnetic resonance imaging (MRI), with liver biopsy serving as a reference standard.METHODSThe study was approved by the local ethics committee, and written informed consent was obtained from all participants and their legal guardians before the study began. Twenty-seven children with NAFLD underwent liver biopsy to assess the presence of nonalcoholic steatohepatitis. The assessment of liver fat fraction was performed using MRI, with a high field magnet and 2D gradient-echo and multiple-echo T1-weighted sequence with low flip angle and single-voxel point-resolved ¹H MR-Spectroscopy (¹H-MRS), corrected for T1 and T2* decays. Receiver operating characteristic curve analysis was used to determine the best cut-off value. Lin coefficient test was used to evaluate the correlation between histology, MRS and MRI-PDFF. A Mann-Whitney U-test and multivariate analysis were performed to analyze the continuous variables.RESULTSAccording to MRS, the threshold value between healthy children and those with NAFLD is 6%; using MRI-PDFF, a cut-off value of 3.5% is suggested. The Lin analysis revealed a good fit between the histology and MRS as well as MRI-PDFF.CONCLUSIONMRS is an accurate and precise method for detecting NAFLD in children.

Assessment of a high‐SNR chemical‐shift‐encoded MRI with complex reconstruction for proton density fat fraction (PDFF) estimation overall and in the low‐fat range

“…Prior studies have proposed various PDFF cutoffs ranging from 3.5–6.9% to discriminate mild steatosis from no steatosis with respect to histology . As standard MRI‐C and Hi‐SNR MRI‐C provide the same performance at these ranges of PDFF cutoffs, it is unlikely that the various cutoffs in the literature are caused by differences in the PDFF sequence parameters, but rather can be linked to differences in subject groups (eg, different PDFF cutoff for adults and children).…”

“…Prior studies have proposed various PDFF cutoffs ranging from 3.5-6.9% to discriminate mild steatosis from no steatosis with respect to histology. 3,[20][21][22]33 As standard MRI-C and Hi-SNR MRI-C provide the same performance at these ranges of PDFF cutoffs, it is unlikely that the various cutoffs in the literature are caused by differences in the PDFF sequence parameters, but rather can be linked to differences in subject groups (eg, different PDFF cutoff for adults and children). More technically, in a chemical-shiftencoded MRI sequence with complex reconstruction that utilizes fat spectral modeling, T Ã 2 and T 1 correction that is acquired using parameters that are within the boundaries of those reasonable to estimate PDFF, we found that the results are the same regardless of changing the parameters, and that accuracy is not limited by SNR.…”

“…Nevertheless, MRI‐C sequences estimate PDFF with a small bias of about 1% with respect to MRS. This may have clinical implications for the early detection of nonalcoholic fatty liver disease (NAFLD), as PDFF cutoffs ranging from 3.5–6.9% have been proposed for the accurate discrimination of any steatosis (defined as grades 1–3 on NASH Clinical Research Network criteria) versus no steatosis (grade 0) diagnosed on biopsy . This relatively wide range for identifying steatosis partly reflects differences in disease severity between study cohorts, but it may also reflect imprecision in the low‐fat range of the MRI‐PDFF estimation methods.…”

“…This may have clinical implications for the early detection of nonalcoholic fatty liver disease (NAFLD), as PDFF cutoffs ranging from 3.5-6.9% have been proposed for the accurate discrimination of any steatosis (defined as grades 1-3 on NASH Clinical Research Network criteria) versus no steatosis (grade 0) diagnosed on biopsy. 3,[20][21][22] This relatively wide range for identifying steatosis partly reflects differences in disease severity between study cohorts, but it may also reflect imprecision in the low-fat range of the MRI-PDFF estimation methods. Additionally, many clinical trials in NASH have used PDFF as an eligibility criterion; typically, PDFF values of !5% are used for this purpose.…”

Неінвазивна Діагностика Фіброзу Печінки У Хворих Із неалкогольною Жировою Хворобою Печінки

“…Порівняно з УЗД сканування КТ та МРТ є кращими за наявності вогнищевого відкладення жиру [17], в інших випадках УЗД є більш чутливим у діагностиці НАЖХП [17,20]. Багатообіцяючим методом вважається магніт-но-резонансна спектроскопія (MRS), що виміряє вміст протонної фракції жиру та рівень тригліцеридів (ТГ) у печінці, починаючи з 5 %, але цей метод використо-вується більше в рамках наукових досліджень [21,22].…”