Publications

@article{Bawden2023-bk,

title = {Comparing magnetic resonance liver fat fraction measurements 

 with histology in fibrosis: the difference between proton 

 density fat fraction and tissue mass fat fraction},

author = {Stephen James Bawden and Caroline Hoad and Philip Kaye and Mary Stephenson and Grace Dolman and Martin W James and Emilie Wilkes and Andrew Austin and Indra Neil Guha and Susan Francis and Penny Gowland and Guruprasad P Aithal},

year  = {2023},

date = {2023-08-01},

journal = {MAGMA},

volume = {36},

number = {4},

pages = {553\textendash563},

publisher = {Springer Science and Business Media LLC},

abstract = {OBJECTIVE: Magnetic resonance spectroscopy (MRS) provides a 

 powerful method of measuring fat fraction. However, previous 

 studies have shown that MRS results give lower values compared 

 with visual estimates from biopsies in fibrotic livers. This 

 study investigated these discrepancies and considered whether a 

 tissue water content correction, as assessed by MRI relaxometry, 

 could provide better agreement. MATERIALS AND METHODS: 110 

 patients were scanned in a 1.5 T Philips scanner and biopsies 

 were obtained. Multiple echo MRS (30 $times$ 30 $times$ 30 mm 

 volume) was used to determine Proton Density Fat Fraction 

 (PDFF). Biopsies were assessed by visual assessment for fibrosis 

 and steatosis grading. Digital image analysis (DIA) was also 

 used to quantify fat fraction within tissue samples. T1 

 relaxation times were then used to estimate tissue water content 

 to correct PDFF for confounding factors. RESULTS: PDFF values 

 across the four visually assessed steatosis grades were 

 significantly less in the higher fibrosis group (F3-F4) compared 

 to the lower fibrosis group (F0-F2). The slope of the linear 

 regression of PDFF vs DIA fat fraction was ~ 1 in the low 

 fibrosis group and 0.77 in the high fibrosis group. Correcting 

 for water content based on T1 increased the gradient but it did 

 not reach unity. DISCUSSION: In fibrotic livers, PDFF 

 underestimated fat fraction compared to DIA methods. Values were 

 improved by applying a water content correction, but fat 

 fractions were still underestimated.},

keywords = {Fatty liver, fibrosis, liver cirrhosis, Liver diseases, Non-alcoholic fatty liver disease},

pubstate = {published},

tppubtype = {article}

}