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}

}

@article{Mattock2021-fz,

title = {Economic evaluation of covered stents for transjugular 

 intrahepatic portosystemic stent shunt in patients with variceal 

 bleeding and refractory ascites secondary to cirrhosis},

author = {Richard Mattock and Dhiraj Tripathi and Frank O'Neill and Joyce Craig and Jennifer Tanner and David Patch and Guruprasad Aithal},

year  = {2021},

date = {2021-08-01},

journal = {BMJ Open Gastroenterol.},

volume = {8},

number = {1},

pages = {e000641},

publisher = {BMJ},

abstract = {OBJECTIVES: Transjugular intrahepatic portosystemic stent shunt 

 (TIPSS) is clinically effective in variceal bleeding and 

 refractory ascites; however, the cost-effectiveness of TIPSS has 

 yet to be evaluated in the UK. This study aimed to establish the 

 cost-effectiveness of (i) pre-emptive TIPSS versus endoscopic 

 band ligation (EBL) in populations with variceal bleeding and 

 (ii) TIPSS versus large volume paracentesis (LVP) in refractory 

 ascites. METHODS: A cost-utility analysis was conducted with the 

 perspective including healthcare costs and quality-adjusted life 

 years (QALYs). A Markov model was constructed with a 2-year time 

 horizon, health states for mortality and survival and 

 probabilities for the development of variceal bleeding, ascites 

 and hepatic encephalopathy. A survival analysis was conducted to 

 extrapolate 12-month to 24-month mortality for the refractory 

 ascites indication. Uncertainty was analysed in deterministic 

 and probabilistic sensitivity analyses. RESULTS: TIPSS was 

 cost-effective (dominant) and cost saving for both indications. 

 For variceal bleeding, pre-emptive TIPSS resulted in 0.209 

 additional QALYs, and saved pounds600 per patient compared 

 with EBL. TIPSS had a very high probability of being 

 cost-effective (95%) but was not cost saving in scenario 

 analyses driven by rates of variceal rebleeding. For refractory 

 ascites, TIPSS resulted in 0.526 additional QALYs and saved 

 pounds17 983 per patient and had a 100% probability of being 

 cost-effective and cost saving when compared with LVP. 

 CONCLUSIONS: TIPSS is a cost-effective intervention for variceal 

 bleeding and refractory ascites. TIPSS is highly cost-saving for 

 refractory ascites. Robust randomised trial data are required to 

 confirm whether pre-emptive TIPSS is cost saving for variceal 

 bleeding.},

keywords = {ascites, bleeding, cost-effectiveness, economic evaluation, liver cirrhosis},

pubstate = {published},

tppubtype = {article}

}