Aims and objectives
The primary objective of the study is to evaluate the diagnostic and staging reliability of a magnetic resonance imaging protocol that uses dual-echo and multi-echo Dixon (MRI-Dixon) sequences in the quantitative diagnosis of hepatic steatosis.MRI has become the gold standard imaging modality for quantification of hepatic fat.
The use of magnetic resonance imaging with Dixon sequences for the quantitative evaluation of hepatic steatosis is an highly promising and unique tool,
since at the moment there is no alternative standard technique,
apart from magnetic resonance proton...
Methods and materials
A population of 80 individuals over 18 years of age with known fatty liver disease or at risk of steatosis (overweight/obese individuals,
individuals with metabolic syndrome and/or diabetes mellitus,
individuals with chronic hepatitis B or C,
individuals with potentially hepatotoxic therapies) was evaluated.
Some clinically healthy individuals were included in the sample as a control.MRI exams were performed with a 1.5 Tesla Magnetom Aera magnetic resonance unit (Siemens Healthcare,
Erlangen,
Germany),
using an 18-channel surface coil (Body 18),
appropriately applied on the patient's upper abdomen...
Results
The results of 77/80 patients were taken into consideration; a scan was suspended due to coughing and in two cases the examination was null due to fat-water swapping artifact,
anartifact deriving from an incorrect determination whether a voxel contains water or fat.[6][7]
A high concordance was calculated between PDFF measurements performed with Dixon at a ROI and MRS (ρ=0.991).
Fig.
5.
The concordance was also high between PDFF measurements relative to the entire segmented hepatic volume (SV) with Dixon-SV and MRS (ρ=0.979 for Dixon-SV and...
Conclusion
MRS had already been recognized as comparable to biopsy and superior to the methods of conventional ultrasound and transient elastography in the quantitative diagnosis of hepatic steatosis in a substantial body of literature [7][8][9][10][11],
which is why we selected it as standard reference.
In our study both techniques (dual-echo and multi-echo) show a high statistical concordance with MRS in the measurement of PDFF,
an instrumental biomarker highly indicative of tissue fat concentration according to recent literature.[12]
Dixon-SV shows a lower concordance compared to the other...
Personal information
MV Raciti,
MD
University of Pavia
Institute of Radiology,
Foundation IRCCS Polyclinic San Matteo,
Pavia,
Italy
Viale Camillo Golgi 19
27100 Pavia
e-mail:
[email protected]
References
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Kanget al.,
“Hepatic fat quantification: a prospective comparison of magnetic resonance spectroscopy and analysis methods for chemical-shift gradient echo magnetic resonance imaging with histologic assessment as the reference standard,”Invest Radiol.,
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[2] M.
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Middletonet al.,
“Agreement Between Magnetic Resonance Imaging Proton Density Fat Fraction Measurements and Pathologist-Assigned Steatosis Grades of Liver Biopsies From Adults With Nonalcoholic Steatohepatitis,”Gastroenterology,
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[3] C.
B.
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Scott B.
Reeder,
Houchun H.,
“Proton...