Aims and objectives
Intriguing applications of Diffusion Weighted Imaging (DWI) in body imaging are the quantitative measures of the Apparent Diffusion Coefficient (ADC).
These measures are made on maps obtained by images with at least two different b-values.In order to obtain reliable quantitative ADC maps it’s mandatory to use fast imaging sequences; Echo Planar Images (EPI) sequences in particular [1].
Images obtained with this method are affected by chemical shift artefacts and require an effective fat suppression technique.Fat suppression methods are employed in abdominal DWI to reduce chemical...
Methods and materials
The study population consists in 10 healthy volunteers (6 males and 4 females,
mean age 25±3 years).
All of them were scanned in 1,5 T Magnetic Resonance,
using phased array coils (32 channels in total).
The volunteers have been acquired with three triggered SE DW EPI [2],
each one with the same parameters and six different b values (0,
50,
400,
800,
1000,
1500 s/mm2),
using three different fat suppression methods: Inversion Recovery (IR),
Spectral Pre-saturation with Inversion Recovery (SPIR) and Spectral Attenuated Inversion Recovery...
Results
The statistical analysis pointed out different results depending on the anatomical part examined.The two ROIs of the liver gave significantly different results in all the three fat suppression methods (p<0,01).
However,
the values obtained with SPIR and SPAIR were more similar (Fig.2).The pancreas resulted to be the most sensitive organ,
where ADC values appeared to be strongly dependent on fat suppression method (p<0,01) (Fig.3).
In kidneys and spleen,
the results obtained with IR and SPAIR were statistically similar,
while the ones obtained using the SPIR...
Conclusion
From the obtained results,
it’s possible to affirm that the ADC values of the abdominal organs depend on the fat saturation method applied.All the calculated values (Tab.1) were inside the range obtained by the literature [4-5],
so it is not possible to state if there is a better technique that should be applied in the DWI.Since the abdomen study includes organs with different characteristics,
it would be interesting to understand the causes behind the variance of the ADC values when the fat saturation method changes,...
Personal information
Diego Cavalli,
MRI Radiographer,IntegratedUniversity Hospitalof Verona,Departmentof Radiology.Policlinico G.B.
Rossi,
Piazzale L.A.
Scuro 10,37134 Verona – Italy.
Phone number:+39-045-812-4556.
e-mail:
[email protected]
References
Cristiano Biagini et al.
Signal-to-Noise Ratio importance in Apparent Diffusion Coefficient measurements using Diffusion-weighted Echo-Planar imaging scans.
Journal of Advances in Physics,
2014
Mehdi P.A.,
Scott A.M.,
Jeffrey J.B.
et al.
Principles and Applications of Echo-planar Imaging: A Review for the General Radiologist.
Radiographics.
2001 May-Jun; 21(3):767-79
Maysam M.J.
Arman P.
et al.
Diffusion-weighted magnetic resonance imaging in cancer: Reported apparent diffusion coefficients,
in-vitro and in-vivo reproducibility.
World J Radiol.
2016 Jan 28;8(1):21-49.
Luisa Nogueira et al.
Breast DWI at 3 T: influence of the...
