According to the relationship between signal intensities and b values, IVIM could be expressed by a mathematical formula as follows:
The nonparametric Mann-Whitney U test was used throughout the study to compare IVIM parameters and [ADC.
Unlike the two b values in DWI from which ADC is calculated according to the mono-exponential model, which mixes diffusion as well as blood flow, IVIM can distinguish diffusion and perfusion components separately using multiple b values through a bi-exponential model algorithm (15, 16).
These 42 consecutive women with cervical cancer (mean age, 50 [+ or -] 9 years; 37 cervical squamous cell carcinomas, four cervical adenocarcinomas, and one cervical adenosquamous carcinoma; 28 IIA + IIB, 10 IIIA + IIIB, and 4 IVA) that was histologically confirmed by biopsy were examined using IVIM MRI at 3 time points: pre-NACT, 3 weeks after the first NACT cycle, and 3 weeks after the second NACT cycle.
All the acquired IVIM MRI images were transferred to a workstation (Advance Workstation 4.
In the biexponential IVIM model, the relationship between signal variation and b factors is expressed as follows: [sup]
2] make it possible to obtain signals of small vessels with slow flow that contributes to the acquisition of IVIM signal (LeBihan & Turner, 1992; LeBihan, 2008).
According to this equation, IVIM theory can obtain the IVIM Image (which contains diffusion and perfusion) and the pure diffusion image called D.
Because IVIM has the potential to provide both diffusion and perfusion information without an exogenous contrast agent, its application for the brain is promising.
To our knowledge, few studies have specifically validated the relationship between the perfusion index derived from IVIM (fast apparent diffusion coefficients [ADC]) and ASL CBF in the human brain.
suggested that D FNx01 mainly depended on the velocity of tubular fluid instead of microperfusion in the kidney by correlated IVIM parameters with computed tomography perfusion parameters on swine model.
Although the present data rendering the feasibility that the microperfusion together with tubular dynamics might be evaluated using biexponential models, they couldn't be separated from each other by IVIM method.