The Pilot Study Of Common Intracranial Tumors Using Intravoxel Incoherent Motion Imaging

Part1The pilot study of benign meningiomas using intravoxel incoherent motion imagingObjectiveTo evaluate the diagnostic performance of monoexponential model and the bi-exponential modeling of intravoxel incoherent motion (IVIM) MR imaging for benign meningiomas in brain.MethodsThis study was approved by local ethics committee, and written informed consent was obtained.60patients with benign meningiomas diagnosed clinically were examined on a3.0T MR scanners (Achieva3.0T TX, Philips, The Netherlands).The scanning protocol included the conventional MR imaging, IVIM MR imaging and contrast-enhanced MR imaging. The IVIM sequence was performed with14b values between0and1000on3orthogonal directions. Finally,22patients were enrolled on the basis of prepared inclusion criteria. Region-of-interest was manually set on the tumor as well as in the normal white matter. All the data were fitted by a mono-exponential model [yielding the apparent diffusion coefficient (ADC)] and the bi-exponential model (yielding the diffusion constant D, the pseudodiffusion coefficient of perfusion D*and the perfusion fraction f). The paired t tests were used to assess differences between the tumor and normal white-matter.ResultsLesions were clearly showed on every sequence. Signal decay curves were bi-exponential in the benign meningiomas. The ADC, D, D*and f values of benign meningiomas were(0.87±0.13) μm2,ms,(0.79±0.10)μm2/ms,(58.68±27.52)μm2/ms,(7.68±3.59)%and those values of the normal white-matter were(0.74±0.06) μm2/ms,(0.69±0.04) μm2/ms,(93.43±31.64) μm2/ms,(4.48±2.39)%, respectively. The differences of the ADC, D, D*and f values between two groups were statistically significant (t=5.793,4.384,-3.559,3.349; P<0.05, respectively).The differences of the ADC and the D values between the benign meningiomas parenchyma were statistically significant (t=0.579, P<0.05).ConclusionsIVIM imaging can describe the tumor and might be a valid and promising method to quantify perfusion and more accurate diffusion in benign meningiomas. Part2The pilot study of gliomas in brain using intravoxel incoherent motion imagingObjectiveTo evaluate the diagnostic performance of monoexponential model and the bi-exponential model using intravoxel incoherent motion (IVIM) MR imaging for gliomas in brain.MethodsThis study was approved by local ethics committee, and written informed consent was obtained.48patients with benign meningiomas diagnosed clinically were examined on a3.0T MR scanners (Achieva3.0T TX, Philips, The Netherlands).The scanning protocol included the conventional MR imaging, IVIM MR imaging and contrast-enhanced MR imaging. The IVIM sequence was performed with14b values between0and1000on3orthogonal directions. Finally,25patients were enrolled on the basis of prepared inclusion criteria. Region-of-interest was manually set on the tumor as well as in the contralateral white matter. All the data fitted to a monoexponential model [yielding the apparent diffusion coefficient (ADC)] and the bi-exponential model (yielding the diffusion constant D, the pseudodiffusion coefficient of perfusion D*and the perfusion fraction f).The significant differences between the tumor and contralateral normal white matter were assessed by using the paired t tests.ResultsLesions were clearly showed on every sequence. Signal decay curves were bi-exponential in the gliomas parenchyma. The ADC,D and f values of gliomas were significantly (P<0.05) higher (1.13±0.36μm2/ms,1.07±0.27μ2m/ms and5.80±3.81%, respectively) than contralateral normal region (0.77±0.08μm2/ms,0.72±0.06μm2/ms and4.09±1.58%, respectively).The D*values were no statistic differences between tumor parenchyma and contralateral normal white matter (P>0.05) ConclusionsIVIM imaging might can describe the tumor and be a valid and promising method to quantify perfusion and more accurate diffusion in brain gliomas.