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Objective To evaluate alterations in phase-shift values in the gray matter of patients with amyotrophic lateral sclerosis (ALS) using susceptibility-weighted imaging (SWI). Methods Twenty patients with definite or probable ALS and 19 age- and sex-matched healthy controls were enrolled. SWI was performed using a 3.0 T magnetic resonance imaging scanner. Phase-shift values were measured in corrected phase images using regions of interest, which were placed on the bilateral precentral gyrus, frontal cortex, caudate nucleus, globus pallidus, and putamen. Results Phase-shift values of the precentral gyrus were significantly lower in ALS patients (−0.176 ± 0.050) than in the control group (−0.119 ± 0.016) on SWI. The average phase-shift values of the frontal cortex, caudate nucleus, globus pallidus, and putamen in ALS patients (−0.089 ± 0.023, −0.065 ± 0.016, −0.336 ± 0.191, and −0.227 ± 0.101, respectively) were not significantly different from those in the healthy controls (−0.885 ± 0.015, −0.079 ± 0.018, −0.329 ± 0.136, and −0.229 ± 0.083, respectively). Conclusions Compared with healthy controls, ALS patients had a lower phase-shift value in the precentral gyrus, which may be related to abnormal iron overload. Thus, SWI is a potential method for identifying ALS patients.

Objective To evaluate the role of minimum apparent diffusion coefficient(MinADC) values in peritumoral edema based on magnetic resonance diffusion weighted imaging in the differential diagnosis between primary central nervous system lymphoma(PCNSL) and glioblastoma(GBM).Methods ADC values in peritumoral edema were measured in 16 patients with PCNSL(diffuse large B cell lymphoma) and 31 patients with GBM(WHO grade 4) confirmed by pathology.Regions of interests were manually drawn on ADC maps on peritumoral edema regions to obtain the MinADC value.Independent samples t-test and receiver operating characteristic analysis were performed for statistical analysis.Results The MinADC value [(1.20-1.45)×10

Objectives We hypothesized that three-dimensional pseudocontinuous arterial spin labelling (pCASL) may have similar efficacy in astrocytic tumour grading as dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI), and the grading accuracy may be further improved when combined with apparent diffusion coefficient (ADC) values. Methods Forty-three patients with astrocytic tumours were studied using diffusion weighted imaging (DWI), pCASL, and DSC-PWI. Histograms of ADC and normalized tumour cerebral blood flow values (nCBF on pCASL and nrCBF on DSC-PWI) were measured and analyzed. Results The mean 10 % ADC value was the DWI parameter that provided the best differentiation between low-grade astrocytoma (LGA) and high-grade astrocytoma (HGA). The nCBF and nrCBF (1.810 ± 0.979 and 2.070 ± 1.048) in LGA were significantly lower than those (4.505 ± 2.270 and 5.922 ± 2.630) in HGA. For differentiation between LGA and HGA, the cutoff values of 0.764 × 10-3 mm2/s for mean 10 % ADC, 2.374 for nCBF, and 3.464 for nrCBF provided the optimal accuracy (74.4 %, 86.1 %, and 88.6 %, respectively). Combining the ADC values with nCBF or nrCBF could further improve the grading accuracy to 97.7 % or 95.3 %, respectively. Conclusions pCASL is an alternative to DSC-PWI for astrocytic tumour grading. The combination of DWI and contrast-free pCASL offers a valuable choice in patients with risk factors. Key Points • pCASL shows positive correlation with DSC-PWI in astrocytic tumour grading. • ADC values based on ADC histograms can be an objective method. • Combination of DWI and pCASL or DSC-PWI can improve grading accuracy.

This study was performed to validate the efficacy of three-dimensional pseudocontinuous arterial spin labeling (pCASL) compared with dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI) in distinguishing radiation-induced brain injury from glioma recurrence in patients with glioma.Both 3D pCASL and DSC-PWI were performed using a 3.0 Tesla scanner in 69 patients with previously resected and irradiated glioma who displayed newly developed abnormal contrast-enhanced lesions. The included patients were classified into a radiation-induced brain injury group (n = 34) and a glioma recurrence group (n = 35) based on subsequent pathologic analysis or clinical-radiological follow-up. Lesion perfusion parameter values (CBF and nCBF on pCASL, nrCBV and nrCBF on DSC-PWI) were measured and compared between the two groups using Student's t test. Pearson correlation analysis was performed to evaluate the correlation between pCASL (CBF and nCBF) and DSC-PWI (nrCBV and nrCBF) values in the contrast-enhanced lesions and in the perifocal edema regions.For the contrast-enhanced lesions, the CBF, nCBF, nrCBV, and nrCBF (29.46 ± 15.08 ml/100 g/min, 1.11 ± 0.50, 1.39 ± 1.15, and 1.30 ± 0.74) in the radiation-induced brain injury group were significantly lower than those (64.52 ± 33.92 ml/100 g/min, 2.73 ± 1.71, 3.39 ± 2.12, and 3.20 ± 1.95) in the glioma recurrence group (P 0.001). The CBF and nCBF demonstrated strong correlation with nrCBV and nrCBF in the contrast-enhanced lesions.Radiation-induced brain injury and glioma recurrence can be reliably distinguished using both 3D pCASL and DSC-PWI. Contrast-free 3D pCASL is a suitable alternative to DSC-PWI for long-term follow-up in glioma patients with postoperative radiotherapy.

Objective To evaluate the diagnostic value of magnetic resonance diffusion-weighted imaging (DWI) and three-dimensional arterial spin labelling perfusion imaging (3D-ASL) in distinguishing cavernous haemangioma from parasellar meningioma, using histological data as a reference standard. Methods Patients with parasellar meningioma or parasellar cavernous haemangioma underwent conventional T1- and T2-weighted magnetic resonance imaging (MRI) followed by DWI and 3D-ASL using a 3.0 Tesla MRI. The minimum apparent diffusion coefficient (minADC) from DWI and the maximal normalized cerebral blood flow (nCBF) from 3D-ASL were measured in each tumour. Diagnosis was confirmed by histology. Results MinADC was significantly lower and nCBF significantly higher in meningioma ( n = 19) than cavernous haemangioma ( n = 15). There was a significant negative correlation between minADC and nCBF ( r = −0.605). Conclusion DWI and 3D-ASL are useful in differentiating cavernous haemangiomas from parasellar meningiomas, particularly in situations when the appearance on conventional MRI sequences is otherwise ambiguous.

To evaluate the efficacy of 3D pseudocontinuous arterial spin labeling (3D pCASL) in the differential diagnosis between mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS) and acute ischemic stroke (AIS).Conventional magnetic resonance imaging (MRI) including TThe lesions of both MELAS and AIS showed high signal intensity on TThe whole-brain 3D pCASL technique might be useful in differentiating MELAS from AIS.3 J. Magn. Reson. Imaging 2017;45:199-206.

To evaluate the role of perfusion weighted imaging (PWI) in the differentiation between recurrent glioma and radiation-induced brain injuries.Twenty-three patients with previously resected and irradiated glioma, presenting newly developed abnormal enhancement, were included in the study. The final diagnosis was determined either histologically or clinicoradiologically. PWI was obtained with a gradient echo echo-planar-imaging (GRE-EPI)technique. The normalized relative cerebral blood volume (rCBV) ratio [rCBV (abnormal enhancement)/rCBV (contralateral tissue)], relative cerebral blood flow (rCBF) ratio [rCBF (abnormal enhancement)/rCBF(contralateral tissue)], mean transit time(MTT) ratio [MTT (abnormal enhancement)/MTT(contralateral tissue)],time to peak(TTP)ratio[TTP(abnormal enhancement)/TTP(contralateral tissue)],and bolus arrive time(BAT)ratio[BAT(abnormal enhancement)/BAT(contralateral tissue)] were calculated. The regions of interest (ROIs) consisting of 20-40mm(2) were placed in the abnormal enhanced areas on postcontrast T1-weighted images.Ten ROIs measurements were performed in each lesion.T test was used to determine whether there was a difference in the rCBV/rCBF/rMTT/rTTP/rBAT ratios between recurrent glioma and irradiated injuries.Significance was set to a P value0.05.Thirteen of the 23 patients were proved recurrent glioma and 10 were proved radiation-induced brain injuries. The rCBV ratio (3.60±3.86 vs. 0.82 ± 0.74, P = 0.000)and rCBF ratio (2.88 ± 2.27 vs. 0.84 ± 0.80, P = 0.000) in glioma recurrence were markedly higher than those in radiation injuries. The areas under rCBV and rCBF ROC curve were both 0.8763. rMTT (P=0.204), rTTP (P=0.260), and rBAT (P=0.071) ratios showed no statistical difference between the two groups.PWI is an effective technique in distinguishing glioma recurrence from radiation injuries,and the ratios of rCBV and rCBF ratio differential diagnosis of critical value to 1.3088 and 1.1235, respectively, can be used as a reliable clinical indicator.