Influence of bronchopulmonary dysplasia on cerebral blood flow in preterm infants: a prospective study based on arterial spin labeling / 中国当代儿科杂志

OBJECTIVES@#To investigate local cerebral blood perfusion in preterm infants with bronchopulmonary dysplasia (BPD) based on cerebral blood flow (CBF) values of arterial spin labeling (ASL).@*METHODS@#A prospective study was conducted on 90 preterm infants with a gestational age of <32 weeks and a birth weight of <1 500 g who were born in the Department of Obstetrics and admitted to the Department of Neonatology in the Third Affiliated Hospital of Zhengzhou University from August 2021 to June 2022. All of the infants underwent cranial MRI and ASL at the corrected gestational age of 35-40 weeks. According to the presence or absence of BPD, they were divided into a BPD group with 45 infants and a non-BPD group with 45 infants. The two groups were compared in terms of the CBF values of the same regions of interest (frontal lobe, temporal lobe, parietal lobe, occipital lobe, thalamus, and basal ganglia) on ASL image.@*RESULTS@#Compared with the non-BPD group, the BPD group had a significantly lower 1-minute Apgar score, a significantly longer duration of assisted ventilation, and a significantly higher incidence rate of fetal distress (P<0.05). After control for the confounding factors such as corrected age and age at the time of cranial MRI by multiple linear regression analysis, compared with the non-BPD group, the BPD group still had higher CBF values of the frontal lobe, temporal lobe, parietal lobe, occipital lobe, basal ganglia, and thalamus at both sides (P<0.05).@*CONCLUSIONS@#BPD can increase cerebral blood perfusion in preterm infants, which might be associated with hypoxia and a long duration of assisted ventilation in the early stage.

Case Report: Arterial Spin Labeling Perfusion MRI Contribution for Clinical Implementation of Brain Disease

@#Currently, ASL is widely used as an additional breakthrough sequence in MRI due to acquiring reliable results. The case report aims to prove the efficacy and effectiveness of a quantitative method of ASL sequence through the calculation of the cerebral blood flow (CBF) on CBF maps in different cases. ASL sequence has been done on four patients with different cases. Then, the authors put 2 regions of interest (ROI) for measurement in normal and different regions on CBF maps and then calculated the average value result from CBF maps. ASL has been proven as a reliable and breakthrough sequence in MRI for detecting brain disease with a non-invasive method through the calculation of CBF value. ASL should be used as an additional protocol in brain examinations because it allows radiologists to assess the significance of CBF values using a quantitative method that is more reliable and non-invasiv

Evaluation of early renal function changes in patients with type 2 diabetes mellitus using BOLD and ASL / 中华放射学杂志

Objective:To noninvasively evaluate the clinical value of early renal function changes in patients with type 2 diabetes mellitus (T2DM) using blood oxygenation level dependent (BOLD) and arterial spin labeling (ASL) MRI.Methods:A total of 63 T2DM patients from Tianjin First Central Hospital from September 2019 to May 2022 were prospectively collected, 30 healthy volunteers (control group) were collected during the same period. According to albumin creatinine ratio (ACR), patients with T2DM were divided into normal albuminuria (NAU, ACR<30 mg/g) group and microalbuminuria (MAU, 30 mg/g≤ACR≤300 mg/g) group, there were 35 and 28 cases respectively. All subjects underwent abdominal BOLD and ASL scans. The values of renal cortical and medullary apparent relaxation rate (R 2*) and renal cortical renal blood flow (RBF) were measured. One-way ANOVA was used to compare the differences in R 2* and RBF among the three groups. Receiver operating characteristic curve was used to analyze relevant parameters to identify the diagnostic effectiveness of each group, and area under the curve (AUC) was compared by Z-test. Results:There were significant differences in renal medullary R 2* and renal cortical RBF among the control group, NAU group and MAU group ( F=45.83, 34.15, P<0.001). There was no significant difference in renal cortical R 2* ( F=2.98, P=0.056). In differentiating the control group from the NAU group, the AUC of renal medullary R 2*, renal cortical RBF and their combined parameters were 0.921 (95%CI 0.827-0.973), 0.704 (95%CI 0.578-0.811), 0.964 (95%CI 0.885-0.994), respectively. The AUC of combined parameters was significantly different from renal cortical RBF ( Z=4.07, P<0.001), but not from renal medullary R 2* ( Z=1.57, P=0.117). In differentiating the NAU from the MAU group, the AUC were 0.898 (95%CI 0.796-0.960), 0.919 (95%CI 0.823-0.973), 0.985 (95%CI 0.881-0.994), respectively. The AUC of combined parameters was significantly different from renal medullary R 2* and renal cortical RBF ( Z=2.39, P=0.017; Z=2.20, P=0.028). Conclusions:The changes of renal oxygenation level and blood flow in early stage of T2DM patients can be evaluated noninvasively and quantitatively using BOLD and ASL. Renal medullary R 2* combined with renal cortex RBF shows better diagnostic efficacy for early renal function changes in diabetes than each single index.

Value of MRI arterial spin labeling technique on the detection of epileptogenic zone in children with drug resistant epilepsy / 中华放射学杂志

Objective:To explore the value of arterial spin labeling (ASL) in detecting epileptogenic zone (EZ) in children with drug-refractory epilepsy (DRE).Methods:From March 2018 to December 2019, 28 children with DRE were collected prospectively in Peking University First Hospital. Structural MRI, ASL sequence, and PET-CT were performed on 28 DRE children. All children underwent surgical treatment. Intraoperative electrocorticogram findings combined with postoperative MRI results were considered the gold standard for locating EZ. A total of 29 EZ were resected in 28 children. Based on the pathological results, the EZ was divided into focal cortical dysplasia (FCD) Ⅰb and Ⅱa group ( n=12), FCD Ⅱ b group ( n=11) and malformation of cortical dysplasia (MCD) group ( n=6). Structural MRI was observed for finding any abnormal changes that could induce epilepsy and was divided into the normal MRI group ( n=13) and the abnormal MRI group ( n=16). The spatial relationship between abnormal areas in the cerebral blood flow (CBF) map and PET images and the gold standard was observed, and the accurate detection rate of EZ was calculated. The region of interest (ROI) on CBF and PET images was drawn. ROIs were defined as EZ, EZ contralateral zone (EZCZ), EZ adjacent zone (EZAZ), EZAZ contralateral zone (EZAZCZ). The CBF and maximum standardized uptake value (SUV max) were measured, and the asymmetry index (AI) value of EZ and EZAZ of CBF and SUV max was calculated respectively. One-way ANOVA was used to compare the difference among 4 regions and 3 pathological types of CBF, SUV max, and AI. The independent sample t-test was used to compare the difference in AI between normal and abnormal MRI groups. Results:In CBF map, the EZ was accurately localized in 89.7% (26/29) of the lesions, in which 24 EZ had decreased perfusion, and 2 EZ had increased perfusion. Among the 24 EZ with decreased perfusion, the CBF of EZ, EZCZ, EZAZ, and EZAZCZ were significantly different( F=8.79, P<0.001). In PET-CT, the EZ was accurately localized in 93.1% (27/29) of the lesions, in which 25 EZ had decreased metabolism, and 2 EZ had increased metabolism. Among the 25 EZ with decreased metabolism, the SUV max of EZ, EZCZ, EZAZ, and EZAZCZ were significantly different ( F=6.40, P=0.001). The AI value of CBF and SUV max of EZ in the abnormal MRI group were larger than those of the normal MRI group, and the difference was statistically significant ( t=3.34, 3.09, P=0.002 , 0.004). There was no statistical difference in the AI values of CBF and SUV max among FCD Ⅰb and Ⅱa group, FCD Ⅱb group and MCD group ( F=2.05, 1.54, P=0.149, 0.234). Conclusions:ASL technology is accurate in detecting EZ. The changes in perfusion and metabolism of normal structural MRI EZ are greater than abnormal structural MRI EZ. There is no obvious difference in CBF and SUVmax changes in different pathological EZ.

Comparison of 3D-arterial spin labeling and digital subtraction angiography in the diagnosis of occlusion and collateral circulation in patients with acute ischemic stroke / 中国医师杂志

Objective:To explore the diagnostic value of 3D-arterial spin labeling (ASL) and digital subtraction angiography (DSA) in the occlusion and collateral circulation (CC) of patients with acute ischemic stroke (AIS).Methods:From January 2019 to June 2020, 53 cases of AIS patients with middle cerebral artery (MCA) occlusion in Langfang Hospital of Traditional Chinese Medicine were selected as the research objects. All patients underwent DSA and 3D ASL examination. According to the gold standard of DSA, the diagnostic value of proximal intra-arterial signal (IAS) in 3D-ASL was observed, and the clinical value of distal IAS in the diagnosis of lateral CC was observed. Univariate and multivariate logistic regression were used to identify risk factors for poor outcome in AIS patients.Results:There were 31 cases with good collateral circulation judged by DSA. Taking DSA as the gold standard, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of digital IAS in diagnosing CC status were 93.55%, 81.82%, 87.88%, 90.00% and 88.68%, respectively. The National Institutes of Health Stroke Scale (NIHSS) score of patients with good CC assessed by 3D-ASL was lower than that of patients with poor CC at admission, and the good prognosis rate at discharge was higher than that of patients with poor CC, with statistically significant difference (all P<0.05). There was no significant difference in clinical data between patients with good CC and those with poor CC, such as gender, age, history of atrial fibrillation, hypertension, diabetes, smoking, drinking, onset to treatment time, treatment methods, etc (all P>0.05). Univariate and multivariate analysis showed that poor CC assessed by ASL was a risk factor for poor prognosis in AIS patients ( OR=5.897, P<0.05). Conclusions:The proximal and distal IAS of 3D-ASL can provide important diagnostic clues for detecting arterial occlusion and collateral perfusion in patients with AIS, and the detection of CC by ASL is of great value for prognosis.

Altered neurovascular coupling in arteriosclerotic cerebral small vessel disease and the correlation with cognitive function / 中华神经科杂志

Objective:To investigate the global and local changes of neurovascular coupling in arteriosclerotic cerebral small vessel disease (aCSVD) and the correlation with cognitive function.Methods:Forty-three patients with confirmed aCSVD from the outpatient department or ward of the Department of Neurology, the First Affiliated Hospital of Anhui Medical University between June 2020 and June 2021 were enrolled in this study. Meanwhile, 48 healthy subjects were selected as controls. Cognitive evaluation, resting-state functional magnetic resonance imaging and 3D pseudo-continuous arterial spin labeling magnetic resonance imaging scanning were performed in all subjects. The global cerebral blood flow-regional homogeneity (ReHo) correlation coefficient and the cerebral blood flow/ReHo ratio were used to evaluate global and local neurovascular coupling. Meanwhile, correlations between the cerebral blood flow/ReHo ratio and neuropsychological assessments were explored in aCSVD patients.Results:Global cerebral blood flow-ReHo coupling was decreased in aCSVD patients compared to healthy controls [aCSVD patients: 0.942(0.933, 0.950), healthy controls: 0.947(0.939, 0.954), Z=-2.11, P=0.035]. aCSVD patients showed decreased cerebral blood flow/ReHo ratio in the right lingual gyrus ( t=-4.45, P<0.05) and increased cerebral blood flow/ReHo ratio in the left ( t=4.91, P<0.05) and right ( t=4.72, P<0.05) inferior parietal lobule. Cerebral blood flow/ReHo ratio of the right inferior parietal lobule was negatively correlated with total score ( r=-0.33, P=0.031) and praxis score ( r=-0.43, P=0.004) in Cambridge Cognitive Examination-Chinese Version subitems and positively correlated with scores of Stroop Color Word Test (SCWT)-color ( r=0.33, P=0.032), SCWT-word ( r=0.34, P=0.025) and Trail Making Test-B ( r=0.31, P=0.043) in aCSVD patients. While the cerebral blood flow/ReHo ratio of the right lingual gyrus was negatively correlated with Visual Replicate-Immediate Recall score ( r=-0.36, P=0.017). Conclusion:aCSVD patients showed abnormal global and local neurovascular coupling, which was associated with attention, executive function, and visual space function.

Prediction of diffuse glioma grade and tumor cell proliferative activity by synthetic MRI combined with three dimensional arterial spin labeling imaging / 中华放射学杂志

Objective:To evaluate the value of synthetic MRI combined with three dimensional-arterial spin labeling (3D-ASL) imaging in the grading of diffuse glioma and its correlation with tumor cell proliferative activity (Ki-67).Methods:This study was prospective. The clinical and imaging manifestations of 66 patients with diffuse glioma who underwent synthetic MRI combined with 3D-ASL imaging from August 2020 to June 2021 in General Hospital of Ningxia Medical University were analyzed. Among 66 patients, there were 36 males and 30 females, aged 4-76 years, and divided into low grade glioma (LGG) group ( n=25) (WHO Ⅱ) and high grade glioma (HGG) group ( n=41) (WHO Ⅲ and vⅣ). T 1, T 2, proton density (PD) and cerebral blood flow (CBF) of tumor parenchyma were measured by GE ADW4.7 postprocessing software. The Ki-67 label index (Ki-67 LI) in postoperative pathological sections was detected by immunohistochemistry. Independent sample t test or Mann-Whitney U test was used to compare the differences of quantitative parameters between HGG group and LGG group. Receiver operating characteristic (ROC) curve was used to analyze the diagnostic efficacy of T 1, PD, CBF and the combination. Spearman test was used to analyze the correlation between the parameters and Ki-67 label index (LI). Results:T 1[(1 573±173)ms], PD[(86.2±2.4)pu] and CBF[(129±48)ml·100 g -1·min -1] in HGG group were significantly higher than those in LGG group [(1 376±134)ms, (83.0±2.5)pu and (77±49)ml·100g -1·min -1 respectively], and difference had statistical significance ( t=-4.86, -5.08, -4.24, P<0.01). ROC confirmed that the area under curve (AUC) of T 1, PD and CBF in differentiating HGG from LGG were 0.847, 0.843 and 0.777, respectively. In multi-parameter analysis, the combination of three parameters had the best diagnostic efficiency (AUC=0.973) and the sensitivity and specificity were 87.8% and 100%, respectively. In LGG and HGG groups, there was no correlation between T 1, T 2, PD, CBF and Ki-67 LI. In the overall cohort, T 1, PD and CBF had slight positive correlation with Ki-67 LI ( r=0.394, 0.411 and 0.406, respectively, all P<0.01). There was no correlation between T 2 and Ki-67 LI ( r=-0.100, P=0.423). Conclusion:Synthetic MRI and 3D-ASL can noninvasively evaluate the pathological grade of glioma and predict the expression of Ki-67, among which T 1 and PD are novel imaging marks.

Nomogram for predicting the response to chemoradiotherapy in advanced nasopharyngeal carcinoma based on arterial spin-labeled perfusion parameters and clinicopathological features / 中华放射学杂志

Objective:To explore the value of nomogram based on arterial spin labeling (ASL) MRI perfusion parameters and clinicopathological features in predicting the response to chemoradiotherapy (CRT) in advanced nasopharyngeal carcinoma (ANPC, stage Ⅲ and Ⅳ).Methods:From June 2018 to January 2021, 70 patients with ANPC confirmed by pathology were prospectively enrolled in Affiliated Hospital of Jiangnan University. Nasopharyngeal MRI plain scan, ASL and contrast-enhanced scan were performed before CRT, and routine MRI re-examination was performed within 1 week after the end of CRT. The pre-CRT perfusion parameter tumor blood flow (TBF) from ASL and clinicopathological features were recorded, and the maximum diameter (MD) of the tumor on T 1WI images was measured. The patients were divided into CRT effective group (48 cases) and ineffective group (22 cases) according to the response evaluation criteria in solid tumors. The independent sample t test was used to compare the differences of TBF, age and MD between effective group and ineffective group. The χ 2 test was used to compare the differences of gender, clinical stage and pathological type between the 2 groups. Using binary logistic regression analysis, clinicopathological model and TBF combined clinicopathological model were constructed, and the nomogram of combined model was constructed. The diagnostic efficacy of the models was obtained by receiver operating characteristic (ROC) curve analysis, and the area under the ROC curves (AUC) of the 3 models were compared by DeLong method. The calibration curve for the nomogram was generated, and the concordance index (C index) was acquired. Results:The TBF of the effective group and the ineffective group were (113±9) and (97±14) ml·100 g -1·min -1, with a statistical difference ( t=5.17, P<0.001). The MD value of the effective group was smaller than that of the ineffective group, with a statistical difference ( t=-2.24, P=0.028). There were statistical differences in clinical stage and pathological type between the 2 groups (χ 2 values were 12.21 and 12.95, respectively, both P<0.001). Three independent predictors, including TBF (OR=7.749), clinical stage (OR=0.129) and pathological type (OR=5.228), were included in logistic regression analysis. The AUC, sensitivity and specificity of TBF model in predicting the response to CRT were 0.843, 87.5% and 72.7%, of clinicopathological model were 0.822, 80.2% and 59.1%, of the nomogram model were 0.893, 81.2% and 90.9%. There was no statistical difference of AUC between the nomogram model and TBF model ( Z=1.23, P=0.215). However, the AUC of the nomogram model was greater than that of the clinicopathological model ( Z=2.47, P=0.031). The calibration curve showed that there was a good concordance index (C index=0.892) between the predicted value of nomogram and the actual clinical observation value. Conclusion:TBF, clinical stage and pathological type are independent predictors of the response to CRT in ANPC patients, and the nomogram based on these three factors has a good ability in predicting the response to CRT.

Application of multiple post labeling delay time arterial spin labeling imaging in the quantitative blood flow analysis of brain subregions in healthy adults / 中华内科杂志

Objective:To explore the normal ranges of perfusion parameters between cerebral hemisphere, cerebellar hemisphere and brain anatomical subregions (56 pairs) in different gender and age groups with multiple post labeling delay time (Multi-PLD) arterial spin labeling (ASL) imaging.Methods:From November 2020 to December 2020, 42 healthy adult volunteers (Male 25, Female 17) were recruited to perform 7 PLD ASL imaging, including 21 young adults (15 males and 6 females, aged 23—35 years) and 21 seniors (10 males and 11 females, aged 36—74 years). The data was processed offline by Cereflow software to obtain arterial arrival time (ATT) and corrected cerebral blood flow (CBF) and cerebral blood volume (CBV) perfusion parameters. SimpleITK standardization function was used to standardize the calculated perfusion image according to the anatomical automatic labeling (AAL) template. Therefore, CBF, ATT, CBV perfusion values of brain subregions were obtained. Paired samples t test, Wilcoxon rank sum test, independent samples t test and Mann-Whitney U test were used to compare the differences of perfusion parameters in the cerebral hemisphere, the cerebellar hemisphere, brain subregions depending on side, gender and age. Pearson correlation analysis was used to compare the correlations of perfusion parameters with age. Results:CBF in 62.5% (35/56) subregions and CBV in 44.6% (25/56) subregions were higher in right side than those in left side. ATT in most brain anatomical subregions (16/56) were higher in left side. The CBF [(35.30±8.31) vs. (34.34±7.53) ml·100g -1·min -1, P=0.021], CBV [(0.47±0.11) vs. (0.45±0.09) ml/100g, P<0.001], ATT [(1.30±0.10) vs. (1.24±0.11) s, P<0.001] in left cerebellar hemisphere were higher than that of right side. The CBF (28/56) of cerebral hemisphere, cerebellar hemisphere and brain subregions was higher in females than that in males, while ATT in 83.9% (47/56) subregions was lower than that in males (all P<0.05). CBV in female subjects was higher only in 5 brain regions (superior occipital gyrus, middle occipital gyrus, inferior occipital gyrus, superior parietal gyrus and cerebelum_7b) (all P<0.05). In young subjects, CBF in 44.6% (25/56) subregions and CBV in 33.9% (19/56) subregions were higher than those in the senior group (all P<0.05). The ATT in most subregions in young group were lower than those in senior group, but the difference was statistically significant only in rectus gyrus ( P=0.026) and paracentral lobule ( P=0.006). The CBF ( r=-0.430, P=0.005) and CBV ( r=-0.327, P=0.035) of cerebral hemisphere were negatively correlated with age. The CBF (24/25, r range:-0.497 —-0.343, all P<0.05) and CBV (16/19, r range:-0.474 —-0.322, all P<0.05) in most subregions were negatively correlated with age, while ATT was positively correlated (gyrus rectus: r=0.311, P=0.045; paracentral lobule: r=0.392, P=0.010). Conclusions:Multi-PLD ASL imaging could be applied for quantitative analysis of brain perfusion. The perfusion parameters of anatomical subregions are different depending on side, gender, and age.

Study of sub-region segmentation of brain metastases based on magnetic resonance perfusion imaging / 中华放射肿瘤学杂志

Objective:To evaluate the feasibility of magnetic resonance (MR) perfusion imaging for sub-region segmentation of brain metastases (BMs), and to provide reference for individualized radiotherapy based on blood flow perfusion heterogeneity in BMs patients.Methods:96 BMs patients were selected, including 55 patients with necrosis and 41 without necrosis. Each patient was scanned with CT simulation and MR simulation before radiotherapy. MIM Maestro 6.8.8 software was used to delineate the gross tumor volume (GTV) and necrosis GTV (GTV N) from enhanced T 1W images and T 2 Propeller images, respectively, and the solid GTV (GTV S) was obtained by the subtraction of the two. Then, the cerebral blood flow map of three dimensional arterial spin labeling (3D-ASL) was employed to determine the high perfused GTV (GTV H) and low perfused GTV (GTV L). The volume and proportion of sub-regions were counted and compared between two groups and the correlation of each sub-region was analyzed. Results:The volume of GTV in the necrosis and non-necrosis groups was 19.56 and 7.34 cm 3, respectively. Besides, the AUC of the ROC between GTV volume and necrosis was 0.749. In the necrosis group, the ratio of GTV N, GTV S, GTV H and GTV L to GTV was 20.47%, 79.53%, 33.03% and 46.50%, respectively (all P<0.05). Among them, the r value between GTV S and GTV was 0.963, 0.849 for GTV L and GTV, and 0.840 for GTV L and GTV S, significantly higher than 0.683 for GTV H and GTV and 0.764 for GTV H and GTV S (all P<0.05). In the non-necrosis group, the ratio of GTV H to GTV was higher than that in the necrosis group (58.95% vs. 33.03%, P<0.05). In addition, the ratio of GTV L to GTV was slightly lower than that in the necrosis group (41.05% vs. 46.50%, P>0.05). The r value between GTV H and GTV was 0.776, significantly higher than 0.574 between GTV L and GTV ( P<0.05). Conclusion:MR-3D-ASL can quantitatively analyze the heterogeneous blood perfusion of BMs, which could guide the sub-region segmentation and local dose escalation of tumors.

Imaging value of intracranial steno-occlusive disease based on silent MR angiography modified with hybrid-arterial spin labeling / 中华放射学杂志

Objective:To investigate the stability and feasibility of improved silent MRA technique based on hybrid-arterial spin labeling(ASL) for imaging intracranial arterial stenosis.Methods:From September 2019 to May 2020, totally 35 patients with suspected intracranial vascular stenosis in Department of Neurology of Northern Jiangsu People′s Hospital were enrolled in this study. Silent MRA and improved silent MRA based on hybrid-ASL technique were performed respectively. The acquisition noise (noise measurement and subjective score) of two kinds of MRA examination were evaluated respectively. Two neuroradiologists performed image quality scoring and signal-to-noise ratio (SNR) measurement of intracranial arteries (including internal carotid artery, vertebrobasilar artery, anterior cerebral artery, middle cerebral artery, and posterior cerebral artery) in the two kinds of MRA images using a double-blind, completely randomized method. Independent sample t-test was used to compare the image quality and SNR of two kinds of MRA images in each segment. Two experts assessed the degree of stenosis at the site of confirmed intracranial artery stenosis. Kappa test was used to assess interobserver and intermodel agreement. Results:There was no significant difference in acquisition noise between improved silent MRA and silent MRA ( P>0.05). In all five segments measured, the image quality scores of internal carotid artery [(4.40±0.49)scores], anterior cerebral artery[(4.30±0.33)scores] and middle cerebral artery [(4.46±0.34)scores] in improved silent MRA were higher than those in silent MRA images [(4.02±0.43)scores, (4.02±0.31)scores, (4.02±0.31)scores; t=2.825, 2.877, 1.683, all P<0.05)]. The SNR of internal carotid artery (9.11±1.23) and middle cerebral artery (8.77±1.87) in improved silent MRA images was higher than that in silent MRA images (7.83±1.33, 8.06±2.67, respectively; t=11.154, 3.268, both P<0.05). A total of 24 patients (38 lesions) with intracranial vascular stenosis were diagnosed by CTA. Improved silent MRA (Kappa=0.89, 95%CI 0.82-0.95) and silent MRA (Kappa=0.85, 95%CI 0.77-0.92) were highly consistent among observers in evaluating the degree of cerebrovascular stenosis.The results of improved silent MRA were highly consistent with those of CTA (Kappa=0.92, 95%CI 0.87-0.98), and those of silent MRA were highly consistent with those of CTA (Kappa=0.85, 95%CI 0.77-0.92). Conclusions:The improved silent MRA is feasible to improve the imaging quality and signal uniformity through efficient marking based on keeping the low noise features. In the diagnosis of intracranial stenosis and occlusive disease, the stability of improved silent MRA imaging improves the diagnostic efficiency of stenosis to a certain extent.

Application Progress of Arterial Spin Labeling Magnetic Resonance Imaging in Renal Perfusion Analysis / 中国医学科学院学报

Arterial spin labeling is a noninvasive,quantitative method for perfusion imaging,which does not need any contrast media.This technique has been used in the renal perfusion analysis.In this article,we briefly introduced this technique and summarized its application in healthy volunteers,acute kidney injury,chronic kidney diseases,renovascular diseases,renal tumors,and renal transplantation.

Arterial spin labeling imaging in evaluation of cerebral blood flow in patients with internal carotid artery stenosis / 中国介入影像与治疗学

Objective: To explore the feasibility of arterial spin labeling (ASL) imaging in assessment of cerebral blood flow (CBF) in patients with internal carotid artery stenosis. Methods: Plain MR, DWI, three dimensional time of flight (3D-TOF) and ASL scanning were performed in 30 patients with unilateral internal carotid artery stenosis. Then the patients were divided into mild stenosis, moderate stenosis and severe stenosis cases according to 3D-TOF imaging. CBF of basal ganglia, centrum semiovale, anterior watershed, frontal lobe and temporal lobe were calculated and compared between the healthy side and the affected side. Results: One side internal carotid artery stenosis was mild in 11 cases, moderate in 9 cases and severe in 10 cases. There was no significant difference of CBF between the healthy side and the affected side of basal ganglia, centrum semiovale, anterior watershed, frontal lobe nor temporal lobe in patients with mild and moderate stenosis (all P> 0.05), while CBF of healthy side of each brain area in patients with severe stenosis were all higher than in the affected side (all P< 0.05). CBF value decreased with the increase of stenosis degree and negatively correlated with the latter (r=-0.966, P< 0.001). Conclusion: ASL can quantitatively and accurately evaluate CBF in patients with internal carotid artery stenosis, which is of great significance for guiding clinical treatment and evaluating curative effect.

Clinical value of dual phase ASL in evaluation of collateral circulation in patients with severe cerebral vascular stenosis / 中国基层医药

Objective@#To investigate the clinical value of dual-phase arterial spin-labeled perfusion imaging(3D-ASL) in the evaluation of collateral circulation compensation in patients with severe cerebrovascular stenosis.@*Methods@#From December 2017 to August 2018, 73 patients with severe cerebral artery stenosis confirmed by MRA in Linfen Central Hospital were collected and studied.The two-phase superconducting magnetic resonance imaging was performed[Post Label Delay(PLD): 1 525ms, 2 525ms] three-dimensional quasli continuous arterial spin labeling(3D-PCASL) imaging.Bilateral phase cerebral blood flow(CBF) was measured on the affected side and mirror side respectively.The CBF values of the affected side and mirror side were compared and analyzed, and the abnormal perfusion cases were compared and analyzed.@*Results@#In 73 patients with severe cerebrovascular stenosis, the CBF values of the bilateral affected side[CBF 1 525ms(18.33±6.42)mL·100g-1·min-1, CBF 2 525ms(34.81±11.68)mL·100g-1·min-1] were lower than those of the mirror side[CBF 1 525ms(41.25±16.84)mL·100g-1·min-1, CBF 2 525ms(47.74±14.90)mL·100g-1·min-1], the differences were statistically significant(Z=-9.348, -7.476, all P<0.001). The ratio of abnormal perfusion in PLD=2525ms group[CBF(34.81±11.68)mL·100g-1·min-1]was higher than that in PLD=1 525ms group[CBF(18.33±6.42)mL·100g-1·min-1], the difference was statistically significant(Z=-9.196, P<0.001). The percentage of abnormal perfusion in PLD group of 2 525ms(56.2%) was lower than that in PLD group of 1 525ms(94.5%), the difference was statistically significant(χ2=5.393, P=0.02).@*Conclusion@#Dual-phase ASL(PLD=1 525ms, 2 525ms) combined with ASL can more accurately evaluate the compensations of fast collateral circulation and slow collateral circulation, and provide individualized treatment.

Clinical value of dual phase ASL in evaluation of collateral circulation in patients with severe cerebral vascular stenosis / 中国基层医药

Objective To investigate the clinical value of dual -phase arterial spin -labeled perfusion imaging(3D-ASL) in the evaluation of collateral circulation compensation in patients with severe cerebrovascular stenosis.Methods From December 2017 to August 2018,73 patients with severe cerebral artery stenosis confirmed by MRA in Linfen Central Hospital were collected and studied.The two-phase superconducting magnetic resonance imaging was performed[ Post Label Delay(PLD):1 525ms,2 525ms] three-dimensional quasli continuous arterial spin labeling(3D-PCASL) imaging.Bilateral phase cerebral blood flow (CBF) was measured on the affected side and mirror side respectively.The CBF values of the affected side and mirror side were compared and analyzed ,and the abnormal perfusion cases were compared and analyzed.Results In 73 patients with severe cerebrovascular stenosis , the CBF values of the bilateral affected side [ CBF 1 525ms (18.33 ±6.42) mL· 100g-1· min-1 ,CBF 2 525ms (34.81 ±11.68)mL· 100g-1· min-1 ] were lower than those of the mirror side [CBF 1 525ms(41.25 ±16.84)mL· 100g-1· min-1 ,CBF 2 525ms(47.74 ±14.90) mL· 100g-1· min-1 ],the differences were statistically significant (Z＝-9.348,-7.476,all P＜0.001).The ratio of abnormal perfusion in PLD ＝2525ms group[ CBF(34.81 ± 11.68)mL· 100g-1· min-1 ] was higher than that in PLD ＝1 525ms group[ CBF(18.33 ±6.42) mL· 100g-1· min-1 ],the difference was statistically significant (Z＝-9.196,P＜0.001).The percentage of abnormal perfusion in PLD group of 2 525ms(56.2%) was lower than that in PLD group of 1 525ms(94.5%),the difference was statisti- cally significant(χ2 ＝5.393,P＝0.02).Conclusion Dual-phase ASL( PLD＝1 525ms,2 525ms) combined with ASL can more accurately evaluate the compensations of fast collateral circulation and slow collateral circulation ,and provide individualized treatment.

Correlation between volume and perfusion changes of deep gray matter nuclei and clinical score in patients with relapsing-remitting multiple sclerosis / 中国医学影像技术

Objective To investigate deep gray matter volume and perfusion changes in patients with relapsing-remitting multiple sclerosis (RRMS) with voxel-based morphometry (VBM) and 3D pseudo-continuous arterial spin labeling (3D pCASL), and to explore the relationship between the changed parameters of deep gray matter and expanded disability status scale (EDSS) and neuropsychological scale scores. Methods Totally 30 RRMS patients (RRMS group) and 24 healthy volunteers (control group) were enrolled and tested with EDSS scale and neuropsychological scale to evaluate memory function. All subjects underwent 3D T1WI and 3D pCASL, and the images were pretreated with SPM 8 and VBM 8 software on the Matlab platform. SPM statistical software was used to analyze the changes of deep gray matter volume and perfusion in RRMS patients, and further extraction of deep gray matter volume, perfusion parameter values in significantly changed brain regions, and correlation analysis was done for EDSS and neuropsychological scores. Results Compared with the control group, the volume of bilateral thalamus, left hippocampus, left putamen and right globus pallidus decreased significantly in RRMS group (all P0.05). Conclusion Volume and perfusion of deep gray matter are changed in RRMS patients, and the decrease volume and perfusion associate with impairment of memory function.

Progresses of arterial spin labeling MRI in end-stage renal disease patients with cognitive impairment / 中国医学影像技术

Cognitive impairment is one of the common neurological complications in end-stage renal disease (ESRD) patients and associates with abnormal cerebral perfusion. Arterial spin labeling (ASL) is a non-invasive and easily repeatable MRI perfusion technique without the use of contrast agent. ASL can quantitively measure the cerebral blood flow and is not influenced by break down of the blood-brain barrier, which makes ASL rapidly expands applications in neurodegenerative diseases. The clinical applications of ASL MRI in ESRD patients with cognitive dysfunction were reviewed in this article.

Consistency and impact factors of FLAIR vascular hyperintensity and arterial transit artifact on three-dimensional arterial spin labeling imaging of unilateral middle cerebral artery stenosis or occlusion / 中国医学影像技术

Objective: To investigate the consistency between FLAIR vascular hyperintensity (FVH) and arterial transit artifact (ATA) on three-dimensional arterial spin labeling (3D-ASL) imaging in patients with unilateral middle cerebral artery (MCA) stenosis or occlusion. Methods: Forty-two patients with MCA stenosis or occlusion underwent multimodal MR scanning included T2 FLAIR and 3D-ASL imaging. The incidence of FVH on T2 FLAIR and ATA on 3D-ASL in post labeling delay (PLD)=1.5 s and PLD=2.5 s was counted, and the differences of FVH and ATA were compared. The correlation of FVH, ATA with degree of vascular stenosis and clinical data were analyzed. Results: There was no statistical difference of incidence between FVH and ATA in patients with unilateral MCA stenosis or occlusion when PLD=1.5 s and PLD= 2.5 s, respectively (χ2=3.96, 3.80, P=0.77, 0.30). The incidence of FVH (r=0.30, P<0.05) and ATA (PLD=1.5 s: r=0.35, P<0.05; PLD=2.5 s: r=0.41, P<0.05) positively correlated with the degree of vascular stenosis. Binary Logistic regression analysis showed that age, systolic blood pressure and high density lipoprotein had negative impact on FVH and ATA. Conclusion: FVH has consistency with ATA in patients with unilateral MCA stenosis or occlusion, both of them can be used as indicators to observe collateral circulation.

Study of the subcortical cerebral blood flow metabolism in patients with Parkinson′s disease using arterial spin labeling magnetic resonance imaging / 中华神经科杂志

Objective@#To investigate alterations of blood perfusion in subcortical regions in patients with Parkinson′s disease (PD) by three dimentional arterial spin labeling (ASL) magnetic resonance imaging (MRI).@*Methods@#Thirty patients with PD and 40 control subjects were recruited from the inpatient and outpatient of the Department of Neurology of Northern Jiangsu People′s Hospital during October 2014 to October 2016, and routine brain MRI and 3D pseudo-continuous pulse ASL were performed on all the subjects. The cerebral blood flow (CBF) maps derived from 3D ASL were coregistered to the Montreal Neurological Institute brain space. The stereo-templates of bilateral caudate nucleus, putamen nucleus, globus pallidum and thalamus from Anatomical Automatic Labeling were used as region of interest (ROI) to exstract absolute CBF values in these subcortical regions, respectively. The CBF ratio (rCBF) values represented by individual whole brain CBF divided by each of the regional CBF were also calculated in consideration of the difference between individual whole brain CBF. The CBF and rCBF values were compared respectively between groups by one-way analysis of variance.@*Results@#The subcortical CBF values (ml·100 g-1·min-1) for each ROI in PD (caudate nucleus (left: 35.32±6.47, right: 36.17±7.07), globus pallidum (left: 40.42±5.83, right: 40.18±5.70), putamen nucleus (left: 41.97±6.12, right: 42.91±6.43) and thalamus (left: 46.58±7.71, right: 49.11±7.10)) were significantly lower than that in the control group (caudate nucleus (left: 41.38±7.05, right: 41.63±6.85), globus pallidum (left: 45.65±8.35, right: 45.53±8.94), putamen nucleus (left: 48.49±8.78, right: 48.99±8.88) and thalamus (left: 54.32±11.94, right: 56.21±11.98), F=13.58, 10.56, 12.11, 10.06, 8.59, 8.23, 9.57, 8.30, P=0.000, 0.002, 0.005, 0.005, 0.001, 0.002, 0.003, 0.005, respectively). The whole brain mean CBF values of each subject were also extracted and compared bewteen groups, and mean CBF values (ml·100 g-1·min-1) in PD patients (42.14±9.61) decreased significantly than those in the control group (51.59±9.67, F=16.42, P<0.01), and there was a 18.31% decrement in whole brain mean CBF in the patient group. However, rCBF values for almost all subcortical ROIs of the patients significantly increased when compared with the control group.@*Conclusions@#The decreased absolute cerebral blood perfusion involved not only subcortical regions, but also the whole brain level in the course of PD. The CBF metabolism in patients with PD may have been redistributed, with relative hyperperfusion in the subcortical brain regions contrast to the whole brain perfusion level of patients themselves.

Application of intravoxel incoherent motion and three-dimensional arterial spin labeling technique in preoperative grading diffuse gliomas / 实用放射学杂志

Objective To investigate the value of intravoxel incoherent motion (IVIM)and three-dimensional arterial spin labeling (3D-ASL)technique in preoperative grading diffuse gliomas.Methods Thirty-one patients with diffuse gliomas proved by pathology were enrolled,including 12 cases with low grade gliomas and 19 cases with high grade gliomas.All patients underwent 3D-ASL and IVIM examination before operation.Original dates were disposed in particular software,then the images of cerebral blood flow (CBF), D? and D were obtained,and ROI were selected and relevant parameter values were calculated.The parameter values were analyzed in SPSS,and unpaired two-tailed student t test were performed to compare parameter values between two groups.P＜0.05 was regarded as statistically significant. ROC analysis curves were performed to acquire optimum threshold value,sensibility and specificity of each parameter.Finally,the sensibility and specificity of the associating screening of 3D-ASL and IVIM were obtained.Results The CBF and relative CBF(rCBF) values of high grade gliomas group [(103.89±27.00)mL/min?100 g and (4.28±0.63)mL/min?100 g]were significantly higher than those of low grade gliomas group [(63.96±22.17)mL/min?100 g and (2.72±0.84)mL/min?100 g];The D? and relative D?(rD?) values of high grade gliomas group [(3.82 ± 0.60 )mm2/s and 1.9 5 ± 0.30 ]were significantly higher than those of low grade gliomas group [(2.54±0.50)mm2/s and 1.28±0.14],the D and relative D (rD)values of high grade gliomas group [(0.58±0.12)mm2/s and 2.40±0.49]were significantly lower than those of low grade gliomas group [(0.75±0.12)mm2/s and 3.1 1±0.42](P＜0.05). Statistical analysis in ROC demonstrated AUC value of 0.879 and 0.917 for CBF and rCBF,optimum threshold value of 79.24 mL/min?100 g and 2.85,sensibility of 84.2% and 100%,specificity of 83.3%and 83.3%;AUC value of 0.925,0.846,0.956 and 0.882 for D?,D ,rD? and rD ,optimum threshold value of 2.95 mm2/s, 0.63 mm2/s,1.40 and 2.95,sensibility of 94.7%,91.7%,94.7%and 75%,specificity of 83.3%,73.3%,91.7% and 94.7%.The sensibility and specificity of the associating screening of 3D-ASL and IVIM were 100% and 9 1.7%.Conclusion IVIM and 3D-ASL can be used to grade diffuse gliomas,and the values of rCBF,rD? and rD are optimal indicator.Combination of IVIM and 3D-ASL can improve the sensibility and specificity of grading diffuse gliomas.