Dynamic Susceptibility Contrast-enhanced Perfusion-weighted Imaging Research Articles

The utility of multiparametric MRI in reducing diagnostic uncertainty for primary central nervous system lymphoma

AimA key limitation in the early treatment initiation in primary central nervous system lymphoma (PCNSL) is the diagnostic delay caused by lack of recognition of a lesion as a possible lymphoma, steroid initiation, and lesion involution, often resulting in inconclusive biopsy. We highlight the importance of multiparametric MRI (MPMRI), which incorporates diffusion weighted imaging (DWI), dynamic susceptibility contrast-enhanced perfusion weighted imaging (DSC-PWI) and proton magnetic resonance spectroscopy (1H-MRS) in addition to standard MRI sequences in resolving diagnostic uncertainty for PCNSL. Materials and methodsWe present a consecutive series of 10 patients at our centre with histology-proven PCNSL (specifically, diffuse large B-cell lymphoma of the CNS) who underwent multiparametric MRI. We retrospectively analyse the qualitative and semi-quantitative parameters and assess their radiological concordance for this diagnosis. ResultsWe note overall low apparent diffusion coefficient on DWI (mean ADCmin of 0.74), high percentage signal recovery on perfusion weighted imaging (mean 170%), a high choline-creatine ratio and a high-grade lipid peak on MRS giving a “twin-tower” appearance. Nine of ten patients had MRMRI findings concordant for PCNSL, defined as at least 3 of 4 parameters being consistent for PCNSL. ConclusionWe propose that concordance between these imaging multiparametric modalities could be used as a radiological predictor of PCNSL, reducing diagnostic delays, providing a more accurate biopsy target, and resulting in quicker treatment initiation.

The cortical high-flow sign of oligodendroglioma, IDH-mutant and 1p/19q-codeleted: comparison between arterial spin labeling and dynamic susceptibility contrast methods.

The cortical high-flow sign with the non-enhancing area was reportedly found to be more frequent with oligodendroglioma, IDH-mutant and 1p/19q codeleted (ODG IDHm-codel) than with IDH-wildtype or astrocytoma, IDH-mutant on arterial spin labeling (ASL) in diffuse gliomas. This study aimed to compare the identification rate of the cortical high-flow sign on ASL in patients with ODG IDHm-codel to that on dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI). Participants consisted of 32 adult ODG IDHm-codel patients with pathologically confirmed. Subtraction images were generated from paired control and label images on ASL. For DSC, dynamic T2*-weighted perfusion weighted images were obtained after pre-bolus of gadolinium-based contrast agent. Regional cerebral blood flow/volume maps were generated based on the concentration-time curve and arterial input function. Tumor-affecting cortices without contrast enhancement on conventional MR imaging were targeted. The identification rate of the cortical high-flow sign was compared between ASL and DSC using the Pearson's Chi-Square test. Frequency of the cortical high-flow sign was significantly higher on ASL (18/32, 56.3%; p < 0.001) than on DSC (5/32, 15.6%). All cases with the positive cortical high-flow sign on DSC were identified on ASL. ASL effectively identifies the cortical high-flow sign in ODG IDHm-codel, surpassing DSC in identification rates.

Dynamic Susceptibility Contrast-Enhanced Perfusion-Weighted Imaging in Differentiation Between Recurrence and Pseudoprogression in High-Grade Glioma: A Meta-analysis.

In glioma patients that have undergone surgical tumor resection, the ability to reliably distinguish between pseudoprogression (PsP) and a recurrent tumor (RT) is of key clinical importance. Accordingly, this meta-analysis evaluated the utility of dynamic susceptibility contrast-enhanced perfusion-weighted imaging as a means of distinguishing between PsP and RT when analyzing patients with high-grade glioma. The PubMed, Web of Science, and Wanfang databases were searched for relevant studies. Pooled analyses of sensitivity, specificity, positive likelihood ratio (PLR), and negative likelihood ratio (NLR) values were conducted, after which the area under the curve (AUC) for summary receiver operating characteristic curves was computed. This meta-analysis ultimately included 21 studies enrolling 879 patients with 888 lesions. Cerebral blood volume-associated diagnostic results were reported in 20 of the analyzed studies, and the respective pooled sensitivity, specificity, PLR, and NLR values were 86% (95% confidence interval [CI], 0.81-0.89), 83% (95% CI, 0.77-0.87), 4.94 (95% CI, 3.61-6.75), and 0.18 (95% CI, 0.13-0.23) for these 20 studies. The corresponding AUC value was 0.91 (95% CI, 0.88-0.93), and the publication bias risk was low ( P = 0.976). Cerebral blood flow-related diagnostic results were additionally reported in 6 of the analyzed studies, with respective pooled sensitivity, specificity, PLR, and NLR values of 85% (95% CI, 0.78-0.90), 85% (95% CI, 0.76-0.91), 5.54 (95% CI, 3.40-9.01), and 0.18 (95% CI, 0.12-0.26). The corresponding AUC value was 0.92 (95% CI, 0.89-0.94), and the publication bias risk was low ( P = 0.373). The present meta-analysis results suggest that dynamic susceptibility contrast-enhanced perfusion-weighted imaging represents an effective diagnostic approach to distinguishing between PsP and RT in high-grade glioma patients.

Three-Dimensional Arterial Spin Labeling for the Evaluation of the Cerebral Hemodynamics in Ischemic and Hemorrhagic Moyamoya Disease

Introduction: Moyamoya disease (MMD) is a vascular disease with significant risk of mortality due to ischemia or hemorrhage in the brain. The goal of the study was to explore three-dimensional arterial spin labeling (3D-ASL) to improve evaluation of cerebral hemodynamics in patients with MMD. Methods: Our study included 54 cases of ischemic MMD and 42 cases of hemorrhagic MMD. Dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI) and 3D-ASL were performed at 3.0 T. Based on these scans, cerebral blood flow (CBF), mean transit time (MTT), and time to peak (TTP) were calculated and compared between patients with different disease subtypes. Receiver operating characteristics analysis was used to assess the diagnostic sensitivity and specificity of different imaging procedures and parameters. Results: Our data suggested that CBF in the lesion area was more severely reduced in patients with hemorrhagic MMD than in those with ischemic MMD. The CBF parameter in 3D-ASL diagnosed hemorrhagic and ischemic MMD with a significant sensitivity and specificity of 80.59% and 57.41%, respectively, with an area under the curve (AUC) of 0.75. We also found that the relative CBF of 3D-ASL was more pronounced decreased and the relative MTT and TTP of DSC-PWI were significantly increased in patients with hemorrhagic MMD than those with ischemic MMD. Specificity and sensitivity and AUC of 3D-ASL were better than the comparison of absolute values from DSC-PWI scans. Conclusion: Our study indicated that 3D-ASL is powerful in differentiating patients with cerebral ischemic or hemorrhagic MMD, providing another diagnostic tool that could potentially improve precision medicine to monitoring MMD patients.

Whole-tumor histogram analysis of diffusion and perfusion metrics for noninvasive pediatric glioma grading

An accurate assessment of the World Health Organization grade is vital for patients with pediatric gliomas to direct treatment planning. We aim to evaluate the diagnostic performance of whole-tumor histogram analysis of diffusion-weighted imaging (DWI) and dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI) for differentiating pediatric high-grade gliomas from pediatric low-grade gliomas. Sixty-eight pediatric patients (mean age, 10.47 ± 4.37years; 42 boys) with histologically confirmed gliomas underwent preoperative MR examination. The conventional MRI features and whole-tumor histogram features extracted from apparent diffusion coefficient (ADC) and cerebral blood volume (CBV) maps were analyzed, respectively. Receiver operating characteristic curves and the binary logistic regression analysis were performed to determine the diagnostic performance of parameters. For conventional MRI features, location, hemorrhage and tumor margin showed significant difference between pediatric high- and low-grade gliomas (all, P < .05). For advanced MRI parameters, ten histogram features of ADC and CBV showed significant differences between pediatric high- and low-grade gliomas (all, P < .05). The diagnostic performance of the combination of DSC-PWI and DWI (AUC = 0.976, sensitivity = 100%, NPV = 100%) is superior to conventional MRI or DWI model, respectively (AUCcMRI = 0.700, AUCDWI = 0.830; both, P < .05). The whole-tumor histogram analysis of DWI and DSC-PWI is a promising method for grading pediatric gliomas.

The Combination of Whole-Brain Features and Local-Lesion Features in DSC-PWI May Improve Ischemic Stroke Outcome Prediction.

Accurate and reliable outcome predictions can help evaluate the functional recovery of ischemic stroke patients and assist in making treatment plans. Given that recovery factors may be hidden in the whole-brain features, this study aims to validate the role of dynamic radiomics features (DRFs) in the whole brain, DRFs in local ischemic lesions, and their combination in predicting functional outcomes of ischemic stroke patients. First, the DRFs in the whole brain and the DRFs in local lesions of dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI) images are calculated. Second, the least absolute shrinkage and selection operator (Lasso) is used to generate four groups of DRFs, including the outstanding DRFs in the whole brain (Lasso (WB)), the outstanding DRFs in local lesions (Lasso (LL)), the combination of them (combined DRFs), and the outstanding DRFs in the combined DRFs (Lasso (combined)). Then, the performance of the four groups of DRFs is evaluated to predict the functional recovery in three months. As a result, Lasso (combined) in the four groups achieves the best AUC score of 0.971, which improves the score by 8.9% compared with Lasso (WB), and by 3.5% compared with Lasso (WB) and combined DRFs. In conclusion, the outstanding combined DRFs generated from the outstanding DRFs in the whole brain and local lesions can predict functional outcomes in ischemic stroke patients better than the single DRFs in the whole brain or local lesions.

Diagnostic Performance of Dynamic Susceptibility Contrast-Enhanced Perfusion-Weighted Imaging in Differentiating Recurrence From Radiation Injury in Postoperative Glioma: A Meta-analysis.

It is important to differentiate between radiation injury (RI) and tumor recurrence (TR) in patients with glioma after surgery and radiotherapy. Our objective was to evaluate the use of dynamic susceptibility contrast-enhanced perfusion-weighted imaging to distinguish between TR and RI in patients with glioma. Relevant studies published until October 2021 were identified in the PubMed, Embase, and Cochrane Library databases. Stata v12.0 and RevMan 5.3 were used for meta-analysis. In total, the meta-analysis incorporated 13 retrospective studies that included 513 patients with 522 lesions. Among the 522 lesions, 329 lesions were TRs and 193 lesions were RIs. The pooled relative cerebral blood volume value was significantly greater in the TR group ( P < 0.00001) with significant heterogeneity ( I2 = 88%). The pooled sensitivity, specificity, positive likelihood ratio (PLR), and negative likelihood ratio (NLR) were 83% (95 confidence interval [CI], 77%-88%), 85% (95 CI, 77%-91%), 5.60 (95 CI, 3.61-8.70), and 0.20 (95% CI, 0.14-0.27), respectively. The heterogeneity of sensitivity ( I2 = 33.18%), specificity ( I2 = 24.01%), PLR ( I2 = 0.00%), and NLR ( I2 = 6.68%) is not significant. The area under the receiver operating characteristic curve was 0.91 (95% CI, 0.88-0.93). The 3.0 T magnetic resonance imaging, high-grade glioma, and Europe/America patient subgroups showed PLR greater than 5 and NLR less than 0.2. There was no significant indication of publication bias in the analysis ( P = 0.496). It is concluded that dynamic susceptibility contrast-enhanced perfusion-weighted imaging is effective for the diagnostic differentiation between TR and RI in patients with glioma.

Non-invasive prediction of p53 and Ki-67 labelling indices and O-6-methylguanine-DNA methyltransferase promoter methylation status in adult patients with isocitrate dehydrogenase wild-type glioblastomas using diffusion-weighted imaging and dynamic susceptibility contrast-enhanced perfusion-weighted imaging combined with conventional MRI

To assess whether conventional magnetic resonance imaging (MRI), diffusion-weighted imaging (DWI), and dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI) could non-invasively predict p53 and Ki-67 labelling index (LI) and O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status in adult isocitrate dehydrogenase (IDH) wild-type glioblastomas. The conventional MRI, DWI, and DSC-PWI results of 120 adult patients with IDH wild-type glioblastomas were reviewed retrospectively and their efficacy was analysed using chi-square tests or Fisher's exact test. Relative minimum apparent diffusion coefficient (rADCmin) and relative maximum cerebral blood volume (rCBVmax) values were compared between glioblastomas with different molecular statuses using the Mann-Whitney U-test. Receiver operating characteristic (ROC) curves and logistic regression were used to evaluate predictive performance. Glioblastomas with a high p53 LI were more likely to show a well-defined enhancement margin (p=0.047). Glioblastomas in the high-Ki-67-LI group demonstrated significantly lower rADCmin (p<0.001) and higher rCBVmax (p=0.001) values than those in the low-Ki-67-LI group. Tumours without MGMT promoter methylation showed lower rADCmin (p<0.001) and higher rCBVmax (p<0.001) values than those with it. The rCBVmax value exhibited a greater efficacy in predicting the MGMT promoter methylation status of adult IDH wild-type glioblastomas than the rADCmin value (p=0.001). The present results suggest that conventional and DWI and DSC-PWI results are influenced by the molecular status of the glioblastoma and indicate that DWI and DSC-PWI may help to identify regions of high invasiveness within heterogeneous glioblastomas.

Perfusion measurement in brain gliomas using velocity-selective arterial spin labeling: comparison with pseudo-continuous arterial spin labeling and dynamic susceptibility contrast MRI.

To evaluate the performance of velocity-selective (VS) ASL among patients with untreated gliomas by comparing with both pseudo-continuous (PC) ASL and dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI). Forty-four consecutive patients with newly diagnosed glioma who underwent preoperative perfusion MRI including VSASL, PCASL, and DSC-PWI between 2017 and 2019 were retrospectively evaluated. Visual inspection was performed to evaluate the tumor signal intensity relative to gray matter based on 1-5 score criteria and weighted kappa was used to evaluate the pair-wise concordance between VSASL or PCASL and DSC-PWI. The relative tumor blood flow (rTBF) was measured from sampling intra-tumoral areas of hot-spot on the blood flow map and normalized against the contralateral normal gray matter blood flow. Linear regression and Bland-Altman analyses were performed to evaluate the correlation and agreement of rTBF measurements between ASL methods and DSC-PWI. The ROC analysis was constructed to determine the diagnostic performance of three perfusion methods for grading gliomas. TBF maps derived from VSASL were more comparable with DSC-PWI than PCASL on visual inspection (weighted kappa of 0.90 vs 0.68). In quantitative analysis, VSASL-rTBF yielded higher correlation with the values from DSC-PWI than PCASL-rTBF (R2 = 80% vs 47%, p < 0.001 for both). Both ASL and DSC-derived rTBF showed good distinction between low-grade and high-grade gliomas (p < 0.001). Compared to PCASL, VSASL yielded superior diagnostic sensitivity, specificity, and accuracy in glioma grading. VSASL showed great promise for accurate quantification of TBF and could potentially improve the diagnostic performance of ASL in preoperative grading of gliomas. •VSASL demonstrated a greater agreement with DSC-PWI than with PCASL on visual inspection and perfusion quantification. •VSASL showed a higher diagnostic sensitivity, negative predictive value, and accuracy than PCASL for glioma grading. •With the advantages of insensitivity to transit delay and no need of prescribing a labeling plane, VSASL could potentially improve the diagnostic performance of ASL for a more accurate, noninvasive quantification of TBF in patients with glioma.

Microvascular Dysfunction in Blood-Brain Barrier Disruption and Hypoperfusion Within the Infarct Posttreatment Are Associated With Cerebral Edema.

Factors contributing to cerebral edema in the post-hyperacute period of ischemic stroke (first 24-72 hours) are poorly understood. Blood-brain barrier (BBB) disruption and postischemic hyperperfusion reflect microvascular dysfunction and are associated with hemorrhagic transformation. We investigated the relationships between BBB integrity, cerebral blood flow, and space-occupying cerebral edema in patients who received acute reperfusion therapy. We performed a pooled analysis of patients treated for anterior circulation large vessel occlusion in the EXTEND-IA TNK and EXTEND-IA TNK part 2 trials who had MRI with dynamic susceptibility contrast-enhanced perfusion-weighted imaging 24 hours after treatment. We investigated the associations between BBB disruption and cerebral blood flow within the infarct with cerebral edema assessed using 2 metrics: first midline shift (MLS) trichotomized as an ordinal scale of negligible (<1 mm), mild (≥1 to <5 mm), or severe (≥5 mm), and second relative hemispheric volume (rHV), defined as the ratio of the 3-dimensional volume of the ischemic hemisphere relative to the contralateral hemisphere. Of 238 patients analyzed, 133 (55.9%) had negligible, 93 (39.1%) mild, and 12 (5.0%) severe MLS at 24 hours. The associated median rHV was 1.01 (IQR, 1.00-1.028), 1.03 (IQR, 1.01-1.077), and 1.15 (IQR, 1.08-1.22), respectively. MLS and rHV were associated with poor functional outcome at 90 days (P<0.002). Increased BBB permeability was independently associated with more edema after adjusting for age, occlusion location, reperfusion, parenchymal hematoma, and thrombolytic agent used (MLS cOR, 1.12 [95% CI, 1.03-1.20], P=0.005; rHV β, 0.39 [95% CI, 0.24-0.55], P<0.0001), as was reduced cerebral blood flow (MLS cOR, 0.25 [95% CI, 0.10-0.58], P=0.001; rHV β, -2.95 [95% CI, -4.61 to -11.29], P=0.0006). In subgroup analysis of patients with successful reperfusion (extended Treatment in Cerebral Ischemia 2b-3, n=200), reduced cerebral blood flow remained significantly associated with edema (MLS cOR, 0.37 [95% CI, 0.14-0.98], P=0.045; rHV β, -2.59 [95% CI, -4.32 to -0.86], P=0.004). BBB disruption and persistent hypoperfusion in the infarct after reperfusion treatment is associated with space-occupying cerebral edema. Further studies evaluating microvascular dysfunction during the post-hyperacute period as biomarkers of poststroke edema and potential therapeutic targets are warranted.

Differentiation between supratentorial pilocytic astrocytoma and extraventricular ependymoma using multiparametric MRI.

The differentiation of supratentorial pilocytic astrocytomas (STPAs) and supratentorial extraventricular ependymomas (STEEs) is clinically pivotal because of distinct therapeutic management and prognosis, which is sometimes challenging to both neuroradiologists and pathologists. To explore and compare the conventional and advanced magnetic resonance imaging (MRI) features between STPA and STEE. A total of 23 patients with STPAs and 23 patients with STEEs were reviewed in this study. All patients performed conventional MRI, susceptibility-weighted imaging (SWI), and diffusion-weighted imaging (DWI), and 34 patients (17 with STPAs and 17 with STEEs) examined dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI) in addition. Clinical data, conventional MRI features, minimum relative apparent diffusion coefficient ratio (rADCmin), and maximum relative cerebral blood volume ratio (rCBVmax) were compared between the two groups and subgroups. The optimal cutoff values of rADCmin and rCBVmax with sensitivity and specificity were calculated. STPA manifested similar to STEE as a solid-cystic mass but more frequently presented with a marked enhancing deep nodule (P = 0.02), no peritumoral edema (P = 0.036), higher rADCmin value (2.0 ± 0.5 vs. 0.9 ± 0.2; P < 0.001), and lower rCBVmax value (2.1 ± 0.4 vs. 14.4 ± 5.5; P < 0.001). The cutoff value of >1.39 for rADCmin and ≤ 2.81 for rCBVmax produced a high sensitivity of 95.65% and 100.0%, respectively, and all produced a specificity of 100.0% in differentiating STPAs from STEEs. Multiparametric MRI techniques including conventional MRI, DWI, and DSC-PWI contribute to the differential diagnosis of STPA and STEE.

Peritumoral Brain Edema in Metastases May Be Related to Glymphatic Dysfunction.

ObjectivesThe proliferation of microvessels with increased permeability is thought to be the cause of peritumoral brain edema (PTBE) in metastases. The contribution of the glymphatic system to the formation of PTBE in brain metastases remains unexplored. We aimed to investigate if the PTBE volume of brain metastases is related to glymphatic dysfunction.Materials and MethodsA total of 56 patients with brain metastases who had preoperative dynamic susceptibility contrast-enhanced perfusion-weighted imaging for calculation of tumor cerebral blood volume (CBV) and diffusion tensor imaging for calculations of tumor apparent diffusion coefficient (ADC), tumor fractional anisotropy (FA), and analysis along perivascular space (ALPS) index were analyzed. The volumes of PTBE, whole tumor, enhancing tumor, and necrotic and hemorrhagic portions were manually measured. Additional information collected for each patient included age, sex, primary cancer, metastasis location and number, and the presence of concurrent infratentorial tumors. Linear regression analyses were performed to identify factors associated with PTBE volume.ResultsAmong 56 patients, 45 had solitary metastasis, 24 had right cerebral metastasis, 21 had left cerebral metastasis, 11 had bilateral cerebral metastases, and 11 had concurrent infratentorial metastases. On univariable linear regression analysis, PTBE volume correlated with whole tumor volume (β = -0.348, P = 0.009), hemorrhagic portion volume (β = -0.327, P = 0.014), tumor ADC (β = 0.530, P <.001), and ALPS index (β = -0.750, P <.001). The associations of PTBE volume with age, sex, tumor location, number of tumors, concurrent infratentorial tumor, enhancing tumor volume, necrotic portion volume, tumor FA, and tumor CBV were not significant. On multivariable linear regression analysis, tumor ADC (β = 0.303; P = 0.004) and ALPS index (β = -0.624; P < 0.001) were the two independent factors associated with PTBE volume.ConclusionMetastases with higher tumor ADC and lower ALPS index were associated with larger peritumoral brain edema volumes. The higher tumor ADC may be related to increased periarterial water influx into the tumor interstitium, while the lower ALPS index may indicate insufficient fluid clearance. The changes in both tumor ADC and ALPS index may imply glymphatic dysfunction, which is, at least, partially responsible for peritumoral brain edema formation.

Multiparametric magnetic resonance imaging features of a canine glioblastoma model.

PurposeTo assess glioblastoma multiforme (GBM) formation with similar imaging characteristics to human GBM using multiparametric magnetic resonance imaging (MRI) in an orthotopic xenograft canine GBM model.Materials and methodsThe canine GBM cell line J3T1 was subcutaneously injected into 6-week-old female BALB/c nude mice to obtain tumour fragments. Tumour fragments were implanted into adult male mongrel dog brains through surgery. Multiparametric MRI was performed with conventional MRI, diffusion-weighted imaging, and dynamic susceptibility contrast-enhanced perfusion-weighted imaging at one week and two weeks after surgery in a total of 15 surgical success cases. The presence of tumour cells, the necrotic area fraction, and the microvessel density (MVD) of the tumour on the histologic specimen were assessed. Tumour volume, diffusion, and perfusion parameters were compared at each time point using Wilcoxon signed-rank tests, and the differences between tumour and normal parenchyma were compared using unpaired t-tests. Spearman correlation analysis was performed between the imaging and histologic parameters.ResultsAll animals showed a peripheral enhancing lesion on MRI and confirmed the presence of a tumour through histologic analysis (92.3%). The normalized perfusion values did not show significant decreases through at least 2 weeks after the surgery (P > 0.05). There was greater cerebral blood volume and flow in the GBM than in the normal-appearing white matter (1.46 ± 0.25 vs. 1.13 ± 0.16 and 1.30 ± 0.22 vs. 1.02 ± 0.14; P < 0.001 and P < 0.001, respectively). The MVD in the histologic specimens was correlated with the cerebral blood volume in the GBM tissue (r = 0.850, P = 0.004).ConclusionOur results suggest that the canine GBM model showed perfusion imaging characteristics similar to those of humans, and it might have potential as a model to assess novel technical developments for GBM treatment.

Efficacy of endovascular intratumoral embolization for meningioma: assessment using dynamic susceptibility contrast-enhanced perfusion-weighted imaging

BackgroundIn preoperative embolization for intracranial meningioma, endovascular intratumoral embolization is considered to be more effective for the reduction of tumorous vascularity than proximal feeder occlusion. In this study, we aimed...

Application value of DSC-PWI in ischemic cerebrovascular disease

Objective To explore the application value in cerebral blood perfusion status of dynamic susceptibility contrast enhanced perfusion weighted imaging (DSC-PWI) in ischemic cerebrovascular disease (ICVD). Methods Retrospective analysis of 31 cases ICVD head magnetic resonance imaging (MRI), diffusion weighted imaging (DWI), magnetic resonance angiography (MRA) and DSC-PWI image in clinical diagnosis, and selectively analyze parameters including relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV), mean transit time (MTT) and time to peak (TTP) for generalize its characteristics. Results 31 cases of ICVD, 16 cases hypoperfusion, rCBF decreased significantly, rCBV decreased, MTT and TTP prolonged, include 7 cases of large vessel disease and 5 cases of small vessel disease. The collateral circulation formed 9 cases, including 3 cases with good compensation, rCBF normal, rCBV normal, MTT and TTP prolonged, 6 cases with bad compensation, rCBF decreased, rCBV normal or increased, MTT and TTP prolonged. The blood reperfusion in 3 cases, rCBF normal or slightly increased, rCBV increased, MTT shortened or normal, and TTP shortened. The excessive perfusion in 3 cases, rCBF significantly increased and rCBV significantly increased, with MTT and TTP shortened. Conclusions DSC-PWI can reliably reflect the perfusion state and collateral circulation compensation of ICVD, so as to guide the selection of clinical treatment program and significantly improve the prognosis of patients. Key words: Hypoxia-ischemia, brain; Magnetic resonance imaging; Dynamic susceptibility contrast enhanced perfusion weighted imaging

Adding DSC PWI and DWI to BT-RADS can help identify postoperative recurrence in patients with high-grade gliomas

The Brain Tumor Reporting and Data System (BT-RADS) category 3 is suitable for identifying cases with intermediate probability of tumor recurrence that do not meet the Response Assessment in Neuro-Oncology (RANO) criteria for progression. The aim of this study was to evaluate the added value of dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC PWI) and diffusion-weighted imaging (DWI) to BT-RADS for differentiating tumor recurrence from non-recurrence in postoperative high-grade glioma (HGG) patients with category 3 lesions. Patients with BT-RADS category 3 lesions were included. The maximal relative cerebral blood volume (rCBVmax) and the mean apparent diffusion coefficient (ADCmean) values were measured. The added value of DSC PWI and DWI to BT-RADS was evaluated by receiver operating characteristic (ROC) curve analysis. Fifty-one of 91 patients had tumor recurrence, and 40 patients did not. There were significant differences in rCBVmax and ADCmean between the tumor recurrence group and non-recurrence group. Compared to BT-RADS alone, the addition of DSC PWI to BT-RADS increased the area under curve (AUC) from 0.76 (95% confidence interval [CI] 0.66-0.84) to 0.90 (95% CI 0.81-0.95) for differentiating tumor recurrence from non-recurrence. The addition of DWI to BT-RADS increased the AUC from 0.76 (95% CI 0.66-0.84) to 0.88 (95% CI 0.80-0.94). The combination of BT-RADS, DSC PWI, and DWI exhibited the best diagnostic performance (AUC = 0.95; 95% CI 0.88-0.98) for differentiating tumor recurrence from non-recurrence. Adding DSC PWI and DWI to BT-RADS can significantly improve the diagnostic performance for differentiating tumor recurrence from non-recurrence in BT-RADS category 3 lesions.

Differentiation between radiation-induced brain injury and glioma recurrence using 3D pCASL and dynamic susceptibility contrast-enhanced perfusion-weighted imaging

PurposeThis 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. MethodsBoth 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. ResultsFor 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. ConclusionRadiation-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.

Differentiating Between Primary Central Nervous System Lymphomas and Glioblastomas: Combined Use of Perfusion-Weighted and Diffusion-Weighted Magnetic Resonance Imaging.

The purpose of this study was to determine whether combined diffusion-weighted imaging and dynamic susceptibility contrast-enhanced perfusion-weighted imaging magnetic resonance imaging can be used to differentiate between common malignant brain tumors, including lymphomas and high-grade gliomas. We evaluated 87 patients with histologically confirmed brain tumors, including 33 primary central nervous system lymphomas (PCNSLs) and 54 glioblastomas (GBMs). All patients underwent conventional magnetic resonance imaging, diffusion-weighted imaging, and perfusion-weighted imaging before surgical removal of the lesion or stereotactic biopsy. The maximum relative cerebral blood volume (rCBV) ratios of GBMs were significantly higher than those of PCNSLs (P < 0.0001). The maximum rCBVs helped to distinguish PCNSLs from GBMs with 97.0% sensitivity, 90.7% specificity, and 0.98 area under the curve. The minimum apparent diffusion coefficients (ADCs) of PCNSLs were significantly lower than those of GBMs (P < 0.0001). At an rCBV cutoff value of 4.0 and a minimum ADC of 1.0× 10-3 mm2/second, it was possible to differentiate between PCNSLs and GBMs. The combination of rCBV and ADC can facilitate the differentiation between PCNSLs and GBMs.

Quantitative Measurement of Cerebral Blood Flow in Enhanced Psedo-continuous Arterial Spin Labeling Perfusion Imaging in Patients with Intracranial Atherosclerotic Stenosis.

Objective To acquire cerebral blood flow (CBF) in patients with severe intracranial atherosclerotic stenosis with enhanced pseudo-continuous arterial spin labeling (e-pCASL) and compare it with the findings of dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC PWI) and pseudo-continuous arterial spin labeling (pCASL). Methods A total of 39 consecutive patients with severe intracranial atherosclerotic stenosis were enrolled in this study. All these patients underwent e-pCASL, pCASL, and DSC PWI. Blood supply territory of the stenosed artery was outlined as region of interest (ROI) and a mirror ROI was applied. Ratios of CBF were calculated as value of ROI/value of mirror ROI. SNK variance analysis was conducted to compare the CBF values of three persufion methods. Factorial analysis of variance and Pearson were employed to analysis the difference and the correlation of e-pCASL CBF ratio, pCASL CBF ratio, and DSC PWI relative cerebral blood flow(rCBF) ratio. Results The e-pCASL CBF ratio, pCASL CBF ratio, and DSC PWI rCBF ratio were not significantly different (P=0.476). TTP showed the CBF ratios were not significantly different between the healthy side and diseased side in patients with severe intracranial atherosclerotic stenosis. ATT showed the correlations of pCASL CBF ratio and DSC PWI rCBF ratio were not affected by ATT. Conclusions e-pCASL with multiple-post labeling delay time and pCASL have good consistency with DSC PWI in the quantitative measurement of hypoperfusion pattern. As an accurate, simple, non-invasive, and repeatable technique, e-pCASL has good correlation with DSC PWI in the quantitative measurement of hypoperfusion pattern that is not affected by ATT.

Basilar artery hypoplasia associated with changes of brainstem potential, transcranial Doppler and perfusion-weighted imaging

Objective: The aim of this study was to observe brainstem hemodynamic alterations associated with basilar artery hypoplasia (BAH). Methods: Nine hundred and fifty-two consecutive patients received emergency multimodal computed tomography; magnetic resonance imaging and magnetic resonance angiogram during the period of January 2011 to December 2014 were included. The vascular risk factors, brainstem auditory evoked potential (BAEP), blink reflex (BR), transcranial Doppler (TCD) and dynamic susceptibility contrast-enhanced perfusion-weighted imaging were completed. Results: There was significant difference in the abnormal rates of TCD and BAEP between BAH and non-BAH patients. A positive correlation between basilar artery diameter and systolic velocity among BAH patients was suggested. V-wave value was used to predict posterior circulation infarction (PCI) with the sensitivity of 0.933 and specificity of 0.50 with the cutoff value of 5.97 s. Abnormal BR rate was also significantly different in BAH and non-BAH patients. The latency of R2 was used to predict PCI with the sensitivity of 0.933 and specificity of 0.50 with the cutoff value of 46.4 ms. The incidence of hypoperfusion was higher in BAH than non-BAH group and it was significant difference. Conclusion: BAH is closely associated with hemodynamic alterations within the pons, which might contribute to vascular vertigo due to regional hypoperfusion.