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.

Effects of intravenous thrombolysis with alteplase on immune function and quality of life in patients with cerebral infarction / 中国基层医药

Objective:To investigate the effects of intravenous thrombolysis with alteplase on immune function and quality of life in patients with cerebral infarction.Methods:Sixty-nine patients with cerebral infarction who received treatment in Rizhao Central Hospital, China between January 2014 and January 2019 were included in this study. They were randomly assigned to receive either intravenous thrombolysis with urokinase (control group, n = 34) or intravenous thrombolysis with alteplase (observation group, n = 35). Therapeutic efficacy and cerebral blood perfusion, immune function and quality of life before and after treatment were evaluated. Results:Effective rate in the observation group was significantly higher than that in the control group [82.86% (29/35) vs. 58.82% (20/34), χ2 = 4.840, P < 0.05]. After treatment, the transit time and peak time in the ischemic area in the observation group were (131.25 ± 25.41) seconds and (99.52 ± 17.50) seconds respectively, which were significantly shorter than those in the control group [(165.33 ± 31.05) seconds, (108.45 ± 12.52) seconds, t = 6.580, 3.215, both P < 0.05). The cerebral blood flow and cerebral blood volume in the observation group were (72.51 ± 21.35) mL/100 mg and (95.36 ± 31.25) mL/100 mg, respectively, which were significantly higher than those in the control group [(62.42 ± 19.35) mL/100 mg, (84.20 ± 28.05) mL/100 mg, t = 2.712, 2.243, both P < 0.05). After treatment, the proportion of CD 8+ cells in the observation group was significantly lower than that in the control group [(25.37 ± 3.73)% vs. (27.42 ± 3.25)%, t = 4.261, P < 0.05]. The proportions of CD 3+, CD 4+, CD 3-CD 16+CD 56+ cells in the observation group were (56.32 ± 6.57)%, (34.69 ± 3.44)%, (13.34 ± 3.75)%, respectively, which were significantly higher than those in the control group [(53.32 ± 4.05)%, (31.69 ± 3.72)%, (11.28 ± 3.06)%, t = 5.395, 3.694, 4.179, P < 0.05]. After treatment, the scores of all dimensions of Short Form 36 Health Status Questionnaire in the observation group were significantly higher than those in the control group (all P < 0.05). Conclusion:Intravenous thrombolysis with alteplase is superior to intravenous thrombolysis with urokinase in the treatment of cerebral infarction because it can better improve immune function and quality of life.

Cerebral Blood Volume Magnetic Resonance Imaging

Cerebral blood volume (CBV) is a hemodynamic correlate of oxygen metabolism and changes due to neuronal activity. CBV alteration may precede other hemodynamic correlates and provide an early indication of hemodynamic impairment. CBV can be easily quantified using magnetic resonance imaging (MRI); moreover, CBV MRI has a strong point of high resolution compared to other neuroimaging modalities. The early and accurate assessments of cerebral metabolism and the brain map with the high resolution of CBV MRI enable advanced neurorehabilitation examinations in a neuroimaging study.

Perfusion-Weighted MRI Parameters for Prediction of Early Progressive Infarction in Middle Cerebral Artery Occlusion

OBJECTIVE: Early progressive infarction (EPI) is frequently observed and related to poor functional outcome in patients with middle cerebral artery (MCA) infarction caused by MCA occlusion. We evaluated the perfusion parameters of magnetic resonance imaging (MRI) as a predictor of EPI. METHODS: We retrospectively analyzed patients with acute MCA territory infarction caused by MCA occlusion. EPI was defined as a National Institutes of Health Stroke Scale increment ≥2 points during 24 hours despite receiving standard treatment. Regional parameter ratios, such as cerebral blood flow and volume (rCBV) ratio (ipsilateral value/contralateral value) on perfusion MRI were analyzed to investigate the association with EPI. RESULTS: Sixty-four patients were enrolled in total. EPI was present in 18 (28%) subjects and all EPI occurred within 3 days after hospitalization. Diabetes mellitus, rCBV ratio and regional time to peak (rTTP) ratio showed statically significant differences in both groups. Multi-variate analysis indicated that history of diabetes mellitus [odds ratio (OR), 6.13; 95% confidence interval (CI), 1.55-24.24] and a low rCBV ratio (rCBV, <0.85; OR, 6.57; 95% CI, 1.4-30.27) was significantly correlated with EPI. CONCLUSION: The incidence of EPI is considerable in patients with acute MCA territory infarction caused by MCA occlusion. We suggest that rCBV ratio is a useful neuro-imaging parameter to predict EPI.

Prediction of Response to Concurrent Chemoradiotherapy with Temozolomide in Glioblastoma: Application of Immediate Post-Operative Dynamic Susceptibility Contrast and Diffusion-Weighted MR Imaging

OBJECTIVE: To determine whether histogram values of the normalized apparent diffusion coefficient (nADC) and normalized cerebral blood volume (nCBV) maps obtained in contrast-enhancing lesions detected on immediate post-operative MR imaging can be used to predict the patient response to concurrent chemoradiotherapy (CCRT) with temozolomide (TMZ). MATERIALS AND METHODS: Twenty-four patients with GBM who had shown measurable contrast enhancement on immediate post-operative MR imaging and had subsequently undergone CCRT with TMZ were retrospectively analyzed. The corresponding histogram parameters of nCBV and nADC maps for measurable contrast-enhancing lesions were calculated. Patient groups with progression (n = 11) and non-progression (n = 13) at one year after the operation were identified, and the histogram parameters were compared between the two groups. Receiver operating characteristic (ROC) analysis was used to determine the best cutoff value for predicting progression. Progression-free survival (PFS) was determined with the Kaplan-Meier method and the log-rank test. RESULTS: The 99th percentile of the cumulative nCBV histogram (nCBV C99) on immediate post-operative MR imaging was a significant predictor of one-year progression (p = 0.033). ROC analysis showed that the best cutoff value for predicting progression after CCRT was 5.537 (sensitivity and specificity were 72.7% and 76.9%, respectively). The patients with an nCBV C99 of < 5.537 had a significantly longer PFS than those with an nCBV C99 of ≥ 5.537 (p = 0.026). CONCLUSION: The nCBV C99 from the cumulative histogram analysis of the nCBV from immediate post-operative MR imaging may be feasible for predicting glioblastoma response to CCRT with TMZ.

True Progression versus Pseudoprogression in the Treatment of Glioblastomas: A Comparison Study of Normalized Cerebral Blood Volume and Apparent Diffusion Coefficient by Histogram Analysis

OBJECTIVE: The purpose of this study was to differentiate true progression from pseudoprogression of glioblastomas treated with concurrent chemoradiotherapy (CCRT) with temozolomide (TMZ) by using histogram analysis of apparent diffusion coefficient (ADC) and normalized cerebral blood volume (nCBV) maps. MATERIALS AND METHODS: Twenty patients with histopathologically proven glioblastoma who had received CCRT with TMZ underwent perfusion-weighted imaging and diffusion-weighted imaging (b = 0, 1000 sec/mm2). The corresponding nCBV and ADC maps for the newly visible, entirely enhancing lesions were calculated after the completion of CCRT with TMZ. Two observers independently measured the histogram parameters of the nCBV and ADC maps. The histogram parameters between the true progression group (n = 10) and the pseudoprogression group (n = 10) were compared by use of an unpaired Student's t test and subsequent multivariable stepwise logistic regression analysis to determine the best predictors for the differential diagnosis between the two groups. Receiver operating characteristic analysis was employed to determine the best cutoff values for the histogram parameters that proved to be significant predictors for differentiating true progression from pseudoprogression. Intraclass correlation coefficient was used to determine the level of inter-observer reliability for the histogram parameters. RESULTS: The 5th percentile value (C5) of the cumulative ADC histograms was a significant predictor for the differential diagnosis between true progression and pseudoprogression (p = 0.044 for observer 1; p = 0.011 for observer 2). Optimal cutoff values of 892 x 10-6 mm2/sec for observer 1 and 907 x 10-6 mm2/sec for observer 2 could help differentiate between the two groups with a sensitivity of 90% and 80%, respectively, a specificity of 90% and 80%, respectively, and an area under the curve of 0.880 and 0.840, respectively. There was no other significant differentiating parameter on the nCBV histograms. Inter-observer reliability was excellent or good for all histogram parameters (intraclass correlation coefficient range: 0.70-0.99). CONCLUSION: The C5 of the cumulative ADC histogram can be a promising parameter for the differentiation of true progression from pseudoprogression of newly visible, entirely enhancing lesions after CCRT with TMZ for glioblastomas.

Evaluation of cerebral circulation time by contrast-enhanced ultrasound in healthy adults / 中华超声影像学杂志

Objective To measure cerebral circulation time(CCT) of a group of normal adults by contrast-enhanced ultrasound. Methods Forty-seven cases of healthy volunteers without any cardio-cerebral disease history were enrolled in the study. Internal carotid artery and vertebral artery were observed and the blood flow was measured with high frequency probe. Contrast-enhanced agent SonoVue was injected bolus into median cubital vein. CCT was measured and calculated according to the contrast curve analysis. Contralateral CCT measurement was repeated when the blood flow signal resume to the baseline intensity. Cerebral blood volume was then calculated according to CCT and cerebral blood flow. Results All the imaging of carotid vessels was presented clearly in all objects. Cerebral blood flow was 603 ～ 990 ml/min with an average (778 ± 171)ml/min. Bi-lateral CCT was measured successfully,the value ranged 4. 1 ～ 10.2 s with average (6.22 ± 1.47) s. There were no significant differences both in contrast of left and right side of the carotid vessels and in contrast of three dosage groups ( P ＞0.05). The cerebral blood volume was 54～96ml with average (76 ± 27)ml. Conclusions Contrast-enhanced ultrasound can be useful in measurement and calculation of CCT and cerebral blood volume.

MR perfusion weighted imaging in evaluation of benign and malignant meningiomas / 中国医学影像技术

Objective To investigate the correlation between relative cerebral blood volume (rCBV) and tumor character of meningiomas. Methods Thirty-six (GradeⅠ: n=30, GradeⅡ+Ⅲ: n=6) patients with meningioma underwent conventional MR and perfusion weighted imaging (PWI) . The pulse sequence of PWI was single shot GRE-EPI-T2~*WI. The CBV maps were calculated from the original data of perfusion images and the maximum rCBV of meningiomas was acquired from CBV maps through measurement on the region of interest (ROI). The differences of rCBV in tumor and edema between benign and malignant tumors were analyzed. Results The mean rCBV in tumor of benign meningioma (9.78±4.69) was higher than that of malignant ones (3.59±0.28) (t=7.168, P0.05). Conclusion CBV map and quantitative study of rCBV are feasible for differential diagnosis of meningiomas and have instructive function for clinical treatment and assessment of prognosis.

Development of the Multi-Parametric Mapping Software Based on Functional Maps to Determine the Clinical Target Volumes / 의학물리

To determine the clinical target volumes considering vascularity and cellularity of tumors, the software was developed for mapping of the analyzed biological clinical target volumes on anatomical images using regional cerebral blood volume (rCBV) maps and apparent diffusion coefficient (ADC) maps. The program provides the functions for integrated registrations using mutual information, affine transform and non-rigid registration. The registration accuracy is evaluated by the calculation of the overlapped ratio of segmented bone regions and average distance difference of contours between reference and registered images. The performance of the developed software was tested using multimodal images of a patient who has the residual tumor of high grade gliomas. Registration accuracy of about 74% and average 2.3 mm distance difference were calculated by the evaluation method of bone segmentation and contour extraction. The registration accuracy can be improved as higher as 4% by the manual adjustment functions. Advanced MR images are analyzed using color maps for rCBV maps and quantitative calculation based on region of interest (ROI) for ADC maps. Then, multi-parameters on the same voxels are plotted on plane and constitute the multi-functional parametric maps of which x and y axis representing rCBV and ADC values. According to the distributions of functional parameters, tumor regions showing the higher vascularity and cellularity are categorized according to the criteria corresponding malignant gliomas. Determined volumes reflecting pathological and physiological characteristics of tumors are marked on anatomical images. By applying the multi-functional images, errors arising from using one type of image would be reduced and local regions representing higher probability as tumor cells would be determined for radiation treatment plan. Biological tumor characteristics can be expressed using image registration and multi-functional parametric maps in the developed software. The software can be considered to delineate clinical target volumes using advanced MR images with anatomical images.

A review of basic principles and methodological applications of BOLD-fMRI / 国际生物医学工程杂志

Functional magnetic resonance imaging(fMRI) is a very powerful method to understand the mechanism of brain function with non-invasive localization, high spatial and temporal resolution. The essential fMRI technique is blood oxygen level dependent (BOLD-fMRI). Basic principles and methodological applications of BOLD-fMRI are reviewed in this paper.

Usefulness of CT Perfusion in the Postoperative Evaluation of Ruptured Aneurysm / 대한뇌혈관외과학회지

OBJECTIVE: Our goal was to evaluate the usefulness of CT perfusion (CTP) in early detection of the post operative cerebral ischemia, alteration of treatment modality and patient prognosis in cerebral aneurysm patients. METHODS: 24 patients who underwent either surgical operation or endovascular coiling for ruptured aneurysms were selected. All patients undertook an angiogram, conventional CT, and CTP scan immediately following surgical operation or endovascular coiling. All patients performed a CT 2 weeks after treatment to evaluate possible development of a cerebral infarction. Postoperative CT results of patients with abnormal postoperative CTP scan findings were compared, and these results were compared with the CT results and clinical symptoms of patients who developed infarction or not. RESULTS: Of the 24 patients evaluated, 11 patients showed abnormal findings on CTP. 9 patients were diagnosed with cerebral infarction through a CT scan done 2 weeks after treatment; all exhibited abnormal CTP results immediately after treatment. Abnormal CTP findings were divided into two groups; patients with abnormal CBF and MTT maps, but with normal CBV maps, and patients with abnormal CBF, CBV and MTT maps. A correlation was seen between abnormality on CBV maps and cerebral infarction. Patients with abnormal CTP findings also exhibited poorer prognostic value. CONCLUSION: Postoperative CTP in ruptured aneurysm patients is a very useful and objective tool in evaluating abnormal cerebral hemodynamics. The CBV map of CTP is the most precisely predictable value of postoperative patient's status and alteration of treatement modality.

Application of dynamic contrast-enhanced perfusion MR imaging in intracranial tumors / 医学研究生学报

Dynamic contrasted-enhanced perfusion MR imaging can provide noninvasive and physical maps of cerebral microcirculation. The tumor vascularities are assessed by calculating cerebral blood volumes of the normal cerebral tissue and tumor tissue from imaging signal intensities. This technique is helpful to better evaluate the histopathological grade of gliomas, determine the biopsy site for tumors. And it is very useful for the preoperative diagnosis of gliomas, solitary metastases, cerebral lymphomas, as well as differentiating tumor recurrence after surgical resection and radiotherapy from radiation necrosis. But there are some limitations in evaluating extraaxial tumors and cerebral tumors with severe breakdown of blood-brain barrier.

Correlation studies of rCBV with VEGF protein expression and MVD in gliomas / 中华放射学杂志

Objective To investigate the correlation of rCBV with vascular endothelial growth factor (VEGF) protein expression and microvessel density (MVD) in gliomas Methods MR examinations were performed preoperatively in 46 patients with suspected supratentorial gliomas All the 46 cases were proved by operation and pathology Immunohistochemical stain methods were used to demonstrate the situation of VEGF protein expression and quantitatively measure the MVD in gliomas The procedures of MR examinations included plain MR scan, PWI and routine contrast enhanced MR scan The pulse sequence of PWI was single shot GRE EPI T  2WI The CBV maps were calculated from the original data of perfusion images and the maximum rCBV of gliomas was acquired from CBV maps through measurement on the region of interest (ROI) According to the situation of VEGF protein expression, all the 46 cases were divided into two groupsincluding positive VEGF protein expression group and negative VEGF protein expression group Mann Whitney U test was used for comparing the difference between the two groups Spearman′s rho correlation analysis was used for observing the correlation between maximum rCBV and MVD in gliomas Results Of the 46 cases; 12 cases were astrocytomas, 3 were oligodendrogliomas, 1 was mixed glioma, 14 were anaplastic astrocytomas, and 16 were glioblastomas multiforme The maximum rCBV value in VEGF(-) group ( n =14) and VEGF(+) group ( n =32) ranged from 0 33～6 63 and 1 03～10 68, with median of 3 08 and 5 95, respectively The difference in maximum rCBV between the two groups was statistically significant ( Mann Whitney U test | z| =2 638, P

Measurement of Regional Cerebral Blood Volume in Normal Rabbits on Perfusion-weighted MR Image

PURPOSE: To evaluate the usefulness of cerebral blood flow measurement applied to perfusion weighted image with short-scan time single shot gradient echo-planar technique in measuring cerebral blood volume(rCBV) of normal rabbits. MATERIALS AND METHODS: With 2.1-3.6 kg weighted rabbits, image is acquired when they are in supine position in children positioner. Perfusion weighted image is acquired to 44 seconds per 1 second successively. After 4 seconds later, Gd-DTPA 2ml are injected into int. jugular vein with 2 ml per second and normal saline is also injected after that. Same technique is applied 2 times per 30 minites in same rabbit. After Image is obtained in two part of cerebral cortex at vertex, convexity, in one of basal ganglia with choosing about 3-5mm2 areas. Curve of signal intensity changes in time sequence is drawn. After this images are transmitted by PC and software IDL, regional cerebral blood volume is measured with imaging processing program made by us. RESULTS: With 22 of 24 rabbits, satisfactory 1-2 signal intensity versus time curve is made. Cerebral blood capacity and contrast media stay time (ST) is measured in two cerebral cortex and basal ganglia refering in parietal cerebral cortex. Mean focal cerebral blood flow capacity ratio in cortex was 0.97+/-0.35 and in basal ganglia, 0.99+/-0.37, mean contrast media stay time in cortex was 9.83+/-1.63 sec and in basal ganglia, 9.42+/-1.14 sec, but there was no statistically significant difference between two areas (p=0.05). CONCLUSION: In cerebral cortex and basal ganglia, there is no difference in mean focal blood volume and mean contrast stay time. Therefore, PWI is useful in cerebral blood flow and early diagnosis, prognosis of cerebral ischemic disease. Hereafter, it is helpful in analysing cerebral blood flow changes with comparison difference in rCBV between normal tissue and ischemic tissue, and that with DWI finding in infarcted patient.

Findings of Perfusion MR Imaging in Acute Middle Cerebral Artery Territory Ischemic Stroke

BACKGROUND: Although a magnetic resonance imaging (MRI) is highly sensitive for changes associated with ischemic stroke, the detection of an acute ischemic lesion is usually impossible within 6 hours of the stroke onset on a conventional MRI. The perfusion MRI is a new imaging technique for diagnosing acute ischemic stroke. We evaluate the clinical usefulness of the perfusion MRI in predicting the final infarct extent in 18 patients with acute middle cerebral artery (MCA) territory ischemic stroke. METHOD: The perfusion MRI was performed within 6 hours after the stroke onset in all patients with a single-section dynamic contrast-enhanced T2*-weighted imaging in conjunction with a conventional routine MRI and MR angiography. Time-concentration curves and cerebral blood volume (CBV) maps were calculated from the dynamic MR imaging data by using numerical integration techniques. We compared findings of CBV maps with infarction on a follow-up CT or MRI. RESULTS: In 14 of 18 patients, the CBV in the occluded MCA territory were decreased. In the remaining 4 patients with a reversible ischemic neurologic deficit (RIND) or transient ischemic attack (TIA), the CBV were increased in 3 and normal in 1. Out of 14 patients with a decreased CBV, two had focal regions of increased CBV within the affected territory, indicating reperfusion hyperemia. The regions of increased or decreased CBV were eventually converted to infarction on follow-up images in all 14 patients. Out of 4 patients with RIND or TIA, one showed focal infarction in centrum semiovale on a follow-up image. CONCLUSIONS: The perfusion MRI was useful for the assessment of hemodynamic change about cerebral perfusion and may predict the extent of final infarction in acute MCA territory ischemic stroke. These results suggest that the perfusion MRI may play an important role in the diagnosis and management of acute ischemic stroke.