Effect of Tongnaoyin on Cerebral Hemodynamics in Patients with Acute Cerebral Infarction of Phlegm and Blood Stasis Syndrome Based on CTA/CTP / 中国实验方剂学杂志

ObjectiveTo investigate the changes in cerebral blood perfusion in patients with acute cerebral infarction after taking Tongnaoyin， a traditional Chinese medicine， based on head and neck computed tomography （CT） angiography （CTA） combined with brain CT perfusion imaging （CTP）. MethodA total of 240 patients with cerebral infarction of phlegm and blood stasis syndrome treated in Jiangsu Province Hospital of Traditional Chinese Medicine from March 2018 to September 2023 were randomly divided into a control group （99 cases） and a Tongnaoyin group （141 cases）. Based on the guidelines， the control group was treated with conventional treatment such as anti-aggregation， anticoagulation， lipid-lowering and plaque stabilization， brain protection， and supportive treatment. The Tongnaoyin group was treated with Tongnaoyin of 200 mL in warm conditions in the morning and evening on the basis of the control group. Both groups underwent CTA combined with CTP within 24 hours after admission， and they were reexamined by CTA and CTP in the sixth month after admission. The degree of intracranial artery stenosis was determined according to the North American Symptomatic Carotid Endarterectomy Trial （NASCET） method. The relative cerebral blood volume （rCBV）， relative cerebral blood flow （rCBF）， mean transit time （MTT）， and time to peak （TTP） of the lesion area before and after treatment were compared. The adverse outcomes of the two groups within six months after discharge were compared. ResultCompared with the group before treatment， the degree of vascular stenosis in the Tongnaoyin group was significantly reduced， and the difference was statistically significant （Z=105.369，P<0.05）. Compared with the control group after treatment， the improvement rate of vascular stenosis in the Tongnaoyin group was higher （χ2=84.179，P<0.01）， and the curative effect was better.After treatment， the rCBV and rCBF of patients in the Tongnaoyin group were significantly increased， and the difference was statistically significant （P<0.01）. MTT and TTP showed a trend of shortening， but the difference was not statistically significant. There was no statistically significant difference in rCBV， rCBF， MTT， and TTP in the control group. Compared with those in the control group after treatment， the rCBV and rCBF in the Tongnaoyin group were significantly increased， while MTT and TTP were significantly reduced （P<0.01）. After six months of discharge， the risk of poor prognosis in the Tongnaoyin group was significantly reduced compared with the control group （P<0.05）. ConclusionTongnaoyin has a good effect on improving cerebral blood perfusion in patients with acute cerebral infarction. It can be used as an effective supplement for the conventional treatment of ischemic stroke to improve clinical efficacy.

Diagnostic and predictive value of CT perfusion imaging in patient with traumatic brain injury / 实用放射学杂志

Objective To investigate the application value of CT perfusion imaging in patient with traumatic brain injury(TBI).Methods Thirty-seven patients with TBI were included retrospectively and divided into mild,moderate,and severe groups according to Glasgow coma scale(GCS)score.Perfusion parameters of the cerebral hemispheres on the injured side and the contralateral side of the level of basal ganglia were compared.After three months,the correlations between perfusion parameters and GCS score at baseline and Glasgow outcome scale-extended(GOSE)score at follow-up were further analyzed,respectively.Results The injured side of TBI patients showed hypo-perfusion compared with that of the contralateral side.The abnormal perfusion volumes of time to maximum of the residual function(Tmax)>10 s was significantly negatively correlated with GOSE score(ρ=-0.55,P=0.01),and could distinguish the good prognosis group from the poor prognosis group with GOSE score[area under the curve(AUC)=0.82,P= 0.01].In the group of patients undergoing decompressive craniectomy,the abnormal perfusion volumes of Tmax>4 s and Tmax>6 s were significantly associated with GCS score(ρ=0.61,P=0.01;ρ=0.53,P=0.03).Conclusion CT perfusion imaging may be useful in assessing the hemodynamics and severity of TBI,and in predicting the clinical prognosis.

Hybrid UNet transformer architecture for ischemic stoke segmentation with MRI and CT datasets.

A hybrid UNet and Transformer (HUT) network is introduced to combine the merits of the UNet and Transformer architectures, improving brain lesion segmentation from MRI and CT scans. The HUT overcomes the limitations of conventional approaches by utilizing two parallel stages: one based on UNet and the other on Transformers. The Transformer-based stage captures global dependencies and long-range correlations. It uses intermediate feature vectors from the UNet decoder and improves segmentation accuracy by enhancing the attention and relationship modeling between voxel patches derived from the 3D brain volumes. In addition, HUT incorporates self-supervised learning on the transformer network. This allows the transformer network to learn by maintaining consistency between the classification layers of the different resolutions of patches and augmentations. There is an improvement in the rate of convergence of the training and the overall capability of segmentation. Experimental results on benchmark datasets, including ATLAS and ISLES2018, demonstrate HUT's advantage over the state-of-the-art methods. HUT achieves higher Dice scores and reduced Hausdorff Distance scores in single-modality and multi-modality lesion segmentation. HUT outperforms the state-the-art network SPiN in the single-modality MRI segmentation on Anatomical Tracings of lesion After Stroke (ATLAS) dataset by 4.84% of Dice score and a large margin of 40.7% in the Hausdorff Distance score. HUT also performed well on CT perfusion brain scans in the Ischemic Stroke Lesion Segmentation (ISLES2018) dataset and demonstrated an improvement over the recent state-of-the-art network USSLNet by 3.3% in the Dice score and 12.5% in the Hausdorff Distance score. With the analysis of both single and multi-modalities datasets (ATLASR12 and ISLES2018), we show that HUT can perform and generalize well on different datasets. Code is available at: https://github.com/vicsohntu/HUT_CT.

Multimodality CT imaging contributes to improving the diagnostic accuracy of solitary pulmonary nodules: a multi-institutional and prospective study.

BACKGROUND: Solitary pulmonary nodules (SPNs) are one of the most common chest computed tomography (CT) abnormalities clinically. We aimed to investigate the value of non-contrast enhanced CT (NECT), contrast enhanced CT (CECT), CT perfusion imaging (CTPI), and dual- energy CT (DECT) used for differentiating benign and malignant SPNs with a multi-institutional and prospective study. PATIENTS AND METHODS: Patients with 285 SPNs were scanned with NECT, CECT, CTPI and DECT. Differences between the benign and malignant SPNs on NECT, CECT, CTPI, and DECT used separately (NECT combined with CECT, DECT, and CTPI were methods of A, B, and C) or in combination (Method A + B, A + C, B + C, and A + B + C) were compared by receiver operating characteristic curve analysis. RESULTS: Multimodality CT imaging showed higher performances (sensitivities of 92.81% to 97.60%, specificities of 74.58% to 88.14%, and accuracies of 86.32% to 93.68%) than those of single modality CT imaging (sensitivities of 83.23% to 85.63%, specificities of 63.56% to 67.80%, and accuracies of 75.09% to 78.25%, all p < 0.05). CONCLUSIONS: SPNs evaluated with multimodality CT imaging contributes to improving the diagnostic accuracy of benign and malignant SPNs. NECT helps to locate and evaluate the morphological characteristics of SPNs. CECT helps to evaluate the vascularity of SPNs. CTPI using parameter of permeability surface and DECT using parameter of normalized iodine concentration at the venous phase both are helpful for improving the diagnostic performance.

Multireader image quality evaluation of dynamic myocardial computed tomography perfusion imaging with a novel four-dimensional noise reduction filter.

BACKGROUND: Dynamic myocardial computed tomography perfusion (CTP) is a novel technique able to depict cardiac ischemia. PURPOSE: To evaluate the impact of a four-dimensional noise reduction filter (similarity filter [4D-SF]) on image quality in dynamic CTP imaging, allowing for substantial radiation dose reduction. MATERIAL AND METHODS: Dynamic CTP datasets of 30 patients (16 women) with suspected coronary artery disease, acquired with a 320-slice CT system, were retrieved, reconstructed with the deep learning-based algorithm of the system (DLR), and filtered with the 4D-SF. For each case, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in six regions of interest (33-38mm2) were calculated before and after filtering, in four-chamber and short-axis views, and t-tested. Furthermore, six radiologists of different expertise evaluated subjective image preference by answering five visual grading analysis-type questions (regarding acceptable level of noise, absence of artifacts, natural appearance, cardiac contour sharpness, diagnostic acceptability) using a 5-point scale. The results were analyzed using visual grade characteristics (VGC) and intraclass correlation coefficient (ICC). RESULTS: Mean SNR in four-chamber view (unfiltered vs. filtered) were: septum=4.1 ± 2.1 versus 7.6 ± 5.6; lateral wall=4.5 ± 2.0 versus 8.0 ± 4.9; CNRseptum=16.6 ± 8.9 versus 31.7 ± 28; lateral wall=16.2 ± 8.9 versus 31.3 ± 28.9. Similar results were obtained in short-axis view. The perceived filtered image quality indicated decreased noise (VGCAUC=0.96) and artifacts (0.65), improved natural appearance (0.59), cardiac contour sharpness (0.74), and diagnostic acceptability (0.78). The inter-observer variability was excellent (ICC=0.79). All results were statistically significant (P < 0.05). CONCLUSION: Similarity filtering after DLR improves image quality, possibly enabling dose reduction in dynamic CTP imaging in patient with suspected chronic coronary syndrome.

Preliminary results of reduced myocardial blood flow in the subacute phase after radiation therapy for thoracic esophageal cancer: A quantitative analysis with stress dynamic myocardial computed tomography perfusion imaging.

BACKGROUND AND PURPOSE: Late adverse cardiac events after radiation therapy (RT) for thoracic malignancies are known, but the underlying mechanisms are poorly understood. This study aimed to determine the radiation dose that can cause MBF alterations in the subacute phase after RT for thoracic esophageal cancer using stress dynamic myocardial computed tomography perfusion imaging (CTP). MATERIALS AND METHODS: Twenty-five patients with esophageal cancer scheduled for RT were prospectively enrolled. The quantitative analysis of MBF by CTP was performed before and 3 months after RT. The mean radiation dose and hyperemic MBF in 15 segments of the left ventricular (LV) myocardium were determined. ΔMBF was calculated in each segment as MBFafter RT - MBFbeforeRT. The myocardial segments were classified into the following 5 groups according to the mean radiation dose: group A, <10 Gy; B1, 10-15 Gy; B2, 15-20 Gy; C, 20-30 Gy; and D, >30 Gy. RESULTS: The final cohort included 22 patients who completed pre- and post-RT CTP. A one-way analysis of variance revealed a significant difference (p=0.005) in ΔMBF among the five groups of LV segments classified by the mean radiation dose. ΔMBF was significantly lower in group C (-7.7 ± 28.9 mL/min/100 g, p=0.020) and group D (-8.4 ± 34.8 mL/min/100 g, p=0.004) in comparison to ΔMBF in group A (4.9 ± 26.1 mL/min/100 g). CONCLUSIONS: This study using CTP early after RT demonstrated a significant reduction of the MBF in the LV segments with ≥20 Gy of radiation. The results might provide important insights into preventing radiotherapy-induced cardiac events.

The Effect of Hemoglobin Concentration on Hyperbaric Oxygen and Non-hyperbaric Oxygen in the Treatment of Hypertensive Intracerebral Hemorrhage After Operation at the High Altitude.

Background: The prognosis of hypertensive intracerebral hemorrhage (HICH) is poor at high altitudes. The objective of this study was to explore whether hyperbaric oxygen (HBO) can improve the results of computed tomography perfusion (CTP) imaging and the neurological function of patients with HICH, and influence the hemoglobin concentration. Method: The patients with HICH were treated with puncture and drainage. Twenty-one patients (51.22% of 41 patients in total) were treated with HBO after the operation, and the other patients received conventional treatment. CTP was performed twice, and all indices were measured. Scatter plots were used to determine the effect of hemoglobin concentration on CTP imaging. Receiver operating characteristic (ROC) curves were plotted to analyze the effects of hemoglobin concentration and hematoma volume on recovery results. The patients were followed up for 6 months. Results: Forty-one patients with HICH were treated with puncture and drainage. In total, 21 were treated with HBO after the operation, and 20 received conventional treatment as the control group. No significant differences in the CBV and CBF values of the two groups were noted before treatment. After 10 days, the values of CBV and CBF in the HBO group were significantly higher than those in the control group. A scatter diagram showed there was no significant in the HBO group, but significant correlation for the CBV and CBF values in the control group's hematoma center and margin. The ROC curves showed that hematoma volume had an influence on prognosis of the control group. The Glasgow Coma Scale (GOS) scores of the HBO group were significantly higher than those of the control group (p < 0.05). Conclusions: HBO therapy can improve the postoperative CBV and CBF values of patients with HICH and ameliorate their prognoses. There was no significant correlation between HBO group and hemoglobin concentration on admission.

"Ebstein's Anomaly" a Potential Cause of Misinterpretation on Myocardial Perfusion Imaging.

Ebstein's anomaly is a rare congenital heart disease. We present the case of a 47-year-old woman with history of Ebstein's anomaly who was referred to nuclear medicine department for a myocardial perfusion single-photon emission computed tomography (SPECT) imaging during pre-anesthetic check-up. Myocardial SPECT perfusion images with (99mTc)-Sestamibi demonstrated medium sizes fixed perfusion defect in the mid and proximal infero-septal wall adjacent inferior wall. This is a cause of potential misinterpretation on myocardial SPECT perfusion imaging as this perfusion defect was due to fibrosis rather than scarred myocardium.

Correlation study between flash dual source CT perfusion imaging and regional lymph node metastasis of non-small cell lung cancer.

BACKGROUND: To explore the correlation of flash dual source computed tomography perfusion imaging (CTPI) and regional lymph node metastasis of non-small cell lung cancer (NSCLC), and to evaluate the value of CT perfusion parameters in predicting regional lymph node metastasis of NSCLC. METHODS: 120 consecutive patients with NSCLC confirmed by postoperative histopathology were underwent flash dual source CT perfusion imaging in pre-operation. The CT perfusion parameters of NSCLC, such as blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability (PMB) were obtained by the image post-processing. Then microvessel density (MVD), luminal vascular number (LVN), luminal vascular area (LVA) and luminal vascular perimeter (LVP) of NSCLC were counted by immunohistochemistry. These cases were divided into group A (patients with lymph node metastasis, 58 cases) and group B (patients without lymph node metastasis, 62 cases) according to their pathological results. The CT perfusion parameters and the microvessel parameters were contrastively analysed between the two groups. Receiver operating characteristic (ROC) curve was used to assess the diagnostic efficiency of CT perfusion parameters in predicting regional lymph node metastasis of NSCLC in pre-operation. RESULTS: Group A presented significantly lower LVA, BF and higher MTT, PMB than Group B (P < 0.05), while BV, LVN, LVP and MVD were no significant difference (P > 0.05). Correlation analysis showed that BF was correlated with LVA and LVP (P < 0.05), while BV, MTT and PMB were not correlated with LVN, LVA and LVP (P > 0.05). All the perfusion parameters were not correlated with MVD. According to the ROC curve analysis, when BF < 85.16 ml/100 ml/min as a cutoff point to predict regional lymph node metastasis of NSCLC, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value were 60.8, 81.7, 71.5, 75.6 and 69.5% respectively. CONCLUSION: Flash dual source CT perfusion imaging can non-invasively indicate the luminal vascular structure of tumor and BF can be used as one of the important indexes in predicting regional lymph node metastasis of NSCLC in pre-operation.

Automated Grading of Cerebral Vasospasm to Standardize Computed Tomography Angiography Examinations After Subarachnoid Hemorrhage.

Background: Computed tomography angiography (CTA) is frequently used with computed tomography perfusion imaging (CTP) to evaluate whether endovascular vasospasm treatment is indicated for subarachnoid hemorrhage patients with delayed cerebral ischemia. However, objective parameters for CTA evaluation are lacking. In this study, we used an automated, investigator-independent, digital method to detect vasospasm, and we evaluated whether the method could predict the need for subsequent endovascular vasospasm treatment. Methods: We retrospectively reviewed the charts and analyzed imaging data for 40 consecutive patients with subarachnoid hemorrhages. The cerebrovascular trees were digitally reconstructed from CTA data, and vessel volume and the length of the arteries of the circle of Willis and their peripheral branches were determined. Receiver operating characteristic curve analysis based on a comparison with digital subtraction angiographies was used to determine volumetric thresholds that indicated severe vasospasm for each vessel segment. Results: The automated threshold-based volumetric evaluation of CTA data was able to detect severe vasospasm with high sensitivity and negative predictive value for predicting cerebral hypoperfusion on CTP, although the specificity and positive predictive value were low. Combining the automated detection of vasospasm on CTA and cerebral hypoperfusion on CTP was superior to CTP or CTA alone in predicting endovascular vasospasm treatment within 24 h after the examination. Conclusions: This digital volumetric analysis of the cerebrovascular tree allowed the objective, investigator-independent detection and quantification of vasospasms. This method could be used to standardize diagnostics and the selection of subarachnoid hemorrhage patients with delayed cerebral ischemia for endovascular diagnostics and possible interventions.

Statistical Analysis Plan for EXtending the time for Thrombolysis in Emergency Neurological Deficits (EXTEND) trial.

BACKGROUND: EXtending the time for Thrombolysis in Emergency Neurological Deficits (EXTEND) is a randomized, multicenter, double-blinded, placebo-controlled phase 3 trial to test the hypothesis of extending the thrombolysis time window to 9 h from stroke onset and in wake-up stroke (WUS) patients. OBJECTIVE: To formulate the detailed statistical analysis plan for the EXTEND trial prior to database lock. This statistical analysis plan is based on the published and registered EXTEND trial protocol and is developed by the blinded steering committee and management team. RESULTS: The developed EXTEND statistical analysis plan is transparent, verifiable, and predetermined before the database lock. It is consistent with reporting standards for clinical trials and provides for clear and open reporting. CONCLUSIONS: Publication of a statistical analysis plan serves to reduce potential trial analysis and reporting bias and outlines pre-specified analyses to quantify the benefits and harms of extending the thrombolysis time window to 9 h from stroke onset and in wake-up stroke patients. Trial registration: ClinicalTrials.gov number NCT00887328 registered 23/Apr/2009 and NCT01580839 (EXTEND International) registered 19/Apr/2012.

Addressing a real-life problem: treatment with intravenous thrombolysis and mechanical thrombectomy in acute stroke patients with an extended time window beyond 4.5 h based on computed tomography perfusion imaging.

BACKGROUND AND PURPOSE: Acute ischemic stroke treatment with intravenous thrombolysis (IVT) is restricted to a time window of 4.5 h after known or presumed onset. Recently, magnetic resonance imaging-guided treatment decision-making in wake-up stroke (WUS) was shown to be effective. The aim of this study was to determine the safety and outcome of IVT in patients with a time window beyond 4.5 h selected by computed tomography perfusion (CTP) imaging. METHODS: We analyzed all consecutive patients last seen well beyond 4.5 h after stroke onset treated with IVT based on CTP between January 2015 and October 2018. CTP was visually assessed to estimate the mismatch between cerebral blood flow and cerebral blood volume maps. Early infarct signs were documented according to Alberta Stroke Program Early CT Score (ASPECTS). Safety data were obtained for mortality and symptomatic intracerebral hemorrhage (sICH). Follow-up was assessed with the modified Rankin Scale (mRS). RESULTS: A total of 70 patients fulfilled the inclusion criteria (mean age ± SD 77.6 ± 11.5 years, 50.0% female). Median National Institutes of Health Stroke Scale score on admission was 8.0 [interquartile range (IQR), 4-14]. The most frequent reasons for an extended time window were WUS (60.0%) and delayed hospital admission (27.1%). Median time from last seen well to IVT was 11.4 h. Median ASPECTS was 10 (IQR, 9-10) and CTP mismatch 90% (IQR, 80%-100%). A total of 24 patients (34.3%) underwent additional mechanical thrombectomy. sICH occurred in four patients (5.7%). At follow-up, 49.3% had an mRS score of 0-2 and 22.4% had an mRS score of 0-1. CONCLUSIONS: In patients presenting in an extended time window beyond 4.5 h, IVT treatment with decision-making based on CTP might be a safe procedure. Further evaluation in clinical trials is needed.

Predictors for basal ganglia viability after mechanical thrombectomy in proximal middle cerebral artery occlusion.

BACKGROUND/PURPOSE: In acute proximal middle cerebral artery (MCA) occlusion covering the lenticulostriate arteries (LSA), ischemic tolerance of basal ganglia is limited due to supposed lack of collateral supply. However, in several patients, basal ganglia (BG) infarction was absent after successful mechanical thrombectomy (MTE). Purpose of our study was to evaluate predictors for BG viability in stroke patients despite prolonged MCA mainstem occlusion. MATERIAL/METHODS: We retrospectively reviewed all stroke patients from our local registry with MCA mainstem occlusion after mechanical thrombectomy between November 2009 and October 2016. All patients underwent non-enhanced post-interventional cranial CT imaging (NCCT) and were classified according to 6 patterns of BG viability: complete: putamen (P) and globus pallidus (GP); partial: P or GP, and combination of complete or partial BG and/or adjacent white matter/cortical (WMC) viability. We compared viability patterns with respect to pre-interventional stroke imaging including NCCT, CT-angiography (CTA), CT perfusion (CTP); demographics, pre- and intra-procedural data and occurrence of post-procedural intracerebral hematoma (ICH). CTP imaging of the affected and contralateral BG-territories were obtained separately and CTA-collateral score (CS) was assessed. RESULTS: A significant correlation between higher collateral score and viability of GP (OR = 1.949; p = .011), P (OR = 2.039, p = .011), and the combination of GP, P and WMC (OR = 2.767, p = .007) was revealed. Higher relative CBV ratio (rCBVR) was significantly associated with viability of the pattern GP + WMC (univariate: OR = 3.160, p = .014; multivariate: OR = 6.058; p = .021). CONCLUSION: CTA collateral score and rCBVR were predictive for BG viability in stroke patients after successful MTE in prolonged complete MCA-mainstem and LSA occlusion.

Volumetric analysis of intracranial vessels: a novel tool for evaluation of cerebral vasospasm.

PURPOSE: Together with other diagnostic modalities, computed tomography angiography (CTA) is commonly used to indicate endovascular vasospasm treatment after subarachnoid hemorrhage (SAH), despite the fact that objective, user-independent parameters for evaluation of CTA are lacking. This exploratory study was designed to investigate whether quantification of vasospasm by automated volumetric analysis of the middle cerebral artery M1 segment from CTA data could be used as an objective parameter to indicate endovascular vasospasm treatment. METHODS: We retrospectively identified SAH patients who underwent transcranial Doppler sonography (TCD), CTA, and CT perfusion (CTP), with or without subsequent endovascular treatment. We determined vessel volume/vessel length of the M1 segments from CTA data and used receiver operating characteristic curve analysis to determine the optimal threshold of vessel volume to predict vasospasm requiring endovascular treatment. In addition, blinded investigators independently analyzed TCD, CTA, and CTP data. RESULTS: Of 45 CTA examinations with corresponding CTP and TCD examinations (24 SAH patients), nine indicated the need for endovascular vasospasm treatment during examination. In our patients, vessel volume < 5.8 µL/mm was moderately sensitive but fairly specific to detect vasospasm requiring endovascular treatment (sensitivity, 67%; specificity, 78%; negative predictive value (NPV), 89%; positive predictive value (PPV), 46%). For CTA, CTP, and TCD, we found NPVs of 96%, 92%, and 89%, PPVs of 40%, 35%, and 35%, sensitivities of 89%, 78%, and 67%, and specificities of 67%, 64%, and 69%, respectively. CONCLUSION: Vessel volumes could provide a new objective parameter for the interpretation of CTA data and could thereby improve multimodal assessment of vasospasm in SAH patients.

Optimized scanning protocol for whole-brain perfusion by third generation dual-source computed tomography: A feasibility study / 第二军医大学学报

Objective To assess the influence of different time sampling modes on perfusion parameters and radiation dose of whole-brain computed tomography perfusion imaging (CTP), and to formulate an optimized scanning protocol for clinical diagnosis requirements. Methods Forty-seven consecutive patients, who underwent cerebral CTP scanning in our hospital between Nov. 2016 and Jun. 2017, were included in this study. Nineteen of them had acute ischemic stroke (AIS) and 28 had AIS symptoms, but no lesions were found by computed tomography or CTP. According to the time-attenuation curve, four scanning protocols were obtained: standard control group (group 1), sampling interval of 3 s (group 2), sampling interval of 3 s in pre-ascending and pro-descending period, and sampling interval of 1.5 s in the intermediate period (group 3), and smapling interval of 1.5 s between the peak of artery and vein and other sampling interval of 3 s (group 4). The perfusion parameters of all subjects were quantitatively measured. Subjective image quality was analyzed and radiation dose was calculated. Results In AIS and non-AIS groups, a total of 10 region of interests were placed in the ischemic area and contralateral brain parenchyma of each patient, and the total numbers of data points of perfusion parameters were 190 and 280, respectively. There were significant differences in blood flow, blood volume and mean transit time (MTT) between the AIS group and non-AIS group (all P0.01). However, inter-group analysis showed that there were no significant differences in the above perfusion parameters between group 3 and group 1 in both the AIS group and non-AIS group (all P0.05). Bland-Altman consistency analysis showed that group 3 and group 1 had good consistency of blood flow, blood volume and MTT in both the AIS group and non-AIS group. Compared with group 1 (standard control group), group 3 had better subjective score and lower radiation dose. Based on the sampling mode of group 3, 2 recommended scanning protocols were established and validated. The perfusion parameters of the 2 recommended scanning protocols were well correlated with those of group 1 in AIS patients and non-AIS patients (all P0.01). Conclusion The scanning protocol, in which sampling interval is 3 s in pre-ascending and pro-descending period and 1.5 s in intermediate period, is in good agreement with the standard scanning mode, and can reduce radiation dose. It may be a whole-brain CTP scanning protocol for the clinical settings.

Perfusion Computer Tomography Assessment of the Effect of Angiotensin II On Blood Flow Distribution in Rabbits with Intrarenal VX2 Tumors.

BACKGROUND/AIMS: Unlike other organs, which only have one set of capillary network, the renal microvasculature consists of two sets of capillary network series connected by efferent arterioles. Angiotensin II constricts the efferent glomerular artery. Hence, renal tumor blood flow (BF) distribution may be different from tumors in other organs. This study aims to investigate the effects of angiotensin II on the hemodynamics of intrarenal VX2 tumors using perfusion computed tomography(CT). METHODS: Twenty-four male New Zealand white rabbits were randomly divided into three groups: groups A (blank controls), group B (negative controls), and group C (angiotensin II-treated animals). Group B and C were established to the model of intrarenal VX2 tumors. Furthermore, perfusion CT of the kidney was performed in each group. Prior to perfusion CT scan in group C, the mean arterial blood was elevated to 150-160 mmHg by angiotensin II. The BF, blood volume (BV), mean transit time (MTT), capillary permeability-surface area product (PS), and relative permeability-surface area product (RPS) of tumors and renal tissues were calculated. RESULTS: Compared with normal renal cortex tissues in group A, the BF, BV and PS values of tumors in group B were significantly lower, MTT was prolonged and RPS increased. Compared with group B, only the RPS of these tumors increased from 83.23 ± 29.17% to 120.94 ± 31.84% by angiotensin II infusion. Angiotensin II significantly increased the RPS value of the renal cortex distant from the tumor (CDT) and the right renal cortex (RRC). CONCLUSIONS: Perfusion CT can accurately observe the influence of angiotensin II on normal and tumor BF in kidneys. This clarifies the effect of angiotensin II on intrarenal tumor hemodynamics.

Computed Tomographic Perfusion Imaging for the Prediction of Response and Survival to Transarterial Chemoembolization of Hepatocellular Carcinoma.

BACKGROUND: The purpose of this retrospective cohort study was to evaluate the clinical value of computed tomographic perfusion imaging (CTPI) parameters in predicting the response to treatment and overall survival in patients with hepatocellular carcinoma (HCC) treated with drug-eluting beads transarterial chemoembolization (DEBTACE). PATIENTS AND METHODS: Between December 2010 and January 2013 eighteen patients (17 men, 1 woman; mean age 69 ± 5.8 years) with intermediate stage HCC underwent CTPI of the liver prior to treatment with DEBTACE. Treatment response was evaluated on follow-up imaging according to modified Response Evaluation Criteria in Solid Tumors. Pre-treatment CTPI parameters were compared between patients with complete response and partial response with a Student t-test. We compared survival times with Kaplan-Meier method. RESULTS: CTPI parameters of patients with complete response and others did not show statistical significant difference. The mean survival time was 25.4 ± 3.2 months (95%; CI: 18.7-32.1). Survival was statistically significantly longer in patients with hepatic blood flow (BF) lower than 50.44 ml/100 ml/min (p = 0.033), hepatic blood volume (BV) lower than 13.32 ml/100 ml (p = 0.028) and time to peak (TTP) longer than 19.035 s (p = 0.015). CONCLUSIONS: CTPI enables prediction of survival in patients with intermediate stage HCC, treated with DEBTACE based on the pre-treatment values of BF, BV and TTP perfusion parameters. CT perfusion imaging can't be used to predict treatment response to DEBTACE.

Computed Tomography Perfusion Imaging for the Diagnosis of Hepatic Alveolar Echinococcosis.

OBJECTIVE: Alveolar echinococcosis (AE) is a rare life-threatening parasitic infection. Computed tomography perfusion (CTP) imaging has the potential to provide both quantitative and qualitative information about the tissue perfusion characteristics. The purpose of this study was the examination of the characteristic features and feasibility of CTP in AE liver lesions. MATERIAL AND METHODS: CTP scanning was performed in 25 patients who had a total of 35 lesions identified as AE of the liver. Blood flow (BF), blood volume (BV), portal venous perfusion (PVP), arterial liver perfusion (ALP), and hepatic perfusion indexes (HPI) were computed for background liver parenchyma and each AE lesion. RESULTS: Significant differences were detected between perfusion values of the AE lesions and background liver tissue. The BV, BF, ALP, and PVP values for all components of the AE liver lesions were significantly lower than the normal liver parenchyma (p<0.01). CONCLUSIONS: We suggest that perfusion imaging can be used in AE of the liver. Thus, the quantitative knowledge of perfusion parameters are obtained via CT perfusion imaging.

Comparison of microvascular perfusion evaluation among IVIM-DWI, CT perfusion imaging and histological microvessel density in rabbit liver VX2 tumors.

OBJECT: To explore microcirculation features with intravoxel incoherent motion (IVIM) and to compare IVIM with CT perfusion imaging (CTPI) and microvessel density (MVD). MATERIALS AND METHODS: Hepatic CTPI and IVIM were performed in 16 rabbit liver VX2 tumor models. Hepatic arterial perfusion (HAP), hepatic arterial perfusion index (HPI), Blood flow (BF), and blood volume (BV) from CTPI were measured. Apparent diffusion coefficient (ADC), true diffusion coefficient (D), perfusion fraction (f), and pseudo-diffusion coefficient (D*) from IVIM were measured. MVD was counted with CD34 stain. The microcirculation features with IVIM were compared with CTPI parameters and MVD. RESULTS: Strong linear correlations were found between D value (0.89±0.21×10-3mm2/s) and HAP (15.83±6.97ml/min/100mg) (r=0.755, P=0.001) and between f value (12.64±6.66%) and BV (9.74±5.04ml/100mg) (r=0.693, P=0.004). Moderate linear correlations were observed between ADC (1.07±0.32×10-3mm2/s) and HAP (r=0.538, P=0.039), respectively; and between D value and MVD (9.31±2.57 vessels at 400×magnification) (r=0.509, P=0.044). No correlations were found between D* (119.90±37.67×10-3mm2/s) and HAP, HPI (68.34±12.91%), BF (4.95±2.16ml/min/100mg), BV. CONCLUSION: IVIM parameters can characterize microcirculation to certain extent and separate it from pure water molecular diffusion. There is fair correlation between D or ADC value and CTPI parameters or MVD, but no correlation between D* or f value and CTPI parameters or MVD except f value and BV, which is still unclear and need further clinical studies to validate.

Characteristics of Cerebral Blood Flow in Brain CT Perfusion Imaging for Vascular Cognitive Impairment / 中国康复理论与实践

@#Objective To evaluate cerebral perfusion through brain computed tomography perfusion imaging (CTP) in order to investigate the relationship between cerebral perfusion and vascular cognitive impairment (VCI).Methods A total of 103 patients with ischemic stroke were recruited, who received thrombolytic therapy and CTP test in the Fourth Affiliated Hospital of China Medical University from December, 2016 to May, 2017. The patients were divided into normal cognitive function group (control group, n=43), vascular cognitive impairment-no dementia group (VCIND group, n=48), and vascular dementia group (VD group, n=12) according to the degree of impairment in cognitive function after the assessment of Mini-Mental State Examination (MMSE) and Clock Drawing Test (CDT). The characteristics of cerebral blood flow perfusion in region of interest of brain CTP were analyzed.Results There was difference in incidence of diabetes among three groups (χ2=7.556, P<0.05). The rate of diabetes was higher in VCIND group and VD group than in the control group. Age and diabetes were the independent risk factors for VCI (OR>1, P<0.05). There was difference in cerebral blood volume (CBV) in frontal lobe, temporal lobe, and parietal lobe among three groups (F>3.216, P<0.05). CBV in frontal lobe, temporal lobe, and parietal lobe reduced in VD group than in the control group (P<0.05), while CBV in frontal lobe and temporal lobe reduced in VD group than in VCIND group (P<0.05). There was difference in mean transit time (MTT) in left temporal lobe, left parietal lobe, and centrum semiovale among three groups, while there was difference in left occipital lobe in time to peak (TTP) among three groups (F>3.116, P<0.05). MTT and TTP were higher in VD group than in the control group and VCIND group (P<0.05). There was no difference in cerebral blood flow (CBF) in both left and right brain, and MTT and TTP in right brain among three groups (P>0.05). CBV in frontal lobe, parietal lobe and right temporal lobe demonstrated positive relationship with the scores of MMSE (r>0.203, P<0.05). CBV in parietal lobe and left frontal lobe also demonstrated positive relationship with the scores of CDT (r>0.214, P<0.05).Conclusion The cerebral blood flow perfusion reduced in different levels of VCI, especially in frontal lobe, temporal lobe and parietal lobe. Cerebral blood flow perfusion reduced with the progress of cognitive impairment, and the left hemisphere injured earlier than the right one. Brain CTP may be applied in the early recognition of VCI.