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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.
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@#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.
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OBJECTIVE: To prospectively evaluate the performance of computed tomography perfusion imaging (CTPI) in predicting the early response to transarterial chemo-lipiodol infusion (TACLI) and survival of patients with colorectal cancer liver metastases (CRLM). MATERIALS AND METHODS: Computed tomography perfusion imaging was performed before and 1 month after TACLI in 61 consecutive patients. Therapeutic response was evaluated on CT scans 1 month and 4 months after TACLI; the patients were classified as responders and non-responders based on 4-month CT scans after TACLI. The percentage change of CTPI parameters of target lesions were compared between responders and non-responders at 1 month after TACLI. The optimal parameter and cutoff value were determined. The patients were divided into 2 subgroups according to the cutoff value. The log-rank test was used to compare the survival rates of the 2 subgroups. RESULTS: Four-month images were obtained from 58 patients, of which 39.7% were responders and 60.3% were non-responders. The percentage change in hepatic arterial perfusion (HAP) 1 month after TACLI was the optimal predicting parameter (p = 0.003). The best cut-off value was -21.5% and patients who exhibited a > or = 21.5% decrease in HAP had a significantly higher overall survival rate than those who exhibited a < 21.5% decrease (p < 0.001). CONCLUSION: Computed tomography perfusion imaging can predict the early response to TACLI and survival of patients with CRLM. The percentage change in HAP after TACLI with a cutoff value of -21.5% is the optimal predictor.
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Colorectal Neoplasms/mortality , Contrast Media/administration & dosage , Ethiodized Oil/administration & dosage , Hepatic Artery/diagnostic imaging , Liver Neoplasms/drug therapy , Perfusion Imaging/methods , Prospective Studies , Survival Rate , Tomography, X-Ray Computed/methodsABSTRACT
Objective To determine the safety and efficacy of intra-arterial recombinant tissue plasminogen activator (r-tPA) for the treatment of acute cerebral infarction (ACI) in patients under the guidance of computed tomography perfusion-based selection within a 6-9 hour window.Methods Sixtythree ACI patients selected by using computed tomography perfusion imaging (CTPI) identifying thresholds for salvageable penumbra were randomly (random number) assigned to the group treated with intra-arterial thrombolysis with r-tPA (group A,n =30) or to the group managed with conventional anti-platelet aggregation agent (group B,n =33) within a 6-9 hour window.The National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin Scale score (mRS) and Barthel Index (BI) were used for evaluating therapeutic efficacy.Global brain digital subtraction angiography (DSA) was done pre-and posttreatment to observe the recanalization of occluded vessels in the group A.All patients were monitored with CT scan within 24 hours to determine the cerebral hemorrhage,an unexpected complication of thrombolysis.Results Compared with pre-treatment,there were significant differences in NIHSS 24 hours after treatment in the group A and 7 days after treatment in both groups (P ＜ 0.01).However,there were no significant differences in NIHSS 24 hours after treatment in the group B.More improvements in NIHSS at 24 hours and 7 days after treatment were observed in the group A than those in group B (P ＜ 0.01),and more patients with favorable outcomes identified by mRS and BI in the group A than those in the group B (P =0.017 and P =0.016,respectively).In addition,twenty patients were showed successful recanalization in the group A and there were 2 cases of cerebral hemorrhage occurred in the group A,and there was no significant difference in the incidence of cerebral hemorrhage within 24 hours between the two groups (P ＞ 0.05).Conclusions Intra-arterial thrombolysis with r-tPA for treatment of acute cerebral infarction was safe and effective within a 6-9 hour window under the guidance of CTPI.
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Computed tomography perfusion imaging can accurately and promptly provide hemodynamic parameters of brain tissues after stroke,and it has a good correlation with the accepted hemodynamic measurement,the parameters got from xenon-computed tomography, functional magnetic resonance imaging and positron emission tomography.Therefore,CTP has been widely used in predicting the studies of ischemic penumbra after stroke.
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@#ObjectiveTo study the mechanism of hemodynamic alternation surrounding the hematoma in the acute stage of intracerebral hemorrhage (ICH) in rats.MethodsSeventy male Sprague Dawley rats were randomly divided into ICH group and sham operated group, which were microinjected with 40 μl fresh autologous blood or saline into the right caudatum respectively. The each group was divided into 7 subgroups at 1h,3h,6h,12h,24h,48h and 72h after the ICH. CT perfusion imaging in measurements of regional cerebral blood flow adjacent to hematomas was performed. The ratios of side to side were measured at the regions around the hematomas by personal computer aided mapping. So the parameters of regional cerebral blood flow(rCBF), regional cerebral blood volume(rCBV) and mean transit time(MTT) were calculated respectively.ResultsThe rCBF and rCBV adjacent to the hematomas were lower than those of the outer region pronouncedly. The alternation of rCBF around the hematoma were fluctuated, which reduced to the valley at 1h after ICH, and then gradually returned to the peaks at 6h and 24h after ICH. In the meantime, the rCBV around the hematoma reduced to the valley at 1h after ICH, and then gradually increased to the peak at 24h after ICH.ConclusionThe abnormal hemodynamic changes can be found in the perihematomal region after ICH. The alternation of rCBF around the hematomas are fluctuated, but the changes of rCBV remain continuous increase. The mass effect of hematoma, intracranial hypertension caused by the mass effect of hematoma, and the autoregulation of cerebral blood flow motivated by the initial depression of cerebral blood flow play a very important role in the changes of cerebral blood flow.