Objective To characterize the features of patent foramen ovale(PFO)-related cryptogenic stroke using diffusion-weighted imaging(DWI)and to investigate the correlation between infarct size and cardiac CT characteristics of PFO.Methods A retrospective,consecutive cohort study was conducted on acute ischemic stroke patients admitted to Neurology Department of Xuanwu Hospital,Capital Medical University from January 2022 to September 2024.Patients were categorized into PFO group,arterio-arterial embolism(AAE)group,and atrial fibrillation(AF)group based on etiological diagnosis.Baseline clinical data,including age,height,body mass index,admission National Institutes of Health stroke scale(NIHSS)score,history of old cerebral infarction,hypertension,diabetes mellitus,coronary heart disease,dyslipidemia,and smoking history were collected and compared.All patients underwent head MR within 24 h of admission.DWI was used to analyze and compare infarct characteristics across the three groups,including lesion number(single or multiple),location(cortical+subcortical,deep white matter,cortical+subcortical+deep white matter,cerebellum+thalamus+brainstem),size(≥15 mm or＜15 mm,based on maximum transverse diameter;for multiple lesions,if any lesion had a maximum diameter≥15 mm,it was categorized as≥15 mm),infarcted vascular territory(anterior,posterior,or both circulations),and specific arterial supply(anterior cerebral artery,middle cerebral artery,posterior cerebral artery,basilar artery,posterior inferior cerebellar artery,superior cerebellar artery,anterior choroidal artery,or multiple arteries).Patients in the PFO group additionally underwent cardiac CT to measure PFO-related parameters:tunnel length,width,height,septum secundum thickness,and fossa ovalis length.Spearman correlation analysis was performed to evaluate the relationship between infarct size and PFO cardiac CT features.Results A total of 232 acute ischemic stroke patients were included(mean age[57±17]years,ranged 19-86 years;141 males,91 females),comprising 116 in the PFO group,36 in the AAE group,and 80 in the AF group.(1)The proportion of males in the PFO group was higher than that in the AF group,it was lower than that in the AAE group.The age,body mass index and proportions of patients with hypertension,diabetes,hyperlipidemia,coronary heart disease were all lower than those in the other two groups(both P＜0.016 7),while other baseline characteristics showed no significant differences(all P＞0.05).(2)The PFO group exhibited a higher proportion of multiple infarcts compared to the AAE group(83.62％[97/116]vs.61.11％[22/36],P＜0.016 7),but a lower proportion than the AF group(83.62％[97/116]vs.98.75％[79/80],P＜0.016 7).The PFO group also showed a significantly higher proportion of cortical+subcortical infarcts(47.41％[55/116]vs.11.11％[4/36]and 6.25％[5/80],respectively,both P＜0.016 7)and infarcts with a maximum diameter＜15 mm compared to both AAE and AF groups(66.38％[77/116]vs.36.11％[13/36]and 11.25％[9/80],respectively,both P＜0.016 7).Furthermore,the PFO group had a lower proportion of anterior circulation infarcts(27.59％[32/116]vs.69.44％[25/36]in AAE group and 67.50％[54/80]in AF group,both P＜0.016 7),but a higher proportion of posterior circulation infarcts(62.07％[72/116]vs.16.67％[6/36]in AAE group and 8.75％[7/80]in AF group,both P＜0.016 7).Specifically,middle cerebral artery infarcts were less common in the PFO group(18.97％[22/116]vs.66.67％[24/36]in AAE group and 52.50％[42/80]in AF group,both P＜0.016 7),while posterior cerebral artery infarcts were more common(48.28％[56/116]vs.8.33％[3/36]in AAE group and 8.75％[7/80]in AF group,both P＜0.016 7).(3)Spearman correlation analysis revealed that infarct size was negatively correlated with PFO tunnel length(rs=-0.429,P=0.029),fossa ovalis length(rs=-0.408,P=0.038),and septum secundum thickness(rs=-0.525,P=0.006),but not correlated with PFO width or height(both P＞0.05).Conclusions PFO-related cryptogenic stroke is predominantly characterized by multiple small infarcts,primarily located in the cortical+subcortical regions and posterior circulation.Infarct size was found to be negatively correlated with PFO tunnel length,fossa ovalis length,and septum secundum thickness.Comprehensive assessment integrating DWI and cardiac CT features may facilitate the identification of PFO-related stroke.These findings warrant further validation through larger,prospective studies.

Objective To characterize the features of patent foramen ovale(PFO)-related cryptogenic stroke using diffusion-weighted imaging(DWI)and to investigate the correlation between infarct size and cardiac CT characteristics of PFO.Methods A retrospective,consecutive cohort study was conducted on acute ischemic stroke patients admitted to Neurology Department of Xuanwu Hospital,Capital Medical University from January 2022 to September 2024.Patients were categorized into PFO group,arterio-arterial embolism(AAE)group,and atrial fibrillation(AF)group based on etiological diagnosis.Baseline clinical data,including age,height,body mass index,admission National Institutes of Health stroke scale(NIHSS)score,history of old cerebral infarction,hypertension,diabetes mellitus,coronary heart disease,dyslipidemia,and smoking history were collected and compared.All patients underwent head MR within 24 h of admission.DWI was used to analyze and compare infarct characteristics across the three groups,including lesion number(single or multiple),location(cortical+subcortical,deep white matter,cortical+subcortical+deep white matter,cerebellum+thalamus+brainstem),size(≥15 mm or＜15 mm,based on maximum transverse diameter;for multiple lesions,if any lesion had a maximum diameter≥15 mm,it was categorized as≥15 mm),infarcted vascular territory(anterior,posterior,or both circulations),and specific arterial supply(anterior cerebral artery,middle cerebral artery,posterior cerebral artery,basilar artery,posterior inferior cerebellar artery,superior cerebellar artery,anterior choroidal artery,or multiple arteries).Patients in the PFO group additionally underwent cardiac CT to measure PFO-related parameters:tunnel length,width,height,septum secundum thickness,and fossa ovalis length.Spearman correlation analysis was performed to evaluate the relationship between infarct size and PFO cardiac CT features.Results A total of 232 acute ischemic stroke patients were included(mean age[57±17]years,ranged 19-86 years;141 males,91 females),comprising 116 in the PFO group,36 in the AAE group,and 80 in the AF group.(1)The proportion of males in the PFO group was higher than that in the AF group,it was lower than that in the AAE group.The age,body mass index and proportions of patients with hypertension,diabetes,hyperlipidemia,coronary heart disease were all lower than those in the other two groups(both P＜0.016 7),while other baseline characteristics showed no significant differences(all P＞0.05).(2)The PFO group exhibited a higher proportion of multiple infarcts compared to the AAE group(83.62％[97/116]vs.61.11％[22/36],P＜0.016 7),but a lower proportion than the AF group(83.62％[97/116]vs.98.75％[79/80],P＜0.016 7).The PFO group also showed a significantly higher proportion of cortical+subcortical infarcts(47.41％[55/116]vs.11.11％[4/36]and 6.25％[5/80],respectively,both P＜0.016 7)and infarcts with a maximum diameter＜15 mm compared to both AAE and AF groups(66.38％[77/116]vs.36.11％[13/36]and 11.25％[9/80],respectively,both P＜0.016 7).Furthermore,the PFO group had a lower proportion of anterior circulation infarcts(27.59％[32/116]vs.69.44％[25/36]in AAE group and 67.50％[54/80]in AF group,both P＜0.016 7),but a higher proportion of posterior circulation infarcts(62.07％[72/116]vs.16.67％[6/36]in AAE group and 8.75％[7/80]in AF group,both P＜0.016 7).Specifically,middle cerebral artery infarcts were less common in the PFO group(18.97％[22/116]vs.66.67％[24/36]in AAE group and 52.50％[42/80]in AF group,both P＜0.016 7),while posterior cerebral artery infarcts were more common(48.28％[56/116]vs.8.33％[3/36]in AAE group and 8.75％[7/80]in AF group,both P＜0.016 7).(3)Spearman correlation analysis revealed that infarct size was negatively correlated with PFO tunnel length(rs=-0.429,P=0.029),fossa ovalis length(rs=-0.408,P=0.038),and septum secundum thickness(rs=-0.525,P=0.006),but not correlated with PFO width or height(both P＞0.05).Conclusions PFO-related cryptogenic stroke is predominantly characterized by multiple small infarcts,primarily located in the cortical+subcortical regions and posterior circulation.Infarct size was found to be negatively correlated with PFO tunnel length,fossa ovalis length,and septum secundum thickness.Comprehensive assessment integrating DWI and cardiac CT features may facilitate the identification of PFO-related stroke.These findings warrant further validation through larger,prospective studies.

Objective:To investigate the impact on image quality of a new deep learning image reconstruction (DLIR) algorithm in dynamic CT myocardial perfusion imaging (CTP) and to explore whether the algorithm affects the quantification of myocardial blood flow (MBF) in swine.Methods:Dynamic CTP imaging was performed in five anesthetized domestic swine [body weight (58.6±1.9) kg], at both rest and stress state. The tube voltages were fixed at 100 kV, and the low-dose and high-dose scanning tube currents were set as 150 mA and 300 mA, respectively. The low-dose (LD) scan data were reconstructed with filtered back projection (FBP) and three different DLIR strengths (low, medium, and high). High-dose (HD) scan data were reconstructed with filtered back projection (FBP) only. Subjective (5-point scale) image quality was evaluated, and objective evaluations included image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) was performed. Linear regression was used to test the linear trend between DLIR algorithm strength and image quality. Data sets normality was determined by the Shapiro-Wilk test. Comparisons between groups were performed using Student′s t test for normally distributed data or the Wilcoxon rank-sum test for non-normally distributed data. Results:The mean effective radiation dose was 7.2 and 3.8 mSv for the HD protocol and the LD protocol, respectively, with statistically significant difference found between two protocols ( t=282.50, P<0.001). The image noise of the images obtained at LD protocol gradually decreased and the image SNR and CNR gradually increased with DLIR algorithm strength increased ( F=60.10,35.87,41.41; P for trend were all<0.001). As for DLIR-high strength (LD) and FBP (HD) images, the image noise values were (31.7±3.1) and (38.2±1.2) HU; SNR were 16.6±2.0 and 13.8±0.8; CNR were 14.5±1.7, 11.6±0.9, respectively, with significant differences found between two groups ( t=5.70, 4.15, 5.68; all P<0.05). The subjective scores of DLIR-high strength (LD) and FBP (HD) images were significantly different (4.8±0.4 and 4.2±0.6, Z=2.12, P<0.05). No significant differences were found between the MBF calculated from FBP (LD) and from DLIR-high strength (LD), with the values as (81.3±17.3) ml·100 ml -1·min -1 vs. (79.9±18.3)ml·100 ml -1·min -1 at rest state; and (99.4±24.9)ml·100 ml -1·min -1 vs. (100.7±27.3) ml·100 ml -1·min -1 at stress state ( t=1.10, 0.89; P>0.05). Conclusion:DLIR-high strength can improve image quality of myocardial CTP in swine, and can reduce radiation dose without influencing the MBF calculation.

Objective:To evaluate the feasibility of making individualized scanning and contrast injection protocol based on body mass index (BMI) and body weight during dynamic myocardial computed perfusion (CTP) imaging in order to get high-quality images while drastically reducing radiation dose.Methods:A total of 128 patients with coronary heart disease diagnosed by coronary CTA (CCTA) performed CTP from June, 2019 to March, 2020 were prospectively enrolled. Patients were divided into six groups: group 1, BMI<24 kg/m 2, ≤60 kg, 70 kV; group 2,BMI<24 kg/m 2, 61≤kg≤70, 70 kV; group 3, BMI 24-28 kg/m 2, 61≤kg≤70, 80 kV; group 4, BMI 24-28 kg/m 2, 71≤kg≤80, 80 kV; group 5, BMI 24-28 kg/m 2,>80 kg, 80 kV;group 6, BMI>28 kg/m 2,>80 kg, 100 kV. 200 mA was fixed for all patients. Contrast agent with iodine containing 370 mg/ml was used in all patients. The iodine delivery rates (IDR) for each group was 0.8, 1.0, 1.2, 1.4, 1.6, 2.0 g/s, respectively. The attenuation and noise of left ventricle (LV) and septal myocardial were measured to calculate signal to noise ratio (SNR) and contrast to noise ratio (CNR) of the images in each group. The Shapiro-Wilk test was conducted to assess the normality of quantitative data. Quantitative variables were compared using one-way ANOVA if normally distributed. Results:The LV attenuation of the six groups were (506±85), (513±77), (510±81), (456±74), (477±111), (462±43) HU, respectively. There was no significant difference among them ( F=2.249, P=0.054). SNR values of LV were 23±8, 20±5, 21±5, 19±4, 19±7, 19±4, and CNR values were 19±7, 17±4, 17±4, 16±4, 15±6, 15±4, respectively. There were no significant differences among them ( F=1.674, 1.736, all P>0.05). Under a single CTP scan, the radiation dose of 70, 80 and 100 kV groups were 1.6, 2.3 and 4.3 mSv, respectively. The does of the 70 kV group and 80 kV group were significantly lower than that of the 100 kV group, and the dose of the 70 kV group was also significantly lower than that of the 80 kV group (all P<0.001). Conclusions:The application of individualized scanning and contrast agent injection protocol based on IDR is feasible in myocardial CTP with successful image quality, and the radiation dose decreases significantly.