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Objective:To investigate the correlation between platelet distribution width(PDW)and cerebral microbleeds(CMB)in the middle-aged and elderly population.Methods:A total of 2 839 subjects who underwent cranial magnetic resonance imaging(MRI)examination at Lishui Hospital of Zhejiang University from May 2016 to December were enrolled in this cross-sectional study.According to MRI results, subjects were divided into the CMB group(n=525)and the non-CMB group(n=2 314). Clinical data and PDW levels were compared between the two groups.CMB-related factors were analyzed by using a logistic regression equation.A receiver operating characteristics(ROC)curve was drawn to analyze the value of PDW levels in predicting the incidence of CMB.Results:The percentage of males, the proportion of smokers, the number of subjects with diabetes and serum creatinine levels were higher in the CMB group than in the non-CMB group[(55.05%(289/525) vs.45.12%(1 044/2 314), 42.67%(224/525) vs.34.67%(802/2 314), 12.76%(67/525) vs.9.51%(220/2 314), (68.91±21.38)μmol/L vs.(66.45±15.40)μmol/L, all P<0.05]. PDW levels were higher in the CMB group than in the non-CMB group(15.52±2.49)% vs.(14.67±2.90)%, χ2=93.75, P<0.05). Multivariate logistic regression analysis showed that the PDW level was an independent risk factor for CMB in the middle-aged and elderly population( OR=1.13, P<0.05). The area under the ROC curve(AUC)of PDW in predicting the incidence of CMB was 0.582, and with 15.95% as the optimal threshold value, the sensitivity and specificity were 75.0% and 41.8%.Patients were divided into the high PDW sub-group(n=1 691)and the low PDW sub-group(n=1 083)based on the PDW cutoff at 15.95%.The number of CMB and the incidence of CMB were higher in the high PDW group than in the low PDW group(0.75 vs.0.48, 23.3% or 394/1 691 vs.12.1% or 131/1 083, χ2=30.37 and 51.28, P<0.05). Conclusions:PDW levels are high in middle-aged and elderly patients with CMB, and elevated PDW levels are an independent risk factor for CMB.
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Objective@#To evaluate image quality and radiation dosage of CT cerebral perfusion (CTP) imaging of 70 kV with different tube current and scanning passes and its diagnostic value for hyperacute cerebral infarction.@*Methods@#A total of 190 patients with suspected hyperacute cerebral infarction in Lishui Central Hospital of Zhejiang Province from December 2017 to February 2019 were selected prospectively, and all patients were divided into 4 groups according to random number table and received non-contrast CT examination and dual-source CT cerebral perfusion imaging with 70 kV protocol simultaneously within 6 hours after the onset of symptoms: group A, 120 mA, 21 scanning time points; group B, 100 mA, 21 scanning time points; group C, 100 mA, 17 scanning time points; group D, 80 mA, 21 scanning time points. The values of perfusion parameters such as cerebral blood flow (CBF), crerbral blood volume (CBV), mean transit time (MTT), time to peak (TTP) were acquired. Image quality was evaluated and effective dose (ED) was recorded. The quantitative variables of image quality and radiation dosage were compared between four groups using one-way analysis of variance test.@*Results@#There was no differences between groups on the CBF, CBV, MTT, TTP maps for all CTP values (P>0.05), and all images could meet the diagnostic requirements. The subjective image quality score of vessel sharpness and overall image quality of both internal carotid artery and middle cerebral artery and the degree of noise of internal carotid in artery in group A was higher than that in group D (P<0.05). The score of vessel sharpness of internal carotid in artery ingroup A was higher than those in both groups B and C (P<0.05). The scores of vessel sharpness of both internal carotid artery and middle cerebral artery internal carotid in artery ingroups B and C were higher than that in group A (P<0.05). The mean EDs of non-contrast CT in group A, B, C, D were 1.10, 2.11, 1.76, 1.42, 1.40 mSv; compared to group A, ED was reduced approximately 16.6% (0.35/2.11), 32.7% (0.69/2.11) and 33.6% (0.71/2.11), respectively (P<0.05). The diagnostic accuracy of low dose dual source CTP for detecting hyperacute cerebral infarction was 93.5% (172/184), while that of non-contrast CT was 52.2% (96/184);for detecting hyperacutelacunar cerebral infarction, it was 72.1% (31/43) and 16.3% (7/43) respectively (P<0.05).@*Conclusion@#Appropriate reduction of tube current (100 mA) and scanning passes (17 scanning time points) can reduce the radiation dosage and acquire comparable image quality for 70 kV protocol CTP. Compared with non-contrast CT, low dose dual-source CTP is more sensitive to hyperacute cerebral infarction, especially hyperacute lacunar cerebral infarction.
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Objective:To investigate the correlation between the enhancement characteristics in arterial phase and the prognosis of patients with massive intrahepatic cholangiocarcinoma (IMCC).Methods:The imaging and clinical data of 92 patients with IMCC who were pathologically confirmed and underwent enhanced MRI or CT in Central Hospital of Lishui from June 2004 to February 2019 were retrospectively analyzed. According to the enhancement pattern of the primary lesion in the arterial phase, patients were divided into rich arterial blood supply group （17 cases） and deficient arterial blood supply group （75 cases）. The clinical data and imaging features of these patients were studied. Differences between measurement data and count data between the two groups were compared using t test and Fisher test. Kaplan-Meier analysis and log-rank test were used to analyze overall survival. The Cox regression multivariate analysis was used to study the relationship between the variables and the risk of death. Result:The enlargement of lymph nodes, long diameter of the primary lesion, CA19-9, treatment and HPD around the primary lesion in arterial phase were statistically different in the two groups ( P<0.05), others were no statistical difference. CA19-9>200 U/ml, lymph node enlargement, HPD around the primary lesion in arterial phase and deficient arterial blood supply were independent factors for the prediction of prognosis in IMCC patients with surgery ( P values were 0.008, 0.002, 0.049 and 0.005, respectively). Lymph node enlargement and deficient arterial blood supply were independent risk factors for the prediction of prognosis in IMCC patients with surgery ( P values are 0.049 and 0.045, respectively). Conclusion:The blood supply characteristics of arterial phase are independent factors for the prognosis of patients with IMCC.
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Objective:To evaluate image quality and radiation dosage of CT cerebral perfusion (CTP) imaging of 70 kV with different tube current and scanning passes and its diagnostic value for hyperacute cerebral infarction.Methods:A total of 190 patients with suspected hyperacute cerebral infarction in Lishui Central Hospital of Zhejiang Province from December 2017 to February 2019 were selected prospectively, and all patients were divided into 4 groups according to random number table and received non-contrast CT examination and dual-source CT cerebral perfusion imaging with 70 kV protocol simultaneously within 6 hours after the onset of symptoms: group A, 120 mA, 21 scanning time points; group B, 100 mA, 21 scanning time points; group C, 100 mA, 17 scanning time points; group D, 80 mA, 21 scanning time points. The values of perfusion parameters such as cerebral blood flow (CBF), crerbral blood volume (CBV), mean transit time (MTT), time to peak (TTP) were acquired. Image quality was evaluated and effective dose (ED) was recorded. The quantitative variables of image quality and radiation dosage were compared between four groups using one-way analysis of variance test.Results:There was no differences between groups on the CBF, CBV, MTT, TTP maps for all CTP values ( P>0.05), and all images could meet the diagnostic requirements. The subjective image quality score of vessel sharpness and overall image quality of both internal carotid artery and middle cerebral artery and the degree of noise of internal carotid in artery in group A was higher than that in group D ( P<0.05). The score of vessel sharpness of internal carotid in artery ingroup A was higher than those in both groups B and C ( P<0.05). The scores of vessel sharpness of both internal carotid artery and middle cerebral artery internal carotid in artery ingroups B and C were higher than that in group A ( P<0.05). The mean EDs of non-contrast CT in group A, B, C, D were 1.10, 2.11, 1.76, 1.42, 1.40 mSv; compared to group A, ED was reduced approximately 16.6% (0.35/2.11), 32.7% (0.69/2.11) and 33.6% (0.71/2.11), respectively ( P<0.05). The diagnostic accuracy of low dose dual source CTP for detecting hyperacute cerebral infarction was 93.5% (172/184), while that of non-contrast CT was 52.2% (96/184);for detecting hyperacutelacunar cerebral infarction, it was 72.1% (31/43) and 16.3% (7/43) respectively ( P<0.05). Conclusion:Appropriate reduction of tube current (100 mA) and scanning passes (17 scanning time points) can reduce the radiation dosage and acquire comparable image quality for 70 kV protocol CTP. Compared with non-contrast CT, low dose dual-source CTP is more sensitive to hyperacute cerebral infarction, especially hyperacute lacunar cerebral infarction.
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Objective To explore the clinical value of the dual-low-dose with low tube voltage for head and neck CTA. Methods One hundred and sixty patients who were clinically suspected head and neck vascular disease underwent CTA procedure were propective selected, and whose body mass index (BMI) was also lower than 25 kg/m2. Forty cases were randomly selected as conventional group(120 kV,150 mAs, iodine 320 mg/ml), the other 120 cases were as the low dose group. The low dose group divided into three subgroups according to the random number table method, which were low iodine group (37 cases;120 kV,150 mAs, iodine 270 mg/ml), low tube voltage group (42 cases;100 kV,150 mAs, iodine 320 mg/ml) and low iodine and tube voltage group (41 cases;100 kV,150 mAs, iodine 270 mg/ml). The carotid bifurcated CT value, standard deviation (SD), signal-to-noise ratio (SNR), iodine intake and effective radiation dose (ED) of the four groups were recorded,all data undertook statistical analysis useing one-way ANOVA. Meanwhile, the subjective image quality score was applied to evaluate the image quality, and the differences among groups were compared by Wilcoxon signed ranks test. Results The image quality score were (2.85±0.19),(2.33 ± 0.34),(2.26 ± 0.32),(2.87 ± 0.22) in the four groups, and there was no statistical difference between groups(P>0.05).The carotid bifurcated CT value were respectively (380±30),(314±27),(514±52) and (425±28) HU in conventional, low iodine, low tube voltage and dual-low-dose groups, and the iodine intake were (18.85±2.10), (15.75±1.78), (18.53±1.98), (15.62±1.92) g, the ED of the four groups were (1.74±0.14), (1.73± 0.11), (1.32 ± 0.08) and (1.35 ± 0.09) mSv, the difference were all statistically significant (P<0.01). Furthermore, the iodine intake and the effective radiation dose in dual-low-dose group were significantly lower than the conventational group. Conclusions Head-and-neck CTA with dual-low-dose scan can provide same quality images as using 100 kV and high dose iodine contrast agent, and which also significantly reduced the ED and iodine intake greatly. Thus, this scanning program has great clinical value.
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Objective To explore the effect of chest circumference index adjusting tube voltage techniquey on image quality and radiation dose at coronary CTA. Methods One hundred and twenty consecutive patients [body mass index(BMI)90 cm, n=20). All patients were examined by coronary CTA. The patients in conventional group were performed using retrospective ECG-gating technology and reconstructed by filtered back projection algorithm. The tube voltage/tube current was 120 kV/1 000 mAs. Prospective ECG?gating technology and iterative algorithm reconstruction were used in low dose group. The tube voltages/currents were 80 kV/150 mAs, 100 kV/150 mAs, 120 kV/150 mAs in A, B, C group, respectively. Image quality was assessed by subjective evaluation (image quality score) and objective evaluation (signal?to?noise ratio).The effective radiation dose was calculated. Analyses of the differences between groups were compared with image quality, radiation dose by single factor variance and Wilcoxon signed ranks test.Results The image quality scores and signal?to?noise ratio of aorta were respectively (3.47 ± 0.38), (3.48 ± 0.27), (3.45 ± 0.32), (3.46±0.29) and (15.5±3.6), (15.8±3.6), (15.8±4.1), (16.2±3.9) in conventional, A, B and C groups, there was no statistical difference between the four groups (P=0.24, 0.43). The effective radiation dose of four groups were respectively (17.15 ± 3.25), (0.88 ± 0.02), (1.38 ± 0.05), (2.32 ± 0.04) mSv, the difference was statistically significant (P=0.02). The effective radiation dose of A, B, C group was significantly lower than that in the conventional group. Conclusion Chest circumference index adjusting tube voltages technology at coronary CT angiography can effectively reduce the effective radiation without compromise of image quality.
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OBJECTIVE: To assess the effect of chest circumference-adapted scanning protocol on radiation exposure and image quality in patients undergoing prospective electrocardiogram (ECG)-triggered coronary CT angiography (CCTA). MATERIALS AND METHODS: One hundred-eighty-five consecutive patients, who had undergone prospective ECG triggering CCTA with a 128-slice CT, were included in the present study. Nipple-level chest circumference, body weight and height were measured before CT examinations. Patients were divided into four groups based on kV/ref.mAs = 100/200, 100/250, 120/200, and 120/250, when patient's chest circumference was 95.0 (n = 32), respectively. Image quality per-segment was independently assessed by two experienced observers. Image noise and attenuation were also measured. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. The effective radiation dose was calculated using CT dose volume index and the dose-length product. RESULTS: A significant correlation was observed between patients' chest circumference and body mass index (r = 0.762, p < 0.001). Chest circumference ranged from 74 to 105 cm, and the mean effective radiation dose was 1.9-3.8 mSv. Diagnostic image quality was obtained in 98.5% (2440/2478) of all evaluated coronary segments without any significant differences among the four groups (p = 0.650). No significant difference in image noise was observed among the four groups (p = 0.439), thus supporting the validity of the chest circumference-adapted scanning protocol. However, vessel attenuation, SNR and CNR were significantly higher in the 100 kV groups than in the 120 kV groups (p < 0.05). CONCLUSION: A measure of chest circumference can be used to adapt tube voltage and current for individualized radiation dose control, with resultant similar image noise and sustained diagnostic image quality.
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Adult , Aged , Female , Humans , Male , Middle Aged , Body Mass Index , Contrast Media , Electrocardiography , Heart/diagnostic imaging , Heart Rate , Prospective Studies , Radiation Dosage , Signal-To-Noise Ratio , Tomography, X-Ray Computed/methods , Waist CircumferenceABSTRACT
Objective To investigate the value of MSCT and its reconstruction technique for etiological factors of adult non traumatic acute abdomen.Methods The CT findings and clinical data of 1 632 adult patients with non traumatic acute abdomen confirmed by clinical treatment or pathological examination from July 2007 to June 2013 were retrospectively analyzed.Six hundred and sixty-four patients underwent plain scan and 968 patients underwent plain and enhanced scan.We observed MSCT manifestations of acute abdomen , calculated the accurate rate of diagnosis , and analyzed causes of missed diagnosis or misdiagnosis.Results CT diagnosis of 1 580 cases were entirely or partially consistent with the final results in 1 632 cases.Overall accuracy rate was 96.8%.Misdiagnosis or missed diagnosis accounted for 3.2% ( 52/1 632 ).The corresponding accuracy rates using CT with various etiology were: urinary system stones 100.0% ( 293/293 ) , appendicitis 99.3% ( 278/280 ) , abdominal tumors 98.3%(227/231), cholecystitis and cholelithiasis 96.4% (213/221), acute pancreatitis 95.8% (159/166), intestinal adhesion 92.6%(100/108), gastrointestinal perforation 97.9%(92/94), internal and external hernia 95.2% ( 59/62 ) , intussusceptions 95.4% ( 42/44 ) , volvulus 91.7% ( 33/36 ) , foreign bodies 95.6%(22/23), ectopic pregnancy 92.3%(12/13), vascular disease 100.0% (16/16), inflammatory bowel disease 77.8%(7/9), and other diseases 75.0%(27/36).The main cause of missed diagnosis was the absence of obvious morphologic changes at early stage of the diseases.Atypical MSCT features resulted in misdiagnosis.Conclusion MSCT is a valuable tool in diagnosing adult non traumatic acute abdomen and its etiology.
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Objective To evaluate the role of spiral CT and its reconstruction techniques in orientation and determination of the nature of small bowel neoplasms.Methods CT manifestations,multiple planar reformation(MPR) and slip thin slice maximum intensity projection(STS-MIP) of 54 cases small bowel noplasms confirmed pathologically were analysed.Results 54 cases of small bowel neoplasm mainly included:adenocarcinoma in 15 cases,stromal tumor in 24 cases,lipoma in 4 cases,lymphoma in 4 cases and adenoma in one case.The accurate rate of orientation and determination of the nature of small bowel neoplasm by CT were all 96.3%(52/54).MPR and STS-MIP can demonstrated the blood supply arteries and drainage veins of tumors.Conclusion Spiral CT and its MPR,STS-MIP have an important clinical value in orientation and determination of the nature of intestinal obstruction by neoplasm.