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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 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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Thyroid nodules are common clinical disease, and most of the nodules are benign. After radiofrequency ablation (RFA) treatment, the volume of benign thyroid nodules will significantly shrink or the nodules will even disappear, thus, the related clinical symptoms induced by the thyroid nodules will be improved. For recent years, radiofrequency ablation has become the treatment of first choice for benign thyroid nodules. This paper aims to make a comprehensive review about the research situation concerning the radiofrequency ablation in the treatment of the benign thyroid nodules so as to provide scientific guidance and basis for the relevant clinical research and treatment.
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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.