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OBJECTIVE To explore the whole-process pharmaceutical care model of iodine contrast medium and promote the rational clinical use of iodine contrast medium. METHODS Clinical Professional Committee on Rational Drug Use of China Medical Education Association and Expert Committee on Drug Evaluation and Clinical Research of Guangdong Pharmaceutical Association organized domestic experts to establish a working group on the Consensus on the whole-process pharmaceutical care for iodine contrast medium. The working group conducted literature searches， evidence-based analysis， and discussions on the development process， indications， contraindications， adverse drug reactions， drug interactions， drug use for special population， pharmaceutical care， and other key topics to summarize the content and process of the whole-process pharmaceutical care for iodine contrast medium. This consensus was ultimately formed. RESULTS The consensus on whole-process pharmaceutical care for iodine contrast medium included an evaluation of the patient， renal function， combined drug use， and hydration regimen before examination， the presence of contrast agent extravasation or suspected acute adverse reactions during examination， observation time points and follow-up after examination， and the presentation of specific work in each stage through pharmaceutical care flowchart. The medication monitoring record form was also formed to record the work situation. CONCLUSIONS The consensus has established a whole-process pharmaceutical care system for iodine contrast medium， providing scientific evidence for clinical physicians and nursing staff in the rational use of such special drugs， and also serving as a reference for pharmacists in providing related pharmaceutical care.
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Although Compartment Syndrome is a common surgical emergency with a plethora of aetiologies, Intravenous extravasation of Computed Tomography (CT) contrast medium causing acute compartment syndrome has been reported very rarely. We present a 61-year-old female who underwent abdominal CT with Intravenous contrast for irreducible, recurrent incisional hernia, presented with persistent excruciating pain and progressive multiple blister formation over the left forearm and hand following intravenous contrast material injection via the left dorsum of the hand. Clinical diagnosis of compartment syndrome was made, X-ray left forearm and hand confirmed soft tissue contrast extravasation. She was taken for emergency decompression fasciotomy of the left forearm and hand compartments, and later partial wound closure and split skin graft into remaining areas were carried out. Clinicians and radiologist should aware of this potential complication for its early recognition, management and prevention.
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Objective:To investigate the feasibility of tube potential of 80 kV combined with personalized contrast agent protocol in carotid artery CT angiography (CTA).Methods:A total of 136 consecutive patients undergoing neck CTA were prospectively enrolled in this study. The patients were randomly divided into Groups A, B, C and D. Tube potential of 100 kV and 15 s contrast agent injection protocol was used for Group A (53 cases) as conventional group, while tube voltage of 80 kV and 10 s contrast agent injection protocol was used for Groups B, C and D as experimental groups, with the contrast agent dosages of 20, 25 and 30 ml used according to the body weights of ≤50 kg(Group B, 20 cases), 50-70 kg (Group C, 38 cases), and 70-90 kg (Group D, 25 cases), respectively. The subjective and objective evaluation results of image quality and the effective doses were compared among the four groups.Results:The effective doses in Groups B, C and D were 1.54±0.91, 1.89±1.08 and 2.14±1.27 mSv, respectively, significantly lower than that in Group A [(5.66±0.56) mSv] ( F=169.34, P<0.05). The image quality of four groups met the requirements of clinical diagnosis. No significant differences were found in subjective evaluation and diagnostic efficacy of the four groups ( P>0.05). The CT number of carotid artery, signal-to-noise ratio and contrast-to-noise ratio of the neck region were significantly lower in Groups B, C and D compared with Group A ( F=14.9, 12.94, 14.43, P<0.05). The CT numbers of target carotid vessel were all higher than 250 HU. Conclusions:The scanning protocol of low tube potential (80 kV) combined with 10 s contrast agent injection protocol could not only reduce the doses of radiation and contrast agent, but also preserve the diagnosis effect. Thus, this scanning protocol was feasible and valuable in clinical application.
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Objective To explore the optimal body size index for the calculation of iodine contrast agent dose required for multiphase liver enhanced CT scans based on the total body weight (TBW),lean body weight (LBW)and body surface area (BSA).Methods Two hundred and twenty enrolled patients were randomly divided into three groups,TBW-group (n＝75),LBW-group (n＝72)and BSA-group (n＝73),and administrated iodine doses were 600 mg I/TBW(kg),780 mg I/LBW(kg)and 22 g I/BSA(m2 ),respectively.All patients had taken upper abdominal plain scans and triple-phase enhanced CT scans.The enhanced values (ΔHU)of the aorta at hepatic arterial phase (HAP),the portal vein and liver parenchyma at portal venous phase (PVP)were compared.The correlation coefficients of adjusted maximal hepatic enhancement(aMHE)with TBW,LBW and BSA in three groups were evaluated,respectively.Results There were no statistical differences in the ΔHU values of the aorta at HAP and the portal vein and liver parenchyma at PVP in the three groups respectively.The smallest variances of the aorta at HAP,the portal vein and liver parenchyma at PVP were found in the LBW group. The aMHE showed mildly positive correlation with TBW (r＝0.230)with a P value of 0.047,but it was consistent with LBW (r＝0.158)and BSA (r＝－0.1 54)with corresponding P values of 0.1 85 and 0.1 9 2 ,respectively.Conclusion Compared with TBW and BSA,iodine contrast agent dose calculated based on the patient’s LBW can improve the patient-to-patient uniformities on aorta,portal vein and liver enhancement during the liver multiphase enhanced CT scans.The LBW is the best body index for the calculation of iodine dose on liver enhanced CT scans.
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Objective: To investigate the effect of individualized contrast administration in improving the enhancement homogeneity in vessels and image quality in coronary CT angiography (CCTA). Methods: Sixty CCTA patients were randomly divided into two groups with different contrast injection protocols: treatment group (n=30) was treated with weight-dependent injection protocol at 22 mg/(g•s) of idion, injection velocity=body mass×22/contrast agent concentration. Control group (n=30) was treated with a different injection protocol. The iodine flow rate in this group was determined by patient body mass index (BMI), iodine flow rate=1.2 g/s, 1.4 g/s and 1.6 g/s. Injection flow rate= iodine flow rate/contrast agent concentration. Theiohexol (350 mg/mL) was used in both groups, and the injection time was fixed at 10 s and contrast agent dose=injection velocity×injection time. The other scanning parameters were the same. The enhancement change rate in AS and the three major arteries was calculated for the patient population. The subjective image quality scores were also compared. Results: The change rates of vascular enhancement at interested blood vessels in treatment group (12.9%, 11.8%, 11.0% and 11.1%, respectively) were significantly lower than those in in control group (23.3%, 18.7%, 16.7% and 20.5%, respectively) (P=0.001). There was no significant difference between the two groups in subjective image quality score (P=0.095). Conclusion: Individualized contrast injection protocol in CCTA can provide us with a more uniform enhancement in coronary arteries, and improve the overall image quality.
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Objective To access the effects of 70 kV tube voltage combined with low dose and low concentration of contrast medium in coronary CT angiography (CCTA)by evaluating the image quality,radiation dose and contrast medium dosage.Methods Ninety patients suspected with coronary artery disease with body mass index(BMI)of less than 25 kg/m2and heart rate (HR)of less than 75 beats per minute were enrolled.The patients were randomly divided into three groups (n=30 for each group):Group A,100 kV of tube voltage with 370 mg I/mL iopromide,1 mL/kg;Group B,80 kV with 270 mg I/mL iodixanol,1 mL/kg;Group C,70 kV with 270 mg I/mL iodixanol,0.8 mL/kg.All the patients underwent CCTA with a 256 row wide-coverage volumetric CT.Automatic tube current modulation technique was applied.The images were reconstructed by adaptive statistical iterative reconstruction V (ASIR-V).The subjective image quality scores were compared with rank-sum test.The signal-to-noise ratio (SNR),contrast-to-noise ratio(CNR),effective dose(ED)and the total iodine intake were calculated and compared with one-way ANOVA.Results No statistically differences in age,gender,heart rate and BMI were observed among the three groups (P>0.05).Subjective image quality scores had no difference among the three groups (P>0.05).The CT values of group C were higher than those of group A(P<0.05).The image noise of group C was higher than that of group A and group B (P<0.05).No significant differences in SNR and CNR were noticed among the three groups (P>0.05).The ED of group B (0.39±0.08)mSv and group C (0.19±0.01)mSv were lower than that of group A (0.81±0.19)mSv (each P<0.05).Compared with group A,the decrease rates of ED of group B and C were 51.8% and 76.5% respectively.Compared with group A and group B,the total iodine intake of group C was decreased by 25% and 21.4% (P<0.05).Conclusion 70 kV of tube voltage combined with low dose and low concentration of contrast medium in CCTA can reduce the radiation dose and iodine intake without compromising image quality.
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Objective To evaluate the feasibility of low tube voltage (80 kV)with low concentration contrast medium iodixanol (270 mg I/mL)in cerebral perfusion using 640-slice volume CT.Methods Patients who underwent CT cerebral perfusion were randomly divided into two groups.Group A:100 kV,320 mg I/mL contrast medium;group B:80 kV,270 mg I/mL contrast medium.The effective dose(ED)was record,the frontal cortex,temporal cortex and occipital cortex were selected as regions of interest(ROI),and the cerebral perfusion parameters (rCBV,rCBF,MTT,TTP)were measured separately.The CT value of the M1 segment of cerebral middle artery, the C7 segment of internal carotid artery,the basilar artery and the surrounding brain tissue were measured.The signal-to-noise radio (SNR)and the contrast-to-noise ratio(CNR)of two groups were compared and analyzed.All data will be statistically analyzed,and the consistency of two physicians for image quality evaluation was analyzed by Kappa analysis.Results The ED of group B was 4.56 mSv, which was reduced by 35.2% compared to group A(7.04 mSv).The perfusion parameters,the CT value of ROI and the SNR,CNR for two groups were of no statistical difference(P>0.05).Conclusion The feasibility of low tube voltage combined with low concentration contrast media is better,which not only meets the requirements of clinical diagnosis,but also reduces the radiation dose and the probability of contrast induced nephropathy.
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With the increasing use of contrast agents,contrast medium-induced acute kidney injury(CI-AKI)has become one of the most important causes of hospital-acquired AKI.The study of adult population showed that the incidence of CI-AKI was approximately 11.0%,CI-AKI extend the patient's prolonged hospitalization,in-creased mortality and increased rates of cardiovascular events.However,little research is available regarding CI-AKI incidence,risk factors,prognostic impact and preventive measures in the pediatric population.How to improve the pre-vention and treatment level of CI-AKI in children is a challenge for pediatricians.
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OBJECTIVE: To evaluate the effect of patient characteristics on popliteal aortic contrast enhancement at lower extremity CT angiography (LE-CTA) scanning. MATERIALS AND METHODS: Prior informed consent to participate was obtained from all 158 patients. All were examined using a routine protocol; the scanning parameters were tube voltage 100 kVp, tube current 100 mA to 770 mA (noise index 12), 0.5-second rotation, 1.25-mm detector row width, 0.516 beam pitch, and 41.2-mm table movement, and the contrast material was 85.0 mL. Cardiac output (CO) was measured with a portable electrical velocimeter within 5 minutes of starting the CT scan. To evaluate the effects of age, sex, body size, CO, and scan delay on the CT number of popliteal artery, the researchers used multivariate regression analysis. RESULTS: A significant positive correlation was seen between the CT number of the popliteal artery and the patient age (r = 0.39, p < 0.01). A significant inverse correlation was observed between the CT number of the popliteal artery and the height (r = −0.48), total body weight (r = −0.52), body mass index (r = −0.33), body surface area (BSA) (r = −0.56), lean body weight (r = −0.56), and CO (r = −0.35) (p < 0.001 for all). There was no significant correlation between the enhancement and the scan delay (r = 0.06, p = 0.47). The BSA, CO, and age had significant effects on the CT number (standardized regression: BSA −0.42, CO −0.22, age 0.15; p < 0.05, respectively). CONCLUSION: The BSA, CO, and age are significantly correlated with the CT number of the popliteal artery on LE-CTA.
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Humans , Angiography , Body Mass Index , Body Size , Body Surface Area , Body Weight , Cardiac Output , Informed Consent , Lower Extremity , Popliteal Artery , Tomography, X-Ray ComputedABSTRACT
OBJECTIVE: We evaluated the effect of various patient characteristics and time-density curve (TDC)-factors on the test bolus-affected vessel enhancement on coronary computed tomography angiography (CCTA). We also assessed the value of generalized linear regression models (GLMs) for predicting enhancement on CCTA. MATERIALS AND METHODS: We performed univariate and multivariate regression analysis to evaluate the effect of patient characteristics and to compare contrast enhancement per gram of iodine on test bolus (ΔHUTEST) and CCTA (ΔHUCCTA). We developed GLMs to predict ΔHUCCTA. GLMs including independent variables were validated with 6-fold cross-validation using the correlation coefficient and Bland–Altman analysis. RESULTS: In multivariate analysis, only total body weight (TBW) and ΔHUTEST maintained their independent predictive value (p < 0.001). In validation analysis, the highest correlation coefficient between ΔHUCCTA and the prediction values was seen in the GLM (r = 0.75), followed by TDC (r = 0.69) and TBW (r = 0.62). The lowest Bland–Altman limit of agreement was observed with GLM-3 (mean difference, −0.0 ± 5.1 Hounsfield units/grams of iodine [HU/gI]; 95% confidence interval [CI], −10.1, 10.1), followed by ΔHUCCTA (−0.0 ± 5.9 HU/gI; 95% CI, −11.9, 11.9) and TBW (1.1 ± 6.2 HU/gI; 95% CI, −11.2, 13.4). CONCLUSION: We demonstrated that the patient's TBW and ΔHUTEST significantly affected contrast enhancement on CCTA images and that the combined use of clinical information and test bolus results is useful for predicting aortic enhancement.
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Humans , Angiography , Body Weight , Cardiac Output , Heart , Iodine , Linear Models , Multivariate AnalysisABSTRACT
[Objective] To investigate the clinical value of using prospective ECG-gating Helical protocol in whole aorta and coronary arteries CT angiography combined with low tube voltage,low contrast medium injection rate and dose technology.[Methods]A total of 60 patients (heart rate≤ 75 bpm and normal heart rhythm) with suspected aortic disease or post-operation were randomly divided into 2 groups:G1 (n =30;tube voltage:80 kV;contrast medium injection rate:3 mL/s;contrast medium dose:0.65 mL/kg)and G2 (n =30;tube voltage:120 kV;contrast medium injection rate:4 mL/s;contrast medium dose:1.2 mL/kg).The two groups underwent aorta angiography with prospective ECG-gating Helical protocol by using 320-detector CT.The mean CT values and standard deviation of aorta,coronaries and adjacent adipose tissue were measured,signal to noise ratio (signal-to-noise ratio,SNR)and contrast to noise ratio (contrast-to-noise ratio,CNR) were calculated.The subjective quality scoring of 3-d post-processing images were evaluated independently by 2 senior radiologists.The mean CT values and standard deviation of aorta,coronaries and adipose tissue,SNR,CNR,subjective quality scoring,contrast medium dose and radiation dose were compared and analyzed.[Results] The abnormal and normal rate of aorta in two groups were 83.33％ (25/30),16.67％ (5/30) and 86.67％ (26/30),13.33％(4/30);while the abnormal and normal rate of coronary arteries in two groups were 43.33％ (13/30),56.67％ (17/30) and 53.33％(16/30),46.67％ (14/30).SNR values of ascending aorta,descending aorta,abdominal aorta,superior mesenteric artery,bilateral renal artery,left main coronary artery,left anterior descending branch,left circumflex branch,right coronary artery and CNR values of abdominal aorta,superior mesenteric artery,bilateral renal artery,left anterior descending branch,left circumflex branch had no statistical significance,while the other indicators were significant differences between the two groups.The radiation dose and the contrast medium dose of G1 was significantly lower than G2 (P ＜ 0.05).There was no difference in the subjective image quality of 3D post-processing images between the two groups (P ＞ 0.05).[Conclusions] Using prospective ECG-gating Helical protocol in whole aorta and coronary arteries CT angiography combined with low tube voltage,low contrast medium injection rate and low contrast medium dose technology can help to reduce radiation and contrast medium dose without impacting on the imaging quality satisfactorily.
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Objective To investigate the value of fractional contrast medium bolus injection in improving the quality of CT portography.MethodsA total of 42 patients were randomly divided into two groups which were all given iohexol (350mgI/mL) as the contrast medium.20 patients in the group A were injected with conventional method (dosage of 100ml, rate of 4mL/s).The group B (22 patients) were treated with fractional contrast medium bolus injection, the first phase with 60mL contrast medium (rate of 4mL/s) and the second phase (10s delayed) with 40mL contrast medium (rate of 4m/s).The tube was washed by 20mL saline with the same rate of injection at both phases.The CT values and the image quality of the branches of the portal vein were evaluated according to the original and postprocessed images.Independent samples test was used to compare the CT values of the portal vein, splenic vein, superior mesenteric vein, hepatic parenchyma and portal vein-liver parenchyma.The subjective evaluation scores of the image quality were compared by wilcoxon.ResultsThe CT values of the portal vein, splenic vein and portal vein-liver parenchyma in the group B were significantly higher than that in the group A (t=3.317,3.523,P<0.01).There was no significant difference in CT values of hepatic parenchyma and superior mesenteric vein between the two groups.Subjective quality score in the group B was superior to that in the group A, and the difference was statistically significant.T The two evaluation physicians agreed well.ConclusionThe technique of fractional contrast medium bolus injection can significantly improve the image quality of CT portograghy.
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Objective To explore the feasibility of low concentration contrast medium and low-voltage combined with adaptive statistical iterative reconstruction(ASRI)technique in enhanced CT imaging of solitary pulmonary nodules. Methods A total of 40 patients with solitary pulmonary nodules who underwent routine exam-inations and were pathologically confirmed from February 2015 to February 2017 were collected and divided into conventional group(conventional dose,high osmolar contrast,using filtered back projection reconstruction)and low dose group(low voltage,low concentration isotonic contrast,iterative reconstruction). Results Subjective scoring of conventional group(3.97 ± 0.57)and low dose group(4.01 ± 0.54)indicated no statistical significance (P > 0.05). No significant difference was found regarding to reconstructed image quality,SNR and CNR in both two groups.The dose length product(DLP)and effective dose(ED)in low dose group were lower than those in the conventional group[(283.52 ± 11.50)mGy/cm vs(370.74 ± 29.56)mGy/cm;(3.65 ± 0.32)mSV vs(5.11±0.25) mSV],and the difference was statistically significant(P < 0.05). Conclusions Low concentration isotonic con-trast agent(iodixanol 270 mgI/L)and low voltage(100 kV)combined with ASIR technology could satisfy the clini-cal need in enhanced CT imaging of solitary pulmonary nodule.
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Objective To investigate the minimum dose of contrast medium when using spectral CT in cranial CTA. Methods Three groups of patients were required to undergo head CTA examination because of their condition,but different doses of contrast agents were injected.Among them,group 30 mL, group B, group 40mL, group C and group 50 mL were A. Results In group A,the lowest rate of excellent image (23.33%), B group, C group had higher rate of excellent image (93.33%, 96.67%), comparison of the data P<0.05; C group the highest rate of adverse reaction of contrast agent (P<0.05),data comparison P<0.05, A group, B group significantly adverse reactions of contrast agent there is no difference between the situation (P>0.05). Conclusion The use of 40 mL iodide contrast medium in the procedure of cranial CTA examination is effective and safe.
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Objective To evaluate the feasibility of 80 kVp tube voltage combined with adaptive statistical iterative reconstruction (ASiR)in low dose contrast media split-bolus 2-phase CTU.Methods Sixty patients with hematuria were recruited in this study.All the patients (80 kVp Group,n=30;120 kVp Group,n=30)underwent split-bolus 2-phase CTU (80 kVp Group:35 mL and 60 mL;120 kVp Group:50 mL and 70 mL).CTU images were reconstructed with 30％ ASiR in 80 kVp Group and with filtered back projection (FBP)in 120 kVp Group.Subjective and objective analysis of CTU images were accomplished by two qualified and independent readers.The radiation dose was evaluated by ED and SSDE.The image score,noise,attenuation value and CNR of urinary tract,and radiation dose were compared by Mann-Whitney rank sum test.Results There was no significant difference in the image quality between two groups (Z =-1.791,P =0.073).The noise of 80 kVp Group were higher than that of 120 kVp Group (Z =-6.299,P <0.001 ), while there was no significant difference of attenuation value between the two groups (Z =-1.204 --0.163,P =0.228 -0.871,except bladder),as well as the CNRs (Z =- 1.818 --0.202,P =0.069 -0.840).The ED and SSDE of 80kVp Group were significantly lower than those of 120 kVp Group (Z =-6.655--6.653,P <0.001).Conclusion The protocol of 80 kVp tube voltage combined with iterative reconstruction in low dose contrast media split-bolus 2-phase CTU is feasible for clinical application,with reduction of radiation dose and acceptable diagnostic image quality.
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Objective To investigate the minimum dose of contrast medium when using spectral CT in cranial CTA. Methods Three groups of patients were required to undergo head CTA examination because of their condition,but different doses of contrast agents were injected.Among them,group 30 mL, group B, group 40mL, group C and group 50 mL were A. Results In group A,the lowest rate of excellent image (23.33%), B group, C group had higher rate of excellent image (93.33%, 96.67%), comparison of the data P<0.05; C group the highest rate of adverse reaction of contrast agent (P<0.05),data comparison P<0.05, A group, B group significantly adverse reactions of contrast agent there is no difference between the situation (P>0.05). Conclusion The use of 40 mL iodide contrast medium in the procedure of cranial CTA examination is effective and safe.
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Objective To evaluate the feasibility of 80 kVp tube voltage combined with adaptive statistical iterative reconstruction (ASiR)in low dose contrast media split-bolus 2-phase CTU.Methods Sixty patients with hematuria were recruited in this study.All the patients (80 kVp Group,n=30;120 kVp Group,n=30)underwent split-bolus 2-phase CTU (80 kVp Group:35 mL and 60 mL;120 kVp Group:50 mL and 70 mL).CTU images were reconstructed with 30％ ASiR in 80 kVp Group and with filtered back projection (FBP)in 120 kVp Group.Subjective and objective analysis of CTU images were accomplished by two qualified and independent readers.The radiation dose was evaluated by ED and SSDE.The image score,noise,attenuation value and CNR of urinary tract,and radiation dose were compared by Mann-Whitney rank sum test.Results There was no significant difference in the image quality between two groups (Z =-1.791,P =0.073).The noise of 80 kVp Group were higher than that of 120 kVp Group (Z =-6.299,P <0.001 ), while there was no significant difference of attenuation value between the two groups (Z =-1.204 --0.163,P =0.228 -0.871,except bladder),as well as the CNRs (Z =- 1.818 --0.202,P =0.069 -0.840).The ED and SSDE of 80kVp Group were significantly lower than those of 120 kVp Group (Z =-6.655--6.653,P <0.001).Conclusion The protocol of 80 kVp tube voltage combined with iterative reconstruction in low dose contrast media split-bolus 2-phase CTU is feasible for clinical application,with reduction of radiation dose and acceptable diagnostic image quality.
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Objective To observe and analyze the therapeutic effect of focal uterine adenomyosis treated with percutaneous microwave ablation by contrast-enhanced ultrasound and dynamic contrast enhanced MRI (DCE-MRI).Methods From January 2013 to July 2016,42 patients with focal uterine adenomyosis voluntarily underwent percutaneous microwave ablation in the tumor hospital of Liaocheng.Contrast-enhanced ultrasound and DCE-MRI were performed before and after percutaneous microwave ablation.The therapeutic effects of percutaneous microwave ablation in treatment of uterine adenomyosis lesions were observed.Results After percutaneous microwave ablation of the 42 cases,the ablated zone showed no enhancement with contrast-enhanced ultrasound and DCE-MRI.Contrast-enhanced ultrasound showed that the volume and ablation rate of ablated zone were (49.0±29.5) cm3 and (91.6± 7.1)％,and that of DCE-MRI were (49.4 ± 29.9)cm3 and (91.9 ± 6.7)％,respectively.The results showed that percutaneous microwave ablation could cure focal uterine adenomyosis at the rate over 90％.Contrast-enhanced ultrasoundand DCE-MRI are in accordance in observing the ablation rate.Conclusions Contrast-enhanced ultrasound can accurately show the ablation rate of focal uterine adenomyosis treated with percutaneous microwave ablation,which is quite consistent with DCE-MRI.Contrast-enhanced ultrasound has its advantages such as identifying the lesions which need immiedately supplemental ablation.
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Objective To investigate the lowest concentration of iodine contast medium which can ensure CT pulmonary angiography (CTPA) imaging quality at tube voltage of 80 kVp.Methods Ten New Zealand rabbits underwent CTPA four times every three days with the iodine concentrations of contrast medium at each time were 350,300,270 and 250 mg I/mL respectively.The attenuation values of trunk pulmonary artery and air around the body on the same level,as well as right and left pulmonary arteries,and the pulmonary artery branches were compared among different groups.Meanwhile,image noise (N),contrasvto-noise ratio (CNR) and signal-to-noise ratio (SNR) were calculated.All those data were analyzed with One way classification ANOVA test.When multiple samples compared,Dunnett-t test was employed.The pulmonary arteries were divided into large and small arteries and assessed by multiple sample Kruskal-Wallis H test and analyzed with LSD-t test when multiple samples compared.When the attenuation of trunk pulmonary artery of different viewers or the different times of the same viewer compared,paired t test was employed.Wilcoxon signed rank testing was employed for comparing the scores of pulmonary arteries among different groups.Results All the images of CTPA could demonstrate sixthorder branches of pulmonary artery.The attenuation of pulmonary arteries of the 300-group was the highest,however no statistical difference was found between 270 and 300-group [major pulmonary arteries:(687.17±167.83) HU,(848.68±185.03) HU,t=-161.52,P =0.097].The CNR (6.3±1.30) and SNR (10.9±2.01) of the 270-group were the highest (t=-45.99,P=0.008;t=3.73,P=0.088),and N (62.84±6.05) was the lowest (t=-11.09,P=0.016).No statistical difference was found between 270-group and other 3 groups.And for the subjective scores of large arteries,no statistical differences (from 350-group to 250 group,3.91±0.35,3.90±0.38,3.90±0.42 and 3.86±0.42,H=6.588,P=0.086) were found.The scores of small arteries of 270-group were lower than those of 350 and 300 group,but the image quality of 270-group (3.34±0.51) met the diagnostic requirements.Conclusion When the tube voltage being 80 kVp,the contrast medium of 270 mg I/mL is more suitable for rabbits' CTPA.Thus,the iodine dose per unit can decrease effectively.
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OBJECTIVE: To evaluate the feasibility and image quality (IQ) of prospectively high-pitch coronary CT angiography (CCTA) with low contrast medium injection rate at 70 kVp. MATERIALS AND METHODS: One hundred and four patients with suspected coronary artery disease (body mass index < 26 kg/m², sinus rhythm and heart rate < 70 beats/min) were prospectively enrolled and randomly divided into two groups. In group A and group B, 28 mL and 40 mL of 370 mgI/mL iodinated contrast media was administrated at a flow rate of 3.5 and 5 mL/s, respectively. CT values, noise, signal-to-noise ratio, contrast-to-noise ratio (CNR) of the proximal segments of coronary arteries and subjective IQ were evaluated. RESULTS: The CT values and noise in group A were significantly lower than those in group B (434–485 Hounsfield units [HU] vs. 772–851 HU, all p < 0.001; 17.8–22.3 vs. 23.3–26.4, all p < 0.005). The CNRs of the right coronary artery and left main artery showed no statistical difference between the two groups (42.1 ± 13.8 vs. 36.8 ± 16.0, p = 0.074; 38.7 ± 10.6 vs. 38.1 ± 17.0, p = 0.819). No statistical difference was observed between the two groups in IQ scores (3.04 ± 0.75 vs. 3.0 ± 0.79, p = 0.526) and diagnostic ratio (96.1% [50/52] vs. 94.2% [49/52], p = 0.647). CONCLUSION: Prospective high-pitch CCTA at 70 kVp with 28 mL of contrast media and injection rate of 3.5 mL/s could provide diagnostic IQ for normal-weight patients with heart rate of < 70 beats/min.