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Objective To investigate the image quality and radiation dose of the wider detector array CT scanner with low dose scanning mode in young children with congenital heart disease.Methods Totally 100 consecutive pediatric patients younger than 3 years with congenital heart disease were enrolled.They were divided into two groups.The low dose group with fifty patients underwent axial CT scanning with ECG gating,and the control group with fifty patients were scanned with volume helical shuttle (VHS) technique.CT number and noise of two groups images at the level of ascending aorta,main pulmonary artery,left ventricle,descending aorta and adjacent muscle were measured,and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated.The double blind method was used to evaluate subjective image quality of the level of intra-cardiac,extra-cardiac and coronary artery.Effective dose was also calculated for both groups.Results No significant difference was found in the CT number,image noise,SNR,and CNR between the two groups in the same anatomic regions (P ＞ 0.05).No significant difference was found in subjective image quality between the two groups for the intra-cardiac and extra-cardiac structure(P ＞0.05).The subjective image quality of coronary artery was significant higher in low dose group than the control group(4.10 ± 0.90 vs.2.88 ± 0.82,Z =-5.818,P ＜ 0.05).Effective dose was (0.57 ± 0.30)mSv in group A and (2.39 ± 1.15)mSv in group B with dose savings of 76％ (t =-11.642,P ＜ 0.05).Conclusions The wider detector array CT scanner with low dose scanning mode can improve image quality with lower radiation dose.
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Objective To investigate the accuracy,image quality and effective dose (ED)of the whole-heart CT scanner in infants with congenital heart disease.Methods Totally 86 consecutive pediatric patients younger than 2 years old with congenital heart disease were enrolled.They were divided into 2 groups:whole-heart CT scanner with low dose group,43 patients(28 males,15 females,aged 12 d -19 months)underwent CT acquisition by using the whole-heart CT,and the other 43 patients(23 males,20 females,aged 19 d-16 months)examined with volume helical shuttle (VHS)of high definition CT were assigned as VHS group.With surgical results as the standard,the sensitivity, specificity,positive predictive value (PPV),negative predictive value (NPV)and the diagnostic accuracy of the 2 groups for cardiovascular abnormalities were evaluated.Attenuation and noise of 2 groups of ascending aorta,main pul-monary artery,and muscle were measured,and the signal -to -noise ratio (SNR)and contrast -to - noise ratio (CNR)were calculated.The double blind method was used to evaluate the subjective image quality of the level of intra-cardiac,extra-cardiac and coronary artery.Both the volumetric CT dose index (CTDIvol)and dose-length product(DLP)of each child were recorded,and the ED was also estimated in both groups.Results By using surgical findings as the reference standard,a total of 124 and 113 separate cardiovascular anomalies were confirmed by the whole-heart CT scanner in the low dose group and the VHS group.The diagnostic accuracy in 2 groups was 99.2%and 98.8%,respectively,without significant difference(χ2＝0.035,P＝0.852).The sensitivity,specificity,PPV and NPV in 2 groups were 97.8%,99.7%,98.4%,99.6% and 95.2%,99.3%,98.2%,98.7%,respectively.No signifi-cant difference was found in the attenuation,image noise,SNR,and CNR between 2 groups in the same anatomic regions (all P＞0. 05).No significant difference was found in subjective image quality between 2 groups on the intra-cardiac and extra-cardiac structure(all P＞0.05).But the subjective image quality of coronary artery was significantly higher in whole-heart CT scanner in the low dose group than that of the VHS group(4.02 ± 0.91 vs.2.79 ± 0.74),and the differ-ence was significant(Z＝ -5.562,P＝0.000).ED was (0.59 ± 0.31)mSv in whole-heart CT scanner in the low dose group and (2.28 ± 1.07)mSv in the VHS group,reflecting dose savings of 74% by using the whole-heart CT scanner with high temporal resolution,and the difference was significant(t＝ -11.285,P＝0.000).Conclusions The whole-heart CT scanner with low dose can improve image quality with lower ED,especially for the image quality of coronary artery,which is an effective examination method for the diagnosis of congenital heart disease of children, especially for complex congenital heart disease.
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Objective To assess the effect of snapshot freeze (SSF) motion correction algorithm on the image quality of coronary CT angiography (CCTA).Methods Thirty-one consecutive patients underwent coronary CTA without heart rate control.All of the CCTA images were reconstructed by the means of both standard (STD) and SSF motion correction.Image quality and interpretability of STD and SSF reconstructions were compared.CCTA images were interpreted with Likert 4-points score system by two experienced radiologists.The image qualities were assessed on per-artery and per-segment level,and interpretability was performed on per-segment,per-artery,and per-patient levels.Comparisons of variables were performed with paired Wilcoxon rank sum test and paired Chi-square test.Results SSF reconstructions showed higher interpretability than STD reconstructions on per-patient [100.0％ (31/31) vs 64.5％ (20/31),x2 =9.09,P =0.002] and per-artery [100.0％ (124/124) v s 83.9％ (104/124),x2 =18.05,P =0.001] and per-segment level [99.0％ (413/417) vs 89.2％ (372/417),x2 =35.56,P =0.001].Image qualities were higher with the use of SSF than STD reconstructions on LAD [3.3 ± 0.7 vs 2.9 ± 1.0,Z =2.70,P=0.007],LCX [3.1 ±0.8 vs 2.5 ± 1.1,Z =3.23,P =0.001] and RCA [3.3 ±0.6 vs 2.1 ±0.9,Z =4.60,P =0.001],but they were similar on LM [3.9 ± 0.4 vs 3.7 ± 0.6,Z =1.89,P =0.059].Image quality was higher with the use of SSF versus STD reconstructions on per-segment [3.5 ± 0.7 vs 3.0 ± 1.0,Z =10.31,P =0.001] level.Conclusions The use of SSF motion correction algorithm improves image quality and interpretability of coronary CTA without heart rate control.
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<p><b>OBJECTIVE</b>To compare the diagnostic value of ¹⁸F-fluorodeoxyglucose-positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) and large-scale diffusion weighted imaging (DWI) for evaluation of non-Hodgkin lymphoma (NHL) bone marrow (BM) infiltration.</p><p><b>METHODS</b>A total of 79 patients with pathologically diagnosed NHL underwent ¹⁸F-FDG PET/CT, large scale DWI and BM pathological examination. BM examination as the "gold standard", the performance (the sensitivity, specificity, accuracy, positive and negative predictive value) of ¹⁸F-FDG PET/CT and large scale DWI for evaluation of BM infiltration was compared and the risk of BM infiltration of different subtypes and sources of NHL was analyzed.</p><p><b>RESULTS</b>25 of 79 cases were diagnosed as BM infiltration by pathological examination with 57 BM sites. Abnormal high BM metabolisms were identified in 22 cases with 56 BM sites by ¹⁸F-FDG PET/CT and 25 cases with 58 BM sites by large-scale DWI. The sensitivity, specificity, accuracy, positive and negative predictive value of ¹⁸F-FDG PET/CT were 80.0%, 96.3%, 91.1%, 90.9%, 91.2%, respectively. And they were 84.0%, 92.6%, 89.9%, 84.0%, and 92.6% by large-scale DWI, respectively. A receiver operating characteristic (ROC) analysis demonstrated that there was no statistical difference in ¹⁸F-FDG PET/CT and large-scale DWI (P>0.05). The area under ROC curve for ¹⁸F-FDG PET/CT and large-scale DWI were 0.911 and 0.883 respectively. The incidences of BM infiltration in aggressive NHL patients by ¹⁸F-FDG PET/CT (21/69, 30.4%) and large-scale DWI (23/69, 33.3%) were higher than those (PET/CT: 10.0%; large-scale DWI: 20.0%; P>0.05) in indolent NHL patients.</p><p><b>CONCLUSION</b>¹⁸F-FDG PET/CT and large-scale DWI had important clinical value in diagnosing BM infiltration of NHL. A combination of ¹⁸F-FDG PET/CT, large-scale DWI and pathological examination could improve the positive rate of BM infiltration in NHL.</p>