Explore the vast range of titles available.

Purpose To compare the spectral performance of four combinations of kVp available in a third generation dual‐source CT (DSCT) on abdominal imaging. Methods An image‐quality phantom was scanned with a DSCT using four kVp pairs (tube “A” voltage/tube “B” voltage): 100/Sn150 kVp, 90/Sn150 kVp, 80/Sn150 kVp, and 70/Sn150 kVp, classic parameters and dose level for abdomen examination (CTDIvol: 11 mGy). The noise power spectrum (NPS) and the task‐based transfer function (TTF) of two inserts were computed on virtual monochromatic images (VMIs) at 40/50/60/70 keV and for mixed, low‐, and high‐kVp images. Detectability index (d’) was computed on VMIs and mixed images to model the detection task of liver metastasis (LM) and hepatocellular carcinoma (HCC). Iodine quantification accuracy was assessed using the Root Mean Square Deviation (RMSDiodine) and the iodine bias (IB). Results Noise magnitude decreased by −55%± 0% between 40 and 70 keV for all kVp pairs. Compared to 70/Sn150 kVp, noise magnitude was increased by 9% ± 0% with 80/Sn150 kVp, by 16% ± 1% with 90/Sn150 kVp and by 24%± 1% with 100/Sn150 kVp. The average NPS spatial frequency (fav) shifted toward higher frequencies as energy level increased for all kVp pairs. Lowest fav values were found for 70/Sn150 kVp and highest for 100/Sn150 kVp. The value of TTF at 50% (f50) shifted toward lower frequencies with increasing energy level. The highest f50 values occurred for 100/Sn150 kVp and the lowest for 80/Sn150 kVp. For both lesions, d’ was highest for 70/Sn150 kVp and lowest for 100/Sn150 kVp. Compared to 70/Sn150 kVp, d’ decreased by −6% ± 3% with 80/Sn150 kVp, by −11% ± 2% with 90/Sn150 kVp and by −13%± 2% with 100/Sn150 kVp. For all acquisitions, the RSMDiodine and IB were the lowest for 100/Sn150 kVp (0.29 ± 0.10 mg/ml and 0.88 ± 0.30 mg/ml, respectively) and increased when the tube “A” voltage decreased (2.34 ± 0.29 mg/ml for 70/Sn150 kVp and 7.42 ± 0.51 mg/ml respectively). Conclusion 70/Sn150 kVp presented the lowest image noise and highest detectability in VMIs of two small focal liver lesions. 100/Sn150 kVp presented the lowest image noise on mixed images and highest accuracy of iodine quantification in iodine images.

Background: Two calcified objects recovered from an adolescent in a burial site in Amiens, France, have been previously identified as hydatid cysts using thin-section petrography. The importance of ancient hydatidosis besides the value of these unique archeological excavated materials encouraged the authors to look at this attractive subject more interdisciplinary by implementing medical radiology. Methods: In the current experiment, which has been carried out in the Radiology Department, Tehran Heart Center (THC), Tehran, Iran, the conventional and dual-energy dual-source CT-scan was used in studying the remaining structures of the two calcified masses. The imaging procedure was carried out based on X-Ray attenuation by two different tube voltages. Results: A high concentration of calcium sediment in the cyst walls was revealed in Hounsfield units, the measuring of the elements in CT. Taking advantage of implementing this imaging technique the oxalate calcium was also shown as the dominant component of the samples. The results were all in favor of diagnosing hydatid cysts. Conclusion: The achieved pictorial results in the present paper have highlighted the important role of CT scan as a noninvasive confirming technique in paleopathological investigations. Using Dual-source dual-energy CT-scan in reconfirming these previously identified hydatid cysts, is an encouraging message towards the necessity of sequential studies on invaluable biological excavated pieces.

This retrospective study was to compare the image quality of right coronary artery (RCA) and effective radiation dose on prospective ECG‐gated method between 320 row computed tomography (CT) and 2nd generation (128‐slice) dual source CT. A total of 215 candidates underwent CT coronary angiography using prospective ECG‐gated method, 120 patients enrolled in 320 row CT group, and 95 patients in dual source CT group. We divided RCA image quality scores as 1/2/3/4, which means excellent/good/adequate/not assessable and heart rates were considered, as well as the radiation dose. There is no statistically significant difference of RCA image quality of Score 1/2 between 320 row CT and 2nd generation dual source CT, but lower heart rate (<70/min) improved RCA image quality. Meanwhile, the 2nd generation dual source CT scan have significant lower radiation dose. For patients with high level heart rate variation, both prospective ECG‐gated method of 320 row CT scan (Toshiba) and 2nd generation dual source CT scan (Siemens) basically provided good image quality on RCA. There is an advantage of effective radiation dose reduction in prospective ECG‐gated method using the 2nd generation dual source CT scan. After the iodine contrast agent was injected into elbow vein, the threshold triggering method was used to carry out prospective gated scanning, and the acquired fault image was reconstructed by the standard post‐processing software of each manufacturer. The radiation dose value is obtained through the dose report automatically generated after each scan.

This chapter contains sections titled: Introduction Cardiac magnetic resonance imaging Cardiac computed tomography Radionuclide scintigraphy Plain film Conclusion References

(1) Background: To evaluate the diagnostic performance of a simulated ultra-low-dose (ULD), high-pitch computed tomography pulmonary angiography (CTPA) protocol with low tube current (mAs) and reduced scan range for detection of pulmonary embolisms (PE). (2) Methods: We retrospectively included 130 consecutive patients (64 ± 16 years, 69 female) who underwent clinically indicated high-pitch CTPA examination for suspected acute PE on a 3rd generation dual-source CT scanner (SOMATOM FORCE, Siemens Healthineers, Forchheim, Germany). ULD datasets with a realistic simulation of 25% mAs, reduced scan range (aortic arch—basal pericardium), and Advanced Modeled Iterative Reconstruction (ADMIRE®, Siemens Healthineers, Forchheim, Germany) strength 5 were created. The effective radiation dose (ED) of both datasets (standard and ULD) was estimated using a dedicated dosimetry software solution. Subjective image quality and diagnostic confidence were evaluated independently by three reviewers using a 5-point Likert scale. Objective image quality was compared using noise measurements. For assessment of diagnostic accuracy, patients and pulmonary vessels were reviewed binarily for affection by PE, using standard CTPA protocol datasets as the reference standard. Percentual affection of pulmonary vessels by PE was computed for disease severity (modified Qanadli score). (3) Results: Mean ED in ULD protocol was 0.7 ± 0.3 mSv (16% of standard protocol: 4.3 ± 1.7 mSv, p < 0.001, r > 0.5). Comparing ULD to standard protocol, subjective image quality and diagnostic confidence were comparably good (p = 0.486, r > 0.5) and image noise was significantly lower in ULD (p < 0.001, r > 0.5). A total of 42 patients (32.2%) were affected by PE. ULD protocol had a segment-based false-negative rate of only 0.1%. Sensitivity for detection of any PE was 98.9% (95% CI, 97.2–99.7%), specificity was 100% (95% CI, 99.8–100%), and overall accuracy was 99.9% (95% CI, 98.6–100%). Diagnoses correlated strongly between ULD and standard protocol (Chi-square (1) = 42, p < 0.001) with a decrease in disease severity of only 0.48% (T = 1.667, p = 0.103). (4) Conclusions: Compared to a standard CTPA protocol, the proposed ULD protocol proved reliable in detecting and ruling out acute PE with good levels of image quality and diagnostic confidence, as well as significantly lower image noise, at 0.7 ± 0.3 mSv (84% dose reduction).

The objective of the present study was to evaluate the application of dual-source CT perfusion imaging and MRI for the diagnosis of primary liver cancer. Sixty-three patients with primary liver cancer were selected between February 2015 and May 2016. All patients underwent examinations by dual-source CT perfusion imaging and MRI. The perfusion parameters of the focus center and normal liver parenchyma by CT examination and the hemodynamic parameters of the focus center and normal liver parenchyma by MRI examination were analyzed. The accuracy rates of the three detection methods (CT perfusion imaging, MRI, and combined examination) were analyzed and compared by ROC curves. Dual-source CT perfusion imaging revealed that blood flow and blood volume of the focus center were significantly higher than those of normal liver parenchyma (P<0.05). MRI examination showed that hepatic arterial perfusion and hepatic perfusion index of the focus center were significantly higher than those of normal liver parenchyma; portal venous perfusion of the focus center was significantly lower than that of normal liver parenchyma (P<0.05); the difference in total liver perfusion between the focus center and normal liver parenchyma was not significant (P>0.05); the accuracy rates of CT perfusion imaging, MRI, and combined examination were 76.19, 85.71, and 95.24% respectively; the area under the curve of CT perfusion imaging was 0.753 (P<0.05), the sensitivity was 79.2% and the specificity was 74.7%; the area under the curve of MRI was 0.846 (P<0.05), the sensitivity was 84.6%, and the specificity was 80.5%; the area under the curve of CT combined with MRI was 0.947 (P<0.05), the sensitivity was 94.6%, and the specificity was 86.5%. In conclusion, the effect of dual-source CT perfusion imaging combined with MRI for examination of primary liver cancer is superior to that of single use of CT or MRI, and has high clinical application and popularization value.

Background To evaluate the ability of low radiation dose dual-source computed tomography (DSCT) to depict the features of morphological univentricular heart and to define accuracy by comparing findings with surgery. Methods Low radiation dose dual-source cardiac computed tomography (CCT) of 33 cases of functional univentricular heart preliminary diagnosis by echocardiography compared with the results of surgery were retrospectively analyzed (aged 1 day to 4 years, median 5 months). The appropriate dose reduction strategies and iterative reconstruction were applied. Results Thirty three univentricular heart patients were classified into three types according to Anderson’s classification method, including 16 cases (48.5%) univentricular of right ventricular type with rudimentary chamber of left ventricle, 11 cases (33.3%) univentricular of left ventricular type with rudimentary chamber of right ventricle and 6 cases (18.2%) univentricular heart of indeterminate type without rudimentary chamber. The extracardiac malformation such as hypoplastic aortic arch, coronary artery fistula, total anomalous pulmonary venous returns or hypoplastic lung were presented frequently. The overall sensitivity and specification of cardiac CT was 100% compared to the results of surgery. The procedural dose-length product was 18 ± 5 mGy-cm, and unadjusted and adjusted radiation doses were 0.25 and 0.64 mSv, respectively. Conclusion Cardiac CT can diagnose accurately and be performed with a low radiation exposure in patients with the functional univentricular heart disease. The aorta, pulmonary artery and lung can be evaluated completely and simultaneously as well. Cardiac CT is an effective advanced non-invasive imaging modality to comprehensive evaluation the functional univentricular heart patients, particularly if cardiac MRI poses a high risk or is contraindicated.

Background：Accurate assessment of intra-as well as extra-cardiac malformations and radiation dosage concerns are especially crucial to infants and children with interrupted aortic arch （IAA）.The purpose of this study is to investigate the value of prospective electrocardiogram （ECG）-triggered dual-source computed tomography （DSCT） angiography with low-dosage techniques in the diagnosis of IAA.Methods：Thirteen patients with suspected IAA underwent prospective ECG-triggered DSCT scan and transthoracic echocardiography （TTE）.Surgery was performed on all the patients.A five-point scale was used to assess image quality.The diagnostic accuracy ofDSCT angiography and TTE was compared with the surgical findings as the reference standard.A nonparametric Chi-square test was used for comparative analysis.P＜0.05 was considered as a significant difference.The mean effective radiation dose （ED） was calculated.Results：Diagnostic DSCT images were obtained for all the patients.Thirteen IAA cases with 60 separate cardiovascular anomalies were confirmed by surgical findings.The diagnostic accuracy of TTE and DSCT for total cardiovascular malformations was 93.7％ and 97.9％ （P＞0.05）,and that for extra-cardiac vascular malformations was 92.3％ and 99.0％ （P ＜ 0.05）,respectively.The mean score of image quality was 3.77 ± 0.83.The mean ED was 0.30 ± 0.04 mSv （range from 0.23 mSv to 0.39 mSv）.Conclusions：In infants and children with IAA,prospective ECG-triggered DSCT with low radiation exposure and high diagnostic efficiency has higher accuracy compared to TTE in detection of extra-cardiac vascular anomalies.

The purpose of this study was to investigate the impact of the presence of one or more premature ventricular contractions (PVCs) during coronary calcium score scan (CS) on image quality and accuracy of subsequent dual-source coronary CT angiography (DS CCTA). Fifty-three out of 502 patients showed one or more PVCs during CS and built the study group. Sixty consecutively registered patients with sinus rhythm formed the control group. Two independent, blinded readers classified 1,723 coronary artery segments as being of diagnostic or non-diagnostic image quality. All segments with diagnostic image quality were assessed for the presence for significant coronary artery stenosis. Accuracy was calculated using conventional angiography as standard of reference. The percentage of DS CCTA data sets with diagnostic image quality was significantly lower in the study group (79.2%) compared to the control group (90.6%, P  < 0.05). The rate of coronary segment with diagnostic image quality was highly significant lower in the study group (89.5%; n  = 723/808) compared to the control group (99.4%; n  = 908/915; P  < 0.001). However, accuracy did not differ in both groups. Significant correlation between non-diagnostic image quality and mean HR was only found in the study group ( P  = 0.019). The presence of one or more PVCs during CS does not affect accuracy but impairs image quality of subsequent DS CCTA. Mean HR is a predictor of non-diagnostic data sets only in the study group, suggesting more aggressive HR control could be beneficial.