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1.

Objective

Prospective evaluation of optimal MR arthrographic concentration of two gadolinium-based agents of different relaxivities, either in saline or iodinated carriers at 1.5, 3 and 7 T field strengths was evaluated in vitro.

Materials and methods

At 1.5, 3.0 and 7.0 T, gadobenate and gadoteridol were studied at different concentrations in both normal saline and iodinated contrast. IRT1W and multi-echo T2FSE sequences were obtained. Signal–concentration relationship of both used agents in different carriers and field strengths was plotted from their collected T1 and T2 values, as well as their derived longitudinal (r1) and transverse (r2) relaxivities.

Results

Significant increase in T1 signal intensity (p < 0.001) of both gadobenate and gadoteridol was observed in higher fields of 3 T and 7 T, stronger for gadoteridol. Contrarily, gadoteridol showed a significantly lesser decrease (p < 0.0001) of T2 signal intensity with increasing field from 3 T to 7 T.Iodinated carriers significantly diminished T2 signal intensity (p < 0.0001) except for highest concentration (10 mmol/L) (p = 0.8899) while this was only significant (p = 0.0279) between extreme concentrations for T1 signal.

Conclusion

On transitioning to high-field (3 T and 7 T) MR arthrography, keeping the least amount of iodine for intra-articular contrast delivery, and when choice is available, gadoteridol is preferable to gadobenate. However, gadobenate was still optimal at 3 T.  相似文献   

2.

Aims

The present study evaluated the effects of BCAA supplementation on exercise performance of pregnant rats.

Methods

In order to assess these effects, Wistar rats were divided into four groups: sedentary not-supplemented (SNS, n = 8); sedentary supplemented (SS, n = 8); trained not-supplemented (TNS, n = 8) and trained supplemented (TS, n = 8). All groups were submitted to the endurance test until exhaustion (ET) and post-effort lactate (PEL) determination before pregnancy (ET-B and PEL-B) and at the 19th day of pregnancy (ET-19 and PEL-19).

Results

The endurance training significantly increased the ET time to exhaustion (p < 0.05). Regardless of BCAA supplementation, both endurance trained groups (TS and TNS) showed a longer time to exhaustion, assessed by ET, compared with the sedentary groups (SS and SNS) (p < 0.05). In the TNS, ET-19 time to exhaustion decreased when compared with the period before pregnancy. On the other hand, ET-19 time to exhaustion was not affected in the TS at the end of the pregnancy period. In addition, TS showed a marked PEL-19 reduction when compared with PEL-B. The data presented herein suggest that BCAA supplementation plays an ergogenic role in the maintenance of exercise performance during pregnancy in rats.  相似文献   

3.

Introduction

Our goal is to study the effects of tennis practice in pre-pubescent boys on bone remodeling, by means of enzyme activity involved in balance of matrix remodeling (MMP2 and MMP9).

Results

Mineral bone density has been found higher in the dominant arm (P < 0.0001) as well as MMP2 and MMP9 levels in plasma (P < 0.05).

Conclusion

Tennis practice in children increases bone remodeling, which can be assessed by MMP dosage, in addition of densitometry technique.  相似文献   

4.

Aims of the study

The aim of this study is to investigate the behavior of the physiological, biochemical and psychological parameters in Brazilian soccer players during a training program.

Materials

Fifteen athletes were evaluated at the beginning (T1), in the middle (T2) and at the end (T3) of the training program. On the first day, at 7:30 am, before the blood collecting at rest for the determination of serum creatine kinase (CK), serum creatinine and serum urea, the athletes had their psychological parameters assessed by the profile of mood state questionnaire (POMS). After 90 min, they performed a 250-m sprint. On the second day at 8:30 am, the athletes had their alactic anaerobic performance measured and, after 40 min, they completed the aerobic test. Friedman test was used to verify the behavior of overtraining markers.

Results

There was a decrease in vigor score in T3 (p = 0.01) compared with T1 and T2. In T3 (p = 0.01), the athletes also showed an increase in serum creatinine levels compared to T1. Furthermore, in the same period, we verified a diminishing in the team performance.

Conclusion

The training program developed between T2 and T3 led to the fall of the vigor score, the increase in serum creatinine concentrations and the diminishing in team performance.  相似文献   

5.

Purpose

To assess the influence of experience and training on the proficiency in coronary CT angiography (CCTA) interpretation of practitioners with different levels of experience.

Methods and materials

Nine radiologist and cardiologist observers with varying prior CCTA experience ranging from novice to expert independently analyzed two case series of 50 catheter-correlated CCTA studies for coronary artery stenosis (0%, ≤49%, 50–74%, 75–99%, or 100%). Results of the first case series were unblinded and presented along with catheter angiography results to each reader before proceeding to the second series. Diagnostic accuracy on a per-segment basis was compared for all readers and both case series, respectively.

Results

Correlation coefficients between CCTA and catheter angiography initially ranged between good (r = 0.87) and poor (r = 0.26), depending on reader experience, and significantly (p < 0.05) improved in the second case series (range: r = 0.42 to r = 0.91). Diagnostic accuracy was significantly (p < 0.05) higher for more experienced readers (range: 96.5–97.8%) as compared to less experienced observers (range: 90.7–93.6%). After completion of the second case series for less experienced readers sensitivity and PPV significantly (p < 0.05) improved (range: 62.7–67.8%/51.4–84.1%), but still remained significantly (p < 0.05) lower as compared to more experienced observers (range: 89.8–93.3%/80.6–93.3%).

Conclusion

The level of experience appears to be a strong determinant of proficiency in CCTA interpretation. Limited one-time training improves proficiency in novice readers, but not to clinically satisfactory levels.  相似文献   

6.

Aim

The aim of the study was to compare aerobic and anerobic abilities of prepubertal children and adults with the critical power concept.

Methods

Sixteen children (10.3 ± 0.9 years) and 15 adults (23.5 ± 3.6 years) performed five tests: a maximal-graded test and four constant load exercises until exhaustion. Critical power (CP) and anaerobic-work capacity (CTA) were determined from the power-1/time (P-t) linear relationship.

Results

Determination coefficients for P-t were 0.94 ± 0.05 in children and 0.96 ± 0.04 in adults. PC values were significantly (p < 0.01) lower in children (2.7 ± 0.4 W/kg) than in adults (3.1 ± 0.3 W/kg). CTA values were significantly (p < 0.001) lower in children (136.4 ± 50.8 J/kg) than in adults (247.1 ± 45.7 J/kg).

Conclusion

Satisfying determination coefficients for CP and CTA were found in children and adults. Children have a lower CP and CTA than adults. This result is in accordance with literature.  相似文献   

7.

Aim

This study examined the effects of 12 weeks of walking programs on serum lipids, high-sensitive C-reactive protein, and lipoprotein-associated phospholipase A2.

Methods

Twenty-six pre-menopausal women (30–49 years) completed 12 weeks of walking programs either at moderate or high intensity (50–55%, 70–75% maximum heart rate reserve, respectively). Estimated maximal oxygen consumption was assessed with a 2-km walking test; body composition, blood lipids, high-sensitive C-reactive protein, and lipoprotein-associated phospholipase A2 were measured before and after the study.

Results

Maximal oxygen consumption increased, favoring high-intensity group; body weights, percent body fat (p < 0.01) and body mass index (p < 0.05) decreased in both exercise groups. There were no significant changes in the measured blood lipids in any of the groups, except for a significant reduction in low-density lipoprotein-cholesterol in high-intensity group (p < 0.05). High-sensitive C-reactive protein and lipoprotein-associated phospholipase A2 levels reduced significantly in high-intensity (p < 0.01) and moderate-intensity (p < 0.05) groups, which were also different from the changes in the control group.

Conclusion

Walking programs with different intensity result in favorable changes; however, for protective effects against cardiovascular diseases, high-intensity walking may be advised due to greater reductions in low-density lipoprotein-cholesterol, and high-sensitive C-reactive protein and lipoprotein-associated phospholipase A2.  相似文献   

8.

Aim

To evaluate the effect of the anaerobic exercise on the enzymatic antioxidant statute in judokas’ regional level, because the effects of anaerobic exercise on the free radicals and antioxidants are relatively rare and have some divergences.

Materials and methods

We made this study on ten male judokas (age = 18.1 ± 1.6 years; weight = 77.2 ± 11.6 kg; height = 176.4 ± 4.6 cm), which carried out 30 seconds anaerobic capacity test (Wingate test). Blood samples were taken, by an intravenous catheter, at rest (R), immediately after the Wingate test (P0) then five minutes later (P5), 10 minutes later (P10) then 20 minutes later (P20). The measured parameters are: the superoxide dismutase (SOD), the glutathion peroxidase (GPx) and the total antioxidant statute (SAT).

Results

The concentration of the SOD increases significantly (p < 0.05) at (P0); and regains the baseline values at (P20). The concentration of GPx increases significantly (p < 0.05) in (P0); in (P10) GPx reaches the baseline values. No significant effect of the anaerobic exercise was observed on the concentration of the SAT. Positive correlation was observed between the SOD and GPx to p < 0.05.

Conclusion

The anaerobic exercise modifies the activity of the antioxidant enzymes with different kinetics.  相似文献   

9.

Objective

This study aimed at determination of the MRI predictors of triple negative breast cancer (TNBC) in comparison to other breast cancer subtypes.

Materials and methods

The study retrospectively enrolled 185 female patients with 206 pathologically confirmed invasive breast cancers with different subtypes by immunohistochemistry. Histopathological analysis as well as MRI features of TNBC was compared to those of other breast cancer subtypes. MRI features included the tumor size, shape, margin, internal enhancement, intratumoral signal intensity on T2-WI, detectability by DW-MRI and ADC values.

Results

TNBCs showed higher histological grades (p < 0.0001) and younger patient age group (p = 0.006) compared to other tumor subtypes. At MRI, TNBCs were of larger size (p < 0.0001), round shape (p < 0.0001), smooth margin (p < 0.0001), with rim enhancement (p < 0.0001) and higher incidence of T2-WI tumoral hyperintensity (p = 0.0002) and intratumoral necrosis (p < 0.0001). No significant difference in tumor detectability was found by DW-MRI, however, TNBCs had higher ADC values (p < 0.0001).

Conclusion

In our study, TNBC patients were of younger age with higher grade malignancy. TNBC MRI predictors were unifocal rim enhancing mass with round shape, smooth margin, higher signal intensity on T2-WI, in addition to relatively larger sizes of tumors associated with high incidence of intratumoral necrosis and higher ADC values.  相似文献   

10.

Purpose

Chronic progressive neuro-Behçet's disease (CPNBD) resembles multiple sclerosis (MS) on patient background and image findings, and therefore is difficult to diagnose. The purpose is to identify the characteristic magnetic resonance imaging (MRI) findings of CPNBD and to clarify the differences between the MRI findings of CPNBD and those of MS.

Materials and methods

The subjects consist of a CPNBD group (n = 4; 1 male and 3 females; mean age, 51 y.o.), a MS group (n = 19; 3 males and 16 females; mean age, 45 y.o.) and a normal control group (n = 23; 10 males and 13 females; mean age, 45 y.o.). Brain stem atrophy, cerebellar atrophy, and leukoencephalopathy were retrospectively evaluated in each subjects. In middle sagittal brain MR images, the prepontine distance was measured as an indirect index of brain stem and cerebellar atrophy and the pontine and mesencephalic distance was measured as a direct index of brain stem atrophy. These indexes were statistically analyzed.

Results

Brain stem atrophy, cerebellar atrophy, and leukoencephalopathy were seen in all CPNBD cases. Prepontine distance was significantly different between the CPNBD group and the MS group (p < 0.05), and between the CPNBD group and the normal control group (p < 0.001). Pontine and mesencephalic distance were significantly different between the CPNBD group and the MS group (p < 0.001, p < 0.01 respectively), and between the CPNBD group and the normal control group (p < 0.001).

Conclusions

Chronic progressive neuro-Behçet's disease should be considered in patients with brain stem and cerebellar atrophy in addition to leukoencephalopathy similar to that seen in multiple sclerosis.  相似文献   

11.

Backgroung

Previous studies showed that maximal oxygen uptake and maximal heart rate were not different during prolonged fasting (ramadan) compared to normal feeding period. However, the effect of ramadan on the blood pressure response during incremental exercise has not been investigated.

Objective

This study aimed to evaluate the evolution of blood pressure during incremental trial in ramadan period.

Methods

Twelve young trained male aged 24 ± 4 yrs participated as voluntary subjects. Their anthropometric parameters, maximal aerobic power and maximal heart were measured in fasting and in normal feeding periods during incremental trial on cycle ergometer.

Results

No significant difference was observed in any anthropometric parameter. Maximal aerobic power of fasting period was significantly less (P < 0,05) compared to normal feeding. Heart rate at rest, at maximal exercise and during a 15 min period of recovery was not significantly affected. Systolic blood pressure of fasting period at maximal power was significantly lower than during the control period (P < 0,05).

Conclusion

Ramadan negatively influences the capacity of maximal power and cardiovascular response at maximal power.  相似文献   

12.

Objective

To prospectively compare subjective and objective image quality in 20% tube current coronary CT angiography (cCTA) datasets between an iterative reconstruction algorithm (SAFIRE) and traditional filtered back projection (FBP).

Materials and methods

Twenty patients underwent a prospectively ECG-triggered dual-step cCTA protocol using 2nd generation dual-source CT (DSCT). CT raw data was reconstructed using standard FBP at full-dose (Group_1a) and 80% tube current reduced low-dose (Group_1b). The low-dose raw data was additionally reconstructed using iterative raw data reconstruction (Group_2). Attenuation and image noise were measured in three regions of interest and signal-to-noise-ratio (SNR) as well as contrast-to-noise-ratio (CNR) was calculated. Subjective diagnostic image quality was evaluated using a 4-point Likert scale.

Results

Mean image noise of group_2 was lowered by 22% on average when compared to group_1b (p < 0.0001–0.0033), while there were no significant differences in mean attenuation within the same anatomical regions. The lower image noise resulted in significantly higher SNR and CNR ratios in group_2 compared to group_1b (p < 0.0001–0.0232). Subjective image quality of group_2 (1.88 ± 0.63) was also rated significantly higher when compared to group_1b (1.58 ± 0.63, p = 0.004).

Conclusions

Image quality of 80% tube current reduced iteratively reconstructed cCTA raw data is significantly improved when compared to standard FBP and consequently may improve the diagnostic accuracy of cCTA.  相似文献   

13.

Objectives

To compare the effectiveness of dark blood (DB) versus bright blood (BB) sequences. To assess the intra and inter-observer variability and inter-study reproducibility between BB versus DB. To evaluate image quality level in the two sequences.

Methods

In a setting of 138 patients we performed CMR using cardiac gated Gradient-multiecho single breath-hold BB and DB sequences in the middle ventricular septum.Each acquisition was repeated during the same exam. Truncation method was used to account for background noise. Image quality (IQ) was assessed using a 5 point grading scale and image analysis was conducted by 2 experienced observers.

Results

Compared with the conventional BB acquisition, the coefficient of correlation and significance of the DB technique was superior for intra-observer reproducibility (p < 0.001), inter-observer reproducibility (p < 0.001) and inter-study reproducibility (p < 0.001). The variability is also lower for DB sequences for T2* values <14 ms. Assessment of artifacts showed a superior score for DB versus BB scans (4 versus 3, p < 0.001).

Conclusions

Improvement in terms of inter observer and inter study variability using DB sequences was obtained. The greatest disparity between them was seen in inter-study reproducibility and higher IQ in DB was seen.Study demonstrates better performance of DB imaging compared to BB in presence of comparable effectiveness.  相似文献   

14.

Background

Diffusion weighted magnetic resonance imaging (DWI) and dynamic contrast-enhanced (DCE) MRI have been considered useful for pathological staging and histological grading in bladder cancer. To our knowledge, no study has combined the two imaging modalities together to assess aggressiveness of bladder cancer.

Objective

To assess the clinical aggressiveness of bladder cancer with DCE MRI and DWI at 3.0 T.

Materials and methods

A total of 59 patients with 69 pathologically confirmed tumor lesions were included in this study. All patients underwent MR examination at 3.0 T basing on DWI and DCE imaging. Tumor staging and histological grade were evaluated. The aggressiveness of bladder cancer was classified as low-, intermediate-, or high-aggressiveness according to its pathological phenotype. Apparent diffusion coefficient (ADC) value and semi-quantitative parameters (wash-in rate and wash-out rate) were determined. The correlation between clinical aggressiveness and ADC value, wash-in rate and wash-out rate were analyzed. In addition, the diagnostic accuracy of the diffusion and semi-quantitative parameters were estimated using receiver operating characteristic curve (ROC).

Results

Aggressiveness of bladder cancer is negatively correlated with ADC value (r = −0.705, p < 0.0001) and wash-out rate (r = −0.719, p < 0.0001). The tumor ADC value is positively correlated with wash-out rate (r = 0.555, p < 0.0001). The diagnostic specificity and accuracy using tumor ADC value and wash-out for the tumor with size <24 mm were better than that tumors with size ≥24 mm. The sensitivity, specificity and accuracy of ADC and wash-out rate in combination in diagnosis of bladder cancer aggressiveness were 96.7%, 94.9% and 95.7%, respectively. ROC curve revealed the diagnostic performance of aggressiveness of bladder cancer using ADC value and wash-out rate were 0.928 (cut-off value: 0.905 × 10−3 mm2/s) and 0.891 (cut-off value: 0.685 min−1), respectively.

Conclusion

ADC and wash-out rate derived from DWI and DCE-MRI at 3.0 T have good potential to assess the aggressiveness of bladder cancer and the accuracy was greater for ADC than for semi-quantitative parameters.  相似文献   

15.

Purpose

To test our hypothesis that distension and displacement in various segments of the healthy thoracic aorta are significant and can be predicted based on clinical characteristics.

Materials and methods

Sixty-one Caucasian volunteers without cardiovascular disease (49 ± 16 years, range 19–82; 28 men, 33 women) divided into two age groups (A: <50, B: ≥50 years) underwent 1.5-T MRI. ECG-gated dynamic data sets were acquired at five locations perpendicular to the thoracic aorta. Aortic distension and Centre of Mass (CoM) displacement were determined as percentages of diastolic aortic diameter. A multiple linear regression model including age group, gender, location, mean arterial blood pressure, heart rate and body mass index was tested.

Results

Mean aortic distension averaged over all locations was 11.2 ± 4.1% (age group A) and 6.7 ± 3.3% (age group B), mean displacement 15.1 ± 8.3% (A) and 11.0 ± 6.2% (B). Systolic and diastolic aortic diameter and CoM position significantly differed at all locations (p < 0.001). Distension and displacement could be predicted based on the regression model (p < 0.001). Age group A and women exhibited significantly greater distension and displacement compared to age group B (p < 0.001) and men (p < 0.01), respectively. Distension increased, displacement decreased from proximal to distal.

Conclusion

Distension and translational displacement are significant at all levels of the thoracic aorta and can be predicted based on clinical characteristics.  相似文献   

16.

Purpose

The effects of vitamins and minerals complex supplementation on maximal voluntary contraction decrease (FMV) and biological markers following an eccentric exercise at old people.

Method

Sixteen elderly subjects took either placebo (Pl group) or vitamins and minerals (Isoxan Senior, NHS, Rungis, France) (group S) for 21 d before an eccentric exercise and for 3 d after the exercise. The FMV and surface EMG activity (RMS) of the vastus lateralis (VL), vastus médialis (VM) and rectus fémoris (RF) were recorded before (Pre), immediately after (Post), 24 h (Post 24) and 48 h (Post 48) after the exercise. CCVThe creatine kinase (CK), lactate déshydrogénase, malondialdéhyde, and tumor necrosis Factor (TNFα) levels were analyzed.

Results

The reduced MVC (S: 11,2 ± 4,8%; Pl: 17,8 ± 10,4%, P < 0,01) after exercise was associated with a significant reduction in RMS VL, RMS VM and RMS RF values for both groups. A faster FMV recovery appeared at 48 h for the S group (P < 0.05). CK and TNFα values increased in post-exercise.

Conclusion

A dietary supplementation of a vitamin and mineral complex does not attenuate the loss of contractile function immediately after the running exercise, and it may accelerate the recovery of maximal force capacity after 48 h by limiting the post-exercise pro-inflammatory processes.  相似文献   

17.

Introduction

To compare the diagnostic performance and inter-observer reproducibility of CT and MRI in detecting colorectal liver metastases (CRLM) of observers with different levels of experience.

Materials and methods

Data from 51 CT and 54 MRI examinations of 105 patients with CRLM were analysed. Intraoperative and histopathological findings served as the reference standard. Analyses were performed by four observers with varying levels of experience regarding imaging of CRLM (reviewers A, B, C and D with respectively >20, >5, <1 and 0 years of experience). Per-segment sensitivity, specificity, Cohen's kappa (κ) for diagnosed segments and Intra-class Correlation Coefficients (ICC) for reported number of lesions were calculated.

Results

CT sensitivity and specificity was for reviewer A 89.71%/94.41%, B 78.50%/88.37%, C 63.55%/85.58%, D 84.11%/78.60% and regarding MRI A 90.40%/95.43%, B 74.40%/90.04%, C 60.00%/85.89% and D 65.60%/75.90%. The overall inter-observer agreement was higher for CT (κ = 0.43, p < 0.001; ICC = 0.75, p < 0.001) than MRI (κ = 0.38, p < 0.001; ICC = 0.65, p < 0.001). The experienced reviewers A and B achieved better agreement for MRI (κ = 0.54, p < 0.001; ICC = 0.77, p < 0.001) than CT (κ = 0.52, p < 0.00; ICC = 0.76, p < 0.001) unlike the less experienced C and D (MRI κ = 0.38, ICC = 0.63 and CT κ = 0.41, ICC = 0.74, respectively, p < 0.001).

Conclusions

The proficiency in detection of CRLM is significantly influenced by observer experience, although CT interpretation is less affected than MRI analysis.  相似文献   

18.

Purpose

The purpose of this study was to compare the diagnostic accuracies of CT and MR imaging for the detection of metastatic retropharyngeal lymph nodes (RLNs) in patients with nasopharyngeal and oropharyngeal squamous cell carcinoma (SCC).

Materials and methods

The study included 38 patients (28 men and 10 women; mean age, 65 years; age range, 48–82 years) with nasopharyngeal (n = 15) and oropharyngeal (n = 23) SCC who underwent both contrast-enhanced CT and MR imaging before chemoradiotherapy. RLNs were classified as malignant or benign on the basis of the results of follow-up MR imaging. Two radiologists independently evaluated the images for diagnosing metastatic RLNs.

Results

Among a total of 68 RLNs (minimum diameter, ≥4 mm) that were detected on gadolinium-enhanced fat-suppressed T1-weighted images, 30 (44%) were malignant and 38 (56%) were benign. The sensitivities of CT versus MRI were 60% versus 97% for observer 1 (p < 0.01) and 37% versus 90% for observer 2 (p < 0.01). The specificities of CT versus MRI were 92% versus 97% for observer 1 (p = 0.50) and 92% versus 100% for observer 2 (p = 0.25). The areas under the receiver operating characteristic curve (AUC) for CT versus MRI were 0.788 versus 0.996 for observer 1 (p < 0.01) and 0.693 versus 0.961 for observer 2 (p < 0.01).

Conclusion

MR imaging was superior to CT for the detection of metastatic RLNs.  相似文献   

19.

Objective

The aim of this study was to elaborate and validate a specific test to evaluate the physical condition of judo players.

Subjects and methods

Twenty-three volunteers, males, aged 22 ± 3.62 years old took part in our experiment. They did the progressive test of Leger et al. (1984), vertical Jump test (Sargent test), Australian shuttle run test and a specific judo test.

Results

The observed results showed significant correlations between muscular power and the number of Uchi-komi on the judo test reference scale (R = 0.52, P < 0.01). Furthermore, there were other correlations between the number of Uchi-komi at the two first sets of specific judo test and the anaerobic power represented by the distance covered in 30s at the Australian shuttle test (R = 0.86, P < 0.01), also between the anaerobic capacity represented by the whole distance covered and the total number of Uchi-komi achieved at the judo test (R = 0.88, P < 0.01).

Conclusion

The test reproduces the physiological characteristics of judo fight. It is a good indicator of the judoka's physical fitness and their cardiovascular adaptation in a physical effort.  相似文献   

20.

Objectives

To compare objective image quality indices in dual-energy CT angiography (DE-CTA) studies of the abdomen and lower extremity using conventional polyenergetic images (PEIs) and virtual monoenergetic images (MEIs) at different kiloelectron volt (keV) levels.

Methods

We retrospectively evaluated 68 dual-source DE-CTA studies. 50 patients (42 men, 71 ± 10 years) underwent abdominal DE-CTA. 18 patients (13 men, 67 ± 10 years) underwent lower extremity DE-CTA. MEIs from 40 to 120 keV were reconstructed. Signal intensity, noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were assessed in infrarenal aorta, superior mesenteric, external iliac, femoral, popliteal, and lower leg arteries. Comparisons between MEIs and PEIs were performed with Dunnett's test.

Results

222 arteries were evaluated. In abdominal arteries 70 keV MEIs showed statistically equal signal intensity, noise and CNR levels (+13%; +31%, −14% on average; all p > 0.05) compared to PEIs; SNR was equal or slightly impaired (−7% on average; p < 0.001–1.00). In lower extremity arteries 60 keV MEIs resulted in significantly higher signal intensity and CNR (+54%; +54% on average; all p < 0.05) compared to PEIs at equal noise levels (+18% on average; all p > 0.05) and equal or higher SNR (+49% on average; p < 0.01–0.35).

Conclusions

Low-keV MEIs lead to equal or higher signal intensity and CNR compared to PEIs. In lower extremity DE-CTA, additional reconstruction of low-keV MEIs at 60 keV might increase diagnostic confidence.  相似文献   

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