ABSTRACT
<p><b>BACKGROUND</b>Multi-detector computed tomography (MDCT) has already been the first line investigation method for diagnosis of pulmonary embolism (PE). Reducing the amount of contrast medium used during CT scanning could decrease the incidental rate of adverse reactions. Our study amied to evaluate the image quality of pulmonary arteries using 64 slice multi-detector CT with small volumes of contrast media injection.</p><p><b>METHODS</b>Forty nonconsecutive patients without PE or other lung diseases were randomly assigned to two groups. Group A underwent CT scanning with 16 x 1.25 mm collimation and a 70 ml contrast injection, while group B had CT with 64 x 0.625 mm collimation and 20 ml of contrast injection. Two readers independently depicted the segmental and subsegmental pulmonary arteries. Reasons we could not analyze the pulmonary artery or that led to misdiagnosis of pulmonary embolism were evaluated, including the degree of contrast enhancement of the main pulmonary artery, and factors that caused misdiagnosis of PE (flow-related artifacts, partial volume artifact, beam-hardening artifacts and enhancement of pulmonary vein). The independent samples t-test, Mann-Whitney U test and Pearson chi-square test were applied.</p><p><b>RESULTS</b>There were no significant differences in image quality of segmental and subsegmental arteries between the two groups. No significant difference was found for factors that made pulmonary arteries non-analyzable or in the misdiagnosis of PE, except the degree of contrast enhancement.</p><p><b>CONCLUSION</b>64 x 0.625 mm collimation with 20 ml contrast injection could depict the pulmonary arteries well.</p>
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Angiography , Methods , Contrast Media , Pulmonary Embolism , Diagnostic Imaging , Tomography, X-Ray Computed , Methods , UltrasonographyABSTRACT
Objective To investigate the effect of MRI in the evaluation of extra-capsular extension (ECE)of prostate cancer.Methods Preoperative MR imaging findings were correlated with histologic findings in 29 patients underwent radical prostatectomy regarding the ECE,the diagnostic accuracy was evaluated retrospectively.Results Histopathological results showed capsular penetration in 9 of 29 patients (31.0%).The sensitivity,specificity,positive predictive value,and negative predictive value of MR imaging were 3/9,90%(18/20),3/5 and 75%(18/24),respectively.The overall accuracy was 72.4% (21/29).Conclusion MR imaging has relatively low sensitivity and high specificity for diagnosis of ECE of prostate cancer,the accuracy is somewhat limited.
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Objective To study the relationship between renal morphology and renal function,and to assess the value of CT as a criterion to grade renal function.Methods Enhancement CT were performed in 89 patients with no local renal disease whose split renal glomerular filtration rates(GFR)were measured by renal dynamic imaging with ~(99)Tc~m-DTPA.The 178 kidneys were divided into normal renal function,mild and severe renal impairment groups according to renal function.Differences between three groups respect to the mean thickness of renal cortex and parenchyma were assessed by ANOVA.Using Pearson's correlation test,the correlation between the renal cortex,parenchyma thicknesses and renal GFR were examined.The value of CT in predicting renal function was assessed by using ROC analysis.Results The renal cortex thicknesses of normal renal function,mild and severe renal impairment groups were(5.9?1.1),(4.6? 1.1),and(3.3?1.0)mm respectively,and the renal parenchyma thicknesses were(26.3?4.2), (21.3?4.6),(16.2?4.6)mm.There were significant differences of renal cortex,parenchyma thicknesses between 3 groups(cortex F=54.78,P
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Objective To detect the change of cerebral perfusion in pediatric patients with Leigh's syndrome (LS)by using MR perfusion technique.Methods Twelve patients with Leigh's syndrome and thirteen normal children were scanned with the sequence of flow-sensitive alternating inversion recovery exempting separate T_1 measurement (FAIREST).Their relative cerebral blood flow(rCBF)values were obtained in regions of bilateral basilar nuclei and bilateral thalami.Student t-test was used to compare them between the two groups and receiver operating characteristic(ROC)curve analysis was carried out.Results Statistical analysis revealed significant difference between two groups in the regions of bilateral basilar nuclei and right thalamus(t =3.26,P =0.002;t =2.25 ,P =0.018 ;t =2.88 ,P =0.004,respectively).The rCBF values for LS group and control group were 0.432?0.158 and 0.619?0.125 for right basilar nuclear, 0.478?0.186 and 0.621?0.123 for left basilar nuclear,0.630?0.189 and 0.833?0.160 for right thalamus,respectively.The areas under the ROC curves were 0.833 and 0.756 for the rCBF of right and left basilar nuclear,respectively.Conclusion Relative CBF maps may reveal changes of cerebral blood flow in some specific brain regions in patients with Leigh's syndrome.It can provide additional information to the clinicians in the evaluation of the disease.