Assessment of Acute Pulmonary Embolism by Computer-Aided Technique: A Reliability Study.

BACKGROUND Acute pulmonary embolism is one of the most common cardiovascular diseases. Computer-aided technique is widely used in chest imaging, especially for assessing pulmonary embolism. The reliability and quantitative analyses of computer-aided technique are necessary. This study aimed to evaluate the reliability of geometry-based computer-aided detection and quantification for emboli morphology and severity of acute pulmonary embolism. MATERIAL AND METHODS Thirty patients suspected of acute pulmonary embolism were analyzed by both manual and computer-aided interpretation of vascular obstruction index and computer-aided measurements of emboli quantitative parameters. The reliability of Qanadli and Mastora scores was analyzed using computer-aided and manual interpretation. RESULTS The time costs of manual and computer-aided interpretation were statistically different (374.90±150.16 versus 121.07±51.76, P<0.001). The difference between the computer-aided and manual interpretation of Qanadli score was 1.83±2.19, and 96.7% (29 out of 30) of the measurements were within 95% confidence interval (intraclass correlation coefficient, ICC=0.998). The difference between the computer-aided and manual interpretation of Mastora score was 1.46±1.62, and 96.7% (29 out of 30) of the measurements were within 95% confidence interval (ICC=0.997). The emboli quantitative parameters were moderately correlated with the Qanadli and Mastora scores (all P<0.001). CONCLUSIONS Computer-aided technique could reduce the time costs, improve the and reliability of vascular obstruction index and provided additional quantitative parameters for disease assessment.

A three-dimensional approach for identifying small pulmonary vessels in smokers.

BACKGROUND: This study aims to develop a computerized scheme that utilizes a differential geometric approach to identify pulmonary vessels and then evaluate the performance of the scheme on the CT images of heavy smokers. METHODS: The scheme consists of two primary steps to segment entire lung vascular tree and identify the number of pulmonary vessels in a cross section. The scheme performance including accuracy, consistency, and efficiency was assessed using 102 chest CT scans. Further assessment was performed on the relationship between pulmonary vessels and the extent of emphysema as well as pulmonary artery alteration. RESULTS: The mean number of vessels in the cross section at the 5th generation was 17.84±4.74 and 17.23±4.85 assessed by computerized scheme and radiologists, respectively, which are significantly different (t = 2.12, p = 0.055). The results were consistent with those obtained by using a semi-automatic tool (r = 0.75, p = 0.01). In addition, in the 5th generation, the mean number of vessels was inversely related to the percentage of the low attenuation area (r = -0.704, p = 0.000), the mean lumen area of pulmonary vessel was inversely related to the mean value of main pulmonary artery diameter (r = -0.617, p = 0.000). The computational time of segmenting vessels was 6.50±0.02 seconds, which is much less than the average 8 minutes of the time spent by radiologists using the semi-automatic tool. CONCLUSION: Applying the computerized scheme yields reasonable performance on the segmentation of pulmonary vessels. The alteration of pulmonary vessels may reflect the presence of pulmonary hypertension, as well as the extent of emphysema.

The Combination of Diffusion- and T2-Weighted Imaging in Predicting Deep Myometrial Invasion of Endometrial Cancer: A Systematic Review and Meta-Analysis.

OBJECTIVE: The aim of this study was to explore the diagnostic difference among the combination of diffusion-weighted imaging (DWI) and T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) in predicting deep myometrial invasion of endometrial cancer. METHODS: A structured search was conducted to identify published studies between January 2005 and April 2014, which assessed depth of myometrial invasion in endometrial cancer by using DCE-MRI or DWI or DWI-T2WI. RESULTS: A total of 15 studies were included. Significant difference was found between DWI-T2WI and DWI in pooled specificity, and also in comparison between DCE-MRI and DWI-T2WI (P < 0.05). In summary, receiver operating characteristic analysis, area under the curve for DWI-T2WI, DWI, and DCE-MRI were 0.94, 0.90, and 0.93, respectively. CONCLUSIONS: Diffusion-weighted imaging-T2WI can improve diagnostic performance in comparison with DWI alone. Meanwhile, DWI-T2WI performs better than DCE-MRI in predicting myometrial invasion of endometrial cancer. It may be an alternative for DCE-MRI in presurgical staging of endometrial cancer.

Fluorodeoxyglucose positron emission tomography and chemotherapy-related tumor marker expression in non-small cell lung cancer.

BACKGROUND: The chemotherapy resistance of non-small cell lung cancer (NSCLC) remains a clinic challenge and is closely associated with several biomarkers including epidermal growth factor receptor (EGFR) ( Drugs 72(Suppl 1):28-36, 012.), p53 ( Med Sci Monit 11(6):HY11-HY20, 2005.) and excision repair cross complementing gene 1 (ERCC1) ( J Thorac Oncol 8(5):582-586, 2013.). Fluorodeoxyglucose positron emission tomography (FDG-PET) is the best non-invasive surrogate for tumor biology with the maximal standardized uptake values (SUVmax) being the most important paradigm. However, there are limited data correlating FDG-PET with the chemotherapy resistant tumor markers. The purpose of this study was to determine the correlation of chemotherapy related tumor marker expression with FDG-PET SUVmax in NSCLC. METHODS: FDG-PET SUVmax was calculated in chemotherapy naïve patients with NSCLC (n=62) and immunohistochemical analysis was performed for EGFR, p53 or ERCC1 on the intraoperative NSCLC tissues. Each tumor marker was assessed independently by two pathologists using common grading criteria. The SUVmax difference based on the histologic characteristics, gender, differentiation, grading and age as well as correlation analysis among these parameters were performed. Multiple stepwise regression analysis was further performed to determine the primary predictor for SUVmax and the receiver operating characteristics (ROC) curve analysis was performed to detect the optimized sensitivity and specificity for SUVmax in suggesting chemotherapy resistant tumor markers. RESULTS: The significant tumor type (P=0.045), differentiation (P=0.021), p53 (P=0.000) or ERCC1 (P=0.033) positivity dependent differences of SUVmax values were observed. The tumor differentiation is significantly correlated with SUVmax (R=-0.327), tumor size (R=-0.286), grading (R=-0.499), gender (R=0.286) as well as the expression levels for p53 (R= -0.605) and ERCC1 (R=-0.644). The expression level of p53 is significantly correlated with SUVmax (R=0.508) and grading (R=0.321). Furthermore, multiple stepwise regression analysis revealed that p53 expression was the primary predictor for SUVmax. When the cut-off value of SUVmax was set at 5.15 in the ROC curve analysis, the sensitivity and specificity of SUVmax in suggesting p53 positive NSCLC were 79.5% and 47.8%, respectively. CONCLUSION: The current study suggests that SUVmax of primary tumor on FDG-PET might be a simple and good non-invasive method for predicting p53-related chemotherapy resistance in NSCLC when we set the cu-off value of SUVmax at 5.15.

Conspicuity of breast lesions at different b values on diffusion-weighted imaging.

BACKGROUND: Diffusion-weighted (DW) imaging has shown potential to differentiate between malignant and benign breast lesions. However, different b values have been used with varied sensitivity and specificity. This study aims to prospectively evaluate the influence of b value on the detection and assessment of breast lesions. METHODS: Institutional review board approval and informed patient consent were obtained. Between February 2010 and September 2010, sixty women suspected of having breast cancer by clinical examination and mammography underwent bilateral breast MRI and DW imaging (with maximum b values of 600, 800, and 1000 s/mm(2)). Conspicuity grades of lesions at different b values on DW images were performed. Signal intensity and apparent diffusion coefficient (ADC) values were recorded and compared among different b values by the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and receiver operating characteristic (ROC) curve. RESULTS: Fifty-seven lesions from 52 recruited patients including 39/57 (68%) malignant and 18/57 (32%) benign were confirmed with pathology. DCE MRI accurately detected 53 lesions with the sensitivity of 93.0% and specificity of 66.7%, and DW imaging accurately detected 51 lesions with the sensitivity of 89.5% and specificity of 100%. There were no significant differences in conspicuity grades compared among the three b values (P = 0.072), although the SNR and CNR of breast lesions decreased significantly with higher b values. Mean ADCs of malignant lesions (b = 600 s/mm(2), 1.07 ± 0.26 × 10-3 mm(2)/s; b = 800 s/mm(2), 0.96 ± 0.22 × 10-3 mm(2)/s; b = 1000 s/mm(2), 0.92 ± 0.26 × 10-3 mm(2)/s) were significantly lower than those of benign lesions (b = 600 s/mm(2), 1.55 ± 0.40 × 10-3 mm(2)/s; b = 800 s/mm(2), 1.43 ± 0.38 × 10-3 mm(2)/s; b = 1000 s/mm(2), 1.49 ± 0.38 × 10-3 mm(2)/s) with all P values <0.001, but there were no significant differences among the three b values (P = 0.303 and 0.840 for malignant and benign lesions, respectively). According to the area under the ROC curves, which were derived from ADC and differentiate malignant from benign lesions, no significant differences were found among the three b values (P = 0.743). CONCLUSIONS: DW imaging is a potential adjunct to conventional MRI in the differentiation between malignant and benign breast lesions. Varying the maximum b value from 600 to 1000 s/mm(2) does not influence the conspicuity of breast lesions on DW imaging at 1.5 T.

Identification of novel low molecular weight serum peptidome biomarkers for non-small cell lung cancer (NSCLC).

AIM: To identify discriminating protein patterns in serum samples among non-small cell lung cancer (NSCLC), chronic obstructive pulmonary disease (COPD), pneumonia, and healthy controls. To discover specific low molecular weight (LMW) serum peptidome biomarkers and establish a diagnostic pattern for NSCLCby using proteomic technology. METHODS: We used magnetic bead-based separation followed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) to identify patients with NSCLC, COPD, and pneumonia. A total of 154 serum samples were analyzed in this study, among which there were 60 serum samples from NSCLC patients, 30 from patients with other lung-related diseases (16 pneumonia patients and 14 patients with COPD) as disease controls, and 64 from healthy volunteers as healthy control. The mass spectra, analyzed using ClinProTools software, distinguished between cancer patients and healthy individuals based on GA algorithm model. RESULTS: In this study, we generated numerous discriminating m/z peaks as well as disease-specific discrimination peaks. A set of five potential biomarkers (m/z: 7,763.24, 1,012.61, 4,153.16, 1,450.55, and 2,878.89) could be used as the diagnostic biomarkers to distinguish NSCLCpatients from healthy controls. In the training set, patients with NSCLC could be identified with sensitivity of 97.5% and specificity of 98.8%. Similar results were obtained in the testing set, showing 80.7% sensitivity and 91.2% specificity. CONCLUSION: Our study demonstrated that a combined application of magnetic beads with MALDI-TOF MS technique was suitable for identification of serum biomarkers for NSCLC.

[Anatomic distribution of embolus at CT pulmonary angiography in patients suspected acute pulmonary embolism].

OBJECTIVE: To summarize and analyse the morphology and distribution of embolus in patients suspected acute pulmonary embolism. METHODS: The CT pulmonary angiography (CTPA) imagings of 279 patients suspected acute pulmonary embolism were analysed retrospectively in Ningxia from January 2004 through June 2006 and in Beijing from September 2005 through October 2006. The incidence of central embolus, peripheral embolus and mixed embolus, and the distribution and the morphology of embolus in different levels of pulmonary arteries were analysed. RESULTS: A total of 279 patients (158 males, 121 females; Median age was 63 years) were recruited. The incidence of central embolus, peripheral embolus and mixed embolus were 3.5%, 40.9% and 55.6%, respectively. There were 1850 emboli found above the segmental pulmonary arterial, 58.2% were found in right pulmonary artery, and 41.8% in left pulmonary artery. For all of the emboli, there were 29.7% in bilateral upper lobes, 18.3% in medial lobe and lingual lobe, and 49.8% in bilateral lower lobes. The percent of A, B and C type embolus were 81.7%, 7.6% and 10.7%, respectively. CONCLUSION: It was not unusual for the peripheral thrombosis, and can be improved to detect peripheral thrombosis by thin-slice CT scan. The distribution of embolus in pulmonary vascular and the distribution of blood flow was consistent, the number of embolus in right lung were more than left lung, and lower lobes more than upper lobes and middle lobes.

[Quantitative evaluation for diagnostic efficacy of computed tomography and magnetic resonance imaging in patients with lumbar disc herniation].

OBJECTIVE: To evaluate the diagnostic performances of CT and MRI in patients with lumbar intervertebral disc herniation through the Meta analytical method. METHOD: The relevant English and Chinese articles published between 1980 and 2010 were searched in PubMed, Medline, Ovid database, Cochrane library and Chinese Periodical Web. According to the criteria for diagnostic researches published by Cochrane Method Group on Screening and Diagnostic Tests, each article was critically appraised and screened with regards to the absolute numbers of true-positive, false-negative, true-negative and false-positive. Statistical analysis was performed by the Meta-Disc version 1.4, SPSS 13.0 and Comprehensive Meta-analysis version II. Heterogeneity was tested and publication bias analyzed. And the pooled weighted sensitivity and specificity and the corresponding 95%CI were calculated. The summary receiver operating characteristic (SROC) curve was performed and the area under the curve (AUC) calculated to summarize and evaluate the diagnostic efficiency of CT and MRI in lumbar intervertebral disc herniation. Finally a sensitivity analysis was performed. RESULTS: According to the criteria of internalization, 9 articles were included. Among them, the themes were CT (n = 3), MRI (n = 3) and CT & MRI (n = 3). Eight was prospectively studied and one retrospectively. At the diagnosis of lumbar intervertebral disc herniation, the pooled weighted sensibility and specificity and 95% confidence interval and area under SROC curve for CT to the lumbar intervertebral disc herniation was 0.73 (0.68 - 0.77), 0.78 (0.72 - 0.82) and 83.5% respectively. The MRI was 0.88 (0.83 - 0.91), 0.79 (0.71 - 0.87) and 88.8% respectively. There was statistically significant difference in the pooled weighted sensibility (P < 0.05); No statistically significant difference was found in the pooled weighted specificity (P > 0.05); And there was statistically significant difference in the AUC curve (P < 0.05). CONCLUSION: After a meta-analysis of the diagnostic value of CT and MRI for the lumbar intervertebral disc herniation, MRI is more accurate than CT in the diagnosis of lumbar intervertebral disc herniation.

[Quantitative evaluations of ischemic stroke based on meta-analysis].

OBJECTIVE: To perform a meta-analysis to explore the evolutions of apparent diffusion coefficient during different stages of ischemic stroke. METHODS: The relevant English and Chinese articles published from 2001 to 2010 were retrieved from the databases of Cochrane Library, Pubmed, Elsevier and Chinese Knowledge Resource Integrated Database (CNKI). According to the criteria of diagnostic researches published by the Cochrane Method Group on Screening & Diagnostic Tests, each article was critically appraised. We tested their heterogeneity, selected the corresponding effect model and calculated pooled weighted effect size and corresponding 95% CI. RESULTS: By the established inclusion criteria, we retrieved 34 studies with 20 English and 14 Chinese articles. The pooled apparent diffusion coefficient (ADC) values of diffusion weighted imaging-magnetic resonance imaging (DWI-MRI) and 95%CI of hyper-acute, acute, sub-acute, chronic stroke were 0.53 (0.45 - 0.60), 0.50 (0.47 - 0.53), 0.66 (0.62 - 0.70), 1.20 (1.01 - 1.38) while those of penumbra and control were 0.70 (0.68 - 0.89) and 0.87 (0.84 - 0.91) respectively. The ADC values of hyper-acute and acute stroke were obviously lower than that of penumbra and it had statistical significance (both P < 0.05). The ADC values of hyper-acute, acute, sub-acute and chronic stroke were obviously different from that of control and it had statistical significance [0.53 (0.45 - 0.60) × 10(-3) s/mm, 0.50 (0.47 - 0.53) × 10(-3)s/mm, 0.66 (0.62 - 0.70) × 10(-3)s/mm, 1.20 (1.01 - 1.38) × 10(-3)s/mm vs 0.87 (0.84 - 0.91) × 10(-3)s/mm, all P < 0.05]. CONCLUSIONS: As indicated by our meta-analysis, the ADC values can quantitatively evaluate different stages of stroke and guide the choices of treatment methods.

[Coronary artery disease diagnosis with 64-slice spiral CT coronary artery angiography in China and abroad: a meta analysis].

OBJECTIVE: This meta-analysis evaluated the accuracy of diagnosing coronary artery disease using 64-section spiral computed tomography, and compared the difference between Chinese studies and abroad studies. METHODS: Relevant English and Chinese articles published from 1998 to 2009 were searched in Cochrane library, Medline, Embase database, OVID database and CNKI. Heterogeneity was tested, pooled weighted sensitivity and specificity and the corresponding 95%CI were calculated. Summary receiver operating characteristic (SROC) curve was drawn and the area under the curve was calculated, differences between studies from China and abroad were compared. RESULTS: A total of 433 articles were searched and 108 articles were included (46 English articles and 62 Chinese articles) after excluding articles of research purposes or design does not match. Because of no gold standard, no blind, can not be calculated literature data, 7 and 20 (P > 0.05), 44 and 6 (P < 0.05), 3 and 1 (P < 0.05) Chinese studies and English articles respectively were excluded. Twenty-seven articles fulfilled all inclusion criteria (8 Chinese and 19 foreign studies) In 8 Chinese studies the pooled weighted sensitivity and specificity and area under SROC curve was 0.892 (95%CI: 0.868 - 0.913), 0.972 (95%CI: 0.966 - 0.977) and 0.983 (95%CI: 0.966 - 1.000) at segment-based analysis. In 19 foreign studies, the pooled weighted sensitivity and specificity and area under SROC curve was 0.971(95%CI: 0.957 - 0.982), 0.878 (95%CI: 0.852 - 0.902) and 0.973 (95%CI: 0.958 - 0.989) at patient-based analysis, 0.917 (95%CI: 0.895 - 0.936), 0.919 (95%CI: 0.909 - 0.928) and 0.974 (95%CI: 0.964 - 0.984) at vessel-based analysis, 0.882 (95%CI: 0.868 - 0.895), 0.959 (95%CI: 0.956 - 0.962) and 0.985 (95%CI: 0.978 - 0.992) at segment-based analysis. Pooled weighted pecificity of 64-section spiral CT angiography at segment-based analysis has significant different between home and abroad (P < 0.05). CONCLUSIONS: Meta-analysis showed that noninvasive 64-section spiral computed tomography could correctly diagnose coronary artery disease with high sensitivity and specificity. Quality of related studies performed in abroad is significantly higher than those performed in China.

[Predicting value of various clinical probability scores for diagnosis of lower limb deep venous thrombosis in Chinese patients].

OBJECTIVE: To evaluate the predicting value of Wells, Kahn, St. André and Constans scores for the diagnosis of deep venous thrombosis in Chinese patients. METHODS: A total of 274 patients suspected with deep venous thrombosis was prospectively blinded evaluated with the four clinical-score systems. Sensitivity, specificity, positive predictive value, negative predictive value and receiver operation curves were calculated for four clinical scores according sonography results. RESULTS: Sonography evidenced deep venous thrombosis in 88 out of 274 patients. The sensitivity, specificity, positive predictive value and negative predictive value was 77.3%, 65.6%, 51.5% and 85.9%, respectively, for Wells score; 58%, 55.9%, 38.3% and 73.8%, respectively, for Kahn score; 64.8%, 55.4%, 40.7% and 76.9%, respectively, for St. André score and 86.4%, 37.6%, 39.6% and 85.4%, respectively, for Constans score. ROC was 0.761 for Wells score, which was similar as that of Constans score (0.759), then followed by St. André score (0.627) and Kahn score (0.591). CONCLUSION: Our results showed that Wells score and Constans score are superior to Kahn score or St. André score for diagnosing patients with suspected deep venous thrombosis in terms of sensitivity, negative prediction value and ROC values.

Role of the Emphysema Index Combined with the Chronic Obstructive Pulmonary Disease Assessment Test Score in the Evaluation of Chronic Obstructive Pulmonary Disease.

Background: This study aimed to evaluate the efficacy of the emphysema index (EI) in distinguishing chronic bronchitis (CB) from chronic obstructive pulmonary disease (COPD) and its role, combined with the COPD Assessment Test (CAT) score, in the evaluation of COPD. Methods: A total of 92 patients with CB and 277 patients with COPD were enrolled in this study. Receiver operating characteristic (ROC) curves were analyzed to evaluate whether the EI can preliminarily distinguish chronic bronchitis from COPD. Considering the heterogeneity of COPD, there might be missed diagnosis of some patients with bronchitis type when differentiating COPD patients only by EI. Therefore, patients with COPD were classified according to the CAT score and EI into four groups: Group 1 (EI < 16%, CAT < 10), Group 2 (EI < 16%, CAT ≥ 10), Group 3 (EI ≥ 16%, CAT < 10), and Group 4 (EI ≥ 16%, CAT ≥ 10). The records of pulmonary function and quantitative computed tomography findings were retrospectively analyzed. Results: ROC curve analysis showed that EI = 16.2% was the cutoff value for distinguishing COPD from CB. Groups 1 and 2 exhibited significantly higher maximal voluntary ventilation (MVV) percent predicted (pred), forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC), maximal midexpiratory flow of 25-75% pred, carbon monoxide-diffusing capacity (DLCO)/alveolar ventilation (VA), FEV1 % pred (p ≤ 0.013), and maximal expiratory flow 50% pred (all p < 0.05) than Group 4. FEV1/FVC and DLCO/VA were significantly lower in Group 3 than in Group 2 (p=0.002 and p < 0.001, respectively). The residual volume/total lung capacity was higher in Group 3 than in Groups 1 and 2 (p < 0.05). Conclusions: The combination of EI and CAT was effective in the evaluation of COPD.

Meta-analysis of quantitative diffusion-weighted MR imaging in the differential diagnosis of breast lesions.

BACKGROUND: To determine, in a meta-analysis, the diagnostic performance of quantitative diffusion-weighted (DW) MR imaging in patients with breast lesions. METHODS: English and Chinese studies published prior to June 2009 to assess the diagnostic performance of quantitative DWI in patients with breast lesions were reviewed and summarized with reference to the inclusion and exclusion criteria. Methodological quality was assessed by using the quality assessment of diagnostic studies (QUADAS) instrument. Publication bias analysis was performed by using Comprehensive Meta-analysis version 2. Meta-Disc version 1.4 was used to describe primary results and explore homogeneity by Chi-square test and inconsistency index; to explore threshold effect by receiver operator characteristic (ROC) space and Spearman correlation coefficient; and to pool weighted sensitivity and specificity by fixed or random effect model. A summary ROC (sROC) curve was constructed to calculate the area under the curve (AUC). RESULTS: Of 65 eligible studies, 13 with 615 malignant and 349 benign lesions were included in the original meta-analysis, among which heterogeneity arising from factors other than threshold effect and publication bias was explored. Methodological quality was moderate. The pooled weighted sensitivity and specificity with corresponding 95% confidence interval (CI) in one homogenous subgroup of studies using maximum b = 1000 s/mm2 were 0.84 (0.80, 0.87) and 0.84 (0.79, 0.88) respectively. AUC of sROC was 0.9085. Sensitivity analysis demonstrated that the pooled estimates were stable and reliable. CONCLUSIONS: Quantitative DWI has a higher specificity to differentiate between benign and malignant breast lesions compared to that of contrast-enhanced MRI. However, large scale randomized control trials (RCTs) are necessary to assess its clinical value because of disunified diffusion gradient factor b and diagnosis threshold.

[Evaluation of peripheral pulmonary embolism by different thickness of CTPA imagings].

OBJECTIVE: to evaluate whether there are difference among different thickness of CTPA imagings for detection of emboli in peripheral pulmonary arteries. METHODS: CTPA Images of 97 patients with acute pulmonary embolism were divided into four series for each patient: 0.625 mm thick original transaxial soure images and 3 series of reconstructed images using the MIP technique with slab thicknesses of 1.25 mm, 2.5 mm, and 5.0 mm. The difference was compared among 4 series of CTPA images for detection of emboli in peripheral pulmonary arteries, and the agreement of 2 observers for detection of emboli in peripheral pulmonary arteries in different thickness images was tested. Chi-Square test was taken for comparison of 4 series of CTPA images for detection of emboli in peripheral pulmonary arteries. Kappa test was taken for the agreement of 2 observers for detection of emboli in peripheral pulmonary arteries. RESULTS: the average images number of 0.625 mm, 1.25 mm, 2.5 mm, 5.0 mm thickness imaging was 403, 201, 101, and 53, respectively. For detecting clots in segmental pulmonary arteries, there was statistically significant difference between 5.0 mm thick imaging and other 3 series imagings (chi(2) = 60.099, P < 0.01), but agreement of 2 observers in each series imaging was excellent (value of κ from 0.751 to 0.973).For clots in sub-segment pulmonary arteries, no statistical significant difference was observed between 0.625 mm and 1.25 mm thick imagings (chi(2) = 1.051, P > 0.05), and superior to 2.5 mm and 5.0 mm thick images (chi(2) = 151.892, 204.553, respectively, P < 0.01), but agreement of two observers in each series imaging was good (value of kappa from 0.611 to 0.935). CONCLUSION: compared with 0.625 mm thick transaxial imaging, 1.25 mm thick MIP imaging is equally sensitive for detecting emboli in peripheral pulmonary arteries, but needs fewer images and less time for image reading.

[A comparison of the predictive values of three clinical scoring systems for suspected acute pulmonary embolism based on multidetector CT angiography].

OBJECTIVE: To explore whether acute pulmonary embolism (APE) can be quantitatively predicated early with 3 clinical scoring systems, with multidetector CT angiography (MDCTA) as the gold standard, and therefore to select a scoring system more suitable for the Chinese. METHODS: Five hundred and seventy consecutive inpatients with highly suspected APE underwent prospective MDCTA at the time of initial diagnosis. Three clinical predication scoring systems (Wells', Geneva' and revised Geneva') were used to estimate APE in low, moderate and high probability groups. Two radiologists independently reviewed the MDCTA without any clinical information. When consensus could not be reached, a third radiologist with 20-years' experience was asked to make the final decision. The threshold value for the prediction of APE by the 3 scoring systems was measured by receiver-operating-characteristics (ROC) analysis. RESULTS: APE was identified in 169 of the 570 cases. Kappa analysis for the 3 scoring systems revealed a low level of agreement: 0.269-0.374, P<0.05. The result of the Geneva score was consistent with that of the revised Geneva score, between them there was an excellent correlation. The positive predictive values of Wells, Geneva, revised Geneva scores for APE were 83.8%, 53.3%, and 61.3% respectively, while the negative predictive values were 85.0%, 80.6%, and 80.0%, respectively. ROC analysis showed that the area under curve (AUC) of Wells, Geneva and revised Geneva score for APE was 0.823 (95% CI: 0.710-0.976), 0.677 (95% CI: 0.646-0.990), and 0.661 (95% CI: 0.631-0.983), respectively. The Wells score showed the best discriminatory ability as compared to the other 2 scores. CONCLUSION: The 3 scoring systems can be used for both inpatients and emergency cases, while the Wells Score may be more accurate for Chinese people for predicting APE.

[Value of combined wells score and D-dimer test on diagnosing patients with deep venous thrombosis].

OBJECTIVE: To evaluate the value of Wells score or/and D-dimer test on diagnosing or excluding deep venous thrombosis (DVT). METHODS: Patients with suspected DVT were retrospectively analyzed. All patients underwent clinical assessment, D-dimer assay and bilateral lower extremity compression sonography within 48 hours of admission. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for diagnosing DVT by Wells score, D-dimer test, and combined Wells score and D-dimer were compared. RESULTS: A total of 274 patients were analyzed. If low probability was defined as negative and moderate and high probabilities were defined as positive, the sensitivity, specificity, PPV and NPV of the Wells score were 78.4%, 66.1%, 52.3% and 86.6%, respectively. At a cut-off of 500 microg/L, the sensitivity, specificity, PPV and NPV of D-dimer test were 73.9%, 66.1%, 50.8% and 84.2%, respectively. If low probability and D-dimer < 500 microg/L were defined as negative, moderate and high probabilities and D-dimer > or = 500 microg/L were defined as positive, the sensitivity, specificity, PPV and NPV of the combined Wells score and D-dimer test were 88.3%, 76.8%, 67.1% and 92.5%, respectively. CONCLUSION: For clinical suspected DVT patients, DVT diagnosis could be reliably obtained by combined Wells score and D-dimer test.

Determination of vascular alteration in smokers by quantitative computed tomography measurements.

A new method of quantitative computed tomography (CT) measurements of pulmonary vessels are applicable to morphological studies and may be helpful in defining the progression of emphysema in smokers. However, limited data are available on the relationship between the smoking status and pulmonary vessels alteration established in longitudinal observations. Therefore, we investigated the change of pulmonary vessels on CTs in a longitudinal cohort of smokers.Chest CTs were available for 287 current smokers, 439 non-smokers, and 80 former smokers who quit smoking at least 2 years after the baseline CT. CT images obtained at the baseline and 1 year later were assessed by a new quantitative CT measurement method, computing the total number of pulmonary vessels (TNV), mean lung density (MLD), and the percentage of low-attenuation areas at a threshold of -950 (density attenuation area [LAA]%950). Analysis of variance (ANOVA) and the independent sample t test were used to estimate the influence of the baseline parameters. The t paired test was employed to evaluate the change between the baseline and follow-up results.The current smokers related to have higher whole-lung MLD, as well as less and lower TNV values than the non-smokers (P <.05). But no significant differences in LAA%950 were found between smokers and non-smokers. After one year, the increase in LAA%950 was more rapid in the current (additional 0.3% per year, P <. 05-.01) than in the former smokers (additional 0.2% per year, P = .3). Additionally, the decline in TNV was faster in the current (additional -1.3 per year, P <.05-.01) than that in the former smokers (additional -0.2 per year, P = .6). Current smoke, pack-years, weight, and lung volume independently predicted TNV at baseline (P <.001) in multivariate analysis.The findings of this study reveal that the decline in the pulmonary vessels in smokers can be measured and related to their smoking status.

A meta-analysis of the accuracy of prostate cancer studies which use magnetic resonance spectroscopy as a diagnostic tool.

OBJECTIVE: We aimed to do a meta-analysis of the existing literature to assess the accuracy of prostate cancer studies which use magnetic resonance spectroscopy (MRS) as a diagnostic tool. MATERIALS AND METHODS: Prospectively, independent, blind studies were selected from the Cochrane library, Pubmed, and other network databases. The criteria for inclusion and exclusion in this study referenced the criteria of diagnostic research published by the Cochrane center. The statistical analysis was adopted by using Meta-Test version 6.0. Using the homogeneity test, a statistical effect model was chosen to calculate different pooled weighted values of sensitivity, specificity, and the corresponding 95% confidence intervals (95% CI). The summary receiver operating characteristic (SROC) curves method was used to assess the results. RESULTS: We chose two cut-off values (0.75 and 0.86) as the diagnostic criteria for discriminating between benign and malignant. In the first diagnostic criterion, the pooled weighted sensitivity, specificity, and corresponding 95% CI (expressed as area under curve [AUC]) were 0.82 (0.73, 0.89), 0.68 (0.58, 0.76), and 83.4% (74.97, 91.83). In the second criterion, the pooled weighted sensitivity, specificity, and corresponding 95% CI were 0.64 (0.55, 0.72), 0.86 (0.79, 0.91) and 82.7% (68.73, 96.68). CONCLUSION: As a new method in the diagnostic of prostate cancer, MRS has a better applied value compared to other common modalities. Ultimately, large scale RCT (randomized controlled trial) randomized controlled trial studies are necessary to assess its clinical value.

Technetium-99m-hexakis-2-methoxyisobutylisonitrile scintigraphy and multidrug resistance-related protein expression in human primary lung cancer.

OBJECTIVE: The occurrence of multidrug resistance (MDR) is a major cause of resistance to chemotherapeutic agents in patients with lung cancer, in part owing to the overexpression of MDR-related proteins. Technetium-99m-hexakis-2-methoxyisobutylisonitrile ((99m)Tc-MIBI) has been shown to be a substrate for some MDR-related proteins. The aim of this study is to evaluate the role of (99m)Tc-MIBI scintigraphy for functional imaging of MDR-related protein phenotypes. METHODS: To determine the correlation between (99m)Tc-MIBI scintigraphy and the expression level of P-glycoprotein (Pgp), multidrug-resistance protein (MRP), and glutathione-S-transferase Pi (GSTpi), 26 patients (17 men and 9 women, median age 57.5 years) with primary lung cancer were investigated. Following intravenous administration of 925 MBq (99m)Tc-MIBI, single-photon emission computed tomography (SPECT) and computed tomography (CT) were performed at 15 min and 2 h. On the basis of the fused images, tumor to background (T/B) ratio of both early and delayed images, and washout rate (WR%) of (99m)Tc-MIBI were calculated. The immunohistochemical staining of Pgp, MRP, and GSTpi was performed, and the expression level was semiquantitated using a pathoimage analysis system. The imaging results were compared with the status of Pgp, MRP, and GSTpi expression. RESULTS: The WR% of (99m)Tc-MIBI showed a significant positive correlation with Pgp expression (r = 0.560, P = 0.003), as no correlation was observed between WR% and MRP or GSTpi (r = 0.354, P = 0.076; r = 0.324, P = 0.106). Neither early T/B nor delayed T/B correlated with the expression level of Pgp, MRP, and GSTpi. WR%, Pgp, and GSTpi expression showed significant differences between squamous cell carcinoma (group A) and adenocarcinoma (group B). There was no significant difference among Pgp, MRP, and GSTpi expression levels in any cases (P > 0.05). CONCLUSIONS: Our data confirmed that (99m)Tc-MIBI scintigraphy is useful for determining the MDR caused by Pgp in patients with primary lung cancer.

[The prevalence of deep venous thrombosis in 337 suspected pulmonary embolism patients].

OBJECTIVE: The purpose of our study was to evaluate the prevalence of deep venous thrombosis(DVT) in suspected pulmonary embolism patients. METHODS: From January 2004 to June 2006, all patients who underwent CT pulmonary angiography combined with lower extremity CT venography or lower extremity sonography were consecutively enrolled in 2 hospitals. The prevalence of deep venous thrombosis in suspected pulmonary embolism patients and the location of DVT were analyzed. The statistical analyses were performed with the SPSS 11.5 statistical software, frequency analysis was performed for descriptive results and chi-square analysis was performed for comparison between groups. RESULTS: Three hundred and thirty-seven consecutive patients were enrolled. There were 189 men and 148 women. The median age was 62 (range from 19 to 84 years old). Pulmonary embolism were diagnosed by CT pulmonary angiography in 144 patients, and DVT was diagnosed by CT venography or lower extremity sonography in 100 patients. The prevalence of DVT in pulmonary embolism patients was 44%, and 76% DVT was located in proximal lower extremity veins. The prevalence of pulmonary embolism in DVT patients was 63%. CONCLUSION: The prevalence of DVT in patients with pulmonary embolism and the prevalence of pulmonary embolism in patients with DVT are both high (44% vs 63%); therefore it is necessary to examine the pulmonary arteries and the lower extremity deep veins at the same time.