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Publications (42)100.96 Total impact

  • [Show abstract] [Hide abstract] ABSTRACT: To identify myocardial fibrosis in hypertrophic cardiomyopathy (HCM) subjects using quantitative cardiac diffusion-weighted imaging (DWI) and to compare its performance with native T1 mapping and extracellular volume (ECV). Thirty-eight HCM subjects (mean age, 53 ± 9 years) and 14 normal controls (mean age, 51 ± 8 years) underwent cardiac magnetic resonance imaging (CMRI) on a 3.0T magnetic resonance (MR) machine with DWI, T1 mapping and late gadolinium enhancement (LGE) imaging as the reference standard. The mean apparent diffusion coefficient (ADC), native T1 value and ECV were determined for each subject. Overall, the HCM subjects exhibited an increased native T1 value (1241.04 ± 78.50 ms), ECV (0.31 ± 0.03) and ADC (2.36 ± 0.34 s/mm2) compared with the normal controls (1114.60 ± 37.99 ms, 0.24 ± 0.04, and 1.62 ± 0.38 s/mm2, respectively) (p < 0.05). DWI differentiated healthy and fibrotic myocardia with an area under the curve (AUC) of 0.93, while the AUCs of the native T1 values (0.93), (p > 0.05) and ECV (0.94), (p > 0.05) exhibited an equal differentiation ability. Both HCM LGE+ and HCM LGE− subjects had an increased native T1 value, ECV and ADC compared to the normal controls (p < 0.05). HCM LGE+ subjects exhibited an increased ECV (0.31 ± 0.04) and ADC (2.43 ± 0.36 s/mm2) compared to HCM LGE− subjects (p < 0.05). HCM LGE+ and HCM LGE− subjects had similar native T1 values (1250 ± 76.36 ms vs. 1213.98 ± 92.30 ms, respectively) (p > 0.05). ADC values were linearly associated with increased ECV (R2 = 0.36) and native T1 values (R2 = 0.40) among all subjects. DWI is a feasible alternative to native T1 mapping and ECV for the identification of myocardial fibrosis in patients with HCM. DWI and ECV can quantitatively characterize the extent of fibrosis in HCM LGE+ and HCM LGE− patients.
    No preview · Article · May 2016 · The International Journal of Cardiovascular Imaging
  • [Show abstract] [Hide abstract] ABSTRACT: Objectives: To evaluate the diagnostic value of T2* mapping compared with ADC mapping in the characterization of low- (Gleason score, ≤ 6) vs intermediate- and high-grade (Gleason score ≥ 7) prostate cancer. Methods: Sixty-two patients who underwent MRI before prostatectomy were evaluated. Two readers independently scored the probabilities of tumours in twelve regions of the prostate on T2* and ADC images. The data were divided into two groups, i.e., low- vs intermediate- and high-grade prostate cancer, and correlated with the histopathological results. The diagnostic performance parameters, areas under the receiver-operating characteristic curves (AUCs) and inter-reader agreements were calculated. Results: For reader 2, the ADC mapping exhibited greater accuracy for the intermediate-grade prostate cancers than the high-grade prostate cancers (0.77 vs 0.83, P<0.05). For both readers, the T2 * mapping exhibited a greater accuracy for the intermediate-grade prostate cancers than the high-grade prostate cancers (reader 1, 0.86 vs. 0.81; reader 2, 0.83 vs 0.78, P<0.05). The AUCs of the T2 * mappings were greater than those of the ADC mappings for the intermediate- and high-grade (reader 1, 0.83 vs. 0.78; reader 2, 0.80 vs 0.75, P<0.05) prostate cancers but not for the low-grade (reader 1, 0.86 vs 0.84; reader 2, 0.83 vs. 0.82, P>0.05) prostate cancers. The weighted κ value of the T2 * mapping was 0.59. Conclusion: T2 * mapping improves the accuracy of the characterization of intermediate- and high-grade but not low-grade prostate cancers compared with ADC mapping. Advances in knowledge: T2 * mapping exhibited greater diagnostic accuracy than ADC mapping in the characterization of intermediate- and high-grade prostate cancers. T2 * mapping exhibited limited value in the characterization of low-grade prostate cancer.
    No preview · Article · Apr 2016 · The British journal of radiology
  • [Show abstract] [Hide abstract] ABSTRACT: Background: T2* relaxation is a primary determinant of image contrast with Gradient echo (GRE) sequences, and it has been widely used across body regions. Purpose: To compare the diagnostic performance of T2* mapping in combination with T2-weighted (T2W) imaging to T2W imaging alone for prostate cancer (PCa) detection. Material and methods: The study included 31 patients (mean age, 62 ± 3 years; age range, 45-78 years) who underwent magnetic resonance imaging (MRI) at 3.0T and histological examination. Three observers with varying experience levels reviewed T2W imaging alone, T2* mapping alone, and T2W imaging combined with T2* mapping. A five-point scale was used to assess the probability of PCa in each segment on MR images. Statistical analysis was performed using Z tests after adjusting for data clustering. Results: The area under the curve (AUC) of T2W imaging and T2* mapping data (observer 1, 0.93; observer 2, 0.90; observer 3, 0.77) was higher than T2W imaging (observer 1, 0.84; observer 2, 0.79; observer 3, 0.69) for all observers (P < 0.01 in all comparisons). The AUC of T2W imaging and T2* mapping data was higher for observers 1 and 2 than for observer 3 (P < 0.01). The sensitivity and specificity of T2W imaging and T2* mapping data (observer 1, 95%, 85%; observer 2, 90%, 83%; and observer 3, 82%, 63%, respectively) was higher than T2W imaging (observer 1, 78%, 79%; observer 2, 76%, 72%; observer 3, 74%, 51%, respectively) for all observers (P < 0.01 for observer 1; P < 0.01 for observers 2 and 3). Conclusion: The addition of T2* mapping to T2W imaging improved the diagnostic performance of MRI in PCa detection.
    No preview · Article · Feb 2016 · Acta Radiologica
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    [Show abstract] [Hide abstract] ABSTRACT: Objectives: To assess the diagnostic value of dual energy spectral CT imaging for colorectal cancer grading using the quantitative iodine density measurements in both arterial phase (AP) and venous phase (VP). Methods: 81 colorectal cancer patients were divided into two groups based on their pathological findings: a low grade group including well (n = 13) and moderately differentiated cancer (n = 24), and a high grade group including poorly differentiated (n = 42) and signet ring cell cancer (n = 2). Iodine density (ID) in the lesions was derived from the iodine-based material decomposition (MD) image and normalized to that in the psoas muscle to obtain normalized iodine density (NID). The difference in ID and NID between AP and VP was calculated. Results: The ID and NID values of the low grade cancer group were, 14.65±3.38mg/mL and 1.70±0.33 in AP, and 21.90±3.11mg/mL and 2.05± 0.32 in VP, respectively. The ID and NID values for the high grade cancer group were 20.63±3.72mg/mL and 2.95±0.72 in AP, and 26.27±3.10mg/mL and 3.51±1.12 in VP, respectively. There was significant difference for ID and NID between the low grade and high grade cancer groups in both AP and VP (all p<0.001). ROC analysis indicated that NID of 1.92 in AP provided 70.3% sensitivity and 97.7% specificity in differentiating low grade cancer from high grade cancer. Conclusions: The quantitative measurement of iodine density in AP and VP can provide useful information to differentiate low grade colorectal cancer from high grade colorectal cancer with NID in AP providing the greatest diagnostic value.
    Preview · Article · Feb 2016 · PLoS ONE
  • [Show abstract] [Hide abstract] ABSTRACT: Rationale and Objectives To assess the feasibility of quantitative T2* mapping at 3.0 T for prostate cancer detection and to investigate the use of T2* values to characterize tumor aggressiveness, with whole-mount step-section pathologic analysis as the reference standard. Materials and Methods Prostate multiecho T2* was performed in 55 consecutive patients with prostate cancer using a multishot fast-field echo sequence at 3.0 T magnetic resonance imaging. T2* mapping was obtained by exponentially fitting the multiecho T2* images pixel by pixel with different echo times for each slice. Generalized estimating equations were used to test the T2* value difference between normal and malignant prostate regions and the association between T2* value and tumor Gleason scores. Results The T2* values of the cancerous prostatic regions (mean: 42.51 ± 0.65 milliseconds) were significantly lower (P < .001) than those of the normal prostatic regions (mean: 74.87 ± 0.99 milliseconds). Adopting a threshold value of 59.27 milliseconds, T2* mapping resulted in 94.8% sensitivity and 77.3% specificity in the identification of prostate cancer. A lower mean T2* value was significantly associated with a higher tumor Gleason score (mean T2* values of 53.53, 43.75, 33.66, and 22.95 milliseconds were associated with Gleason score of 3 + 3, 3 + 4, 4 + 3, and ≥8, respectively P < .05). Conclusions From these preliminary data, quantitative T2* mapping seems to be a potential method in the characterization of prostate cancer. T2* mapping may provide additional quantitative information that significantly correlated with prostate cancer aggressiveness.
    No preview · Article · Aug 2014 · Academic Radiology
  • Guang-yu Wu · Qing Lu · Lian-ming Wu · Jin Zhang · Xiao-xi Chen · Jian-rong Xu
    [Show abstract] [Hide abstract] ABSTRACT: Purpose To evaluate the performance of computed tomographic urography (CTU), static-fluid magnetic resonance urography (static-fluid MRU) and combinations of CTU, static-fluid MRU and diffusion weighted imaging (DWI) in the diagnosis of upper urinary tract cancer. Material and Methods Between January 2010 and June 2011, patients with suspected UUT cancer underwent CTU, static-fluid MRU and DWI(b = 1000 s/mm2) within a 1-week period. The diagnostic performances of CTU, static-fluid MRU and combinations of CTU, static-fluid MRU and DWI for upper urinary tract cancer were prospectively evaluated. The ureteroscopic and histopathologic findings were compared with the imaging findings. Results Compared to static-fluid MRU alone(sensitivity: 76%/75%, reader 1/reader 2), combining DWI with MRI can increase the sensitivity (sensitivity: 84%/84%, p = 0.031/p = 0.016) of upper urinary tract cancer diagnosis. CTU had greater sensitivity (95%/94%) and accuracy(92/91%) than both static-fluid MRU (sensitivity: p < 0.001/p < 0.001 and accuracy: 83%/81%, p = 0.001/p < 0.001) and static-fluid MRU with DWI (sensitivity:p = 0.023/p = 0.039 and accuracy: 87%/85%, p = 0.042/p = 0.049) for the diagnosis of upper urinary tract cancers. Compared with CTU alone, CTU with DWI did not significantly increase sensitivity, specificity or accuracy. However, the diagnostic confidence was improved when the combined technique was used (p = 0.031/p = 0.024). Moreover, there was no significant change in sensitivity, specificity,accuracy or diagnostic confidence when static-fluid MRU was used in combination with CTU and DWI. Conclusion Although there is a potential role for static-fluid MRU and static-fluid MRU with DWI in urinary tract imaging, CTU is still the better choice for the diagnosis of upper urinary tract cancer. Combining DWI with CTU can help improve confidence in upper urinary tract cancer diagnoses.
    No preview · Article · Jun 2014 · European journal of radiology
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    [Show abstract] [Hide abstract] ABSTRACT: To investigate the potential value of histogram analysis of apparent diffusion coefficient (ADC) obtained at standard (700 s/mm(2)) and high (1500 s/mm(2)) b values on a 3.0-T scanner in the differentiation of bladder cancer from benign lesions and in assessing bladder tumors of different pathologic T stages and to evaluate the diagnostic performance of ADC-based histogram parameters. In all, 52 patients with bladder lesions, including benign lesions (n = 7) and malignant tumors (n = 45; T1 stage or less, 23; T2 stage, 7; T3 stage, 8; and T4 stage, 7), were retrospectively evaluated. Magnetic resonance examination at 3.0 T and diffusion-weighted imaging were performed. ADC maps were obtained at two b values (b = 700 and 1500 s/mm(2); ie, ADC-700 and ADC-1500). Parameters of histogram analysis included mean, kurtosis, skewness, and entropy. The correlations between these parameters and pathologic results were revealed. Receiver operating characteristic (ROC) curves were generated to determine the diagnostic value of histogram parameters. Significant differences were found in mean ADC-700, mean ADC-1500, skewness ADC-1500, and kurtosis ADC-1500 between bladder cancer and benign lesions (P = .002-.032). There were also significant differences in mean ADC-700, mean ADC-1500, and kurtosis ADC-1500 among bladder tumors of different pathologic T stages (P = .000-.046). No significant differences were observed in other parameters. Mean ADC-1500 and kurtosis ADC-1500 were significantly correlated with T stage, respectively (ρ = -0.614, P < .001; ρ = 0.374, P = .011). ROC analysis showed that the combination of mean ADC-1500 and kurtosis ADC-1500 has the maximal area under the ROC curve (AUC, 0.894; P < .001) in the differentiation of benign lesions and malignant tumors, with a sensitivity of 77.78% and specificity of 100%. AUCs for differentiating low- and high-stage tumors were 0.840 for mean ADC-1500 (P < .001) and 0.696 for kurtosis ADC-1500 (P = .015). Histogram analysis of ADC-1500 at 3.0 T can be useful in evaluation of bladder lesions. A combination of mean ADC-1500 and kurtosis ADC-1500 may be more beneficial in the differentiation of benign and malignant lesions. Mean ADC-1500 was the most promising parameter for differentiating low- from high-stage bladder cancer.
    Full-text · Article · May 2014 · Academic radiology
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    [Show abstract] [Hide abstract] ABSTRACT: To quantitatively assess the imaging characteristics of sellar lesion in dual-energy computed tomography (CT) imaging for differentiation of sellar meningiomas and pituitary adenomas during the arterial phase (AP) and venous phase (VP). 51 patients with sellar/parasellar tumors (33 macroadenomas and 18 meningiomas) were examined with CT spectral imaging during the AP and the VP. Iodine concentrations were derived from iodine-based material-decomposition CT images and normalized to the iodine concentration in the aorta. The difference in Normalized iodine concentrations (NICs), HU curve slope (λHU), and mean CT values of lesions between the AP and VP were calculated. The two-sample t test was performed to compare quantitative parameters between sellar meningiomas and pituitary adenomas. NICs, λHU, and mean CT values in patients with sellar meningiomas differed significantly from those in patients with pituitary adenomas: Mean NICs were 43.52 mg/mL±1.35 versus 9.23 mg/mL ±2.44, respectively, during the AP and 52.13 mg/mL ±1.04 versus 24.37 mg/mL ±2.23 respectively, during the VP. λHU were -3.03±3.42 versus -0.53±0.23, respectively, during the AP and -2.96±0.41 versus -0.47±0.25, respectively, during the VP. Mean CT values were 193.63±2.08 versus 63.98±2.85, respectively, during the AP and 203.98±0.18 versus 77.66±0.91, respectively, during the VP. The combination of NIC and Mean CT value during VP had highest sensitivity (90.9%) and specificity (100%) among all phases. Quantitative dual-energy CT imaging has promising potential for diagnostic differentiation of sellar meningiomas and pituitary adenomas.
    Preview · Article · Mar 2014 · PLoS ONE
  • Lian-Ming Wu · Xiao-Xi Chen · Yu-Lai Li · Jia Hua · Jie Chen · Jiani Hu · Jian-Rong Xu
    [Show abstract] [Hide abstract] ABSTRACT: To evaluate the ability of diffusion-weighted magnetic resonance imaging (DWI) in differentiating malignant thyroid nodules from benign lesions with a meta-analysis. Articles in English and Chinese language relating to the accuracy of DWI for this utility were retrieved. Pooled estimation and subgroup analysis data were obtained by statistical analysis. A total of seven studies (17 subsets) with 358 patients, who fulfilled all of the inclusion criteria, were considered for the analysis. No publication bias was found (bias = 7.03, P > .05). Methodological quality was relatively high. DWI sensitivity was 0.91 (95% confidence interval [CI], 0.87-0.94) and specificity was 0.93 (95% CI, 0.86-0.96). Overall, positive likelihood ratio was 12.24 (95% CI, 6.47-23.20) and negative likelihood ratio was 0.99 (95% CI, 0.06-0.15). Diagnostic odds ratio was 123.78 (95% CI, 56.85-269.48). The area under the curve of the summary receiver operating characteristic was 0.94 (95% CI, 0.92-0.96). In patients with high pretest probabilities, DWI enabled confirmation of malignant thyroid lesion; in patients with low pretest probabilities, DWI enabled exclusion of malignant thyroid lesion. Worst-case-scenario (pretest probability, 50%) posttest probabilities were 92% and 9% for positive and negative DWI results, respectively. A limited number of small studies suggests that quantitative DWI is a reliable diagnostic method for differentiation between benign and malignant thyroid lesions.
    No preview · Article · Dec 2013 · Academic radiology
  • Xiao-Xi Chen · Lian-Ming Wu · Weibo Chen · Jianrong Xu
    [Show abstract] [Hide abstract] ABSTRACT: PURPOSE To assess the feasibility of quantitative T2 star mapping at 3.0 T for prostate cancer detection and to investigate the use of T2 star values to characterize tumor aggressiveness, with whole mount step-section pathologic analysis as the reference standard. METHOD AND MATERIALS Prostate multi-echo T2 star was performed in Fifty-five consecutive patients with prostate cancer using a multishot fast field echo (mFFE) sequence at 3.0T MRI. T2 star mapping was obtained by exponentially fitting the multi-echo T2 star images pixel-by-pixel with different echo times for each slice. Generalized estimating equations were used to test the T2 star value difference between benign and malignant prostate regions and the association between T2 star value and tumor Gleason scores. RESULTS The T2 star values of the cancerous prostatic regions (mean: 42.51 + 0.65 ms) were significantly lower (P <0.001) than those of the benign prostatic regions (mean: 74.87+ 0.99 ms). Adopting a threshold value of 59.27 ms. T2 star mapping resulted in 94.8% sensitivity, 77.3% specificity in the identification of prostate cancer. A lower mean T2 star value was significantly associated with a higher tumor Gleason score (mean T2 star values of [53.53, 43.75, 33.66, and 22.95] ms were associated with Gleason score of 3 + 3, 3 + 4, 4 + 3, and 8 or higher, respectively p<0.05). CONCLUSION From these preliminary data quantitative T2 star mapping seems a potential method in the characterization of prostate cancer. T2 star mapping provided additional quantitative information that significantly correlated with prostate cancer aggressiveness. CLINICAL RELEVANCE/APPLICATION T2 star mapping seems a potential method in the characterization of prostate cancer.
    No preview · Conference Paper · Dec 2013
  • Guang-Yu Wu · Qing Lu · Lian-Ming Wu · Wenkong · Xiao-Xi Chen · Jian-Rong Xu
    [Show abstract] [Hide abstract] ABSTRACT: Diffusion-weighted magnetic resonance imaging (DW-MRI) has been considered to be useful in diagnosing upper urinary tract (UUT) disease; however, the value of DW-MRI with different b values has not been reported. To evaluate the performance of using conventional MRI alone and in combination with DWI with different b values in diagnosing UUT cancer. Seventy patients with suspected UUT cancer underwent conventional MRI (T1-weighted and T2-weighted) and DW-MRI (b = 500 and 1500 s/mm(2)) on a 3 T-MRI scanner. The ureteroscopic and histopathologic findings were compared with the imaging findings. The utility of detecting UUT cancer using conventional MRI (set A), combined DW-MRI (b = 500 s/mm(2)) and conventional MRI (set B), and combined DW-MRI (b = 1500 s/mm(2)) and conventional MRI (set C) were independently evaluated by two readers. A total of 32 patients had verified cancer; 23 patients had benign UUT diseases, and 15 had no abnormality. Sets B and C had significantly improved diagnostic accuracy for UUT cancer compared with set A; the specificity in diagnosing UUT cancer was significantly improved when using set C compared with sets A and B. In patients without UUT obstructions, improved sensitivity and accuracy in diagnosis was achieved when using sets B and C compared with set A. Using DW-MRI in combination with conventional MRI provides increased diagnostic accuracy and sensitivity in patients without UUT obstruction. The combination of conventional MRI and DW-MRI with a higher b value (1500 s/mm(2)) improved the specificity in diagnosing UUT cancer compared to conventional sequences and DW-MRI with a lower b value (500 s/mm(2)).
    No preview · Article · Oct 2013 · Acta Radiologica
  • Lian-Ming Wu · Jian-Rong Xu · Jia Hua · Hai-Yan Gu · Jiong Zhu · Jiani Hu
    [Show abstract] [Hide abstract] ABSTRACT: To assess diffusion-weighted magnetic resonance imaging (DWI-MRI) performed with apparent diffusion coefficient (ADC) values for the detection of cervical lymphadenopathy. Studies evaluating DWI-MRI for the detection of cervical lymphadenopathy were systematically searched for in the MEDLINE, EMBASE, Cancerlit, and Cochrane Library and other database from January 1995 to November 2010. By node-based data analyses, Cochrane methodology was used for the results of this meta-analysis. Eight studies enrolling a total of 229 individuals were eligible for inclusion. Significant differences were found between malignant nodes and benign nodes of the mean ADC value (WMD [weighted-mean difference]: 1.19, 95% CI: [1.02, 1.35] × 10−3 mm2/s, [P < 0.05]). In the secondary outcomes, significant differences were found between lymphomatous nodes and benign nodes (WMD: 1.33, 95% CI: [0.89, 1.77] × 10−3 mm2/s), and nodes originating from highly or moderately differentiated cancer (WMD: 0.24, 95% CI: [0.21, 0.28] × 10−3 mm2/s, [P < 0.05]), and nodes originating from poorly differentiated cancers (WMD: 0.10, 95% CI: [0.06, 0.14] × 10−3 mm2/s, [P < 0.05]). DWI-MRI performed with ADC values shows significant differences among malignant nodes, lymphomatous nodes, and benign nodes in cervical lymphadenopathy. J. Magn. Reson. Imaging 2012;38:663–670.
    No preview · Article · Sep 2013 · Journal of Magnetic Resonance Imaging
  • Lian-Ming Wu · Jian-Rong Xu · Hai-Yan Gu · Jia Hua · Jie Chen · Jiong Zhu · Wei Zhang · Jiani Hu
    [Show abstract] [Hide abstract] ABSTRACT: Gadoxetic acid is a recently developed hepatobiliary-specific contrast material used for magnetic resonance imaging (MRI) which enables highly sensitive detection of hepatocellular carcinoma (HCC). We performed a meta-analysis of all available studies of the diagnostic performance of gadoxetic acid-enhanced MRI (Gd-EOB-MRI) for detection of HCC in patients with chronic liver disease. Databases including MEDLINE and EMBASE were searched for relevant original articles published from January 2000 to April 2012. Pooled estimation and subgroup analysis data were obtained by statistical analysis. Across 10 studies of 570 patients, Gd-EOB-MRI sensitivity was 0.91 (95 % CI 0.77, 0.97) and specificity was 0.93 (95 % CI 0.85, 0.97). Overall, LR+ was 13.6 (95 % CI 5.6, 33.2), LR- was 0.10 (95 % CI 0.04, 0.27), and DOR was 140.36 (95 % CI 28, 696). Among patients with high pre-test probabilities, MRI enabled confirmation of HCC; among patients with low pre-test probabilities, MRI enabled exclusion of HCC. Worst-case-scenario (pre-test probability, 50 %) post-test probabilities were 93 and 9 % for positive and negative MRI results, respectively. In studies in which both Gd-EOB-MRI and contrast enhanced computed tomography (CE-CT) were performed, Gd-EOB-MRI was more sensitive than CE-CT (0.93 vs. 0.78; p < 0.05). Subgroup analysis suggested average lesion size (<2 vs. >2 cm) did not affect the diagnostic accuracy of the test (p > 0.05). A limited number of small studies suggest Gd-EOB-MRI has good diagnostic performance in the detection of HCC among patients with chronic liver disease. It is also confirmed to be a reliable tool for evaluation of small early-stage HCC.
    No preview · Article · Jul 2013 · Digestive Diseases and Sciences
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    Lian-Ming Wu · Jie Chen · Jiani Hu · Hai-Yan Gu · Jian-Rong Xu · Jia Hua
    [Show abstract] [Hide abstract] ABSTRACT: Breast cancer is the most common cancer in women worldwide. However, it remains a difficult diagnosis problem to differentiate between benign and malignant breast lesions, especially in small early breast lesions. To assess the diagnostic value of diffusion-weighted imaging (DWI) combined with T2-weighted imaging (T2WI) for small breast cancer characterization. Fifty-eight patients (65 lesions) with a lesion <2 cm in diameter underwent 3.0 Tesla breast magnetic resonance imaging (MRI) including DWI and histological analysis. Three observers with varying experience levels reviewed MRI. The probability of breast cancer in each lesion on MR images was recorded with a 5-point scale. Areas under the receiver-operating characteristic curve (AUCs) were compared by using the Z test; sensitivity and specificity were determined with the Z test after adjusting for data clustering. AUC of T2WI and DWI (Observer 1, 0.95; Observer 2, 0.91; Observer 3, 0.83) was greater than that of T2WI (Observer 1, 0.80; Observer 2, 0.74; Observer 3, 0.70) for all observers (P < 0.0001 in all comparisons). Sensitivity of T2WI and DWI (Observer 1, 90%; Observer 2, 93%; and Observer 3, 86%) was greater than that of T2WI alone (Observer 1, 76%; Observer 2, 83%; Observer 3, 79%) for all observers (P < 0.0001 in all comparisons). Specificity of T2WI and DWI was greater than that of T2WI alone for observer 1 (89% vs. 72%, P < 0.01) and observer 2 (94% vs. 78%, P < 0.001). DWI combined with T2WI can improve the diagnostic performance of MRI in small breast cancer characterization. It should be considered selectively in the preoperative evaluation of patients with small lesions of the breast.
    Preview · Article · Jul 2013 · Acta Radiologica
  • [Show abstract] [Hide abstract] ABSTRACT: Rationale and objectives: To prospectively assess the incremental value of diffusion-weighted imaging (DWI) combined with T2-weighted images (T2WI) in determining the T stage of bladder cancer by using pathologic findings as the reference standard. Materials and methods: This study is approved by the institutional review board; informed consent was waived. The study includes 362 patients (age range, 48-87 years; mean, 71 years) who underwent 3.0-T magnetic resonance imaging and histologic examination. Three observers with varying experience levels reviewed the T2WI data alone, DWI data alone, and combined T2WI and DWI data. Sensitivity, specificity, accuracy, and area under curve (AUC) were determined with the Z test after adjusting for data clustering. Results: For differentiating Tis to T1 tumors from T2 to T4 tumors, the AUCs for T2WI and DWI (0.97 for observer 1 and 0.96 for observer 2) were greater than those for the DWI alone (0.92 for observer 1 and 0.90 for observer 2) (P < .05). Observer 3 had similar AUCs for T2WI and DWI compared to DWI alone. The accuracy of T2WI and DWI (observer 1, 98%; observer 2, 96%; observer 3, 92%) was greater than that of DWI alone (observer 1, 92%; observer 2, 90%; observer 3, 87%) for all observers (P < .05). The specificity of T2WI and DWI (observer 1, 100%; observer 2, 98%; observer 3, 93%) was greater than that of DWI alone (observer 1, 92%; observer 2, 90%; observer 3, 87%) for all observers (P < .05). Sensitivity was not improved even when T2WI and DWI were used. For differentiating Tis to T2 Tumors from T3 to T4 Tumors, the overall accuracy, specificity, and AUC for diagnosing T2 or higher stages were not significantly improved by combiningT2WI and DWI. Conclusions: T2WI combined with DWI can be a reliable sequence for preoperative evaluation of T stage urinary bladder cancer. It is particularly more useful in differentiating T1 or lower tumors from T2 or higher tumors compared to DWI alone.
    No preview · Article · Jun 2013 · Academic radiology
  • Lian-Ming Wu · Jiong Zhu · Jiani Hu · Yan Yin · Hai-Yan Gu · Jia Hua · Jie Chen · Jian-Rong Xu
    [Show abstract] [Hide abstract] ABSTRACT: Objective: This meta-analysis aimed to evaluate the accuracy of magnetic resonance imaging (MRI) in predicting responses in patients with locally advanced rectal cancer after preoperative neoadjuvant therapy. Methods: Articles in English language relating to the accuracy of MRI for this utility were retrieved. Methodological quality was assessed by Quality Assessment of Diagnostic Accuracy Studies tool. Pooled estimation and subgroup analysis data were obtained by statistical analysis. Results: Fourteen studies involved 751 pathologically confirmed patients met the inclusion criteria. Methodological quality was relatively high. To predict histopathological response in locally advanced rectal cancer by MRI, the pooled sensitivity and specificity were 0.78 [95 % confidence intervals (CI), 0.65, 0.87] and 0.81 (95 % CI, 0.72, 0.87), respectively. Positive likelihood ratio and negative likelihood ratio were 4.1 (95 %CI, 2.9, 5.8) and 0.27 (95 % CI, 0.17, 0.43), respectively. Subgroup analysis showing that imaging was performed at 3.0 T MRI devices had higher pooled sensitivity (0.92, 95 % CI, 0.84, 1.00) than the subgroup of MRI with ≤1.5 T (0.68, 95 % CI, 0.53, 0.82) (p < 0.05).The sensitivity and specificity of T2-weighted imaging (T2WI) with diffusion-weighted imaging (DWI) were 0.92 (95 % CI, 0.81, 1.00) and 0.75 (95 % CI, 0.54, 0.95); those of T2WI alone were 0.64 (95 % CI, 0.47, 0.82) and 0.88 (95 % CI, 0.81, 0.94) (p > 0.05). Conclusion: This meta-analysis indicates that MRI is an accurate tool in predicting pathologic response after preoperative therapy in patients with locally advanced rectal cancer. It is suggested to perform MRI by 3.0 T devices, which might be sensitive to identify responder. The addition of DWI to T2WI showed a non-significant improvement in sensitivity, which deserves further investigation.
    No preview · Article · Mar 2013 · International Journal of Colorectal Disease
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    Lian-Ming Wu · Jian-Rong Xu · Jiani Hu
    No preview · Article · Feb 2013 · American Journal of Roentgenology
  • Lian-Ming Wu · Jian-Rong Xu · Jiani Hu
    No preview · Article · Feb 2013 · American Journal of Roentgenology
  • Lian-Ming Wu · Jiani Hu · Hai-Yan Gu · Jia Hua · Jian-Rong Xu
    [Show abstract] [Hide abstract] ABSTRACT: PurposeTo perform a meta-analysis of all available studies of the diagnostic performance of diffusion-weighted magnetic resonance imaging (DW-MRI) in patients with hepatic metastases.Methods Databases including MEDLINE and EMBASE were searched for relevant original articles published from January 2000 to February 2012. We determined sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR+ and LR–), diagnostic odds ratio (DOR) and constructed summary receiver operating characteristic curves using hierarchical regression models.ResultsAcross 11 studies (537 patients), DW-MRI sensitivity was 0.87 (95% confidence interval (CI), 0.80, 0.91) and specificity was 0.90 (95% CI, 0.86, 0.93). Overall, LR+ was 8.52 (95% CI, 6.17, 11.77), LR– was 0.15 (95% CI, 0.10, 0.22) and DOR was 57.36 (95% CI, 38.29, 85.93). In studies in which both DW-MRI and contrast-enhanced magnetic resonance imaging (CE-MRI) were performed, the comparison of DW-MRI performance with that of CE-MRI suggested no major differences against these two methods (p > 0.05). DW-MRI combined CE-MRI had higher sensitivity and specificity than DW-MRI alone (97% versus 86% and 91% versus 90%, respectively) (p < 0.05). The subgroup in which DW-MRI examinations were performed with a 3.0 Tesla (T) device had higher pooled specificity (0.91, 95% CI, 0.88–0.95) than the subgroup of DW-MRI with 1.5 T device (0.81, 95% CI, 0.67, 0.94) (p < 0.05). Average lesion size (⩽1.5 cm versus >1.5 cm) did not influence the diagnostic accuracy of the test (p > 0.05).Conclusion Our results demonstrate DW-MRI has good diagnostic performance in the overall evaluation of hepatic metastases and equivalent to CE-MRI. Combination of CE-MRI and DW-MRI can improve the diagnostic accuracy of magnetic resonance (MR) imaging. Our study further confirms that DW-MRI can accurately detect hepatic metastases regardless of the lesion size. It is suggested to perform DW-MRI by 3.0 T devices, which might have high specificity to identify liver metastases.
    No preview · Article · Feb 2013 · European journal of cancer (Oxford, England: 1990)
  • Lian-Ming Wu · Jian-Rong Xu · Hai-Yan Gu · Jia Hua · Jiani Hu
    [Show abstract] [Hide abstract] ABSTRACT: GOALS:: To evaluate the overall diagnostic accuracy of magnetic resonance imaging (MRI) in assessing the activity of Crohn's disease (CD) in the small bowel. BACKGROUND:: Cross-sectional imaging techniques are playing an increasing role in the evaluation of suspected CD. Advantages of MRI include a lack of ionizing radiation, the ability to provide dynamic information regarding bowel distention and motility, improved soft-tissue contrast, and a relatively safe intravenous contrast agent profile. STUDY:: Two reviewers searched MEDLINE, EMBASE, and other electronic databases to identify studies in which MRI imaging was evaluated for assessing the activity of CD in the small bowel from January 2001 to September 2011. Bivariate random-effects meta-analytic methods were used to estimate summary, sensitivity, specificity, and receiver operating characteristic curves. RESULTS:: MRI had a pooled sensitivity of 0.87 [95% confidence interval (CI): 0.77, 0.93] and a pooled specificity of 0.91 (95% CI: 0.81, 0.96). Overall, likelihood ratio (LR)+ was 9.5 (95% CI: 4.4, 20.6) and LR- was 0.14 (95% CI: 0.08, 0.26). In patients with high pretest probabilities, MRI enabled confirmation of active CD; in patients with low pretest probabilities, MRI enabled exclusion of active CD. Worst-case-scenario (pretest probability, 50%) posttest probabilities were 90% and 13% for positive and negative MRI results, respectively. CONCLUSIONS:: A limited number of small studies suggest that MRI has high sensitivity and specificity for diagnosis of active CD in the small bowel; MRI will likely also prove to be suitable as the primary modality for active CD imaging surveillance.
    No preview · Article · Jan 2013 · Journal of clinical gastroenterology