[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.
[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.
[Show abstract][Hide abstract] ABSTRACT: To evaluate the clinical value of MR multi-imaging techniques in diagnosing and preoperative assessment of pancreaticobiliary tumor.
MR multi-imaging techniques, including MR cross-sectional imaging, MR cholangiopancreatography (MRCP) and 3D dynamic contrast-enhanced MR angiography (3D DCE MRA), were performed to make prospective diagnosis and preoperative evaluation in 28 patients with suspected pancreaticobiliary tumors. There were 17 cases of pancreatic adenocarcinoma, 8 cases of biliary system carcinoma and 3 cases of non-neoplastic lesions.
Using MR multi-imaging techniques, the accuracy in diagnosing the patients with pancreaticobiliary tumors was 89.3% (25/28). The accuracy in detecting the range of tumor invasion was 80.3% (57/71). The sensitivity, specificity, accuracy, positive and negative predictive value of MR multi-imaging techniques in preoperative assessment of the resectability of pancreaticobiliary tumor were 83.3%, 89.5%, 88.0%, 71.4%, and 94.4%, respectively. There was well diagnostic consistency between MR multi-imaging techniques and CT (kappa = 0.64, P<0.01). The fusion image could be made from MRCP and 3D DCE MRA images.
MR multi-imaging techniques can integrate the advantages of various MR images. The non-invasive "all-in-one" MR imaging protocol is the efficient method in diagnosing, staging and preoperative assessment of pancreaticobiliary tumor.
World Journal of Gastroenterology 07/2005; 11(24):3756-61. · 2.55 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To evaluate the clinical value of various imageological methods in diagnosing the pancreato-biliary diseases and to seek the optimal procedure.
Eighty-two cases of pancreato-biliary diseases confirmed by surgery and pathology were analyzed. There were 38 cases of cholelithiasis, 34 cases of pancreato-biliary tumors and 10 other cases. The imageological methods included B-US, CT, ERCP, PTC, cross-sectional MRI and MR cholangiopancreatography (MRCP).
The accuracy rate of MRCP in detecting the location of pancreato-biliary obstruction was 100%. In differentiating malignant from benign obstruction, the sensitivity of the combination of MRCP and cross-sectional MRI was 82.3%, the specificity was 93.8%, and the accuracy rate was 89.0%. The accuracy rate for determining the nature of obstruction was 87.8%, which was superior to that of B-US (P=0.0000) and CT (P=0.0330), but there was no significant difference between direct cholangiopancreatography and the combination of MRCP and conventional MRI (P=0.6666).
In most cases, MRCP can substitute direct cholangiopancreatography for diagnosis. The combination of MRCP and cross-sectional MRI should be considered as an important means in diagnosing the pancreato-biliary diseases, pre-operative assessment and post-operative follow-ups.
World Journal of Gastroenterology 01/2004; 9(12):2824-7. · 2.55 Impact Factor