AIM:To investigate the use of multi-b-value diffusionweighted imaging in diagnosing pancreatic cancer.METHODS:We retrospectively analyzed 33 cases of pancreatic cancer and 12 cases of benign pancreatic tumors at the S...AIM:To investigate the use of multi-b-value diffusionweighted imaging in diagnosing pancreatic cancer.METHODS:We retrospectively analyzed 33 cases of pancreatic cancer and 12 cases of benign pancreatic tumors at the Second Affiliated Hospital of Kunming Medical University from December 2008 to January2011.The demographic characteristics,clinical presentation,routine magnetic resonance imaging and diffusion weighted imaging(DWI)features with different b values were reviewed.Continuous data were expressed as mean±SD.Comparisons between pancreatic cancer and benign pancreatic tumors were performed using the Student’s t test.A probability of P<0.05 was considered statistically significant.RESULTS:Thirty-three patients with pancreatic cancer were identified.The mean age at diagnosis was 60±5.6 years.The male:female ratio was 21:12.Twenty cases were confirmed by surgical resection and 13 by biopsy of metastases.T1 weighted images demonstrated a pancreatic head mass in 16 patients,a pancreatic body mass in 10 cases,and a pancreatic tail mass with pancreatic atrophy in 7 cases.Eight patients had hepatic metastases,13 had invasion or envelopment of mesenteric vessels,4 had bone metastases,and 8had lymph node metastases.DWI demonstrated an irregular intense mass with unclear margins.Necrotic tissue demonstrated an uneven low signal.A b of 1100s/mm2was associated with a high intensity signal with poor anatomical delineation.A b of 700 s/mm2was associated with apparent diffusion coefficients(ADCs)that were useful in distinguishing benign and malignant pancreatic tumors(P<0.05).b values of 50,350,400,450 and 1100 s/mm2were associated with ADCs that did not differentiate the two tumors.CONCLUSION:Low b value images demonstrated superior anatomical details when compared to high b value images.Tumor tissue definition was high and contrast with the surrounding tissues was good.DWI was useful in diagnosing pancreatic cancer.展开更多
This study examined the effect of different b values on diffusion-weighted MR imaging （DWI） of human prostate by using single-shot spin echo echo planar imaging （SE-EPI） sequences, observed the normal appearances ...This study examined the effect of different b values on diffusion-weighted MR imaging （DWI） of human prostate by using single-shot spin echo echo planar imaging （SE-EPI） sequences, observed the normal appearances and measured apparent diffusion coefficient （ADC） values in anatomical regions of normal prostate. Twenty-four healthy volunteers （mean age： 32 y） were studied by using a 1.5T system with a phased array surface multicoil. Two kinds of single-shot SE-EPI sequence were used to perform DWI in the prostate in volunteers, with five b values being 0, 30, 300, 500 to 1000 s/mm2. The image quality with different imaging parameters was analyzed and the ADC values in anatomical regions of normal prostate were measured. DWI of prostate was successfully obtained in all volunteers. The images were of good quality, without artifacts containing pixels within the prostate. The contrast was good between the different anatomical regions of the prostatic gland, i.e., the peripheral zone （PZ）, which exhibited higher signal intensity, and the central gland （CG）. Signal intensity contrast was related to the magnitude of b values. The ADC values in PZ and CG were （1.27±0.22）×10-3 mm2/s and （1.01±0.17）×10-3 mm2/s,respectively. The ADC values were found to be significantly higher in PZ than in CG （P〈0.05, paired t-test）. Significant differences were found between the slice-selecting component and both the read-out and phase-encoding components of the ADC values. It is concluded that SE-EPI is a suitable DWI sequence for human prostate. The contrast between PZ and CG is good when b values are low, while the diffusion and ADC values are accurate when b values are high. ADC values are higher in PZ than in CG in normal prostate. Diffusional anisotropy is present in normal prostatic tissue.展开更多
Objective To evaluate the value of MRI diffusion weighted imaging in localization of prostate cancer with whole-mount step section pathology. Methods We treated 36 patients using laparoscopic radical prostatectomy fro...Objective To evaluate the value of MRI diffusion weighted imaging in localization of prostate cancer with whole-mount step section pathology. Methods We treated 36 patients using laparoscopic radical prostatectomy from Oct. 2009 to Jun. 2010. Patients who did not have an MRL /DWI examination or a surgical history of pros-展开更多
Diffusion-weighted imaging (DWI) as a new technique of magnetic resonance imaging (MRI) is used to detect focal hepatic lesions. This study was designed to evaluate the significance of DWI to differentiate focal hepat...Diffusion-weighted imaging (DWI) as a new technique of magnetic resonance imaging (MRI) is used to detect focal hepatic lesions. This study was designed to evaluate the significance of DWI to differentiate focal hepatic lesions less than 3 cm in diameter by the quantitation of apparent diffusion coefficient (ADC) values. METHODS:DWI using 1.5T MRI scanner unit was performed with a spin-echo single-shot echo planar imaging (EPI) in 56 cases of small focal hepatic lesions, including hepatocellular carcinoma (11), hepatic metastatic tumor (15 ), hepatic cavernous hemangioma (14), and hepatic cyst (16).The ADC values of these lesions were calculated respectively. The ratios of the ADC values of lesion/liver in hepatocellular carcinomas and hepatic metastatic tumors were also estimated. RESULTS:The mean ADC values (mm2/s) were (0.93±0.06) ×10-3 in hepatocellular carcinomas, (1.09±0.18)×10-3 in hepatic metastatic tumors,(1.95±0.38)×10-3 in hepatic cavernous hemangiomas, and (3.18±0.33) ×10-3 in hepatic cysts. The ratios of ADC values of lesion/liver were 0.90±0.06 and 1.15±0.14 in hepatocellular carcinoma and hepatic metastatic tumors respectively, which were significantly different (P<0.05). CONCLUSION:The measurement of ADC values and the ratios of ADC values of lesion/liver are helpful in MR diagnosis and differentiation of focal hepatic lesions.展开更多
Aim: To investigate the diagnostic efficiency of apparent diffusion coefficient value (ADC) in differentiating benign from malignant breast lesions at 3.0 T diffusion-weighted imaging with different pair of b value. M...Aim: To investigate the diagnostic efficiency of apparent diffusion coefficient value (ADC) in differentiating benign from malignant breast lesions at 3.0 T diffusion-weighted imaging with different pair of b value. Methods: Total 110 patients with 107 lesions (44 benign and 63 malignant) were selected for our study with five different b-values 0, 400, 800, 1200 and 1600 s/mm<sup>2</sup>. ADC values were calculated using different pairs of b values. The cut-off ADC values and diagnostic efficiency were evaluated by receiver operating characteristic analysis. Comparison of Mean ADC value for breast lesions was determined by using independent sample t test. ROC curves were used for diagnostic efficiency of ADC using different pairs of b values. Results: With increase of b value, mean ADC value decreases. The mean ADC values for benign were 1.73 × 10<sup>-3</sup> mm<sup>2</sup>/s for b 0 and 400, 1.57 × 10<sup>-3</sup> mm<sup>2</sup>/s for b 0 and 800, 1.43 × 10<sup>-3</sup> mm<sup>2</sup>/s for b 0 and 1200 and 1.30 × 10<sup>-3</sup> mm<sup>2</sup>/s for b 0 and 1600 s/mm<sup>2</sup>. The mean ADC values for the malignant breast lesion were 1.21 × 10<sup>-3</sup> mm<sup>2</sup>/s for b 0 and 400, 1.06 × 10<sup>-3</sup> mm<sup>2</sup>/s for b 0 and 800, 0.94 × 10<sup>-3</sup> mm<sup>2</sup>/s for b 0 and 1200 and 0.86 × 10<sup>-3</sup> mm<sup>2</sup>/s for b 0 and 1600 s/mm<sup>2</sup>. ADC diagnostic efficiency for benign and malignant lesion for all the pair of b value combination was significant (p > 0.05). The sensitivity, specificity, PPV, NPV and accuracy were 80.95%, 90.9%, 92.72%, 76.92%, 85.04% for b 0 and 400;84.12%, 90.9%, 92.98%, 80%, 86.91% for b 0 and 800;84.12%, 90.9%, 92.98%, 80%, 86.91% for b 0 and 1200;84.12%, 90.9%, 92.98%, 80%, 86.91% for b 0 and 1600 s/mm<sup>2</sup> respectively. Conclusion: DWI is effective in differentiating benign and malignant breast lesion at 3.0 Tesla using ADC with higher b value combination.展开更多
Background： The aim of this study was to assess the performance of apparent diffusion coefficient （ADC） measurement obtained with diffusion-weighted magnetic resonance imaging （DW-MRI） to distinguish renal cell c...Background： The aim of this study was to assess the performance of apparent diffusion coefficient （ADC） measurement obtained with diffusion-weighted magnetic resonance imaging （DW-MRI） to distinguish renal cell carcinomas （RCCs） from small benign solid renal tumors （〈4 cm）. Methods： In this cross-sectional study, 49 consecutive patients with histopathologically confirmed small solid renal tumors, and seven healthy volunteers were imaged using nonenhanced MRI and DW-MRI. The ADC map was calculated using the b values of 0, 50, 400, and 600 s/ mm2 and values compared via the Kruskal-Wallis and Mann-Whitney tests. The utility of ADC for differentiating RCCs and benign lesions was assessed using a receiver operating characteristic curve. Multiple nonenhanced MRI features were analyzed by Logistic regression. Results： The tumors consisted of 33 cases of clear-cell RCCs （ccRCCs） and 16 cases of benign tumors, including 14 cases of minimal fat angiomyolipomas and 2 cases ofoncocytomas. The ADCs showed significant differences among benign tumors （[0.90 ±0.52] x 10 x mm2/s）, ccRCCs （[1.53 ± 0.31 ] x 10 ^3 mm2/s） and the normal renal parenchyma （[2.22 ± 0.12]x 10^-3 mmVs） （P 〈 0.001）. Moreover, there was statistically significant difference between high and low-grade ccRCCs （P = 0.004）. Using a cut-offADC of 1.36± 10 3 mm2/s, DW-MRI resulted in an area under the curve （AUC）, sensitivity, and specificity equal to 0.839, 75.8%, and 87.5%, respectively. Nonenhanced MRI alone and the combination of imaging methods led to an AUC, sensitivity and specificity equal to 0.919, 93.9%, and 81.2%, 0.998, 97%, and 100%, respectively. The Logistic regression showed that the location of the center of the tumor （inside the contour of the kidney） and appearance of stiffblood vessel were significantly helpful for diagnosing ccRCCs. Conclusions： DW-MRI has potential in distinguishing ccRCCs from benign lesions in human small solid renal tumors （〈4 cm）, and in increasing the accuracy for diagnosing ccRCCs when combined with nonenhanced MRI.展开更多
文摘AIM:To investigate the use of multi-b-value diffusionweighted imaging in diagnosing pancreatic cancer.METHODS:We retrospectively analyzed 33 cases of pancreatic cancer and 12 cases of benign pancreatic tumors at the Second Affiliated Hospital of Kunming Medical University from December 2008 to January2011.The demographic characteristics,clinical presentation,routine magnetic resonance imaging and diffusion weighted imaging(DWI)features with different b values were reviewed.Continuous data were expressed as mean±SD.Comparisons between pancreatic cancer and benign pancreatic tumors were performed using the Student’s t test.A probability of P<0.05 was considered statistically significant.RESULTS:Thirty-three patients with pancreatic cancer were identified.The mean age at diagnosis was 60±5.6 years.The male:female ratio was 21:12.Twenty cases were confirmed by surgical resection and 13 by biopsy of metastases.T1 weighted images demonstrated a pancreatic head mass in 16 patients,a pancreatic body mass in 10 cases,and a pancreatic tail mass with pancreatic atrophy in 7 cases.Eight patients had hepatic metastases,13 had invasion or envelopment of mesenteric vessels,4 had bone metastases,and 8had lymph node metastases.DWI demonstrated an irregular intense mass with unclear margins.Necrotic tissue demonstrated an uneven low signal.A b of 1100s/mm2was associated with a high intensity signal with poor anatomical delineation.A b of 700 s/mm2was associated with apparent diffusion coefficients(ADCs)that were useful in distinguishing benign and malignant pancreatic tumors(P<0.05).b values of 50,350,400,450 and 1100 s/mm2were associated with ADCs that did not differentiate the two tumors.CONCLUSION:Low b value images demonstrated superior anatomical details when compared to high b value images.Tumor tissue definition was high and contrast with the surrounding tissues was good.DWI was useful in diagnosing pancreatic cancer.
基金supported by a grant from Key Project of Science and Technology Research of Hubei Province of China (No. 2005AA304B08).
文摘This study examined the effect of different b values on diffusion-weighted MR imaging （DWI） of human prostate by using single-shot spin echo echo planar imaging （SE-EPI） sequences, observed the normal appearances and measured apparent diffusion coefficient （ADC） values in anatomical regions of normal prostate. Twenty-four healthy volunteers （mean age： 32 y） were studied by using a 1.5T system with a phased array surface multicoil. Two kinds of single-shot SE-EPI sequence were used to perform DWI in the prostate in volunteers, with five b values being 0, 30, 300, 500 to 1000 s/mm2. The image quality with different imaging parameters was analyzed and the ADC values in anatomical regions of normal prostate were measured. DWI of prostate was successfully obtained in all volunteers. The images were of good quality, without artifacts containing pixels within the prostate. The contrast was good between the different anatomical regions of the prostatic gland, i.e., the peripheral zone （PZ）, which exhibited higher signal intensity, and the central gland （CG）. Signal intensity contrast was related to the magnitude of b values. The ADC values in PZ and CG were （1.27±0.22）×10-3 mm2/s and （1.01±0.17）×10-3 mm2/s,respectively. The ADC values were found to be significantly higher in PZ than in CG （P〈0.05, paired t-test）. Significant differences were found between the slice-selecting component and both the read-out and phase-encoding components of the ADC values. It is concluded that SE-EPI is a suitable DWI sequence for human prostate. The contrast between PZ and CG is good when b values are low, while the diffusion and ADC values are accurate when b values are high. ADC values are higher in PZ than in CG in normal prostate. Diffusional anisotropy is present in normal prostatic tissue.
文摘Objective To evaluate the value of MRI diffusion weighted imaging in localization of prostate cancer with whole-mount step section pathology. Methods We treated 36 patients using laparoscopic radical prostatectomy from Oct. 2009 to Jun. 2010. Patients who did not have an MRL /DWI examination or a surgical history of pros-
基金This study was supported by the Natural Science Foundation of Guangdong Province, China (No.101595 and No. 32830).
文摘Diffusion-weighted imaging (DWI) as a new technique of magnetic resonance imaging (MRI) is used to detect focal hepatic lesions. This study was designed to evaluate the significance of DWI to differentiate focal hepatic lesions less than 3 cm in diameter by the quantitation of apparent diffusion coefficient (ADC) values. METHODS:DWI using 1.5T MRI scanner unit was performed with a spin-echo single-shot echo planar imaging (EPI) in 56 cases of small focal hepatic lesions, including hepatocellular carcinoma (11), hepatic metastatic tumor (15 ), hepatic cavernous hemangioma (14), and hepatic cyst (16).The ADC values of these lesions were calculated respectively. The ratios of the ADC values of lesion/liver in hepatocellular carcinomas and hepatic metastatic tumors were also estimated. RESULTS:The mean ADC values (mm2/s) were (0.93±0.06) ×10-3 in hepatocellular carcinomas, (1.09±0.18)×10-3 in hepatic metastatic tumors,(1.95±0.38)×10-3 in hepatic cavernous hemangiomas, and (3.18±0.33) ×10-3 in hepatic cysts. The ratios of ADC values of lesion/liver were 0.90±0.06 and 1.15±0.14 in hepatocellular carcinoma and hepatic metastatic tumors respectively, which were significantly different (P<0.05). CONCLUSION:The measurement of ADC values and the ratios of ADC values of lesion/liver are helpful in MR diagnosis and differentiation of focal hepatic lesions.
文摘Aim: To investigate the diagnostic efficiency of apparent diffusion coefficient value (ADC) in differentiating benign from malignant breast lesions at 3.0 T diffusion-weighted imaging with different pair of b value. Methods: Total 110 patients with 107 lesions (44 benign and 63 malignant) were selected for our study with five different b-values 0, 400, 800, 1200 and 1600 s/mm<sup>2</sup>. ADC values were calculated using different pairs of b values. The cut-off ADC values and diagnostic efficiency were evaluated by receiver operating characteristic analysis. Comparison of Mean ADC value for breast lesions was determined by using independent sample t test. ROC curves were used for diagnostic efficiency of ADC using different pairs of b values. Results: With increase of b value, mean ADC value decreases. The mean ADC values for benign were 1.73 × 10<sup>-3</sup> mm<sup>2</sup>/s for b 0 and 400, 1.57 × 10<sup>-3</sup> mm<sup>2</sup>/s for b 0 and 800, 1.43 × 10<sup>-3</sup> mm<sup>2</sup>/s for b 0 and 1200 and 1.30 × 10<sup>-3</sup> mm<sup>2</sup>/s for b 0 and 1600 s/mm<sup>2</sup>. The mean ADC values for the malignant breast lesion were 1.21 × 10<sup>-3</sup> mm<sup>2</sup>/s for b 0 and 400, 1.06 × 10<sup>-3</sup> mm<sup>2</sup>/s for b 0 and 800, 0.94 × 10<sup>-3</sup> mm<sup>2</sup>/s for b 0 and 1200 and 0.86 × 10<sup>-3</sup> mm<sup>2</sup>/s for b 0 and 1600 s/mm<sup>2</sup>. ADC diagnostic efficiency for benign and malignant lesion for all the pair of b value combination was significant (p > 0.05). The sensitivity, specificity, PPV, NPV and accuracy were 80.95%, 90.9%, 92.72%, 76.92%, 85.04% for b 0 and 400;84.12%, 90.9%, 92.98%, 80%, 86.91% for b 0 and 800;84.12%, 90.9%, 92.98%, 80%, 86.91% for b 0 and 1200;84.12%, 90.9%, 92.98%, 80%, 86.91% for b 0 and 1600 s/mm<sup>2</sup> respectively. Conclusion: DWI is effective in differentiating benign and malignant breast lesion at 3.0 Tesla using ADC with higher b value combination.
文摘Background： The aim of this study was to assess the performance of apparent diffusion coefficient （ADC） measurement obtained with diffusion-weighted magnetic resonance imaging （DW-MRI） to distinguish renal cell carcinomas （RCCs） from small benign solid renal tumors （〈4 cm）. Methods： In this cross-sectional study, 49 consecutive patients with histopathologically confirmed small solid renal tumors, and seven healthy volunteers were imaged using nonenhanced MRI and DW-MRI. The ADC map was calculated using the b values of 0, 50, 400, and 600 s/ mm2 and values compared via the Kruskal-Wallis and Mann-Whitney tests. The utility of ADC for differentiating RCCs and benign lesions was assessed using a receiver operating characteristic curve. Multiple nonenhanced MRI features were analyzed by Logistic regression. Results： The tumors consisted of 33 cases of clear-cell RCCs （ccRCCs） and 16 cases of benign tumors, including 14 cases of minimal fat angiomyolipomas and 2 cases ofoncocytomas. The ADCs showed significant differences among benign tumors （[0.90 ±0.52] x 10 x mm2/s）, ccRCCs （[1.53 ± 0.31 ] x 10 ^3 mm2/s） and the normal renal parenchyma （[2.22 ± 0.12]x 10^-3 mmVs） （P 〈 0.001）. Moreover, there was statistically significant difference between high and low-grade ccRCCs （P = 0.004）. Using a cut-offADC of 1.36± 10 3 mm2/s, DW-MRI resulted in an area under the curve （AUC）, sensitivity, and specificity equal to 0.839, 75.8%, and 87.5%, respectively. Nonenhanced MRI alone and the combination of imaging methods led to an AUC, sensitivity and specificity equal to 0.919, 93.9%, and 81.2%, 0.998, 97%, and 100%, respectively. The Logistic regression showed that the location of the center of the tumor （inside the contour of the kidney） and appearance of stiffblood vessel were significantly helpful for diagnosing ccRCCs. Conclusions： DW-MRI has potential in distinguishing ccRCCs from benign lesions in human small solid renal tumors （〈4 cm）, and in increasing the accuracy for diagnosing ccRCCs when combined with nonenhanced MRI.
