Diffusion-weighted magnetic resonance imaging(DWI)is a well established method for the evaluation of intracranial diseases,such as acute stroke.DWI for extracranial application is more difficult due to physiological m...Diffusion-weighted magnetic resonance imaging(DWI)is a well established method for the evaluation of intracranial diseases,such as acute stroke.DWI for extracranial application is more difficult due to physiological motion artifacts and the heterogeneous composition of the organs.However,thanks to the newer technical development of DWI,DWI has become increasingly used over the past few years in extracranial organs including the abdomen and pelvis.Most previous studies of DWI have been limited to the evaluation of diffuse parenchymal abnormalities and focal lesions in abdominal organs,whereas there are few studies about DWI for the evaluation of the biliopancreatic tract.Although further studies are needed to determine its performance in evaluating bile duct,gallbladder and pancreas diseases,DWI has potential in the assessment of the functional information on the biliopancreatic tract concerning the status of tissue cellularity,because increased cellularity is associated with impeded diffusion,as indicated by a reduction in the apparent diffusion coefficient.The detection of malignant lesions and their differentiation from benign tumor-like lesions in the biliopancreatic tract could be improved using DWI in conjunction with findings obtained with conventional magnetic resonance cholagiopancreatography.Additionally,DWI can be useful for the assessment of the biliopancreatic tract in patients with renal impairment because contrast-enhanced computed tomography or magnetic resonance scans should be avoided in these patients.展开更多
Objective To assess the reproducibility of whole-body diffusion weighted imaging(WB-DWI) technique in healthy volunteers under normal breathing with background body signal suppression.Methods WB-DWI was performed on 3...Objective To assess the reproducibility of whole-body diffusion weighted imaging(WB-DWI) technique in healthy volunteers under normal breathing with background body signal suppression.Methods WB-DWI was performed on 32 healthy volunteers twice within two-week period using short TI inversion-recovery diffusion-weighted echo-planar imaging sequence and built-in body coil.The volunteers were scanned across six stations continuously covering the entire body from the head to the feet under normal breathing.The bone apparent diffusion coefficient(ADC) and exponential ADC(eADC) of regions of interest(ROIs) were measured.We analyzed correlation of the results using paired-t-test to assess the reproducibility of the WB-DWI technique.Results We were successful in collecting and analyzing data of 64 WB-DWI images.There was no significant difference in bone ADC and eADC of 824 ROIs between the paired observers and paired scans(P>0.05).Most of the images from all stations were of diagnostic quality.Conclusion The measurements of bone ADC and eADC have good reproducibility.WB-DWI technique under normal breathing with background body signal suppression is adequate.展开更多
Objective: The aim of our study was to investigate the value of Diffusion-weighted MR imaging (DWl) for evaluating differential diagnosis of pulmonary isolated lesions. Methods: Twenty-seven consecutive patients e...Objective: The aim of our study was to investigate the value of Diffusion-weighted MR imaging (DWl) for evaluating differential diagnosis of pulmonary isolated lesions. Methods: Twenty-seven consecutive patients enrolled in this study, all of whom underwent single direction DWl examinations and received a histologic and clinical diagnosis. Diffusion factor B value was 300, 500, 800 s/mm2, respectively. DWl images of twenty cases could be satisfied to measurement and diagnosis and success rate was percent 74. Among these, lung tuberculoma 5 cases, harmatoma 3 cases, peripheral lung cancer 12 cases. The apparent diffusion coefficient (ADC) values of the lesions were measured. Statistical analyses were performed with the independent samples t test for comparing difference of ADC values between malignant nodules and benign nodules at different 8 value. Results: DWI images of twenty cases could be satisfied and its success rate was percent 74. When B value was 300 s/mm2, ADC values of malignant nodules and benign nodules were 0.002192±0.0006091 mm2/s, 0.002454 ± 0.0007892 mm2/s, respectively, and P = 0.442. When B value was 500 s/mm2, ADC value of malignant nodules and benign nodules were 0.002065 ± 0.0006769 mm2/s, 0.002871± 0.0007746 mm2/s, respectively, and P = 0.033. When B value was 800 s/mm2, ADC value of malignant nodules and benign nodules were 0.001646 ± 0.0004292 mm2/s, 0.002651 + 0.0008041 mm2/s, respectively, and P = 0.009. There were the most different between malignant nodules and benign nodules at B value 800 and statistical significance. Conclusion: Lung DWl imaging is helpful to diagnosis and differential diagnosis between malignant and benign isolated nodules. The ADC value of benign lesions was statistically higher than that of malignant tumors.展开更多
基金Supported by Clinical research grant from Pusan National University Hospital
文摘Diffusion-weighted magnetic resonance imaging(DWI)is a well established method for the evaluation of intracranial diseases,such as acute stroke.DWI for extracranial application is more difficult due to physiological motion artifacts and the heterogeneous composition of the organs.However,thanks to the newer technical development of DWI,DWI has become increasingly used over the past few years in extracranial organs including the abdomen and pelvis.Most previous studies of DWI have been limited to the evaluation of diffuse parenchymal abnormalities and focal lesions in abdominal organs,whereas there are few studies about DWI for the evaluation of the biliopancreatic tract.Although further studies are needed to determine its performance in evaluating bile duct,gallbladder and pancreas diseases,DWI has potential in the assessment of the functional information on the biliopancreatic tract concerning the status of tissue cellularity,because increased cellularity is associated with impeded diffusion,as indicated by a reduction in the apparent diffusion coefficient.The detection of malignant lesions and their differentiation from benign tumor-like lesions in the biliopancreatic tract could be improved using DWI in conjunction with findings obtained with conventional magnetic resonance cholagiopancreatography.Additionally,DWI can be useful for the assessment of the biliopancreatic tract in patients with renal impairment because contrast-enhanced computed tomography or magnetic resonance scans should be avoided in these patients.
文摘Objective To assess the reproducibility of whole-body diffusion weighted imaging(WB-DWI) technique in healthy volunteers under normal breathing with background body signal suppression.Methods WB-DWI was performed on 32 healthy volunteers twice within two-week period using short TI inversion-recovery diffusion-weighted echo-planar imaging sequence and built-in body coil.The volunteers were scanned across six stations continuously covering the entire body from the head to the feet under normal breathing.The bone apparent diffusion coefficient(ADC) and exponential ADC(eADC) of regions of interest(ROIs) were measured.We analyzed correlation of the results using paired-t-test to assess the reproducibility of the WB-DWI technique.Results We were successful in collecting and analyzing data of 64 WB-DWI images.There was no significant difference in bone ADC and eADC of 824 ROIs between the paired observers and paired scans(P>0.05).Most of the images from all stations were of diagnostic quality.Conclusion The measurements of bone ADC and eADC have good reproducibility.WB-DWI technique under normal breathing with background body signal suppression is adequate.
文摘Objective: The aim of our study was to investigate the value of Diffusion-weighted MR imaging (DWl) for evaluating differential diagnosis of pulmonary isolated lesions. Methods: Twenty-seven consecutive patients enrolled in this study, all of whom underwent single direction DWl examinations and received a histologic and clinical diagnosis. Diffusion factor B value was 300, 500, 800 s/mm2, respectively. DWl images of twenty cases could be satisfied to measurement and diagnosis and success rate was percent 74. Among these, lung tuberculoma 5 cases, harmatoma 3 cases, peripheral lung cancer 12 cases. The apparent diffusion coefficient (ADC) values of the lesions were measured. Statistical analyses were performed with the independent samples t test for comparing difference of ADC values between malignant nodules and benign nodules at different 8 value. Results: DWI images of twenty cases could be satisfied and its success rate was percent 74. When B value was 300 s/mm2, ADC values of malignant nodules and benign nodules were 0.002192±0.0006091 mm2/s, 0.002454 ± 0.0007892 mm2/s, respectively, and P = 0.442. When B value was 500 s/mm2, ADC value of malignant nodules and benign nodules were 0.002065 ± 0.0006769 mm2/s, 0.002871± 0.0007746 mm2/s, respectively, and P = 0.033. When B value was 800 s/mm2, ADC value of malignant nodules and benign nodules were 0.001646 ± 0.0004292 mm2/s, 0.002651 + 0.0008041 mm2/s, respectively, and P = 0.009. There were the most different between malignant nodules and benign nodules at B value 800 and statistical significance. Conclusion: Lung DWl imaging is helpful to diagnosis and differential diagnosis between malignant and benign isolated nodules. The ADC value of benign lesions was statistically higher than that of malignant tumors.