AIM To investigate the utility of renal diffusion tensor imaging(DTI) to detect early renal damage in patients with type 2 diabetes.METHODS Twenty-six diabetic patients(12 with microalbuminuria(MAU), and 14 with normo...AIM To investigate the utility of renal diffusion tensor imaging(DTI) to detect early renal damage in patients with type 2 diabetes.METHODS Twenty-six diabetic patients(12 with microalbuminuria(MAU), and 14 with normoalbuminuria) and fourteen healthy volunteers were prospectively included in this study. Renal DTI on 3.0 T MR was performed, and estimated glomerular filtration rate(e GFR) was recorded for each subject. Mean cortical and medullary fractional anisotropy(FA) values were calculated by placing multiple representative regions of interest. Mean FA values were statistically compared among groups. Correlations between FA values and e GFR were evaluated. RESULTS Both cortical and medullary FA were significantly reduced in diabetic patients compared to healthy controls(0.403 ± 0.064 vs 0.463 ± 0.047, P = 0.004, and 0.556 ± 0.084 vs 0.645 ± 0.076, P = 0.002, respectively). Cortical FA was significantly lower in diabetic patients with NAU than healthy controls(0.412 ± 0.068 vs 0.463 ± 0.047, P = 0.02). Medullary FA in diabetic patients with NAU and healthy controls were similar(0.582 ± 0.096 vs 0.645 ± 0.076, P = 0.06). Both cortical FA and medullary FA correlated with e GFR(r = 0.382, P = 0.015 and r = 0.552, P = 0.000, respectively).CONCLUSION FA of renal parenchyma on DTI might serve as a more sensitive biomarker of early diabetic nephropathy than MAU.展开更多
Kidney transplantation has emerged as the treatment of choice for many patients with end-stage renal disease, which is a significant cause of morbidity and mortality. Given the shortage of clinically available donor k...Kidney transplantation has emerged as the treatment of choice for many patients with end-stage renal disease, which is a significant cause of morbidity and mortality. Given the shortage of clinically available donor kidneys and the significant incidence of allograft dysfunction, a noninvasive and accurate assessment of the allograft renal function is critical for postoperative management. Prompt diagnosis of graft dysfunction facilitates clinical intervention of kidneys with salvageable function. New advances in magnetic resonance imaging(MRI) technology have enabled the calculation of various renal parameters that were previously not feasible to measure noninvasively. Diffusion-weighted imaging provides information on renal diffusion and perfusion simultaneously, with quantification by the apparent diffusion coefficient, the decrease of which reflects renal function impairment. Diffusion-tensor imaging accounts for the directionality of molecular motion and measures fractional anisotropy of the kidneys. Blood oxygen level-dependent MR evaluates intrarenal oxygen bioavailability, generating the parameter of R2*(reflecting the concentration of deoxyhemoglobin). A decrease in R2* could happen during acute rejection. MR nephro-urography/renography demonstrates structural data depicting urinary tract obstructions and functional data regarding the glomerular filtration and blood flow. MR angiography details the transplant vasculature and is particularly suitable for detecting vascular complications, with good correlation with digital subtraction angiography. Other functional MRI technologies, such as arterial spin labeling and MR spectroscopy, are showing additional promise. This review highlights MRI as a comprehensive modality to diagnose a variety of etiologies of graft dysfunction, including prerenal(e.g., renal vasculature), renal(intrinsic causes) and postrenal(e.g., obstruction of the collecting system) etiologies.展开更多
Functional magnetic resonance imaging(MRI) provided critical functional information in addition to the anatomicprofiles offered by conventional MRI, and has been enormously used in the initial diagnosis and followed e...Functional magnetic resonance imaging(MRI) provided critical functional information in addition to the anatomicprofiles offered by conventional MRI, and has been enormously used in the initial diagnosis and followed evaluation of various diseases. Diffusion tensor imaging(DTI) is a newly developed and advanced technique that measures the diffusion properties including both diffusion motion and its direction in situ, and has been extensively applied in central nerve system with acknowledged success. Technical advances have enabled DTI in abdominal and pelvic organs. Its application is increasing, yet remains less understood. A systematic overview of clinical application of DTI in abdominal and pelvic organs such as liver, pancreas, kidneys, prostate, uterus, etc., is therefore presented. Exploration of techniques with less artifacts and more normative postprocessing enabled generally satisfactory image quality and repeatability of measurement. DTI appears to be more valuable in the evaluation of diffused diseases of organs with highly directionally arranged structures, such as the assessment of function impairment of native and transplanted kidneys. However, the utility of DTI to diagnose focal lesions, such as liver mass, pancreatic and prostate tumor, remains limited. Besides, diffusion of different layers of the uterus and the fiber structure disruption can be depicted by DTI. Finally, a discussion of future directions of research is given. The underlying heterogeneous pathologic conditions of certain diseases need to be further differentiated, and it is suggested that DTI parameters might potentially depict certain pathologic characterization such as cell density. Nevertheless, DTI should be better integrated into the current multi-modality evaluation in clinical practice.展开更多
AIM： To systematically evaluate the accuracy of 18-fu-orodeoxy-D-glucose-positron emission tomography （18-FDG PET） to assess response to neoadjuvant che-motherapy in bone and soft tissue sarcomas.METHODS： Studies ...AIM： To systematically evaluate the accuracy of 18-fu-orodeoxy-D-glucose-positron emission tomography （18-FDG PET） to assess response to neoadjuvant che-motherapy in bone and soft tissue sarcomas.METHODS： Studies published in English language re-garding the accuracy of F-18 FDG PET for the indication were retrieved from MEDLINE. The QUADAS tool was utilized for methodological quality appraisal. Relevant data were extracted, and quantitative data synthesis included pooled estimation and subgroup analysis. RESULTS： A total of ffteen studies involving 420 pa-tients with pathologically confrmed sarcoma were col-lected. Methodological quality was relatively high. The pooled sensitivity and specifcity of PET to predict histo-pathological response were 87% （95%CI： 81%-91%） and 83% （95%CI： 77%-87%）, respectively. Ten stud-ies employed a lower standardized uptake value （SUV） after chemotherapies （mostly 2.5） and/or a higher SUV reduction rate （mostly around 50%） as PET criteria of good response. Subgroup analysis showed that PET ex-hibited a signifcantly better specifcity in osteosarcoma （OS） and Ewing sarcoma （ES） than in soft-tissue sarco-ma （STS） （91% vs 75%, P 〈 0.05）, and a higher speci-fcity in pediatric patients than in adults （90% vs 74%, P 〈 0.01）. PET yielded a lower specifcity in ifosfamide-contained chemotherapies than in the alternative regi-men （70% vs 97%, P 〈 0.01）.CONCLUSION： F-18 FDG PET is promising to predict neoadjuvant therapy response in sarcoma, especially in pediatric patients with OS or ES. Certain chemothera-peutic agents could potentially cause false positives of PET.展开更多
基金Supported by the Fundamental Research Funds for the Central Universities,University of Electronic Science and Technology of China,No.ZYGX2015J125
文摘AIM To investigate the utility of renal diffusion tensor imaging(DTI) to detect early renal damage in patients with type 2 diabetes.METHODS Twenty-six diabetic patients(12 with microalbuminuria(MAU), and 14 with normoalbuminuria) and fourteen healthy volunteers were prospectively included in this study. Renal DTI on 3.0 T MR was performed, and estimated glomerular filtration rate(e GFR) was recorded for each subject. Mean cortical and medullary fractional anisotropy(FA) values were calculated by placing multiple representative regions of interest. Mean FA values were statistically compared among groups. Correlations between FA values and e GFR were evaluated. RESULTS Both cortical and medullary FA were significantly reduced in diabetic patients compared to healthy controls(0.403 ± 0.064 vs 0.463 ± 0.047, P = 0.004, and 0.556 ± 0.084 vs 0.645 ± 0.076, P = 0.002, respectively). Cortical FA was significantly lower in diabetic patients with NAU than healthy controls(0.412 ± 0.068 vs 0.463 ± 0.047, P = 0.02). Medullary FA in diabetic patients with NAU and healthy controls were similar(0.582 ± 0.096 vs 0.645 ± 0.076, P = 0.06). Both cortical FA and medullary FA correlated with e GFR(r = 0.382, P = 0.015 and r = 0.552, P = 0.000, respectively).CONCLUSION FA of renal parenchyma on DTI might serve as a more sensitive biomarker of early diabetic nephropathy than MAU.
基金Supported by Scientific Research Subject of Health Department of Sichuan,China,No.070045
文摘Kidney transplantation has emerged as the treatment of choice for many patients with end-stage renal disease, which is a significant cause of morbidity and mortality. Given the shortage of clinically available donor kidneys and the significant incidence of allograft dysfunction, a noninvasive and accurate assessment of the allograft renal function is critical for postoperative management. Prompt diagnosis of graft dysfunction facilitates clinical intervention of kidneys with salvageable function. New advances in magnetic resonance imaging(MRI) technology have enabled the calculation of various renal parameters that were previously not feasible to measure noninvasively. Diffusion-weighted imaging provides information on renal diffusion and perfusion simultaneously, with quantification by the apparent diffusion coefficient, the decrease of which reflects renal function impairment. Diffusion-tensor imaging accounts for the directionality of molecular motion and measures fractional anisotropy of the kidneys. Blood oxygen level-dependent MR evaluates intrarenal oxygen bioavailability, generating the parameter of R2*(reflecting the concentration of deoxyhemoglobin). A decrease in R2* could happen during acute rejection. MR nephro-urography/renography demonstrates structural data depicting urinary tract obstructions and functional data regarding the glomerular filtration and blood flow. MR angiography details the transplant vasculature and is particularly suitable for detecting vascular complications, with good correlation with digital subtraction angiography. Other functional MRI technologies, such as arterial spin labeling and MR spectroscopy, are showing additional promise. This review highlights MRI as a comprehensive modality to diagnose a variety of etiologies of graft dysfunction, including prerenal(e.g., renal vasculature), renal(intrinsic causes) and postrenal(e.g., obstruction of the collecting system) etiologies.
文摘Functional magnetic resonance imaging(MRI) provided critical functional information in addition to the anatomicprofiles offered by conventional MRI, and has been enormously used in the initial diagnosis and followed evaluation of various diseases. Diffusion tensor imaging(DTI) is a newly developed and advanced technique that measures the diffusion properties including both diffusion motion and its direction in situ, and has been extensively applied in central nerve system with acknowledged success. Technical advances have enabled DTI in abdominal and pelvic organs. Its application is increasing, yet remains less understood. A systematic overview of clinical application of DTI in abdominal and pelvic organs such as liver, pancreas, kidneys, prostate, uterus, etc., is therefore presented. Exploration of techniques with less artifacts and more normative postprocessing enabled generally satisfactory image quality and repeatability of measurement. DTI appears to be more valuable in the evaluation of diffused diseases of organs with highly directionally arranged structures, such as the assessment of function impairment of native and transplanted kidneys. However, the utility of DTI to diagnose focal lesions, such as liver mass, pancreatic and prostate tumor, remains limited. Besides, diffusion of different layers of the uterus and the fiber structure disruption can be depicted by DTI. Finally, a discussion of future directions of research is given. The underlying heterogeneous pathologic conditions of certain diseases need to be further differentiated, and it is suggested that DTI parameters might potentially depict certain pathologic characterization such as cell density. Nevertheless, DTI should be better integrated into the current multi-modality evaluation in clinical practice.
基金Supported by Scientific Research Subject of Health Department of Sichuan,China,No.070045
文摘AIM： To systematically evaluate the accuracy of 18-fu-orodeoxy-D-glucose-positron emission tomography （18-FDG PET） to assess response to neoadjuvant che-motherapy in bone and soft tissue sarcomas.METHODS： Studies published in English language re-garding the accuracy of F-18 FDG PET for the indication were retrieved from MEDLINE. The QUADAS tool was utilized for methodological quality appraisal. Relevant data were extracted, and quantitative data synthesis included pooled estimation and subgroup analysis. RESULTS： A total of ffteen studies involving 420 pa-tients with pathologically confrmed sarcoma were col-lected. Methodological quality was relatively high. The pooled sensitivity and specifcity of PET to predict histo-pathological response were 87% （95%CI： 81%-91%） and 83% （95%CI： 77%-87%）, respectively. Ten stud-ies employed a lower standardized uptake value （SUV） after chemotherapies （mostly 2.5） and/or a higher SUV reduction rate （mostly around 50%） as PET criteria of good response. Subgroup analysis showed that PET ex-hibited a signifcantly better specifcity in osteosarcoma （OS） and Ewing sarcoma （ES） than in soft-tissue sarco-ma （STS） （91% vs 75%, P 〈 0.05）, and a higher speci-fcity in pediatric patients than in adults （90% vs 74%, P 〈 0.01）. PET yielded a lower specifcity in ifosfamide-contained chemotherapies than in the alternative regi-men （70% vs 97%, P 〈 0.01）.CONCLUSION： F-18 FDG PET is promising to predict neoadjuvant therapy response in sarcoma, especially in pediatric patients with OS or ES. Certain chemothera-peutic agents could potentially cause false positives of PET.
