Magnetic resonance imaging(MRI) is a reliable and accurate imaging method for the evaluation of patients with pancreatic ductal adenocarcinoma(PDAC). Diffusion-weighted imaging(DWI) is a relatively recent technologica...Magnetic resonance imaging(MRI) is a reliable and accurate imaging method for the evaluation of patients with pancreatic ductal adenocarcinoma(PDAC). Diffusion-weighted imaging(DWI) is a relatively recent technological improvement that expanded MRI capabilities, having brought functional aspects into conventional morphologic MRI evaluation. DWI can depict the random diffusion of water molecules within tissues(the so-called Brownian motions). Modifications of water diffusion induced by different factors acting on the extracellular and intracellular spaces, as increased cell density, edema, fibrosis, or altered functionality of cell membranes, can be detected using this MR sequence. The intravoxel incoherent motion(IVIM) model is an advanced DWI technique that consent a separate quantitative evaluation of all the microscopic random motions that contribute to DWI, which are essentially represented by molecular diffusion and blood microcirculation(perfusion). Technological improvements have made possible the routine use of DWI during abdominal MRI study. Several authors have reported that the addition of DWI sequence can be of value for the evaluation of patients with PDAC, especially improving the staging; nevertheless, it is still unclear whether and how DWI could be helpful for identification, characterization, prognostic stratification and follow-up during treatment. The aim of this paper is to review up-to-date literature data regarding the applications of DWI and IVIM to PDACs.展开更多
Diffusion-weighted imaging(DWI), dynamic contrastenhanced magnetic resonance imaging(DCE-MRI) and perfusion computed tomography(CT) are technical improvements of morphologic imaging that can evaluate functional proper...Diffusion-weighted imaging(DWI), dynamic contrastenhanced magnetic resonance imaging(DCE-MRI) and perfusion computed tomography(CT) are technical improvements of morphologic imaging that can evaluate functional properties of hepato-bilio-pancreatic tumors during conventional MRI or CT examinations.Nevertheless, the term "functional imaging" is commonly used to describe molecular imaging techniques, as positron emission tomography(PET)CT/MRI, which still represent the most widely used methods for the evaluation of functional properties of solid neoplasms; unlike PET or single photon emission computed tomography, functional imaging techniques applied to conventional MRI/CT examinations do not require the administration of radiolabeled drugs or specific equipments. Moreover, DWI and DCE-MRI can be performed during the same session, thus providing a comprehensive "one-step" morphological and functional evaluation of hepato-bilio-pancreatic tumors. Literature data reveal that functional imaging techniques could be proposed for the evaluation of these tumors before treatment, given that they may improve staging and predict prognosis or clinical outcome. Microscopic changes within neoplastic tissues induced by treatments can be detected and quantified with functional imaging,therefore these techniques could be used also for posttreatment assessment, even at an early stage. The aim of this editorial is to describe possible applications of new functional imaging techniques apart frommolecular imaging to hepatic and pancreatic tumors through a review of up-to-date literature data, with a particular emphasis on pathological correlations,prognostic stratification and post-treatment monitoring.展开更多
AIMTo describe magnetic resonance(MR)imaging features of pancreatic neuroendocrine neoplasms(PanNENs)according to their grade and tumor-nodes-metastases stage by comparing them to histopathology and to determine the a...AIMTo describe magnetic resonance(MR)imaging features of pancreatic neuroendocrine neoplasms(PanNENs)according to their grade and tumor-nodes-metastases stage by comparing them to histopathology and to determine the accuracy of MR imaging features in predicting their biological behavior.METHODSThis study was approved by our institutional review board;requirement for informed patient consent was waived due to the retrospective nature of the study.Preoperative MR examinations of 55 PanNEN patients(29 men,26 women;mean age of 57.6 years,range 21-83 years)performed between June 2013 and December 2015 were reviewed.Qualitative and quantitative features were compared between tumor grades and stages determined by histopathological analysis.RESULTSIll defined margins were more common in G2-3 and stage III-IV PanNENs than in G1 and low-stage tumors(P<0.001);this feature had high specificity in the identification of G2-3 and stage III-IV tumors(90.3%and 96%,95%CI:73.1-97.5 and 77.7-99.8).The mean apparent diffusion coefficient value was significantly lower in G2-3 and stage III-IV lesions compared to well differentiated and low-stage tumors(1.09×10<sup>-3</sup>mm<sup>2</sup>/s vs 1.45×10<sup>-3</sup>mm<sup>2</sup>/s and 1.10×10<sup>-3</sup>mm<sup>2</sup>/s vs 1.53×10<sup>-3</sup>mm<sup>2</sup>/s,P=0.003 and 0.001).Receiving operator characteristic analysis determined optimal cut-offs of 1.21 and 1.28×10<sup>-3</sup>mm<sup>2</sup>/s for the identification of G2-3 and stage III-IV tumors,with sensitivity and specificity values of 70.8/80.7%and 64.5/64%(95%CI:48.7-86.6/60-92.7 and 45.4-80.2/42.6-81.3).CONCLUSIONMR features of PanNENs vary according to their grade of differentiation and their stage at diagnosis and could predict the biological behavior of these tumors.展开更多
文摘Magnetic resonance imaging(MRI) is a reliable and accurate imaging method for the evaluation of patients with pancreatic ductal adenocarcinoma(PDAC). Diffusion-weighted imaging(DWI) is a relatively recent technological improvement that expanded MRI capabilities, having brought functional aspects into conventional morphologic MRI evaluation. DWI can depict the random diffusion of water molecules within tissues(the so-called Brownian motions). Modifications of water diffusion induced by different factors acting on the extracellular and intracellular spaces, as increased cell density, edema, fibrosis, or altered functionality of cell membranes, can be detected using this MR sequence. The intravoxel incoherent motion(IVIM) model is an advanced DWI technique that consent a separate quantitative evaluation of all the microscopic random motions that contribute to DWI, which are essentially represented by molecular diffusion and blood microcirculation(perfusion). Technological improvements have made possible the routine use of DWI during abdominal MRI study. Several authors have reported that the addition of DWI sequence can be of value for the evaluation of patients with PDAC, especially improving the staging; nevertheless, it is still unclear whether and how DWI could be helpful for identification, characterization, prognostic stratification and follow-up during treatment. The aim of this paper is to review up-to-date literature data regarding the applications of DWI and IVIM to PDACs.
文摘Diffusion-weighted imaging(DWI), dynamic contrastenhanced magnetic resonance imaging(DCE-MRI) and perfusion computed tomography(CT) are technical improvements of morphologic imaging that can evaluate functional properties of hepato-bilio-pancreatic tumors during conventional MRI or CT examinations.Nevertheless, the term "functional imaging" is commonly used to describe molecular imaging techniques, as positron emission tomography(PET)CT/MRI, which still represent the most widely used methods for the evaluation of functional properties of solid neoplasms; unlike PET or single photon emission computed tomography, functional imaging techniques applied to conventional MRI/CT examinations do not require the administration of radiolabeled drugs or specific equipments. Moreover, DWI and DCE-MRI can be performed during the same session, thus providing a comprehensive "one-step" morphological and functional evaluation of hepato-bilio-pancreatic tumors. Literature data reveal that functional imaging techniques could be proposed for the evaluation of these tumors before treatment, given that they may improve staging and predict prognosis or clinical outcome. Microscopic changes within neoplastic tissues induced by treatments can be detected and quantified with functional imaging,therefore these techniques could be used also for posttreatment assessment, even at an early stage. The aim of this editorial is to describe possible applications of new functional imaging techniques apart frommolecular imaging to hepatic and pancreatic tumors through a review of up-to-date literature data, with a particular emphasis on pathological correlations,prognostic stratification and post-treatment monitoring.
文摘AIMTo describe magnetic resonance(MR)imaging features of pancreatic neuroendocrine neoplasms(PanNENs)according to their grade and tumor-nodes-metastases stage by comparing them to histopathology and to determine the accuracy of MR imaging features in predicting their biological behavior.METHODSThis study was approved by our institutional review board;requirement for informed patient consent was waived due to the retrospective nature of the study.Preoperative MR examinations of 55 PanNEN patients(29 men,26 women;mean age of 57.6 years,range 21-83 years)performed between June 2013 and December 2015 were reviewed.Qualitative and quantitative features were compared between tumor grades and stages determined by histopathological analysis.RESULTSIll defined margins were more common in G2-3 and stage III-IV PanNENs than in G1 and low-stage tumors(P<0.001);this feature had high specificity in the identification of G2-3 and stage III-IV tumors(90.3%and 96%,95%CI:73.1-97.5 and 77.7-99.8).The mean apparent diffusion coefficient value was significantly lower in G2-3 and stage III-IV lesions compared to well differentiated and low-stage tumors(1.09×10<sup>-3</sup>mm<sup>2</sup>/s vs 1.45×10<sup>-3</sup>mm<sup>2</sup>/s and 1.10×10<sup>-3</sup>mm<sup>2</sup>/s vs 1.53×10<sup>-3</sup>mm<sup>2</sup>/s,P=0.003 and 0.001).Receiving operator characteristic analysis determined optimal cut-offs of 1.21 and 1.28×10<sup>-3</sup>mm<sup>2</sup>/s for the identification of G2-3 and stage III-IV tumors,with sensitivity and specificity values of 70.8/80.7%and 64.5/64%(95%CI:48.7-86.6/60-92.7 and 45.4-80.2/42.6-81.3).CONCLUSIONMR features of PanNENs vary according to their grade of differentiation and their stage at diagnosis and could predict the biological behavior of these tumors.
