BACKGROUND Early thrombolytic therapy is crucial to treat acute cerebral infarction,especially since the onset of thrombolytic therapy takes 1-6 h.Therefore,early diagnosis and evaluation of cerebral infarction is imp...BACKGROUND Early thrombolytic therapy is crucial to treat acute cerebral infarction,especially since the onset of thrombolytic therapy takes 1-6 h.Therefore,early diagnosis and evaluation of cerebral infarction is important.AIM To investigate the diagnostic value of magnetic resonance multi-delay threedimensional arterial spin labeling(3DASL)and diffusion kurtosis imaging(DKI)in evaluating the perfusion and infarct area size in patients with acute cerebral ischemia.METHODS Eighty-four patients who experienced acute cerebral ischemia from March 2019 to February 2021 were included.All patients in the acute stage underwent magnetic resonance-based examination,and the data were processed by the system’s own software.The apparent diffusion coefficient(ADC),average diffusion coefficient(MD),axial diffusion(AD),radial diffusion(RD),average kurtosis(MK),radial kurtosis(fairly RK),axial kurtosis(AK),and perfusion parameters post-labeling delays(PLD)in the focal area and its corresponding area were compared.The correlation between the lesion area of cerebral infarction under MK and MD and T2-weighted imaging(T2WI)was analyzed.RESULTS The DKI parameters of focal and control areas in the study subjects were compared.The ADC,MD,AD,and RD values in the lesion area were significantly lower than those in the control area.The MK,RK,and AK values in the lesion area were significantly higher than those in the control area.The MK/MD value in the infarct lesions was used to determine the matching situation.MK/MD<5 mm was considered matching and MK/MD≥5 mm was considered mismatching.PLD1.5s and PLD2.5s perfusion parameters in the central,peripheral,and control areas of the infarct lesions in MK/MD-matched and-unmatched patients were not significantly different.PLD1.5s and PLD2.5s perfusion parameter values in the central area of the infarct lesions in MK/MD-matched and-unmatched patients were significantly lower than those in peripheral and control areas.The MK and MD maps showed a lesion area of 20.08±5.74 cm^(2) and 22.09±5.58 cm^(2),respectively.T2WI showed a lesion area of 19.76±5.02 cm^(2).There were no significant differences in the cerebral infarction lesion areas measured using the three methods.MK,MD,and T2WI showed a good correlation.CONCLUSION DKI parameters showed significant difference between the focal and control areas in patients with acute ischemic cerebral infarction.3DASL can effectively determine the changes in perfusion levels in the lesion area.There was a high correlation between the area of the infarct lesions diagnosed by DKI and T2WI.展开更多
Objective To explore the value of magnetic resonance diffusion kurtosis imaging in diagnosing early tiny changes of brain tissue after mild traumatic brain injury.Methods A total of 22 patients with mild traumatic bra...Objective To explore the value of magnetic resonance diffusion kurtosis imaging in diagnosing early tiny changes of brain tissue after mild traumatic brain injury.Methods A total of 22 patients with mild traumatic brain injury(study group)and 20 healthy subjects(control group)were enrolled in this study,and diffusion kurtosis imaging magnetic resonance scanning was employed in all subjects.fractional anisotropy,fractional anisotropy of kurtosis,mean kurtosis,axial kurtosis and radial kurtosis of diffusion kurtosis imaging parameters in the genu of corpus callosum,splenium corporis callosi,internal capsule,thalamus,putamen,cortex of frontal lobe,temporal lobe and parietal lobe at control group,the injured side and the mirror regions were measured,and the results were compared between the two groups.The receiver operating characteristic curve was used to evaluate the ability of different parameters in diagnosing mild traumatic brain injury.Results Compared with the control group,in the study group fractional anisotropy values of bilateral genu of corpus callosum,splenium corporis callosi,internal capsule and thalamus were significantly reduced,and fractional anisotropy of kurtosis values of bilateral thalamus and putamen were significantly reduced,and the differences were statistically significant(P<0.05).Compared with the control group,in the study group mean kurtosis and axial kurtosis values of bilateral genu of corpus callosum,posterior limb of Internal capsule,thalamus,putamen and cortex of temporal lobe were significantly reduced,while radial kurtosis values in the genu of corpus callosum,thalamus,cortex of frontal lobe,temporal lobe at the injured side were increased,and the differences were statistically significant(P<0.05).Conclusion DKI techniques can sensitively detect the early tiny pathologic changes of cerebral tissue in mild traumatic brain injury patients,which provide more imaging evidence for the clinical early diagnosis treatment and prognosis.展开更多
Background:Due to development of magnetic resonance-based functional imaging, it is easier to detect micro-structural alterations of tumor tissues. The aim of this study was to conduct a preliminary evaluation of the ...Background:Due to development of magnetic resonance-based functional imaging, it is easier to detect micro-structural alterations of tumor tissues. The aim of this study was to conduct a preliminary evaluation of the correlation of non-Gaussian diffusion kurtosis imaging (DKI) parameters with expression of molecular markers (epidermal growth factor receptor [ EGFR];anaplastic lymphoma kinase [ ALK];Ki-67 protein) in patients with advanced lung adenocarcinoma, using routine diffusion-weighted imaging as the reference standard. Methods::Data from patients with primary lung adenocarcinoma diagnosed at Cancer Hospital, Chinese Academy of Medical Sciences (CHCAMS) from 2016 to 2019 were collected for retrospective analysis. The pathologic and magnetic resonance imaging data of 96 patients who met the inclusion criteria were included in this study. Specifically, the Kapp and Dapp parameters measured from the DKI model;apparent diffusion coefficient (ADC) value from the diffusion-weighted imaging model;and the EGFR, ALK, and Ki-67 biomarkers detected by immunohistochemistry and/or molecular biology techniques after biopsy or surgery were evaluated. The relations between quantitative parameters (ADC, Kapp, Dapp) and pathologic outcomes ( EGFR, ALK, and Ki-67 expression) were analyzed by Spearman correlation test. Results:Of the 96 lung adenocarcinoma lesions (from 96 patients), the number of EGFR- and ALK-positive and high Ki-67 expressing lesions were 53, 12, and 83, respectively. The Kapp values were significantly higher among patients with EGFR-positive mutations (0.81 ± 0.12 vs. 0.66 ± 0.10, t = 6.41, P < 0.001), ALK rearrangement-negative (0.76 ± 0.12 vs. 0.60 ± 0.15, t = 4.09, P < 0.001), and high Ki-67 proliferative index (PI) (0.76 ± 0.12 vs. 0.58 ± 0.13, t = 4.88, P < 0.001). The Dapp values were significantly lower among patients with high Ki-67 PI (3.19 ± 0.69 μm 2/ms vs. 4.20 ± 0.83 μm 2/ms, t = 4.80, P < 0.001) and EGFR-positive mutations (3.11 ± 0.73 μm 2/ms vs. 3.59 ± 0.77 μm ^2/ms, t = 3.12, P = 0.002). The differences in mean Dapp (3.73 ± 1.26 μm^ 2/ms vs. 3.26 ± 0.68 μm 2/ms, t = 1.96, P = 0.053) or ADC values ([1.34 ± 0.81] × 10^ -3 mm ^2/s vs. [1.33 ± 0.41] × 10 ^-3 mm ^2/s, t = 0.07, P = 0.941) between the groups with or without ALK rearrangements were not statistically significant. The ADC values were significantly lower among patients with EGFR-positive mutation ([1.19 ± 0.37] × 10 ^-3 mm^ 2/s vs. [1.50 ± 0.53] × 10 ^-3 mm ^2/s, t = 3.38, P = 0.001) and high Ki-67 PI ([1.28 ± 0.39] × 10 -3 mm 2/s vs. [1.67 ± 0.77] × 10^ -3 mm^ 2/s, t = 2.88, P = 0.005). Kapp was strongly positively correlated with EGFR mutations ( r = 0.844, P = 0.008), strongly positively correlated with Ki-67 PI ( r = 0.882, P = 0.001), and strongly negatively correlated with ALK rearrangements ( r = -0.772, P = 0.001). Dapp was moderately correlated with EGFR mutations ( r = -0.650, P = 0.024) or Ki-67 PI ( r = -0.734, P = 0.012). ADC was moderately correlated with Ki-67 PI ( r = -0.679, P = 0.033). Conclusions:The Kapp value of DKI parameters was strongly correlated with different expression of EGFR, ALK, and Ki-67 in advanced lung adenocarcinoma. The results potentially indicate a surrogate measure of the status of different molecular markers assessed by non-invasive imaging tools.展开更多
Degenerative disc disease is the most common cause of low back pain. Intervertebral disc abnormalities are commonly evaluated by magnetic resonance imaging (MRI), and Pfirrmann’s system involves the use of T2-weighte...Degenerative disc disease is the most common cause of low back pain. Intervertebral disc abnormalities are commonly evaluated by magnetic resonance imaging (MRI), and Pfirrmann’s system involves the use of T2-weighted images (T2WI) to classify disc degeneration. However, as this classification is based on visual evaluation, it is not possible to quantify degeneration using this method. The present study was performed to establish an MRI-based intervertebral disc classification system using diffusional kurtosis imaging (DKI), to quantify intervertebral disc water content according to the Pfirrmann classification. Sagittal mean diffusional kurtosis (MK) mapping was performed for the L3/4, L4/5, and L5/S1 intervertebral discs in 32 patients (15 female, 17 male;age range, 24 - 82 years;mean age, 57.7 years). The degree of disc degeneration was assessed in the midsagittal section on T2WI according to the Pfirrmann classification (grade I - V). The relationships between MK values, which are correlated with intervertebral disc composition changes, and grade of degeneration determined using the Pfirrmann classification were analyzed. The MK values tended to decrease with increasing grade of degeneration, and differed significantly between grades I and IV, but not between grade IV and V (P < 0.05, Mann-Whitney U test). DKI is an effective means of detecting the early stages of disc degeneration. Therefore, DKI may be a useful diagnostic tool for quantitative assessment of intervertebral disc degeneration.展开更多
Brain development is one of the most fascinating subjects in the field of biological sciences. Nonetheless, our scientific commu- nity still faces challenges in trying to understand the concepts that define the underl...Brain development is one of the most fascinating subjects in the field of biological sciences. Nonetheless, our scientific commu- nity still faces challenges in trying to understand the concepts that define the underlying mechanisms of neural tissue devel- opment. After all, it is a very complex subject to grasp and many of the processes that take place during central nervous system maturation are yet to be ascertained. Despite this challenge, we have come to recognize that understanding the natural course of normal brain tissue development on both microscopic and macroscopic scales is the key to deciphering the mechanisms through which these neural networks also heal and regenerate. Realizing this concept, my good friend and colleague, Dr. Sar- ah Milla, and I decided to take on a human study to investigate brain maturation using non-invasive imaging techniques in the pediatric population at New York University （NYU） School of Medicine （Paydar et al., 2013）. Our research subjects included 59 normal infants with an age spectrum ranging from birth to approximately 5 years of age, when the brain is in its most active stage of development. We implemented a Magnetic Resonance Imaging （MRI） diffusion technique called Diffusional Kurtosis Imaging （DKI） to investigate the microstructural changes that occur in both the white matter （WM） and gray matter （GM） in the developing brain.展开更多
Diffusion-weighted magnetic resonance imaging(DWMRI) is considered part of the standard imaging protocol for the evaluation of patients with prostate cancer.It has been proven valuable as a functional tool for qualita...Diffusion-weighted magnetic resonance imaging(DWMRI) is considered part of the standard imaging protocol for the evaluation of patients with prostate cancer.It has been proven valuable as a functional tool for qualitative and quantitative analysis of prostate cancer beyond anatomical MRI sequences such as T2-weighted imaging. This review discusses ongoing controversies in DW-MRI acquisition, including the optimal number of b-values to be used for prostate DWI, and summarizes the current literature on the use of advanced DWMRI techniques. These include intravoxel incoherent motion imaging, which better accounts for the nonmono-exponential behavior of the apparent diffusion coefficient as a function of b-value and the influence of perfusion at low b-values. Another technique is diffusion kurtosis imaging(DKI). Metrics from DKI reflect excess kurtosis of tissues, representing its deviation from Gaussian diffusion behavior. Preliminary results suggest that DKI findings may have more value than findings from conventional DW-MRI for the assessment of prostate cancer.展开更多
The prevalence of neurodegenerative diseases is increasing as human longevity increases. The objective biomarkers that enable the staging and early diagnosis of neurodegenerative diseases are eagerly anticipated. It h...The prevalence of neurodegenerative diseases is increasing as human longevity increases. The objective biomarkers that enable the staging and early diagnosis of neurodegenerative diseases are eagerly anticipated. It has recently become possible to determine pathological changes in the brain without autopsy with the advancement of diffusion magnetic resonance imaging techniques. Diffusion magnetic resonance imaging is a robust tool used to evaluate brain microstructural complexity and integrity, axonal order, density, and myelination via the micron-scale displacement of water molecules diffusing in tissues. Diffusion tensor imaging, a type of diffusion magnetic resonance imaging technique is widely utilized in clinical and research settings;however, it has several limitations. To overcome these limitations, cutting-edge diffusion magnetic resonance imaging techniques, such as diffusional kurtosis imaging, neurite orientation dispersion and density imaging, and free water imaging, have been recently proposed and applied to evaluate the pathology of neurodegenerative diseases. This review focused on the main applications, findings, and future directions of advanced diffusion magnetic resonance imaging techniques in patients with Alzheimer's and Parkinson's diseases, the first and second most common neurodegenerative diseases, respectively.展开更多
Hepatocellular carcinoma(HCC) is one of the major causes of morbidity and mortality in patients with chronic liver disease. Transarterial chemoembolization(TACE) can significantly improve the survival rate of patients...Hepatocellular carcinoma(HCC) is one of the major causes of morbidity and mortality in patients with chronic liver disease. Transarterial chemoembolization(TACE) can significantly improve the survival rate of patients with HCC and is the first treatment choice for patients who are not suitable for surgical resections. The evaluation of the response to TACE treatment affects not only the assessment of the therapy efficacy but also the development of the next step in the treatment plan. The use of imaging to examine changes in tumor volume to assess the response of solid tumors to treatment has been controversial. In recent years, the emergence of new imaging technology has made it possible to observe the response of tumors to treatment prior to any morphological changes. In this article, the advances in studies reporting the use of computed tomography perfusion imaging, diffusionweighted magnetic resonance imaging(MRI), intravoxel incoherent motion, diffusion kurtosis imaging, magnetic resonance spectroscopy, magnetic resonance perfusionweighted imaging, blood oxygen level-dependent MRI, positron emission tomography(PET)/computed tomography and PET/MRI to assess the TACE treatment response are reviewed.展开更多
Inhibition of Notch1 signaling has been shown to promote astrocyte-derived neurogenesis after stroke.To investigate the regulatory role of Notch1 signaling in this process,in this study,we used a rat model of stroke b...Inhibition of Notch1 signaling has been shown to promote astrocyte-derived neurogenesis after stroke.To investigate the regulatory role of Notch1 signaling in this process,in this study,we used a rat model of stroke based on middle cerebral artery occlusion and assessed the behavior of reactive astrocytes post-stroke.We used theγ-secretase inhibitor N-[N-(3,5-diuorophenacetyl)-1-alanyl]-S-phenylglycine t-butylester(DAPT)to block Notch1 signaling at 1,4,and 7 days after injury.Our results showed that only administration of DAPT at 4 days after stroke promoted astrocyte-derived neurogenesis,as manifested by recovery of white matter fiber bundle integrity on magnetic resonance imaging,which is consistent with recovery of neurologic function.These findings suggest that inhibition of Notch1 signaling at the subacute stage post-stroke mediates neural repair by promoting astrocyte-derived neurogenesis.展开更多
BACKGROUND Hepatocellular carcinoma(HCC)is a major cause of cancer-related mortality worldwide.Transcatheter arterial chemoembolization(TACE)has been performed as a palliative treatment for patients with HCC.However,H...BACKGROUND Hepatocellular carcinoma(HCC)is a major cause of cancer-related mortality worldwide.Transcatheter arterial chemoembolization(TACE)has been performed as a palliative treatment for patients with HCC.However,HCC is easy to recur after TACE.Magnetic resonance imaging(MRI)has clinical potential in evaluating the TACE treatment effect for patients with liver cancer.However,traditional MRI has some limitations.AIM To explore the clinical potential of diffusion kurtosis imaging(DKI)in predicting recurrence and cellular invasion of the peritumoral liver zone of HCC after TACE.METHODSSeventy-six patients with 82 HCC nodules were recruited in this study and underwent DKI afterTACE. According to pathological examinations or the overall modified response evaluationcriteria in solid tumors (mRECIST) criterion, 48 and 34 nodules were divided into true progressionand pseudo-progression groups, respectively. The TACE-treated area, peritumoral liver zone, andfar-tumoral zone were evaluated on DKI-derived metric maps. Non-parametric U test and receiveroperating characteristic curve (ROC) analysis were used to evaluate the prediction performance ofeach DKI metric between the two groups. The independent t-test was used to compare each DKImetric between the peritumoral and far-tumoral zones of the true progression group.RESULTSDKI metrics, including mean diffusivity (MD), axial diffusivity (DA), radial diffusivity (DR), axialkurtosis (KA), and anisotropy fraction of kurtosis (Fak), showed statistically different valuesbetween the true progression and pseudo-progression groups (P < 0.05). Among these, MD, DA,and DR values were higher in pseudo-progression lesions than in true progression lesions,whereas KA and FAk values were higher in true progression lesions than in pseudo-progressionlesions. Moreover, for the true progression group, the peritumoral zone showed significantlydifferent DA, DR, KA, and FAk values from the far-tumoral zone. Furthermore, MD values of theliver parenchyma (peritumoral and far-tumoral zones) were significantly lower in the trueprogression group than in the pseudo-progression group (P < 0.05).CONCLUSIONDKI has been demonstrated with robust performance in predicting the therapeutic response ofHCC to TACE. Moreover, DKI might reveal cellular invasion of the peritumoral zone by moleculardiffusion-restricted change.展开更多
文摘BACKGROUND Early thrombolytic therapy is crucial to treat acute cerebral infarction,especially since the onset of thrombolytic therapy takes 1-6 h.Therefore,early diagnosis and evaluation of cerebral infarction is important.AIM To investigate the diagnostic value of magnetic resonance multi-delay threedimensional arterial spin labeling(3DASL)and diffusion kurtosis imaging(DKI)in evaluating the perfusion and infarct area size in patients with acute cerebral ischemia.METHODS Eighty-four patients who experienced acute cerebral ischemia from March 2019 to February 2021 were included.All patients in the acute stage underwent magnetic resonance-based examination,and the data were processed by the system’s own software.The apparent diffusion coefficient(ADC),average diffusion coefficient(MD),axial diffusion(AD),radial diffusion(RD),average kurtosis(MK),radial kurtosis(fairly RK),axial kurtosis(AK),and perfusion parameters post-labeling delays(PLD)in the focal area and its corresponding area were compared.The correlation between the lesion area of cerebral infarction under MK and MD and T2-weighted imaging(T2WI)was analyzed.RESULTS The DKI parameters of focal and control areas in the study subjects were compared.The ADC,MD,AD,and RD values in the lesion area were significantly lower than those in the control area.The MK,RK,and AK values in the lesion area were significantly higher than those in the control area.The MK/MD value in the infarct lesions was used to determine the matching situation.MK/MD<5 mm was considered matching and MK/MD≥5 mm was considered mismatching.PLD1.5s and PLD2.5s perfusion parameters in the central,peripheral,and control areas of the infarct lesions in MK/MD-matched and-unmatched patients were not significantly different.PLD1.5s and PLD2.5s perfusion parameter values in the central area of the infarct lesions in MK/MD-matched and-unmatched patients were significantly lower than those in peripheral and control areas.The MK and MD maps showed a lesion area of 20.08±5.74 cm^(2) and 22.09±5.58 cm^(2),respectively.T2WI showed a lesion area of 19.76±5.02 cm^(2).There were no significant differences in the cerebral infarction lesion areas measured using the three methods.MK,MD,and T2WI showed a good correlation.CONCLUSION DKI parameters showed significant difference between the focal and control areas in patients with acute ischemic cerebral infarction.3DASL can effectively determine the changes in perfusion levels in the lesion area.There was a high correlation between the area of the infarct lesions diagnosed by DKI and T2WI.
基金This work was supported by the Zhangjiakou Key Research and Development Program(1921136H).
文摘Objective To explore the value of magnetic resonance diffusion kurtosis imaging in diagnosing early tiny changes of brain tissue after mild traumatic brain injury.Methods A total of 22 patients with mild traumatic brain injury(study group)and 20 healthy subjects(control group)were enrolled in this study,and diffusion kurtosis imaging magnetic resonance scanning was employed in all subjects.fractional anisotropy,fractional anisotropy of kurtosis,mean kurtosis,axial kurtosis and radial kurtosis of diffusion kurtosis imaging parameters in the genu of corpus callosum,splenium corporis callosi,internal capsule,thalamus,putamen,cortex of frontal lobe,temporal lobe and parietal lobe at control group,the injured side and the mirror regions were measured,and the results were compared between the two groups.The receiver operating characteristic curve was used to evaluate the ability of different parameters in diagnosing mild traumatic brain injury.Results Compared with the control group,in the study group fractional anisotropy values of bilateral genu of corpus callosum,splenium corporis callosi,internal capsule and thalamus were significantly reduced,and fractional anisotropy of kurtosis values of bilateral thalamus and putamen were significantly reduced,and the differences were statistically significant(P<0.05).Compared with the control group,in the study group mean kurtosis and axial kurtosis values of bilateral genu of corpus callosum,posterior limb of Internal capsule,thalamus,putamen and cortex of temporal lobe were significantly reduced,while radial kurtosis values in the genu of corpus callosum,thalamus,cortex of frontal lobe,temporal lobe at the injured side were increased,and the differences were statistically significant(P<0.05).Conclusion DKI techniques can sensitively detect the early tiny pathologic changes of cerebral tissue in mild traumatic brain injury patients,which provide more imaging evidence for the clinical early diagnosis treatment and prognosis.
基金a grant from Chinese Academy of Medical Sciences Initiative for Innovative Medicine Program(No.2017-I2M-1-005).
文摘Background:Due to development of magnetic resonance-based functional imaging, it is easier to detect micro-structural alterations of tumor tissues. The aim of this study was to conduct a preliminary evaluation of the correlation of non-Gaussian diffusion kurtosis imaging (DKI) parameters with expression of molecular markers (epidermal growth factor receptor [ EGFR];anaplastic lymphoma kinase [ ALK];Ki-67 protein) in patients with advanced lung adenocarcinoma, using routine diffusion-weighted imaging as the reference standard. Methods::Data from patients with primary lung adenocarcinoma diagnosed at Cancer Hospital, Chinese Academy of Medical Sciences (CHCAMS) from 2016 to 2019 were collected for retrospective analysis. The pathologic and magnetic resonance imaging data of 96 patients who met the inclusion criteria were included in this study. Specifically, the Kapp and Dapp parameters measured from the DKI model;apparent diffusion coefficient (ADC) value from the diffusion-weighted imaging model;and the EGFR, ALK, and Ki-67 biomarkers detected by immunohistochemistry and/or molecular biology techniques after biopsy or surgery were evaluated. The relations between quantitative parameters (ADC, Kapp, Dapp) and pathologic outcomes ( EGFR, ALK, and Ki-67 expression) were analyzed by Spearman correlation test. Results:Of the 96 lung adenocarcinoma lesions (from 96 patients), the number of EGFR- and ALK-positive and high Ki-67 expressing lesions were 53, 12, and 83, respectively. The Kapp values were significantly higher among patients with EGFR-positive mutations (0.81 ± 0.12 vs. 0.66 ± 0.10, t = 6.41, P < 0.001), ALK rearrangement-negative (0.76 ± 0.12 vs. 0.60 ± 0.15, t = 4.09, P < 0.001), and high Ki-67 proliferative index (PI) (0.76 ± 0.12 vs. 0.58 ± 0.13, t = 4.88, P < 0.001). The Dapp values were significantly lower among patients with high Ki-67 PI (3.19 ± 0.69 μm 2/ms vs. 4.20 ± 0.83 μm 2/ms, t = 4.80, P < 0.001) and EGFR-positive mutations (3.11 ± 0.73 μm 2/ms vs. 3.59 ± 0.77 μm ^2/ms, t = 3.12, P = 0.002). The differences in mean Dapp (3.73 ± 1.26 μm^ 2/ms vs. 3.26 ± 0.68 μm 2/ms, t = 1.96, P = 0.053) or ADC values ([1.34 ± 0.81] × 10^ -3 mm ^2/s vs. [1.33 ± 0.41] × 10 ^-3 mm ^2/s, t = 0.07, P = 0.941) between the groups with or without ALK rearrangements were not statistically significant. The ADC values were significantly lower among patients with EGFR-positive mutation ([1.19 ± 0.37] × 10 ^-3 mm^ 2/s vs. [1.50 ± 0.53] × 10 ^-3 mm ^2/s, t = 3.38, P = 0.001) and high Ki-67 PI ([1.28 ± 0.39] × 10 -3 mm 2/s vs. [1.67 ± 0.77] × 10^ -3 mm^ 2/s, t = 2.88, P = 0.005). Kapp was strongly positively correlated with EGFR mutations ( r = 0.844, P = 0.008), strongly positively correlated with Ki-67 PI ( r = 0.882, P = 0.001), and strongly negatively correlated with ALK rearrangements ( r = -0.772, P = 0.001). Dapp was moderately correlated with EGFR mutations ( r = -0.650, P = 0.024) or Ki-67 PI ( r = -0.734, P = 0.012). ADC was moderately correlated with Ki-67 PI ( r = -0.679, P = 0.033). Conclusions:The Kapp value of DKI parameters was strongly correlated with different expression of EGFR, ALK, and Ki-67 in advanced lung adenocarcinoma. The results potentially indicate a surrogate measure of the status of different molecular markers assessed by non-invasive imaging tools.
文摘Degenerative disc disease is the most common cause of low back pain. Intervertebral disc abnormalities are commonly evaluated by magnetic resonance imaging (MRI), and Pfirrmann’s system involves the use of T2-weighted images (T2WI) to classify disc degeneration. However, as this classification is based on visual evaluation, it is not possible to quantify degeneration using this method. The present study was performed to establish an MRI-based intervertebral disc classification system using diffusional kurtosis imaging (DKI), to quantify intervertebral disc water content according to the Pfirrmann classification. Sagittal mean diffusional kurtosis (MK) mapping was performed for the L3/4, L4/5, and L5/S1 intervertebral discs in 32 patients (15 female, 17 male;age range, 24 - 82 years;mean age, 57.7 years). The degree of disc degeneration was assessed in the midsagittal section on T2WI according to the Pfirrmann classification (grade I - V). The relationships between MK values, which are correlated with intervertebral disc composition changes, and grade of degeneration determined using the Pfirrmann classification were analyzed. The MK values tended to decrease with increasing grade of degeneration, and differed significantly between grades I and IV, but not between grade IV and V (P < 0.05, Mann-Whitney U test). DKI is an effective means of detecting the early stages of disc degeneration. Therefore, DKI may be a useful diagnostic tool for quantitative assessment of intervertebral disc degeneration.
文摘Brain development is one of the most fascinating subjects in the field of biological sciences. Nonetheless, our scientific commu- nity still faces challenges in trying to understand the concepts that define the underlying mechanisms of neural tissue devel- opment. After all, it is a very complex subject to grasp and many of the processes that take place during central nervous system maturation are yet to be ascertained. Despite this challenge, we have come to recognize that understanding the natural course of normal brain tissue development on both microscopic and macroscopic scales is the key to deciphering the mechanisms through which these neural networks also heal and regenerate. Realizing this concept, my good friend and colleague, Dr. Sar- ah Milla, and I decided to take on a human study to investigate brain maturation using non-invasive imaging techniques in the pediatric population at New York University （NYU） School of Medicine （Paydar et al., 2013）. Our research subjects included 59 normal infants with an age spectrum ranging from birth to approximately 5 years of age, when the brain is in its most active stage of development. We implemented a Magnetic Resonance Imaging （MRI） diffusion technique called Diffusional Kurtosis Imaging （DKI） to investigate the microstructural changes that occur in both the white matter （WM） and gray matter （GM） in the developing brain.
文摘Diffusion-weighted magnetic resonance imaging(DWMRI) is considered part of the standard imaging protocol for the evaluation of patients with prostate cancer.It has been proven valuable as a functional tool for qualitative and quantitative analysis of prostate cancer beyond anatomical MRI sequences such as T2-weighted imaging. This review discusses ongoing controversies in DW-MRI acquisition, including the optimal number of b-values to be used for prostate DWI, and summarizes the current literature on the use of advanced DWMRI techniques. These include intravoxel incoherent motion imaging, which better accounts for the nonmono-exponential behavior of the apparent diffusion coefficient as a function of b-value and the influence of perfusion at low b-values. Another technique is diffusion kurtosis imaging(DKI). Metrics from DKI reflect excess kurtosis of tissues, representing its deviation from Gaussian diffusion behavior. Preliminary results suggest that DKI findings may have more value than findings from conventional DW-MRI for the assessment of prostate cancer.
基金supported by research grants from the program for Brain/MINDS Beyond program from the Japan Agency for Medical Research and Development(AMED)under Grant Number JP18dm0307024(to KK)MEXT-Supported Program for the Private University Research Branding Project+1 种基金ImPACT Program of Council for Science,Technology and Innovation(Cabinet Office,Government of Japan)JSPS KAKENHI Grant Number JP16K10327(to KK)
文摘The prevalence of neurodegenerative diseases is increasing as human longevity increases. The objective biomarkers that enable the staging and early diagnosis of neurodegenerative diseases are eagerly anticipated. It has recently become possible to determine pathological changes in the brain without autopsy with the advancement of diffusion magnetic resonance imaging techniques. Diffusion magnetic resonance imaging is a robust tool used to evaluate brain microstructural complexity and integrity, axonal order, density, and myelination via the micron-scale displacement of water molecules diffusing in tissues. Diffusion tensor imaging, a type of diffusion magnetic resonance imaging technique is widely utilized in clinical and research settings;however, it has several limitations. To overcome these limitations, cutting-edge diffusion magnetic resonance imaging techniques, such as diffusional kurtosis imaging, neurite orientation dispersion and density imaging, and free water imaging, have been recently proposed and applied to evaluate the pathology of neurodegenerative diseases. This review focused on the main applications, findings, and future directions of advanced diffusion magnetic resonance imaging techniques in patients with Alzheimer's and Parkinson's diseases, the first and second most common neurodegenerative diseases, respectively.
基金Supported by Projects of Department of Science and Technology of Sichuan Province,No.2016JY0105
文摘Hepatocellular carcinoma(HCC) is one of the major causes of morbidity and mortality in patients with chronic liver disease. Transarterial chemoembolization(TACE) can significantly improve the survival rate of patients with HCC and is the first treatment choice for patients who are not suitable for surgical resections. The evaluation of the response to TACE treatment affects not only the assessment of the therapy efficacy but also the development of the next step in the treatment plan. The use of imaging to examine changes in tumor volume to assess the response of solid tumors to treatment has been controversial. In recent years, the emergence of new imaging technology has made it possible to observe the response of tumors to treatment prior to any morphological changes. In this article, the advances in studies reporting the use of computed tomography perfusion imaging, diffusionweighted magnetic resonance imaging(MRI), intravoxel incoherent motion, diffusion kurtosis imaging, magnetic resonance spectroscopy, magnetic resonance perfusionweighted imaging, blood oxygen level-dependent MRI, positron emission tomography(PET)/computed tomography and PET/MRI to assess the TACE treatment response are reviewed.
基金supported by the National Natural Science Foundation of China,Nos.81801660(to XZH)and 81771788(to YMY)。
文摘Inhibition of Notch1 signaling has been shown to promote astrocyte-derived neurogenesis after stroke.To investigate the regulatory role of Notch1 signaling in this process,in this study,we used a rat model of stroke based on middle cerebral artery occlusion and assessed the behavior of reactive astrocytes post-stroke.We used theγ-secretase inhibitor N-[N-(3,5-diuorophenacetyl)-1-alanyl]-S-phenylglycine t-butylester(DAPT)to block Notch1 signaling at 1,4,and 7 days after injury.Our results showed that only administration of DAPT at 4 days after stroke promoted astrocyte-derived neurogenesis,as manifested by recovery of white matter fiber bundle integrity on magnetic resonance imaging,which is consistent with recovery of neurologic function.These findings suggest that inhibition of Notch1 signaling at the subacute stage post-stroke mediates neural repair by promoting astrocyte-derived neurogenesis.
基金the Greater Bay Area Institute of Precision Medicine,No.KCH2310094Shanghai Sailing Program,No.22YF1405000+1 种基金Research Startup Fund of Huashan Hospital Fudan University,No.2021QD035and Clinical Research Plan of SHDC,No.SHDC2020CR3020A.
文摘BACKGROUND Hepatocellular carcinoma(HCC)is a major cause of cancer-related mortality worldwide.Transcatheter arterial chemoembolization(TACE)has been performed as a palliative treatment for patients with HCC.However,HCC is easy to recur after TACE.Magnetic resonance imaging(MRI)has clinical potential in evaluating the TACE treatment effect for patients with liver cancer.However,traditional MRI has some limitations.AIM To explore the clinical potential of diffusion kurtosis imaging(DKI)in predicting recurrence and cellular invasion of the peritumoral liver zone of HCC after TACE.METHODSSeventy-six patients with 82 HCC nodules were recruited in this study and underwent DKI afterTACE. According to pathological examinations or the overall modified response evaluationcriteria in solid tumors (mRECIST) criterion, 48 and 34 nodules were divided into true progressionand pseudo-progression groups, respectively. The TACE-treated area, peritumoral liver zone, andfar-tumoral zone were evaluated on DKI-derived metric maps. Non-parametric U test and receiveroperating characteristic curve (ROC) analysis were used to evaluate the prediction performance ofeach DKI metric between the two groups. The independent t-test was used to compare each DKImetric between the peritumoral and far-tumoral zones of the true progression group.RESULTSDKI metrics, including mean diffusivity (MD), axial diffusivity (DA), radial diffusivity (DR), axialkurtosis (KA), and anisotropy fraction of kurtosis (Fak), showed statistically different valuesbetween the true progression and pseudo-progression groups (P < 0.05). Among these, MD, DA,and DR values were higher in pseudo-progression lesions than in true progression lesions,whereas KA and FAk values were higher in true progression lesions than in pseudo-progressionlesions. Moreover, for the true progression group, the peritumoral zone showed significantlydifferent DA, DR, KA, and FAk values from the far-tumoral zone. Furthermore, MD values of theliver parenchyma (peritumoral and far-tumoral zones) were significantly lower in the trueprogression group than in the pseudo-progression group (P < 0.05).CONCLUSIONDKI has been demonstrated with robust performance in predicting the therapeutic response ofHCC to TACE. Moreover, DKI might reveal cellular invasion of the peritumoral zone by moleculardiffusion-restricted change.
