Objective:To explore the value of multimodal MRI enhancement scanning and diffusion-weighted imaging in differentiating non-puerperal mastitis(NPM)and breast cancer.Methods:From September 2022 to September 2024,56 pat...Objective:To explore the value of multimodal MRI enhancement scanning and diffusion-weighted imaging in differentiating non-puerperal mastitis(NPM)and breast cancer.Methods:From September 2022 to September 2024,56 patients with breast diseases were selected as samples and grouped according to disease type.Twenty-eight patients with breast cancer were included in Group A,and 28 patients with NPM were included in Group B.All patients underwent multimodal MRI enhancement scanning and diffusion-weighted imaging.The MRI results,time-signal intensity curves,ADC values,lesion intensity,and imaging signs were compared between the two groups.Results:There were no significant differences in enhancement characteristics,lymph node enlargement,and margins between Group A and Group B(P>0.05).The proportion of outflow curves in Group A was higher than that in Group B(P<0.05).The ADC value in Group A was lower than that in Group B,and the lesion intensity was higher than that in Group B(P<0.05).There were significant differences in imaging signs,such as abscess or sinus,ascending time-signal curve,and mammary duct dilation between Group A and Group B(P<0.05).Conclusion:Multimodal MRI enhancement scanning and diffusion-weighted imaging techniques can be used to diagnose breast diseases.Comprehensive analysis of time-signal intensity curves,lesion intensity,imaging signs,and ADC values can differentiate between NPM and breast cancer.展开更多
Diffusion-weighted magnetic resonance imaging(DWI)has become an essential tool in the field of pancreatic magnetic resonance imaging,enabling the detection,characterization,prediction,and evaluation of pancreatic dise...Diffusion-weighted magnetic resonance imaging(DWI)has become an essential tool in the field of pancreatic magnetic resonance imaging,enabling the detection,characterization,prediction,and evaluation of pancreatic diseases.In this article,we review the acquisition parameters,postprocessing techniques,and quantitative methods utilized in pancreatic DWI.Various postprocessing models,including monoexponential,biexponential,stretched exponential and non-Gaussian kurtosis models,as well as deep learning networks,have been used to assess the clinical utility of these models in diagnosing pancreatic diseases.The single-shot echo-planar imaging sequence is the most commonly used sequence for DWI data acquisition in clinical settings,and the apparent diffusion coefficient(ADC)calculated using the monoexponential model is the most widely used quantitative parameter in clinical practice.The repeatability threshold for the ADC of a normal pancreas is 37%for test-retest scans,but the repeatability threshold for pancreatic tumors needs to be further investigated.Complex postprocessing models exploring novel DWI-based biomarkers beyond ADC to assess histological features,and artificial intelligence in DWI postprocessing and data analyses hold promise in the diagnosis of pancreatic diseases.Future work should focus on standardizing protocols,conducting multicentre studies,and exploring variety of methods to improve the accuracy of quantitative DWI results to increase the clinical effectiveness of DWI in patients with pancreatic diseases.展开更多
BACKGROUND Colorectal cancer is a malignancy with a high risk of lymph node metastasis and poor prognosis,and thus requires an accurate diagnosis.AIM To assess the diagnostic value of combined magnetic resonance T2-we...BACKGROUND Colorectal cancer is a malignancy with a high risk of lymph node metastasis and poor prognosis,and thus requires an accurate diagnosis.AIM To assess the diagnostic value of combined magnetic resonance T2-weighted imaging(T2WI)and diffusion-weighted imaging(DWI)in colorectal cancer.METHODS We included 120 patients with suspected colorectal cancer who underwent magnetic resonance imaging.Surgical pathology was used as the gold standard for comparison.Combined T2WI and DWI showed higher diagnostic efficacy than either of the two methods used individually.RESULTS The combined method achieved 94.74%sensitivity,95.45%specificity,95.00%accuracy,94.74%positive predictive value,and 95.45%negative predictive value in qualitative diagnosis.It showed 94.44%sensitivity,95.00%specificity,94.74%accuracy,94.44%positive predictive value,and 95.00%negative predictive value in clinical staging.Finally,it showed 94.74%sensitivity,94.59%specificity,94.74%accuracy,94.74%positive predictive value,and 94.59%negative predictive value in diagnosing lymph node metastasis.These results were highly consistent with that of the gold standard.CONCLUSION This study combined T2WI and DWI for accurate diagnosis of colorectal cancer,aiding clinical staging and lymph node metastasis assessment.This approach is promising for clinical application.展开更多
We aimed to evaluate the feasibility of simultaneous image acquisition of multiple instantaneous switchable scan(MISS)for prostate magnetic resonance imaging(MRI)on 3T.Fifty-three patients were scanned with MRI due to...We aimed to evaluate the feasibility of simultaneous image acquisition of multiple instantaneous switchable scan(MISS)for prostate magnetic resonance imaging(MRI)on 3T.Fifty-three patients were scanned with MRI due to suspected prostate cancer.Twenty-eight of them got histological results.First,two readers assessed the structure delineation and image quality based on images of conventional T2-weighted imaging(T2WI)and diffusion-weighted imaging(DWI)(CTD).Second,two readers identified the index lesion together,and then,reader one evaluated the contrast of index lesion on T2WI and signal ratio on apparent diffusion coefficient map.Third,they assigned Prostate Imaging Reporting and Data System(PI-RADS)score in consensus for the index lesion.After 4 weeks,the images of MISS were reviewed by the same readers following the same process.Finally,two readers gave preference for image interpretation,respectively.Kappa coefficient,Wilcoxon signed-rank test,paired-sample t-test,Bland-Altman analysis,and receiver operating characteristic(ROC)analysis were used for statistical analysis.The acquisition time of CTD was 6 min and 10 st while the acquisition time of MISS was 4 min and 30 s.Interobserver agreements for image evaluation were k=0.65 and k=0.80 for CTD and MISS,respectively.MISS-T2WI showed better delineation for seminal vesicles than CTD-T2WI(reader 1:P<0.001,reader 2:P=0.001).The index lesion demonstrated higher contrast in MISS-T2WI(P<0.001).The FI-RADS scores based on CTD and MISS exhibited high ability in predicting clinically significant cancer(area under curve[AUC]=0.828 vs 0.854).Readers preferred to use MISS in 41.5%-47.2%of cases.MISS showed comparable performance to conventional technique with less acquisition time.展开更多
Objective To qualitatively assess the diagnostic performance of dynamic contrast enhancement(DCE),diffusionweighted imaging(DWI),and T2-weighted imaging(T2WI),alone or in combination,in the evaluation of breast cancer...Objective To qualitatively assess the diagnostic performance of dynamic contrast enhancement(DCE),diffusionweighted imaging(DWI),and T2-weighted imaging(T2WI),alone or in combination,in the evaluation of breast cancer.Methods We retrospectively reviewed the records of 394 consecutive patients with pathologically confirmed breast lesions who had undergone 3-T magnetic resonance imaging(MRI).The morphological characteristics of breast lesions were evaluated using DCE,DWI,and T2WI based on BI-RADS lexicon descriptors by trained radiologists.Patients were categorized into mass and non-mass groups based on MRI characteristics of the lesions,and the differences between benign and malignant lesions in each group were compared.Clinical prediction models for breast cancer diagnosis were constructed using logistic regression analysis.Diagnostic efficacies were compared using the area under the receiver operating characteristic curve(AUC)and DeLong test.Results For mass-like lesions,all the morphological parameters significantly differentiated benign and malignant lesions on consensus DCE,DWI,and T2WI(P<0.05).The combined method(DCE+DWI+T2WI)had a higher AUC(0.865)than any of the individual modality(DCE:0.786;DWI:0.793;T2WI:0.809)(P<0.05).For non-mass-like lesions,DWI signal intensity was a significant predictor of malignancy(P=0.036),but the model using DWI alone had a low AUC(0.669).Conclusion Morphological assessment using the combination of DCE,DWI,and T2WI provides better diagnostic value in differentiating benign and malignant breast mass-like lesions than assessment with only one of the modalities.展开更多
AIM： To evaluate the utility of diffusion-weighted imaging （DWl） in screening and differential diagnosis of benign and malignant focal hepatic lesions. METHODS： Magnetic resonance imaging （MRI） examinations were...AIM： To evaluate the utility of diffusion-weighted imaging （DWl） in screening and differential diagnosis of benign and malignant focal hepatic lesions. METHODS： Magnetic resonance imaging （MRI） examinations were performed using the Signa Excite Xl Twin Speed 1.5T system （GE Healthcare, Milwaukee, Wl, USA）. Seventy patients who had undergone MRI of the liver [29 hepatocellular carcinomas （HCC）, four cholangiocarcinomas, 34 metastatic liver cancers, 10 hemangiomas, and eight cysts] between April 2004 and August 2008 were retrospectively evaluated. Visualization of lesions, relative contrast ratio （RCR）, and apparent diffusion coefficient （ADC） were compared between benign and malignant lesions on DWl. Su- perparamagnetic iron oxide （SPIO） was administered to 59 patients, and RCR was compared pre- and postadministration.RESULTS： DWI showed higher contrast between malignant lesions （especially in multiple small metastatic cancers） and surrounding liver parenchyma than did contrast-enhanced computed tomography. ADCs （mean±SD × 10^-3 mm2/s） were significantly lower （P 〈 0.05） in malignant lesions （HCC： 1.31 ± 0.28 and liver metastasis： 1.11 ± 0.22） and were significantly higher in benign lesions （hemangioma： 1.84 ± 0.37 and cyst： 2.61 ± 0.45） than in the surrounding hepatic tissues. RCR between malignant lesions and surrounding he- patic tissues significantly improved after SPIO administration, but RCRs in benign lesions were not improved.CONCLUSION： DWI is a simple and sensitive method for screening focal hepatic lesions and is useful for differential diagnosis.展开更多
Objective： To assess if diffusion-weighted magnetic resonance （MR） imaging without apparent diffusion coefficient （ADC） values provides added diagnostic value in combination with conventional MR imaging in the de...Objective： To assess if diffusion-weighted magnetic resonance （MR） imaging without apparent diffusion coefficient （ADC） values provides added diagnostic value in combination with conventional MR imaging in the detection and characterization of small nodules in cirrhotic liver. Methods： Two observers retrospectively and independently analyzed 86 nodules （_〈3 em） certified pathologically in 33 patients with liver cirrhosis, including 48 hepatocellular carcinoma （HCC） nodules, 13 high-grade dysplastic nodules （HDN）, 10 low-grade dysplastic nodules （LDNs） and 15 other benign nodules. All these focal nodules were evaluated with conventional MR images （Tl-weighted, T2-weighted and dynamic gadolinium-enhanced images） and breath-hold diffusion-weighted images （DWI） （b=500 s/mm2）. The nodules were classified by using a scale of 1-3 （1, not seen; 3, well seen） on DWI for qualitative assessment. These small nodules were characterized by two radiologists. ADC values weren＇t measured. The diagnostic performance of the combined DWI-conventional images and the conventional images alone was evaluated using receiver operating characteristic （ROC） curves. The area under the curves （Az）, sensitivity and specificity values for characterizing different small nodules were also calculated. Results： Among 48 HCC nodules, 33 （68.8%） were graded as 3 （well seen）, 6 （12.5%） were graded as 2 （partially obscured）, and 9 weren＇t seen on DWI. Among 13 HDNs, there were 3 （23.1%） and 4 （30.8%） graded as 3 and 2 respectively. Five （50%） of 10 benign nodules were partially obscured and slightly hyperintense. For 86 nodules, the average diagnostic accuracy of combined DWI-conventional images was 82.56%, which was increased significantly compared with conventional MR images with 76.17%. For HCC and HDN, the diagnostic accuracy of combined DWI-conventional images increased from 78.69% to 86.07 %. Conclusions： Diffusion-weighted MR imaging does provide added diagnostic value in the detection and characterization of HDN and HCC, and it may not be helpful for LDN and regenerative nodule （RN） in cirrhotic liver.展开更多
Diffusion-weighted imaging (DWI) is an established diagnostic method of acute stroke. The latest advances in magnetic resonance imaging (MRI) technology have greatly expanded the utility of DWI in the examination of v...Diffusion-weighted imaging (DWI) is an established diagnostic method of acute stroke. The latest advances in magnetic resonance imaging (MRI) technology have greatly expanded the utility of DWI in the examination of various organs. Recent studies have revealed the usefulness of DWI for imaging of the liver, kidney, ovary, and breast. We report a patient with acute pancreatitis detected by DWI and discussed the efficacy of DWI in diagnosing acute pancreatitis. A 50-year old man presented with a primary complaint of abdominal pain. We performed both DWI and computed tomography (CT) for this patient. The signal intensity in a series of DWI was measured and the apparent diffusion coefficient (ADC) values were calculated to differentiate inflammation from normal tissue. Two experienced radiologists evaluated the grade of acute pancreatitis by comparing the CT findings. Initially, the pancreas and multiple ascites around the pancreas produced a bright signal and ADC values were reduced on DWI. As the inflammation decreased, the bright signal faded to an iso-signal and the ADC values returned to their normal level. There was no difference in the abilities of DWI and CT images to detect acute pancreatitis. However, our case indicates that DWI can evaluate the manifestations of acute pancreatitis using no enhancement material andhas the potential to replace CT as a primary diagnostic strategy for acute pancreatitis.展开更多
BACKGROUND The Liver Imaging Reporting and Data System(LI-RADS), supported by the American College of Radiology(ACR), has been developed for standardizing the acquisition, interpretation, reporting, and data collectio...BACKGROUND The Liver Imaging Reporting and Data System(LI-RADS), supported by the American College of Radiology(ACR), has been developed for standardizing the acquisition, interpretation, reporting, and data collection of liver imaging examinations in patients at risk for hepatocellular carcinoma(HCC). Diffusionweighted imaging(DWI), which is described as an ancillary imaging feature of LI-RADS, can improve the diagnostic efficiency of LI-RADS v2017 with gadoxetic acid-enhanced magnetic resonance imaging(MRI) for HCC.AIM To determine whether the use of DWI can improve the diagnostic efficiency of LIRADS v2017 with gadoxetic acid-enhanced magnetic resonance MRI for HCC.METHODS In this institutional review board-approved study, 245 observations of high risk of HCC were retrospectively acquired from 203 patients who underwent gadoxetic acid-enhanced MRI from October 2013 to April 2018. Two readers independently measured the maximum diameter and recorded the presence of each lesion and assigned scores according to LI-RADS v2017. The test was used to determine the agreement between the two readers with or without DWI. In addition, the sensitivity(SE), specificity(SP), accuracy(AC), positive predictive value(PPV), and negative predictive value(NPV) of LI-RADS were calculated.Youden index values were used to compare the diagnostic performance of LIRADS with or without DWI.RESULTS Almost perfect interobserver agreement was obtained for the categorization of observations with LI-RADS(kappa value: 0.813 without DWI and 0.882 with DWI). For LR-5, the diagnostic SE, SP, and AC values were 61.2%, 92.5%, and71.4%, respectively, with or without DWI; for LR-4/5, they were 73.9%, 80%, and75.9% without DWI and 87.9%, 80%, and 85.3% with DWI; for LR-4/5/M, they were 75.8%, 58.8%, and 70.2% without DWI and 87.9%, 58.8%, and 78.4% with DWI; for LR-4/5/TIV, they were 75.8%, 75%, and 75.5% without DWI and 89.7%,75%, and 84.9% with DWI. The Youden index values of the LI-RADS classification without or with DWI were as follows: LR-4/5: 0.539 vs 0.679; LR-4/5/M: 0.346 vs 0.467; and LR-4/5/TIV: 0.508 vs 0.647.CONCLUSION LI-RADS v2017 has been successfully applied with gadoxetate-enhanced MRI for patients at high risk for HCC. The addition of DWI significantly increases the diagnostic efficiency for HCC.展开更多
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
AIM: To investigate dynamic characteristics and pathological mechanism of signal in rabbit VX-2 tumor model on diffusion-weighted imaging (DWI) after chemoembolization. METHODS: Forty New Zealand rabbits were included...AIM: To investigate dynamic characteristics and pathological mechanism of signal in rabbit VX-2 tumor model on diffusion-weighted imaging (DWI) after chemoembolization. METHODS: Forty New Zealand rabbits were included in the study and forty-seven rabbit VX-2 tumor models were raised by implanting directly and intrahepatically after abdominal cavity opened. Forty VX-2 tumor models from them were divided into four groups. DWI was performed periodically and respectively for each group after chemoembolization. All VX-2 tumor samples of each group were studied by pathology. The distinction of VX-2 tumors on DWI was assessed by their apparent diffusion coefficient (ADC) values. The statistical significance between different time groups, different area groups or different b-value groups was calculated by using SPSS12.0 software. RESULTS: Under b-value of 100 s/mm2, ADC values were lowest at 16 h after chemoembolization in area of VX-2 tumor periphery, central, and normal liver parenchyma around tumor, but turned to increase with further elongation of chemoembolization treatment. The distinction of ADC between different time groups was significant respectively (F = 7.325, P < 0.001; F = 2.496, P < 0.048; F = 6.856, P < 0.001). Cellular edema in the area of VX-2 tumor periphery or normal liver parenchyma around tumor, increased quickly in sixteen h after chemoembolization but, from the 16th h to the 48th h, cellular edema in the area of normal liver parenchyma around tumor decreased gradually and that in the area of VX-2 tumor periphery decreased lightly at, and then increased continually. After chemoembolization, Cellular necrosis in the area of VX-2 tumor periphery was more significantly high than that before chemoembolization. The areas of dead cells in VX-2 tumors manifested low signal and high ADC value, while the areas of viable cells manifested high signal and low ADC value. CONCLUSION: DWI is able to detect and differentiate tumor necrotic areas from viable cellular areas before and after chemoembolization. ADC of normal liver parenchyma and VX-2 tumor are influenced by intracellular edema, tissue cellular death and microcirculation disturbance after chemoembolization.展开更多
AIM: To investigate whether intra-procedural diffusion- weighted magnetic resonance imaging can predict response of hepatocellular carcinoma (HCC) during trans- catheter arterial chemoembolization (TACE). METHODS: Six...AIM: To investigate whether intra-procedural diffusion- weighted magnetic resonance imaging can predict response of hepatocellular carcinoma (HCC) during trans- catheter arterial chemoembolization (TACE). METHODS: Sixteen patients (15 male), aged 59 ±11 years (range: 42-81 years) underwent a total of 21 separate treatments for unresectable HCC in a hybrid magnetic resonance/interventional radiology suite. Ana- tomical imaging and diffusion-weighted imaging (b = 0, 500 s/mm2) were performed on a 1.5-T unit. Tumor enhancement and apparent diffusion coefficient (ADC, mm2/s) values were assessed immediately before and at 1 and 3 mo after TACE. We calculated the percent change (PC) in ADC values at all time points. We compared follow-up ADC values to baseline values using a paired t test (α = 0.05). RESULTS: The intra-procedural sensitivity, specificity, and positive and negative predictive values (%) for detecting a complete or partial 1-mo tumor response using ADC PC thresholds of ±5%, ±10%, and ±15% were 77, 67, 91, and 40; 54, 67, 88, and 25; and 46, 100, 100, and 30, respectively. There was no clear predictive value for the 3-mo follow-up. Compared to baseline, the immediate post-procedure and 1-mo mean ADC values both increased; the latter obtaining statistical significance (1.48 ± 0.29 mm2/s vs 1.65 ± 0.35 × 10-3 mm2/s, P < 0.014). CONCLUSION: Intra-procedural ADC changes of > 15% predicted 1-mo anatomical HCC response with the greatest accuracy, and can provide valuable feedback at the time of TACE.展开更多
AIM:To evaluate the clinical value of diffusion-weighted magnetic resonance imaging(DW-MRI)in predicting the response of rectal cancer to neoadjuvant chemoradiation.METHODS:This prospective study was approved by our i...AIM:To evaluate the clinical value of diffusion-weighted magnetic resonance imaging(DW-MRI)in predicting the response of rectal cancer to neoadjuvant chemoradiation.METHODS:This prospective study was approved by our institutional review board,and informed consent was obtained from each patient.Fifteen patients(median age 56 years)with locally advanced rectal cancer were treated in our hospital from June 2006 to December 2007.All patients were stageⅢB-C according to the results of MRI and endorectal ultrasound examinations.All patients underwent pelvic irradiation with 45 Gy/25 fx per 35 days.The concurrent chemotherapy regimen consisted of capecitabine 625mg/m2,bid(Monday-Friday),and oxaliplatin 50 mg/m2,weekly.The patients underwent surgery 5-8 wk after the completion of neoadjuvant therapy.T downstaging was defined as the downstaging of the tumor from cT3to ypT0-2 or from cT4 to ypT0-3.Good regression was defined as TRG 3-4,and poor regression was defined as TRG 0-2.Diffusion-weighted magnetic resonance images were obtained prior to and weekly during the course of neoadjuvant chemoradiation,and the apparent diffusion coefficient(ADC)values were calculated from the acquired tumor images.RESULTS:Comparison with the mean pretreatment tumor ADC revealed an increase in the mean tumor ADC during the course of neoadjuvant chemoradiation,especially at the 2ndweek(P=0.004).We found a strong negative correlation between the mean pretreatment tumor ADC and tumor regression after neoadjuvant chemoradiation(P=0.021).In the T downstage and tumor regression groups,we found a significant increase in the mean ADC at the 2ndweek of neoadjuvant therapy(P=0.011;0.004).CONCLUSION:DW-MRI might be a valuable clinical tool to help predict or assess the response of rectal cancer to neoadjuvant chemoradiation at an early timepoint.展开更多
BACKGROUND The activity staging of Crohn’s disease(CD)in the terminal ileum is critical in developing an accurate clinical treatment plan.The activity of terminal ileum CD is associated with the microcirculation of i...BACKGROUND The activity staging of Crohn’s disease(CD)in the terminal ileum is critical in developing an accurate clinical treatment plan.The activity of terminal ileum CD is associated with the microcirculation of involved bowel walls.Dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)and diffusionweighted imaging(DWI)can reflect perfusion and permeability of bowel walls by providing microcirculation information.As such,we hypothesize that DCE-MRI and DWI parameters can assess terminal ileum CD,thereby providing an opportunity to stage CD activity.AIM To evaluate the value of DCE-MRI and DWI in assessing activity of terminal ileum CD.METHODS Forty-eight patients with CD who underwent DCE-MRI and DWI were enrolled.The patients’activity was graded as remission,mild and moderate-severe.The transfer constant(Ktrans),wash-out constant(Kep),and extravascular extracellular volume fraction(Ve)were calculated from DCE-MRI and the apparent diffusion coefficient(ADC)was obtained from DWI.Magnetic Resonance Index of Activity(MaRIA)was calculated from magnetic resonance enterography.Differences in these quantitative parameters were compared between normal ileal loop(NIL)and inflamed terminal ileum(ITI)and among different activity grades.The correlations between these parameters,MaRIA,the Crohn’s Disease Activity Index(CDAI),and Crohn’s Disease Endoscopic Index of Severity(CDEIS)were examined.Receiver operating characteristic curve analyses were used to determine the diagnostic performance of these parameters in differentiating between CD activity levels.RESULTS Higher Ktrans(0.07±0.04 vs 0.01±0.01),Kep(0.24±0.11 vs 0.15±0.05)and Ve(0.27±0.07 vs 0.08±0.03),but lower ADC(1.41±0.26 vs 2.41±0.30)values were found in ITI than in NIL(all P<0.001).The Ktrans,Kep,Ve and MaRIA increased with disease activity,whereas the ADC decreased(all P<0.001).The Ktrans,Kep,Ve and MaRIA showed positive correlations with the CDAI(r=0.866 for Ktrans,0.870 for Kep,0.858 for Ve,0.890 for MaRIA,all P<0.001)and CDEIS(r=0.563 for Ktrans,0.567 for Kep,0.571 for Ve,0.842 for MaRIA,all P<0.001),while the ADC showed negative correlations with the CDAI(r=-0.857,P<0.001)and CDEIS(r=-0.536,P<0.001).The areas under the curve(AUC)for the Ktrans,Kep,Ve,ADC and MaRIA values ranged from 0.68 to 0.91 for differentiating inactive CD(CD remission)from active CD(mild to severe CD).The AUC when combining the Ktrans,Kep and Ve was 0.80,while combining DCE-MRI parameters and ADC values yielded the highest AUC of 0.95.CONCLUSION DCE-MRI and DWI parameters all serve as measures to stage CD activity.When they are combined,the assessment performance is improved and better than MaRIA.展开更多
Diffusion-weighted imaging (DWI) is one of the magnetic resonance imaging (MRI) sequences providing qualitative as well as quantitative information at a cellular level. It has been widely used for various applications...Diffusion-weighted imaging (DWI) is one of the magnetic resonance imaging (MRI) sequences providing qualitative as well as quantitative information at a cellular level. It has been widely used for various applications in the central nervous system. Over the past decade, various extracranial applications of DWI have been increasingly explored, as it may detect changes even before signal alterations or morphological abnormalities become apparent on other pulse sequences. Initial results from abdominal MRI applications are promising, particularly in oncological settings and for the detection of abscesses. The purpose of this article is to describe the clinically relevant basic concepts of DWI, techniques to perform abdominal DWI, its analysis and applications in abdominal visceral MR imaging, in addition to a brief overview of whole body DWI MRI.展开更多
Objective： To investigate the role of apparent diffusion coefficient （ADC） from diffusion-weighted magnetic resonance imaging （DW-MRI） when applied to the 7th TNM classification in the staging and prognosis of ga...Objective： To investigate the role of apparent diffusion coefficient （ADC） from diffusion-weighted magnetic resonance imaging （DW-MRI） when applied to the 7th TNM classification in the staging and prognosis of gastric cancer （GC）. Methods： Between October 2009 and May 2014, a total of 89 patients with non-metastatic, biopsy proven GC underwent 1.5T DW-MRI, and then treated with radical surgery. Tumor ADC was measured retrospectively and compared with final histology following the 7th TNM staging （local invasion, nodal involvement and according to the different groups -- stage Ⅰ, Ⅱ and Ⅲ）. Kaplan-Meier curves were also generated. The follow-up period is updated to May 2016. Results： Median follow-up period was 33 months and 45/89 （51%） deaths from GC were observed. ADC was significantly different both for local invasion and nodal involvement （P〈0.001）. Considering final histology as the reference standard, a preoperative ADC cut-offof 1.80×10-3 mm^2/s could distinguish between stages I and Ⅱ and an ADC value of ≤1.36-10-3 mm^2/s was associated with stage Ⅲ（P〈0.001）. Kaplan-Meier curves demonstrated that the survival rates for the three prognostic groups were significantly different according to final histology and ADC cut-offs （P〈0.001）. Conclusions： ADC is different according to local invasion, nodal involvement and the 7th TNM stage groups for GC, representing a potential, additional prognostic biomarker. The addition of DW-MRI could aid in the staging and risk stratification of GC.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
AIM: To evaluate the accuracy of diffusion-weighted imaging(DWI) without bowel preparation,the optimal b value and the changes in apparent diffusion coefficient(ADC) in detecting ulcerative colitis(UC).METHODS: A tota...AIM: To evaluate the accuracy of diffusion-weighted imaging(DWI) without bowel preparation,the optimal b value and the changes in apparent diffusion coefficient(ADC) in detecting ulcerative colitis(UC).METHODS: A total of 20 patients who underwent 3T magnetic resonance imaging(MRI) without bowel preparation and colonoscopy within 24 h were recruited.Biochemical indexes,including C-reactive protein(CRP),erythrocyte sedimentation rate,hemoglobin,leucocytes,platelets,serum iron and albumin,were determined.Biochemical examinations were then performed within 24 h before or after MR colonography was conducted.DWI was performed at various b values(b = 0,400,600,800,and 1000 s/mm2).Two radiologists independently and blindly reviewed conventional- and contrast-enhanced MR images,DWI and ADC maps; these radiologists also determined ADC in each intestinal segment(rectum,sigmoid,left colon,transverse colon,and right colon).Receiver operating characteristic(ROC) analysis was performed to assess the diagnostic performance of DWI hyperintensity from various b factors,ADC values and different radiological signs to detect endoscopic inflammation in the corresponding bowel segment.Optimal ADC threshold was estimated by maximizing the combination of sensitivity and specificity.MRfindings were correlated with endoscopic results and clinical markers; these findings were then estimated by ROC analysis.RESULTS: A total of 100 segments(71 with endoscopic colonic inflammation; 29 normal) were included.The proposed total magnetic resonance score(MR-score-T) was correlated with the total modified Baron score(Baron-T; r = 0.875,P < 0.0001); the segmental MR score(MR-score-S) was correlated with the segmental modified Baron score(Baron-S; r = 0.761,P < 0.0001).MR-score-T was correlated with clinical and biological markers of disease activity(r = 0.445 to 0.831,P < 0.05).MR-score-S > 1 corresponded to endoscopic colonic inflammation with a sensitivity of 85.9%,a specificity of 82.8% and an area under the curve(AUC) of 0.929(P < 0.0001).The accuracy of DWI hyperintensity was significantly greater at b = 800 than at b = 400,600,or 1000 s/mm2(P < 0.05) when endoscopic colonic inflammation was detected.DWI hyperintensity at b = 800 s/mm2 indicated endoscopic colonic inflammation with a sensitivity of 93.0%,a specificity of 79.3% and an AUC of 0.867(P < 0.0001).Quantitative analysis results revealed that ADC values at b = 800 s/mm2 differed significantly between endoscopic inflamed segment and normal intestinal segment(1.56 ± 0.58 mm2/s vs 2.63 ± 0.46 mm2/s,P < 0.001).The AUC of ADC values was 0.932(95% confidence interval: 0.881-0.983) when endoscopic inflammation was detected.The threshold ADC value of 2.18 × 10-3 mm2/s indicated that endoscopic inflammation differed from normal intestinal segment with a sensitivity of 89.7% and a specificity of 80.3%.CONCLUSION: DWI combined with conventional MRI without bowel preparation provides a quantitative strategy to differentiate actively inflamed intestinal segments from the normal mucosa to detect UC.展开更多
There have been numerous studies done to explore the diagnostic performance of quanti- tative diffusion-weighted （DW） MR imaging to differentiate between benign and malignant pancre- atic masses. However, the result...There have been numerous studies done to explore the diagnostic performance of quanti- tative diffusion-weighted （DW） MR imaging to differentiate between benign and malignant pancre- atic masses. However, the results have been inconsistent. We performed a meta-analysis to investigate whether DW-MR imaging can differentiate between these two diseases. Databases including MEDLINE, EMBASE and Cochrane Library were utilized to find relevant articles published between January 2001 and January 2014. A Stata version 12.0 and a Meta-Disc version 1.4 were used to de- scribe primary results. Twelve studies with 594 patients, which fulfilled the inclusion criteria, were enrolled for the analysis. The pooled sensitivity and specificity of DW imaging was 0.91 （95% CI： 0.84, 0.95） and 0.86 （95% CI： 0.76, 0.93） respectively. The area under the curve of the summary re- ceiver operating characteristic was 0.95 （95% CI： 0.93, 0.96）. The results indicated that DW imaging might be a valuable tool for differentiating benign and malignant pancreatic masses.展开更多
AIM: To investigate the diagnostic ability of single-shot echo-planar imaging(EPI) diffusion-weighted imaging (DWI) to differentiate between malignant and benign pancreatic lesions. METHODS: A computerized search was ...AIM: To investigate the diagnostic ability of single-shot echo-planar imaging(EPI) diffusion-weighted imaging (DWI) to differentiate between malignant and benign pancreatic lesions. METHODS: A computerized search was performed on Pub Med, MEDLINE and EMBASE up to August 2014. Nine studies(10 sets of data) with a total of 304 malignant pancreatic lesions and 188 benign pancreatic lesions were included. The characteristics of each study included the study name, year of publication, magnetic resonance modalities used, patient population, strength of field, pulse time, repetition time, echo time(TE), maximum b factor, mean age, mean body weight, fat suppression, number of benign and malignant lesions, and true positive, true negative, false positive and false negative results. All analyses were performed using Meta-Di Sc and Stata 11.0.RESULTS: The pooled sensitivity and specificity of singleshot EPI DWI were 0.83(95%CI: 0.79-0.87) and 0.77(95%CI: 0.70-0.83), respectively. The positive likelihood ratio and negative likelihood ratio were 5.09(95%CI: 2.19-11.84) and 0.23(95%CI: 0.15-0.36), respectively. The P value for the χ2 heterogeneity for all pooled estimates was < 0.05. From the fitted summary receiver operating characteristic curve, the area under the curve and Q* index were 0.89 and 0.82, respectively. Publication bias was not present(t = 0.58, P = 0.58). Meta-regression analysis indicated that fat suppression, mean age, TE, and maximum b factor were not sources of heterogeneity(all P > 0.05). CONCLUSION: Single-shot EPI DWI is useful to differentiate between malignant and benign pancreatic lesions. Lesion size ≥ 2 cm is the limit for the diagnosis of early lesions.展开更多
文摘Objective:To explore the value of multimodal MRI enhancement scanning and diffusion-weighted imaging in differentiating non-puerperal mastitis(NPM)and breast cancer.Methods:From September 2022 to September 2024,56 patients with breast diseases were selected as samples and grouped according to disease type.Twenty-eight patients with breast cancer were included in Group A,and 28 patients with NPM were included in Group B.All patients underwent multimodal MRI enhancement scanning and diffusion-weighted imaging.The MRI results,time-signal intensity curves,ADC values,lesion intensity,and imaging signs were compared between the two groups.Results:There were no significant differences in enhancement characteristics,lymph node enlargement,and margins between Group A and Group B(P>0.05).The proportion of outflow curves in Group A was higher than that in Group B(P<0.05).The ADC value in Group A was lower than that in Group B,and the lesion intensity was higher than that in Group B(P<0.05).There were significant differences in imaging signs,such as abscess or sinus,ascending time-signal curve,and mammary duct dilation between Group A and Group B(P<0.05).Conclusion:Multimodal MRI enhancement scanning and diffusion-weighted imaging techniques can be used to diagnose breast diseases.Comprehensive analysis of time-signal intensity curves,lesion intensity,imaging signs,and ADC values can differentiate between NPM and breast cancer.
基金Supported by National Natural Science Foundation of China,No.62472315Shanghai Science and Technology Innovation Action Plan Medical Innovation Research Project,No.20Y11912500.
文摘Diffusion-weighted magnetic resonance imaging(DWI)has become an essential tool in the field of pancreatic magnetic resonance imaging,enabling the detection,characterization,prediction,and evaluation of pancreatic diseases.In this article,we review the acquisition parameters,postprocessing techniques,and quantitative methods utilized in pancreatic DWI.Various postprocessing models,including monoexponential,biexponential,stretched exponential and non-Gaussian kurtosis models,as well as deep learning networks,have been used to assess the clinical utility of these models in diagnosing pancreatic diseases.The single-shot echo-planar imaging sequence is the most commonly used sequence for DWI data acquisition in clinical settings,and the apparent diffusion coefficient(ADC)calculated using the monoexponential model is the most widely used quantitative parameter in clinical practice.The repeatability threshold for the ADC of a normal pancreas is 37%for test-retest scans,but the repeatability threshold for pancreatic tumors needs to be further investigated.Complex postprocessing models exploring novel DWI-based biomarkers beyond ADC to assess histological features,and artificial intelligence in DWI postprocessing and data analyses hold promise in the diagnosis of pancreatic diseases.Future work should focus on standardizing protocols,conducting multicentre studies,and exploring variety of methods to improve the accuracy of quantitative DWI results to increase the clinical effectiveness of DWI in patients with pancreatic diseases.
文摘BACKGROUND Colorectal cancer is a malignancy with a high risk of lymph node metastasis and poor prognosis,and thus requires an accurate diagnosis.AIM To assess the diagnostic value of combined magnetic resonance T2-weighted imaging(T2WI)and diffusion-weighted imaging(DWI)in colorectal cancer.METHODS We included 120 patients with suspected colorectal cancer who underwent magnetic resonance imaging.Surgical pathology was used as the gold standard for comparison.Combined T2WI and DWI showed higher diagnostic efficacy than either of the two methods used individually.RESULTS The combined method achieved 94.74%sensitivity,95.45%specificity,95.00%accuracy,94.74%positive predictive value,and 95.45%negative predictive value in qualitative diagnosis.It showed 94.44%sensitivity,95.00%specificity,94.74%accuracy,94.44%positive predictive value,and 95.00%negative predictive value in clinical staging.Finally,it showed 94.74%sensitivity,94.59%specificity,94.74%accuracy,94.74%positive predictive value,and 94.59%negative predictive value in diagnosing lymph node metastasis.These results were highly consistent with that of the gold standard.CONCLUSION This study combined T2WI and DWI for accurate diagnosis of colorectal cancer,aiding clinical staging and lymph node metastasis assessment.This approach is promising for clinical application.
文摘We aimed to evaluate the feasibility of simultaneous image acquisition of multiple instantaneous switchable scan(MISS)for prostate magnetic resonance imaging(MRI)on 3T.Fifty-three patients were scanned with MRI due to suspected prostate cancer.Twenty-eight of them got histological results.First,two readers assessed the structure delineation and image quality based on images of conventional T2-weighted imaging(T2WI)and diffusion-weighted imaging(DWI)(CTD).Second,two readers identified the index lesion together,and then,reader one evaluated the contrast of index lesion on T2WI and signal ratio on apparent diffusion coefficient map.Third,they assigned Prostate Imaging Reporting and Data System(PI-RADS)score in consensus for the index lesion.After 4 weeks,the images of MISS were reviewed by the same readers following the same process.Finally,two readers gave preference for image interpretation,respectively.Kappa coefficient,Wilcoxon signed-rank test,paired-sample t-test,Bland-Altman analysis,and receiver operating characteristic(ROC)analysis were used for statistical analysis.The acquisition time of CTD was 6 min and 10 st while the acquisition time of MISS was 4 min and 30 s.Interobserver agreements for image evaluation were k=0.65 and k=0.80 for CTD and MISS,respectively.MISS-T2WI showed better delineation for seminal vesicles than CTD-T2WI(reader 1:P<0.001,reader 2:P=0.001).The index lesion demonstrated higher contrast in MISS-T2WI(P<0.001).The FI-RADS scores based on CTD and MISS exhibited high ability in predicting clinically significant cancer(area under curve[AUC]=0.828 vs 0.854).Readers preferred to use MISS in 41.5%-47.2%of cases.MISS showed comparable performance to conventional technique with less acquisition time.
文摘Objective To qualitatively assess the diagnostic performance of dynamic contrast enhancement(DCE),diffusionweighted imaging(DWI),and T2-weighted imaging(T2WI),alone or in combination,in the evaluation of breast cancer.Methods We retrospectively reviewed the records of 394 consecutive patients with pathologically confirmed breast lesions who had undergone 3-T magnetic resonance imaging(MRI).The morphological characteristics of breast lesions were evaluated using DCE,DWI,and T2WI based on BI-RADS lexicon descriptors by trained radiologists.Patients were categorized into mass and non-mass groups based on MRI characteristics of the lesions,and the differences between benign and malignant lesions in each group were compared.Clinical prediction models for breast cancer diagnosis were constructed using logistic regression analysis.Diagnostic efficacies were compared using the area under the receiver operating characteristic curve(AUC)and DeLong test.Results For mass-like lesions,all the morphological parameters significantly differentiated benign and malignant lesions on consensus DCE,DWI,and T2WI(P<0.05).The combined method(DCE+DWI+T2WI)had a higher AUC(0.865)than any of the individual modality(DCE:0.786;DWI:0.793;T2WI:0.809)(P<0.05).For non-mass-like lesions,DWI signal intensity was a significant predictor of malignancy(P=0.036),but the model using DWI alone had a low AUC(0.669).Conclusion Morphological assessment using the combination of DCE,DWI,and T2WI provides better diagnostic value in differentiating benign and malignant breast mass-like lesions than assessment with only one of the modalities.
文摘AIM： To evaluate the utility of diffusion-weighted imaging （DWl） in screening and differential diagnosis of benign and malignant focal hepatic lesions. METHODS： Magnetic resonance imaging （MRI） examinations were performed using the Signa Excite Xl Twin Speed 1.5T system （GE Healthcare, Milwaukee, Wl, USA）. Seventy patients who had undergone MRI of the liver [29 hepatocellular carcinomas （HCC）, four cholangiocarcinomas, 34 metastatic liver cancers, 10 hemangiomas, and eight cysts] between April 2004 and August 2008 were retrospectively evaluated. Visualization of lesions, relative contrast ratio （RCR）, and apparent diffusion coefficient （ADC） were compared between benign and malignant lesions on DWl. Su- perparamagnetic iron oxide （SPIO） was administered to 59 patients, and RCR was compared pre- and postadministration.RESULTS： DWI showed higher contrast between malignant lesions （especially in multiple small metastatic cancers） and surrounding liver parenchyma than did contrast-enhanced computed tomography. ADCs （mean±SD × 10^-3 mm2/s） were significantly lower （P 〈 0.05） in malignant lesions （HCC： 1.31 ± 0.28 and liver metastasis： 1.11 ± 0.22） and were significantly higher in benign lesions （hemangioma： 1.84 ± 0.37 and cyst： 2.61 ± 0.45） than in the surrounding hepatic tissues. RCR between malignant lesions and surrounding he- patic tissues significantly improved after SPIO administration, but RCRs in benign lesions were not improved.CONCLUSION： DWI is a simple and sensitive method for screening focal hepatic lesions and is useful for differential diagnosis.
基金supported by the Capital Medical Development Foundation(Grant No.2011-2015-02)the National Basic Research Program of China (973 Program)(Grant No.2011CB707705)the Capital Characteristic Clinical Application Research(Grant No.Z121107001012115)
文摘Objective： To assess if diffusion-weighted magnetic resonance （MR） imaging without apparent diffusion coefficient （ADC） values provides added diagnostic value in combination with conventional MR imaging in the detection and characterization of small nodules in cirrhotic liver. Methods： Two observers retrospectively and independently analyzed 86 nodules （_〈3 em） certified pathologically in 33 patients with liver cirrhosis, including 48 hepatocellular carcinoma （HCC） nodules, 13 high-grade dysplastic nodules （HDN）, 10 low-grade dysplastic nodules （LDNs） and 15 other benign nodules. All these focal nodules were evaluated with conventional MR images （Tl-weighted, T2-weighted and dynamic gadolinium-enhanced images） and breath-hold diffusion-weighted images （DWI） （b=500 s/mm2）. The nodules were classified by using a scale of 1-3 （1, not seen; 3, well seen） on DWI for qualitative assessment. These small nodules were characterized by two radiologists. ADC values weren＇t measured. The diagnostic performance of the combined DWI-conventional images and the conventional images alone was evaluated using receiver operating characteristic （ROC） curves. The area under the curves （Az）, sensitivity and specificity values for characterizing different small nodules were also calculated. Results： Among 48 HCC nodules, 33 （68.8%） were graded as 3 （well seen）, 6 （12.5%） were graded as 2 （partially obscured）, and 9 weren＇t seen on DWI. Among 13 HDNs, there were 3 （23.1%） and 4 （30.8%） graded as 3 and 2 respectively. Five （50%） of 10 benign nodules were partially obscured and slightly hyperintense. For 86 nodules, the average diagnostic accuracy of combined DWI-conventional images was 82.56%, which was increased significantly compared with conventional MR images with 76.17%. For HCC and HDN, the diagnostic accuracy of combined DWI-conventional images increased from 78.69% to 86.07 %. Conclusions： Diffusion-weighted MR imaging does provide added diagnostic value in the detection and characterization of HDN and HCC, and it may not be helpful for LDN and regenerative nodule （RN） in cirrhotic liver.
文摘Diffusion-weighted imaging (DWI) is an established diagnostic method of acute stroke. The latest advances in magnetic resonance imaging (MRI) technology have greatly expanded the utility of DWI in the examination of various organs. Recent studies have revealed the usefulness of DWI for imaging of the liver, kidney, ovary, and breast. We report a patient with acute pancreatitis detected by DWI and discussed the efficacy of DWI in diagnosing acute pancreatitis. A 50-year old man presented with a primary complaint of abdominal pain. We performed both DWI and computed tomography (CT) for this patient. The signal intensity in a series of DWI was measured and the apparent diffusion coefficient (ADC) values were calculated to differentiate inflammation from normal tissue. Two experienced radiologists evaluated the grade of acute pancreatitis by comparing the CT findings. Initially, the pancreas and multiple ascites around the pancreas produced a bright signal and ADC values were reduced on DWI. As the inflammation decreased, the bright signal faded to an iso-signal and the ADC values returned to their normal level. There was no difference in the abilities of DWI and CT images to detect acute pancreatitis. However, our case indicates that DWI can evaluate the manifestations of acute pancreatitis using no enhancement material andhas the potential to replace CT as a primary diagnostic strategy for acute pancreatitis.
基金National Natural Science Foundation of China,No.81471658Science and Technology Support Program of Sichuan Province,No.2017SZ0003
文摘BACKGROUND The Liver Imaging Reporting and Data System(LI-RADS), supported by the American College of Radiology(ACR), has been developed for standardizing the acquisition, interpretation, reporting, and data collection of liver imaging examinations in patients at risk for hepatocellular carcinoma(HCC). Diffusionweighted imaging(DWI), which is described as an ancillary imaging feature of LI-RADS, can improve the diagnostic efficiency of LI-RADS v2017 with gadoxetic acid-enhanced magnetic resonance imaging(MRI) for HCC.AIM To determine whether the use of DWI can improve the diagnostic efficiency of LIRADS v2017 with gadoxetic acid-enhanced magnetic resonance MRI for HCC.METHODS In this institutional review board-approved study, 245 observations of high risk of HCC were retrospectively acquired from 203 patients who underwent gadoxetic acid-enhanced MRI from October 2013 to April 2018. Two readers independently measured the maximum diameter and recorded the presence of each lesion and assigned scores according to LI-RADS v2017. The test was used to determine the agreement between the two readers with or without DWI. In addition, the sensitivity(SE), specificity(SP), accuracy(AC), positive predictive value(PPV), and negative predictive value(NPV) of LI-RADS were calculated.Youden index values were used to compare the diagnostic performance of LIRADS with or without DWI.RESULTS Almost perfect interobserver agreement was obtained for the categorization of observations with LI-RADS(kappa value: 0.813 without DWI and 0.882 with DWI). For LR-5, the diagnostic SE, SP, and AC values were 61.2%, 92.5%, and71.4%, respectively, with or without DWI; for LR-4/5, they were 73.9%, 80%, and75.9% without DWI and 87.9%, 80%, and 85.3% with DWI; for LR-4/5/M, they were 75.8%, 58.8%, and 70.2% without DWI and 87.9%, 58.8%, and 78.4% with DWI; for LR-4/5/TIV, they were 75.8%, 75%, and 75.5% without DWI and 89.7%,75%, and 84.9% with DWI. The Youden index values of the LI-RADS classification without or with DWI were as follows: LR-4/5: 0.539 vs 0.679; LR-4/5/M: 0.346 vs 0.467; and LR-4/5/TIV: 0.508 vs 0.647.CONCLUSION LI-RADS v2017 has been successfully applied with gadoxetate-enhanced MRI for patients at high risk for HCC. The addition of DWI significantly increases the diagnostic efficiency for HCC.
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.
基金the National Natural Science Foundation of China, No. 30070235, 30470508
文摘AIM: To investigate dynamic characteristics and pathological mechanism of signal in rabbit VX-2 tumor model on diffusion-weighted imaging (DWI) after chemoembolization. METHODS: Forty New Zealand rabbits were included in the study and forty-seven rabbit VX-2 tumor models were raised by implanting directly and intrahepatically after abdominal cavity opened. Forty VX-2 tumor models from them were divided into four groups. DWI was performed periodically and respectively for each group after chemoembolization. All VX-2 tumor samples of each group were studied by pathology. The distinction of VX-2 tumors on DWI was assessed by their apparent diffusion coefficient (ADC) values. The statistical significance between different time groups, different area groups or different b-value groups was calculated by using SPSS12.0 software. RESULTS: Under b-value of 100 s/mm2, ADC values were lowest at 16 h after chemoembolization in area of VX-2 tumor periphery, central, and normal liver parenchyma around tumor, but turned to increase with further elongation of chemoembolization treatment. The distinction of ADC between different time groups was significant respectively (F = 7.325, P < 0.001; F = 2.496, P < 0.048; F = 6.856, P < 0.001). Cellular edema in the area of VX-2 tumor periphery or normal liver parenchyma around tumor, increased quickly in sixteen h after chemoembolization but, from the 16th h to the 48th h, cellular edema in the area of normal liver parenchyma around tumor decreased gradually and that in the area of VX-2 tumor periphery decreased lightly at, and then increased continually. After chemoembolization, Cellular necrosis in the area of VX-2 tumor periphery was more significantly high than that before chemoembolization. The areas of dead cells in VX-2 tumors manifested low signal and high ADC value, while the areas of viable cells manifested high signal and low ADC value. CONCLUSION: DWI is able to detect and differentiate tumor necrotic areas from viable cellular areas before and after chemoembolization. ADC of normal liver parenchyma and VX-2 tumor are influenced by intracellular edema, tissue cellular death and microcirculation disturbance after chemoembolization.
基金Supported by National Institutes of Health R01 CA126809
文摘AIM: To investigate whether intra-procedural diffusion- weighted magnetic resonance imaging can predict response of hepatocellular carcinoma (HCC) during trans- catheter arterial chemoembolization (TACE). METHODS: Sixteen patients (15 male), aged 59 ±11 years (range: 42-81 years) underwent a total of 21 separate treatments for unresectable HCC in a hybrid magnetic resonance/interventional radiology suite. Ana- tomical imaging and diffusion-weighted imaging (b = 0, 500 s/mm2) were performed on a 1.5-T unit. Tumor enhancement and apparent diffusion coefficient (ADC, mm2/s) values were assessed immediately before and at 1 and 3 mo after TACE. We calculated the percent change (PC) in ADC values at all time points. We compared follow-up ADC values to baseline values using a paired t test (α = 0.05). RESULTS: The intra-procedural sensitivity, specificity, and positive and negative predictive values (%) for detecting a complete or partial 1-mo tumor response using ADC PC thresholds of ±5%, ±10%, and ±15% were 77, 67, 91, and 40; 54, 67, 88, and 25; and 46, 100, 100, and 30, respectively. There was no clear predictive value for the 3-mo follow-up. Compared to baseline, the immediate post-procedure and 1-mo mean ADC values both increased; the latter obtaining statistical significance (1.48 ± 0.29 mm2/s vs 1.65 ± 0.35 × 10-3 mm2/s, P < 0.014). CONCLUSION: Intra-procedural ADC changes of > 15% predicted 1-mo anatomical HCC response with the greatest accuracy, and can provide valuable feedback at the time of TACE.
文摘AIM:To evaluate the clinical value of diffusion-weighted magnetic resonance imaging(DW-MRI)in predicting the response of rectal cancer to neoadjuvant chemoradiation.METHODS:This prospective study was approved by our institutional review board,and informed consent was obtained from each patient.Fifteen patients(median age 56 years)with locally advanced rectal cancer were treated in our hospital from June 2006 to December 2007.All patients were stageⅢB-C according to the results of MRI and endorectal ultrasound examinations.All patients underwent pelvic irradiation with 45 Gy/25 fx per 35 days.The concurrent chemotherapy regimen consisted of capecitabine 625mg/m2,bid(Monday-Friday),and oxaliplatin 50 mg/m2,weekly.The patients underwent surgery 5-8 wk after the completion of neoadjuvant therapy.T downstaging was defined as the downstaging of the tumor from cT3to ypT0-2 or from cT4 to ypT0-3.Good regression was defined as TRG 3-4,and poor regression was defined as TRG 0-2.Diffusion-weighted magnetic resonance images were obtained prior to and weekly during the course of neoadjuvant chemoradiation,and the apparent diffusion coefficient(ADC)values were calculated from the acquired tumor images.RESULTS:Comparison with the mean pretreatment tumor ADC revealed an increase in the mean tumor ADC during the course of neoadjuvant chemoradiation,especially at the 2ndweek(P=0.004).We found a strong negative correlation between the mean pretreatment tumor ADC and tumor regression after neoadjuvant chemoradiation(P=0.021).In the T downstage and tumor regression groups,we found a significant increase in the mean ADC at the 2ndweek of neoadjuvant therapy(P=0.011;0.004).CONCLUSION:DW-MRI might be a valuable clinical tool to help predict or assess the response of rectal cancer to neoadjuvant chemoradiation at an early timepoint.
基金Medical Innovation Program of Fujian Province,No.2018-CX-30Startup Fund for Scientific Research of Fujian Medical University,No.2018QH1054.
文摘BACKGROUND The activity staging of Crohn’s disease(CD)in the terminal ileum is critical in developing an accurate clinical treatment plan.The activity of terminal ileum CD is associated with the microcirculation of involved bowel walls.Dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)and diffusionweighted imaging(DWI)can reflect perfusion and permeability of bowel walls by providing microcirculation information.As such,we hypothesize that DCE-MRI and DWI parameters can assess terminal ileum CD,thereby providing an opportunity to stage CD activity.AIM To evaluate the value of DCE-MRI and DWI in assessing activity of terminal ileum CD.METHODS Forty-eight patients with CD who underwent DCE-MRI and DWI were enrolled.The patients’activity was graded as remission,mild and moderate-severe.The transfer constant(Ktrans),wash-out constant(Kep),and extravascular extracellular volume fraction(Ve)were calculated from DCE-MRI and the apparent diffusion coefficient(ADC)was obtained from DWI.Magnetic Resonance Index of Activity(MaRIA)was calculated from magnetic resonance enterography.Differences in these quantitative parameters were compared between normal ileal loop(NIL)and inflamed terminal ileum(ITI)and among different activity grades.The correlations between these parameters,MaRIA,the Crohn’s Disease Activity Index(CDAI),and Crohn’s Disease Endoscopic Index of Severity(CDEIS)were examined.Receiver operating characteristic curve analyses were used to determine the diagnostic performance of these parameters in differentiating between CD activity levels.RESULTS Higher Ktrans(0.07±0.04 vs 0.01±0.01),Kep(0.24±0.11 vs 0.15±0.05)and Ve(0.27±0.07 vs 0.08±0.03),but lower ADC(1.41±0.26 vs 2.41±0.30)values were found in ITI than in NIL(all P<0.001).The Ktrans,Kep,Ve and MaRIA increased with disease activity,whereas the ADC decreased(all P<0.001).The Ktrans,Kep,Ve and MaRIA showed positive correlations with the CDAI(r=0.866 for Ktrans,0.870 for Kep,0.858 for Ve,0.890 for MaRIA,all P<0.001)and CDEIS(r=0.563 for Ktrans,0.567 for Kep,0.571 for Ve,0.842 for MaRIA,all P<0.001),while the ADC showed negative correlations with the CDAI(r=-0.857,P<0.001)and CDEIS(r=-0.536,P<0.001).The areas under the curve(AUC)for the Ktrans,Kep,Ve,ADC and MaRIA values ranged from 0.68 to 0.91 for differentiating inactive CD(CD remission)from active CD(mild to severe CD).The AUC when combining the Ktrans,Kep and Ve was 0.80,while combining DCE-MRI parameters and ADC values yielded the highest AUC of 0.95.CONCLUSION DCE-MRI and DWI parameters all serve as measures to stage CD activity.When they are combined,the assessment performance is improved and better than MaRIA.
文摘Diffusion-weighted imaging (DWI) is one of the magnetic resonance imaging (MRI) sequences providing qualitative as well as quantitative information at a cellular level. It has been widely used for various applications in the central nervous system. Over the past decade, various extracranial applications of DWI have been increasingly explored, as it may detect changes even before signal alterations or morphological abnormalities become apparent on other pulse sequences. Initial results from abdominal MRI applications are promising, particularly in oncological settings and for the detection of abscesses. The purpose of this article is to describe the clinically relevant basic concepts of DWI, techniques to perform abdominal DWI, its analysis and applications in abdominal visceral MR imaging, in addition to a brief overview of whole body DWI MRI.
文摘Objective： To investigate the role of apparent diffusion coefficient （ADC） from diffusion-weighted magnetic resonance imaging （DW-MRI） when applied to the 7th TNM classification in the staging and prognosis of gastric cancer （GC）. Methods： Between October 2009 and May 2014, a total of 89 patients with non-metastatic, biopsy proven GC underwent 1.5T DW-MRI, and then treated with radical surgery. Tumor ADC was measured retrospectively and compared with final histology following the 7th TNM staging （local invasion, nodal involvement and according to the different groups -- stage Ⅰ, Ⅱ and Ⅲ）. Kaplan-Meier curves were also generated. The follow-up period is updated to May 2016. Results： Median follow-up period was 33 months and 45/89 （51%） deaths from GC were observed. ADC was significantly different both for local invasion and nodal involvement （P〈0.001）. Considering final histology as the reference standard, a preoperative ADC cut-offof 1.80×10-3 mm^2/s could distinguish between stages I and Ⅱ and an ADC value of ≤1.36-10-3 mm^2/s was associated with stage Ⅲ（P〈0.001）. Kaplan-Meier curves demonstrated that the survival rates for the three prognostic groups were significantly different according to final histology and ADC cut-offs （P〈0.001）. Conclusions： ADC is different according to local invasion, nodal involvement and the 7th TNM stage groups for GC, representing a potential, additional prognostic biomarker. The addition of DW-MRI could aid in the staging and risk stratification of GC.
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.
文摘AIM: To evaluate the accuracy of diffusion-weighted imaging(DWI) without bowel preparation,the optimal b value and the changes in apparent diffusion coefficient(ADC) in detecting ulcerative colitis(UC).METHODS: A total of 20 patients who underwent 3T magnetic resonance imaging(MRI) without bowel preparation and colonoscopy within 24 h were recruited.Biochemical indexes,including C-reactive protein(CRP),erythrocyte sedimentation rate,hemoglobin,leucocytes,platelets,serum iron and albumin,were determined.Biochemical examinations were then performed within 24 h before or after MR colonography was conducted.DWI was performed at various b values(b = 0,400,600,800,and 1000 s/mm2).Two radiologists independently and blindly reviewed conventional- and contrast-enhanced MR images,DWI and ADC maps; these radiologists also determined ADC in each intestinal segment(rectum,sigmoid,left colon,transverse colon,and right colon).Receiver operating characteristic(ROC) analysis was performed to assess the diagnostic performance of DWI hyperintensity from various b factors,ADC values and different radiological signs to detect endoscopic inflammation in the corresponding bowel segment.Optimal ADC threshold was estimated by maximizing the combination of sensitivity and specificity.MRfindings were correlated with endoscopic results and clinical markers; these findings were then estimated by ROC analysis.RESULTS: A total of 100 segments(71 with endoscopic colonic inflammation; 29 normal) were included.The proposed total magnetic resonance score(MR-score-T) was correlated with the total modified Baron score(Baron-T; r = 0.875,P < 0.0001); the segmental MR score(MR-score-S) was correlated with the segmental modified Baron score(Baron-S; r = 0.761,P < 0.0001).MR-score-T was correlated with clinical and biological markers of disease activity(r = 0.445 to 0.831,P < 0.05).MR-score-S > 1 corresponded to endoscopic colonic inflammation with a sensitivity of 85.9%,a specificity of 82.8% and an area under the curve(AUC) of 0.929(P < 0.0001).The accuracy of DWI hyperintensity was significantly greater at b = 800 than at b = 400,600,or 1000 s/mm2(P < 0.05) when endoscopic colonic inflammation was detected.DWI hyperintensity at b = 800 s/mm2 indicated endoscopic colonic inflammation with a sensitivity of 93.0%,a specificity of 79.3% and an AUC of 0.867(P < 0.0001).Quantitative analysis results revealed that ADC values at b = 800 s/mm2 differed significantly between endoscopic inflamed segment and normal intestinal segment(1.56 ± 0.58 mm2/s vs 2.63 ± 0.46 mm2/s,P < 0.001).The AUC of ADC values was 0.932(95% confidence interval: 0.881-0.983) when endoscopic inflammation was detected.The threshold ADC value of 2.18 × 10-3 mm2/s indicated that endoscopic inflammation differed from normal intestinal segment with a sensitivity of 89.7% and a specificity of 80.3%.CONCLUSION: DWI combined with conventional MRI without bowel preparation provides a quantitative strategy to differentiate actively inflamed intestinal segments from the normal mucosa to detect UC.
基金supported by the Science Foundation for Distinguished Young Scholars of Sichuan Province,China(No.2012JQ0060)
文摘There have been numerous studies done to explore the diagnostic performance of quanti- tative diffusion-weighted （DW） MR imaging to differentiate between benign and malignant pancre- atic masses. However, the results have been inconsistent. We performed a meta-analysis to investigate whether DW-MR imaging can differentiate between these two diseases. Databases including MEDLINE, EMBASE and Cochrane Library were utilized to find relevant articles published between January 2001 and January 2014. A Stata version 12.0 and a Meta-Disc version 1.4 were used to de- scribe primary results. Twelve studies with 594 patients, which fulfilled the inclusion criteria, were enrolled for the analysis. The pooled sensitivity and specificity of DW imaging was 0.91 （95% CI： 0.84, 0.95） and 0.86 （95% CI： 0.76, 0.93） respectively. The area under the curve of the summary re- ceiver operating characteristic was 0.95 （95% CI： 0.93, 0.96）. The results indicated that DW imaging might be a valuable tool for differentiating benign and malignant pancreatic masses.
基金Supported by Key Program of Scientific Research of Fujian Medical University,FMU 09ZD014
文摘AIM: To investigate the diagnostic ability of single-shot echo-planar imaging(EPI) diffusion-weighted imaging (DWI) to differentiate between malignant and benign pancreatic lesions. METHODS: A computerized search was performed on Pub Med, MEDLINE and EMBASE up to August 2014. Nine studies(10 sets of data) with a total of 304 malignant pancreatic lesions and 188 benign pancreatic lesions were included. The characteristics of each study included the study name, year of publication, magnetic resonance modalities used, patient population, strength of field, pulse time, repetition time, echo time(TE), maximum b factor, mean age, mean body weight, fat suppression, number of benign and malignant lesions, and true positive, true negative, false positive and false negative results. All analyses were performed using Meta-Di Sc and Stata 11.0.RESULTS: The pooled sensitivity and specificity of singleshot EPI DWI were 0.83(95%CI: 0.79-0.87) and 0.77(95%CI: 0.70-0.83), respectively. The positive likelihood ratio and negative likelihood ratio were 5.09(95%CI: 2.19-11.84) and 0.23(95%CI: 0.15-0.36), respectively. The P value for the χ2 heterogeneity for all pooled estimates was < 0.05. From the fitted summary receiver operating characteristic curve, the area under the curve and Q* index were 0.89 and 0.82, respectively. Publication bias was not present(t = 0.58, P = 0.58). Meta-regression analysis indicated that fat suppression, mean age, TE, and maximum b factor were not sources of heterogeneity(all P > 0.05). CONCLUSION: Single-shot EPI DWI is useful to differentiate between malignant and benign pancreatic lesions. Lesion size ≥ 2 cm is the limit for the diagnosis of early lesions.
