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OBJECTIVE@#To evaluate the diagnostic value of dynamic contrast enhanced (DCE) of multiparametric magnetic resonance imaging (mpMRI) for prostate imaging reporting and data system (PI-RADS) 4 lesion in prostate peripheral zone.@*METHODS@#The clinical data of patients with PI-RADS 4 lesion in prostate peripheral zone who underwent prostate biopsy from January 2018 to September 2021 in Peking University First Hospital were retrospectively included. According to DCE status, the patients were divided into the conventional group (4 points for diffusion-weighted imaging) and the comprehensive group (3 points for diffusion-weighted imaging + 1 point for DCE positive). Pearson's chi-square test or Fisher's exact test for comparison was conducted between prostate cancer and non-cancer patients. Univariate and multivariate Logistic regression were performed to analyze the correlation of positive biopsy with age, total prostate specific antigen (PSA), free PSA/total PSA (f/tPSA), prostate volume (PV), PSA density (PSAD) and DCE status.@*RESULTS@#Among the 267 prostate biopsy patients, 217 cases were diagnosed as prostatic cancer (81.27%) and 50 cases were non-cancer (18.73%). Statistical analysis between the prostatic cancer group and the non-cancer group showed that there were significant differences in age, tPSA, PV and PSAD (all P < 0.05), but no significant differences in f/tPSA between the two groups. About different PI-RADS 4 lesion groups, the conventional group and the comprehensive group showed significant difference in biopsy results (P=0.001), and the conventional group had a higher positive rate. The PV of comprehensive group was larger than that of the conventional group. Among the prostate cancer patients diagnosed by biopsy, statistical analysis between the conventional group and comprehensive group showed that there were not significant differences in International Society of Urological Pathology (ISUP) grade and distinguishing clinically significant prostate cancer (all P > 0.05). Logistic univariate analysis showed that the diagnosis of prostate cancer was related to age, tPSA, f/tPSA, PV and DCE group status (all P < 0.05). Multivariate analysis showed that age, tPSA, PV and DCE group status (all P < 0.05) were independent risk factors for the diagnosis of prostatic cancer.@*CONCLUSION@#tPSA, f/tPSA, PV and PSAD are the indicators to improve the diagnosis of prostatic cancer with PI-RADS 4 lesion in peripheral zone lesions. DCE status is worth considering, so that we can select patients for biopsy more accurately, reduce the rate of missed diagnosis of prostate cancer as well as avoid unnecessary prostate puncture.
Subject(s)
Male , Humans , Prostatic Neoplasms/pathology , Prostate-Specific Antigen , Multiparametric Magnetic Resonance Imaging , Magnetic Resonance Imaging/methods , Retrospective StudiesABSTRACT
OBJECTIVES@#With the increasing detection rate of lung nodules, the qualitative problem of lung nodules has become one of the key clinical issues. This study aims to evaluate the value of combining dynamic contrast-enhanced (DCE) MRI based on time-resolved imaging with interleaved stochastic trajectories-volume interpolated breath hold examination (TWIST-VIBE) with T1 weighted free-breathing star-volumetric interpolated breath hold examination (T1WI star-VIBE) in identifying benign and malignant lung nodules.@*METHODS@#We retrospectively analyzed 79 adults with undetermined lung nodules before the operation. All nodules of patients included were classified into malignant nodules (n=58) and benign nodules (n=26) based on final diagnosis. The unenhanced T1WI-VIBE, the contrast-enhanced T1WI star-VIBE, and the DCE curve based on TWIST-VIBE were performed. The corresponding qualitative [wash-in time, wash-out time, time to peak (TTP), arrival time (AT), positive enhancement integral (PEI)] and quantitative parameters [volume transfer constant (Ktrans), interstitium-to-plasma rate constant (Kep), and fractional extracellular space volume (Ve)] were evaluated. Besides, the diagnostic efficacy (sensitivity and specificity) of enhanced CT and MRI were compared.@*RESULTS@#There were significant differences in unenhanced T1WI-VIBE hypo-intensity, and type of A, B, C DCE curve type between benign and malignant lung nodules (all P<0.001). Pulmonary malignant nodules had a shorter wash-out time than benign nodules (P=0.001), and the differences of the remaining parameters were not statistically significant (all P>0.05). After T1WI star-VIBE contrast-enhanced MRI, the image quality was further improved. Compared with enhanced CT scan, the sensitivity (82.76% vs 80.50%) and the specificity (69.23% vs 57.10%) based on MRI were higher than that of CT (both P<0.001).@*CONCLUSIONS@#T1WI star-VIBE and dynamic contrast-enhanced MRI based on TWIST-VIBE were helpful to improve the image resolution and provide more information for clinical differentiation between benign and malignant lung nodules.
Subject(s)
Adult , Humans , Retrospective Studies , Magnetic Resonance Imaging , Plasma , Tomography, X-Ray Computed , LungABSTRACT
Magnetic resonance imaging (MRI) is a very important imaging method for diagnosis and treatment of prostate cancer (PCa) in clinical practice. As functional MRI is growing and maturing, its quantitative parameters are expected to enhance the clinical value of MRI furtherly. Intravoxel incoherent motion diffusion imaging, diffusion tensor imaging, and diffusion kurtosis imaging, which were derived from diffusion weighted imaging, have provided richer and more accurate parameters. The newly-developed magnetic resonance elastography can complement the mechanical characteristics of PCa.
Subject(s)
Humans , Male , Diffusion Magnetic Resonance Imaging , Diffusion Tensor Imaging , Magnetic Resonance Imaging , Motion , Prostatic Neoplasms/diagnostic imagingABSTRACT
:To explore the value of quantitative perfusion histogram parameters of dynamic contrast-enhanced magnetic resonance imaging （DCE-MRI） in pathological classification of uterine leiomyoma and its correlation with Ki-67 protein expression. Thirty five patients with uterine leiomyoma confirmed by operation and pathology at Shaoxing People's Hospital from October 2015 to September 2017 were analyzed retrospectively，including 15 cases of ordinary type，8 cases of cellular type and 12 cases of degenerative type. All patients were examined by pelvic DCE-MRI before operation，and the histogram parameters （median，mean，skewness，kurtosis，energy，entropy） of various quantitative perfusion parameters，including volume transport constant （K），rate constant （K），extravascular extracellular space distribute volume per unit tissue volume （V），blood plasma volume per unit volume of tissue （V） were calculated，and the efficacy of different parameters in pathological classification of uterine leiomyoma was evaluated by ROC curve. The expression of Ki-67 protein in uterine leiomyoma was detected by immunohistochemical method，and the correlation between histogram parameters and Ki-67 protein expression was analyzed by Pearson and Spearman correlation analysis. The median and mean values of K，K，V and V in the cellular group were higher than those in the degenerative group and the ordinary group（<0.05 or <0.01），while the skewness of V，the skewness and kurtosis of K in the cellular group were lower than those in the ordinary group （all <0.05）. The entropy of K in the cellular group was higher than that in the degenerative group and the ordinary group （all < 0.05）. The entropy of V in the cellular group was higher than that in the ordinary group （<0.01）. The median，mean，skewness of K，median and mean of K，median and mean of V，median，mean，energy and entropy of V were correlated with Ki-67 expression（all <0.05）. The results of ROC curve analysis showed that the median threshold of K was 0.994/min，the sensitivity and specificity for the diagnosis of cellular uterine leiomyoma were 100.0% and 77.8% respectively，and the area under the ROC curve was 0.949. When the mean threshold of K was 1.170/min，the sensitivity and specificity for diagnosing cellular uterine leiomyoma were 100.0% and 77.8% respectively，and the area under the ROC curve was 0.958. The area under the ROC curve of K （entropy），K （median，mean），V （median，mean，entropy） in the diagnosis of cellular uterine leiomyoma were 0.755-0.907. :DCE-MRI quantitative perfusion histogram parameters have high diagnostic value in differentiating pathological types of uterine leiomyoma，especially for cellular uterine leiomyoma.
Subject(s)
Humans , Contrast Media , Leiomyoma/diagnostic imaging , Magnetic Resonance Imaging , Perfusion , Retrospective StudiesABSTRACT
Objective: To explore the value of dynamic contrast-enhanced MR imaging (DCE-MRI) of original plaque to predict carotid artery in-stent restenosis (ISR). Methods: Forty cases of the patients with carotid atherosclerosis who were to undergo the carotid artery stenting (CAS) were included in this study. All participants underwent vessel wall MR imaging (VW-MRI) and DCE-MRI within one week before CAS. Carotid digital subtraction angiography (DSA) were performed at the sixth month to reassess the stenosis of stent. The correlation between DCE-MRI and ISR was evaluated. Results: The level of Ktran in ISR group was significantly higher than that in non-ISR group (P=0.000), and so was the vP (P=0.037). Ktrans could independently predict ISR (OR=1.43, 95%CI 1.17-1.56, P=0.012), and the cut-off value of Ktrans was 0.09 min-1 (sensitivity=100%, specificity=87.5%). Conclusion: Intraplaque inflammation may lead to excessive intimal hyperplasia after ISR. Ktrans could be a risk predictor of ISR with high sensitivity and specificity. DCE-MRI could be an effective tool to predict ISR.
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Objective: To evaluate the value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in predicting the efficacy of foam sclerotherapy and selecting sclerosants for endovascular sclerosis of venous malformations. Methods: A retrospective analysis was conducted for 56 patients with venous malformations who underwent intravascular sclerotherapy and DCE-MRI examination from January 2018 to June 2019 in Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine. All the patients were firstly treated with foam sclerotherapy. During the surgery, the surgeons determined whether to subsequently use ethanol, depending on the immediate therapeutic effect of foam sclerotherapy. Among them the 40 cases were treated with foam sclerotherapy only (foam sclerotherapy group) and the other 16 cases (ethanol group) with subsequent ethanol. The basic characteristics and DCE-MRI parameters of the two groups were compared. Logistic regression was used to analyze the risk factors of selecting different sclerosing agents, and the receiver operator characteristic curve was applied to assess the efficacy of these risk factors. Results: There were no significant differences in the gender, age, lesion location, pre-treatment volume and presence or absence of phleboliths between foam sclerotherapy group and ethanol group. The lesion classification, maximum intensity time ratio (MITR) and peak enhancement percentage showed significant differences between the two groups. Multivariate Logistic regression analysis showed that the lesion classification and MITR were two independent factors for the selection of sclerosing agents. The area under curve (AUC) of MITR was 0.947, while the AUC of lesion classification was 0.844. After the combination of these two parameters, the AUC was 0.969 with the sensitivity of 93.8% and the specificity of 90.0%. Conclusion: DCE-MRI can be helpful for clinical selection of appropriate sclerosing agents to improve the effectiveness of venous malformations treatment.
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BACKGROUND: As a non-invasive detection method, dynamic contrast-enhanced magnetic resonance imaging is widely used in the field of tumor. It can be used for the differentiation of benign and malignant tumors, the grading of tumor grade and the prediction and evaluation of prognosis. In recent years, the application research in the field of bone and joint has gradually become a hot spot, which can be used in the determination of bone marrow blood perfusion, the evaluation of bone tissue activity, the early detection of bone perfusion abnormality and the evaluation of blood circulation of joint inflammatory lesions. OBJECTIVE: To summarize the technical situation of dynamic contrast-enhanced magnetic resonance imaging and its application research in bone and joint. METHODS: The keywords were “(bone OR joint) AND (dynamic contrast-enhanced MRI) OR dynamic contrast-enhanced magnetic resonance imaging) OR DCE-MRI” in English and Chinese, respectively. The first author searched PubMed, Springerlink and China National Knowledge Infrastructure databases for the articles published between 1984 and 2019. The relevant literature was reviewed on the application of dynamic contrast-enhanced magnetic resonance imaging in bone and joint in recent years. Finally, 55 articles were summarized and analyzed. RESULTS AND CONCLUSION: (1) At present, dynamic contrast-enhanced magnetic resonance imaging technology and data processing have not been standardized. T1WI imaging is mainly used in bone and joint. Qualitative, semi-quantitative and full quantitative analysis of its data is feasible. (2) Qualitative analysis and semi-quantitative analysis are simple and easy to operate. Quantitative indicators are clear, can objectively describe the shape of the curve, but cannot reflect the concentration of contrast agent between tissues and blood vessels, and are easily affected by the sequence of scanning parameters, so cannot detect the pharmacokinetic information of tissue. Quantitative analysis can obtain the concentration changes and generation parameters of contrast media between substructures in tissues, and evaluate the microangiogenesis and function of tissues. (3) Dynamic contrast-enhanced magnetic resonance imaging can noninvasively evaluate the microcirculation perfusion of bone and joint. It has certain reference value for the discussion of the pathogenesis, diagnosis and differential diagnosis, prediction of prognosis, evaluation of curative effect and choice of treatment of many bone and joint diseases.
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@#AIM:To investigate the characteristics of color Doppler sonography and MRI in orbital solitary fibrous tumor(SFT). <p>METHODS: It was a retrospective case series study. A total of 12 cases of orbital solitary fibrous tumors were recruited from April 2013 to August 2018 in Tianjin Medical University Eye Hospital. Color Doppler sonography and MRI plain scan and DCE-MRI were applied in all cases. <p>RESULTS: Of 12 cases, 7 cases were males and 5 were females, with the duration of symptoms ranged from 3mo-20y, with an average course of 3.2y; 6 cases were the primary cases and 6 cases were relapse cases. All lesions involved one side of the orbit, of which 8 cases were in the left orbit and 4 in the right. Of 12 cases, there were 5 tumors in intraconal space, 3 in the extraconal space, and 4 in intra and extraconal space. Well-circumscribed lesions showed oval shape in 9 cases and the left 3 were irregular. 12 cases showed hypoechoic and 2 cases heterogeneous signal on color Doppler sonography; All cases had flow signals on CDFI, and showed arterial spectrum on PW. On T1WI, all lesions demonstrated isointense. On T2WI, 5 lesions showed hypointense, 3 lesions showed isointense and 4 lesions slight hyperintense, of which 3 lesions showed heterogeneous signal. After contrast enhancement, all cases demonstrated markedly enhancement, with homogeneous enhancement in 10 cases and heterogeneous enhancement in 2 cases. The time-intensity curves(TIC)of 7 cases exhibited a rapid washout pattern, and 5 cases a rapid plateau pattern on DCE-MRI. <p>CONCLUSION: Color Doppler sonography features of orbital SFT include hypoechoic and flow signals. Heterogeneous signals on T2WI, marked enhancement, and a rapidly enhancing and slow washout pattern TIC on DCE-MRI are the typical MRI features of orbital SFT.
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Aims: The main objectives of our study were to evaluate the role of Multiparametric MRI (mp-MRI) in diagnosis of carcinoma prostate and to compare the various MRI sequences used in MRI in evaluating carcinoma prostate with histopathological diagnosis kept as reference standard. Materials and Methods: This prospective cross-sectional study of 40 patients was performed by using various sequences used in mp-MRI i.e. T2 weighted imaging (T2WI), Diffusion Weighted Imaging (DWI), Magnetic Resonance Spectroscopy (MRS) and Dynamic Contrast Enhanced study (DCE). Findings of mp-MRI sequences were compared with histopathological diagnosis. Statistical analysiswasperformed using SPSS computer statistical program for window release 16. Results: Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of DCE in diagnosing carcinoma prostate were 88.89%, 50.00%, 94.12% and 33.33% respectively where assensitivities, specificities, PPVs, NPVs of DWI and MRS were same in our study i.e. 94.44%, 75.00%, 97.14% and 60.00%respectively. Overall sensitivity, specificity, PPV, NPV of mp-MRI by combining these sequences were found to be 97.22%, 75%, 97.22% and 75% respectively. Diagnostic accuracies of DWI, DCE and MRS were 92.5%, 85% and 92.5% respectively and overall diagnostic accuracy after combining these sequences in mp-MRI was 95%. Conclusions: mp-MRI including all the sequences has very good role in evaluation of carcinoma prostate. Diagnostic accuracy of mp-MRI increases when all sequences used together to assess prostatic lesions, so all the sequences should be used together in prostate cancer evaluation rather than using individual sequences.
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PURPOSE: To evaluate the usefulness of wash-in color map in detecting early enhancement of prostate focal lesion compared to whole dynamic contrast-enhanced MRI (DEC MRI) images. MATERIALS AND METHODS: This study engaged 50 prostate cancer patients who underwent multiparametric MRI and radical prostatectomy as subjects. An expert [R1] and a trainee [R2] independently evaluated early enhancement and recorded the time needed to review 1) a wash-in color map and 2) whole DCE MRI images. RESULTS: The review of whole DCE images by R1 showed fair agreement with color map by R1, whole images by R2, and color map by R2 (weighted kappa values = 0.59, 0.44, and 0.58, respectively). Both readers took a significantly shorter time to review the color maps as compared to whole images (P < 0.001). CONCLUSION: A trainee could achieve better agreement with an expert when using wash-in color maps than when using whole DCE MRI images. Also, color maps took a significantly shorter evaluation time than whole images.
Subject(s)
Humans , Magnetic Resonance Imaging , Prostate , Prostatectomy , Prostatic NeoplasmsABSTRACT
Objective To investigate the difference of blood supply in different areas of the normal femoral head in adults.Methods A retrospective study analyzed the DCE-MRI parameters data of 2 5 normal adults (25 right hips)in our hospital.The femoral head was assumed to be a sphere.On T1 WI of DCE-MRI,the right femoral head was divided into three parts equally in coronal,sagittal, and transverse plane respectively.Time to peak(TTP),maximum of enhancement at first past(fEmax),maximum of enhancement (Emax)were measured in three parts and compared in coronal,sagittal and transverse plane respectively.Results (1 )In coronal plane,there were no significant differences between the three parts in TTP,fEmax and Emax.(2 )In transverse plane,fEmax and Emax were lower in the transverse superior zone than that in the transverse central zone significantly (P＝0.024 and P＝0.001)and the transverse inferior zone(P＝0.005 and P＝0.018).TTP was higher in the transverse superior zone than that in the transverse central zone and the transverse inferior zone(P＝0.005 and P＝0.018).(3)In sagittal plane,fEmax and Emax were lower in the sagittal lateral zone than that in the sagittal centralzone (P＝0.019 and P＝0.041)and sagittal medial zone (P＝0.047 and P＝0.01 1).TTP was higher in the sagittal lateral zone than that in the sagittal central zone and the sagittal medial zone(P＝0.014 and P＝0.010).There were no significant differences between other paired zones of the any values.Conclusion DCE-MRI can show the microcirculation in the normal adult femoral head in a non-invasive way.According to DCE-MRI parameters,there are poor perfusions on the transversesuperior and sagittallateral zones of the normal femoral head in adults.
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Objective To evaluate the value of MR DWI combined with dynamic contras-t enhanced (DCE)scanning in the differential diagnosis of orbital lymphoma and inflammatory pseudotumor.Methods The clinical and imaging data of 1 5 cases with orbital lymphoma and 10 cases with inflammatory pseudotumor confirmed by surgery and pathology were analyzed retrospectively.25 patients were performed with conventional MR scanning,DWI scanning and DCE scanning.ADW4.7 software was used for DWI images and DCE images pos-t processing for analyzing the two groups of lesions in the TIC subtyping.Independent sample t test statistical analysis was used for comparing two groups of ADC values and Tmax values.The ROC curve was used for determining the statistically significant differences in measurement data of the threshold.With pathologic and immunohistochemical results as the gold standard,the accuracy,sensitivity and specificity of DWI combined with DCE in the diagnosis of orbital lymphoma and inflammatory pseudotumor were further detected.Results Among the 1 5 patients with orbital lymphoma,8 cases (8/15)occurred in the lacrimal gland area,5 cases (5/1 5)occurred in the outer cone space and 2 cases (2/15)occurred in the eyelid.Among the 10 patients with inflammatory pseudotumor,6 cases (6/10)occurred in the lacrimal gland and 4 cases (4/10)in the bulb.Among the 25 patients,9 of them had the TIC curve of outflow,6 of them had the TIC curve of platform and 10 of them had the TIC curve of inflow.The ADC value of orbital lymphoma was (0.573 ±0.1 1 6)×10－3 mm2/s,and the Tmax value was (248.2±1 59.4)ms.The ADC value of inflammatory pseudotumor was (1.186±0.244)×10－3 mm2/s,and the Tmax value was (5 5 7.6 ±98.7)ms.With the ADC＝0.885×10－3 mm2/s for the threshold,the AUC was 0.9 3 6 ,with diagnostic accuracy of 9 1.3%, the sensitivity of 90.1% and specificity of 80%.With the Tmax＝481.2 ms as the threshold,the AUC was 0.927,with the diagnosis accuracy rate of 88%,the sensitivity of 80%,and the specificity of 86.7%. Finally,DWI combined with DCE could reach the AUC 0.945, diagnostic accuracy of 89.5%,sensitivity of 93.3%,and specificity of 82.6%.Conclusion Conventional MRI scan combining DWI with DCE could show the histological components of the lesion of orbital tumor,which is of certain significance for the qualitative diagnosis of orbital lymphoma and inflammatory pseudotumor.
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Objective To explore the application of DCE-MRI and DWI in the preoperative diagnosis of breast cancer.Methods
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Objective To investigate the relationship between histogram analysis of DCE-MRI quantitative parameters and clinical stage of nasopharyngeal carcinoma (NPC).Methods 70 patients with NPC confirmed by pathology underwent MRI examination and staging.NPC tumors were measured by full-volume ROI setting method,and the obtained DCE-MRI quantitative parameters were analyzed by histogram.Spearman correlation coefficients were obtained to evaluate the potential correlation between the DCE-MRI histogram quantitative parameters and NPC clinical stages.Results The histogram-based Ktrans (mean,10 th,75 th,90 th),Kep (mean,10 th,kurtosis),and Ve (mean,90 th,skewness)had correlation with T stage (P＜0.05,respectively).The histogram-based Ktrans (mean)and Ve (mean,90 th) showed correlation with N stage (P＜0.05,respectively).The histogram-based Kep (kurtosis)and Ve (mean)had correlation with M stage (P＜0.05,respectively).The histogram-based Kep had no correlation with N stage,and Ktrans had no correlation with M stage. The histogram-based Ktrans (mean,10 th,75 th,90 th),Kep (10 th,75 th,kurtosis)and Ve (mean,75 th,90 th)had correlation with overall stage (P＜0.05,respectively).Conclusion The histogram analysis of DCE-MRI quantitative parameters showed that the multiple parameters associated with NPC overall stages.DCE-MRI quantitative parameters non-invasively reflect the aggressiveness and progression of NPC.The histogram analysis of DCE-MRI quantitative parameters may play a role in clinical stage of NPC.
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Objective To assess the contribution of contrast-enhanced spectral mammography (CESM) in detecting breast carcinoma of dense breasts. Methods To retrospectively analyze the imaging and clinical data of 52 female patients with breast carcinoma which were confirmed by pathology in Tai'an Central Hospital of Shandong Province from April 2017 to April 2018.All cases classified as dense or uneven dense breasts by DM examination underwent Ultrasound (US), digital mammography (DM), CESM, dynamic contrast enhanced MRI (DCE-MRI).The breast imaging report and data system (BI-RADS) and breast density classification were both evaluated using the 5th edition of BI-RADS. The efficacy of US, DM, DM+CESM, DCE-MRI in detecting breast carcinoma (BI-RADS 5) was evaluated by χ2 test. Results Histopathology confirmed that 87 lesions were malignant and 35 lesions were benign. The sensitivity of US, DM, DM +CESM, DCE-MRI were 66.67％(58/87), 64.37％(56/87), 100.00％(87/87), 100.00％(87/87) and the specificity were 94.28％(33/35), 74.28％(26/35), 85.71％(30/35), 51.43％(18/35), respectively. There was statistically significant difference in specificity (χ2=9.545, P=0.002) and BI-RADS 5 category, detection 39.08％(34/87), 22.99％(20/87), respectively (χ2=5.263, P=0.022) between the DM + CESM group and DCE-MRI group. Conclusion In dense breasts, CESM has a high application value in breast carcinoma diagnosis.
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Dynamic contrast enhanced (DCE) magnetic resonance (MR) imaging plays an important role in non-invasive detection and characterization of primary and metastatic lesions in the liver. Recently, efforts have been made to improve spatial and temporal resolution of DCE liver MRI for arterial phase imaging. Review of recent publications related to arterial phase imaging of the liver indicates that there exist primarily two approaches: breath-hold and free-breathing. For breath-hold imaging, acquiring multiple arterial phase images in a breath-hold is the preferred approach over conventional single-phase imaging. For free-breathing imaging, a combination of three-dimensional (3D) stack-of-stars golden-angle sampling and compressed sensing parallel imaging reconstruction is one of emerging techniques. Self-gating can be used to decrease respiratory motion artifact. This article introduces recent MRI technologies relevant to hepatic arterial phase imaging, including differential subsampling with Cartesian ordering (DISCO), golden-angle radial sparse parallel (GRASP), and X-D GRASP. This article also describes techniques related to dynamic 3D image reconstruction of the liver from golden-angle stack-of-stars data.
Subject(s)
Artifacts , Hand Strength , Image Processing, Computer-Assisted , Liver , Magnetic Resonance Imaging , MethodsABSTRACT
Objective To evaluate the value of quantitative analysis of dynamic contrast-enhanced MRI (DCE-MRI) and diffusion weighted imaging (DWI) for differentiating malignant from benign orbital lymphoproliferative disorder(OLPD). Methods Forty-three patients with OLPDs(20 patients with benign OLPDs and 23 patients with orbital lymphoma) confirmed by histopathology or clinical follow-up were enrolled in this retrospective study.Quantitative parameters of DCE-MRI including volume transfer constant (Ktrans), flux rate constant (Kep), and extravascular extracellular volume fraction (Ve) and mean apparent diffusion coefficient(ADC)values were obtained. χ2test and t test were used to compare the differences of qualitative and quantitative parameters between two groups. Receiver operating characteristic (ROC) curve analyses were used to evaluate the diagnostic ability of each parameter and its combination. Results Malignant group showed significantly lower mean ADC values and higher Kepvalues than benign group [ADC:(0.674±0.126)×10-3mm2/s vs(1.030±0.304)×10-3mm2/s,P<0.001;Kep:(1.299±0.566)/min vs(0.787± 0.311)/min, P= 0.001], while no significant differences was found on Ktrans(P= 0.637) and Ve(P= 0.023). ROC analyses results indicated that,a sensitivity of 95.7%,specificity of 80.0% and area under curve(AUC) of 0.896 could be obtained,when using ADC=0.809×10-3mm2/s as the cut-off value.Setting the Kepvalue of 0.863/min as the cut-off value, a sensitivity of 91.3%, specificity of 75.0% and AUC of 0.848 could be obtained. When combination of mean ADC and Kepwas used, optimal diagnostic performance could be obtained (AUC, 0.926;sensitivity, 91.3%;specificity, 90.0%). Conclusion Mean ADC values and Kepare significant variables in predicting malignant OLPDs. Combination of DWI and DCE-MRI can further improve the diagnostic capability in differentiating malignant from benign OLPDs.
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Objective To investigate the value of quantitative analysis parameters of dynamic contrast-enhanced MRI (DCE-MRI) in distinguishing low or high grade prostate cancer.Methods Data of DCE-MRI in 26 patients with prostate cancer confirmed by surgical pathology following radical prostatectomy were retrospectively analyzed.These patients were divided into low grade prostate cancer (n=10) group or high grade prostate cancer group (n=16).The parameters,including transport constant (K trans),rat constant (Kep) and extravascular extracellular volume fraction (Vc.) were measured and compared between the two groups.ROC curve was used to determine the efficacy of the parameters in distinguishing low or high grade prostate cancer.The correlation between the parameters and Gleason score were assessed.Results Ktrans,Kep and Ve values in the low grade prostate cancer group was (0.22± 0.07)/min,(1.24 ± 0.57)/min and 0.21±0.08 respectively,and (0.36±0.10)/min,(1.82±0.66)/min,0.21±0.10 respectively in the high grade prostate cancer group.The differences of K trans and Kep were statistically significant between the two groups (both P＜0.05),while of Vc.was not statistically significant (P=0.994).The area under ROC curves of K trans and keapvalues for distinguishing low or high grade prostate cancers was 0.872 and 0.737,respectively.No correlation was found between any parameters nor Gleason scores (all P＞0.05).Conclusion K trans and Kep,the quantitative analysis parameters of DCE-MRI,contribute to the differential diagnosis of low and high grade prostate cancer.
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Objective To investigate the value of stretched-exponential model of DWI in differential diagnosis of benign and malignant breast lesions.Methods Totally 58 patients with 63 breast lesions (33 benign,30 malignant lesions) were enrolled.All the patients underwent multiple b value DWI and dynamic contrast enhancement MRI (DCE-MRI) scans.The values of ADC,DDC and water molecular diffusion heterogeneity index (α) were calculated,and the time signal intensity curve (TIC) was obtained.All the parameters were compared between benign and malignant breast lesions.The diagnostic performance of different parameters was evaluated with ROC curve.Results ADC,DDC and α value of malignant lesions was (1.01±0.19)×10-3 mm2/s,(0.89±0.23)×10-3 mm2/s and 0.75±0.09,while of benign lesions was (1.41±0.27)× 10-3 mm2/s,(1.49±0.29)× 10-3mm2/s and 0.87±0.07,respectively.All 3 parameters in malignant lesions were lower than those in benign lesions (all P＜0.01).Taking 1.22 × 10-3 mm2/s as the optimal threshold,the area under the curve (AUC) of DDC was the largest as 0.958,and the corresponding diagnostic sensitivity and specificity was 96.67％ and 81.82％,respectively.AUC value was 0.976 by combining DDC with TIC,and the corresponding diagnostic sensitivity and specificity was 93.33％ and 93.94％,respectively.Conclusion The stretched-exponential model DWI can differentiate breast lesions,and diagnostic performance of combination of DDC and TIC is better than ADC or DCE.
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Background and purpose: The technique of dynamic contrast-enhanced MRI (DCE-MRI) is widely applied in differential diagnosis between benign and malignant tumor and therapeutic estimation of neoadjuvant chemotherapy in clinic. However, there is no standard quantitative measurement method. This study aimed to assess the variability of different region of interest (ROI) selections for tumor bed of breast cancer using DCE-MRI, and to ascertain the optimal ROI delineation. Methods: We retrospectively analyzed DCE-MRI of 30 patients diagnosed with breast cancer by pathology. The ROIs were delineated by 2 different observers using iCAD software with 4 methods, including whole tumor (Whole), the slice containing the most enhancing voxels (SliceMax), 3 slices centered in SliceMax (Partial) and the 5％ most enhancing contiguous voxels within SliceMax (5Max), to generate the volume transfer constant (Ktrans), the extracellular volume fraction (Ve) and rate constant (Kep). And the reproducibilities of the measurements were assessed using the Bland-Altman method. Results: In the analysis of ROIs delineation, the Ktrans, Ve and Kep reported by different observers were 1.26±0.54 vs 1.25±0.53, 0.75±0.23 vs 0.73±0.22 and 1.93±1.46 vs 1.95±1.51 (P＞0.05) using the method of Whole, and 1.28±0.43 vs 1.26±0.43, 0.74±0.21 vs 0.80±0.27, 1.95±1.53 vs 1.93±1.43 (P＞0.05) using the method of Partial, and 1.30±0.33 vs 1.32±0.33, 0.77±0.20 vs 0.73±0.24, 1.82±1.53 vs 1.87±1.45 (P＞0.05) using the method of SliceMax, and 1.31±0.35 vs 1.35±0.33, 0.77±0.20 vs 0.98±0.25, 1.97±1.36 vs 1.73±1.55 using the method of 5Max (P＜0.05). Using the methods of ROI delineation except 5Max, there was no significant difference between Ktrans, Ve and Kep reported by different observers. The bias vs limits of agreement were 0.002 vs-0.013 to 0.012,-0.003 vs-0.023 to 0.017, 0.006 vs-0.018 to 0.029,-0.035 vs-0.054 to 0.018 measured with Whole method, SliceMax, Partial and 5Max respectively using the Bland-Altman method. Conclusion: It may be reliable to measure functional parameters of primary tumors in breast cancer using DCE-MRI according to the methods of Whole, Partial and SliceMax.