ABSTRACT
BACKGROUND: Although traditional plain scan and enhanced magnetic resonance imaging has been used for skeletal muscle imaging for many years, it is not enough to evaluate the microscopic changes of diseased tissue or the activity of diseased tissue. Dynamic contrast-enhanced magnetic resonance imaging can capture this information and advantages are shown in orthopedic imaging examination. OBJECTIVE: To review the progress of dynamic contrast-enhanced magnetic resonance imaging in orthopedics clinics. METHODS: The relevant documents from January 1900 to February 2020 were retrieved in the CNKI database, PubMed database, Web of Science and Wanfang database by computer. The search terms were “dynamic contrast-enhanced magnetic resonance imaging; skeletal muscle tumor; arthritis; spine; fracture” in Chinese, and “dynamic contrast enhanced magnetic resonance imaging (DCE-MRI); osteomuscular tumor; arthritis; spinal surgery; fracture” in English. RESULTS AND CONCLUSION: (1) At present, there is a general lack of consensus on the best scanning method for acquiring dynamic contrast-enhanced magnetic resonance imaging images and the ideal method for analyzing such images in clinical applications. The parameter analysis methods are mainly qualitative, semi-quantitative and quantitative analysis. (2) Dynamic contrast-enhanced magnetic resonance imaging has been widely used in non-invasive detection, qualitative and therapeutic monitoring of different diseases such as heart failure, breast cancer, prostate cancer, renal rejection and liver tumors. The clinical application in orthopedics is not mature enough, but has unlimited potential: It can be used to assess the blood flow after femoral neck fracture and to predict the viability of the femoral head, the regional perfusion of nonunion after fracture, bone perfusion of arthritis and other entities, and detection of deformed blood vessels. Compared with conventional imaging, in contrast, dynamic contrast-enhanced magnetic resonance imaging can also better assess the relationship between changes in lumbar spine perfusion, disc degeneration, and endplate perfusion at different stages.
ABSTRACT
Objective: To explore the value of dynamic enhanced MRI (DCE-MRI) quantitative parameter global histogram in differential diagnosis of breast ductal carcinoma in situ (DCIS) and DCIS with micro-invasion (DCIS-Mi). Methods: Totally 41 patients with DCIS-Mi and 37 patients with DCIS underwent DCE-MRI before operation. The volume transport constant (Ktrans), rate constant (Kep) and plasma volume fraction (Vp) were calculated, and the parameters of the global histogram were recorded, including mean, median and the quantiles of 10%, 25%, 50%, 75% and 90% (P10, P25, P50, P75 and P90). The parameters were compared between DCIS-Mi and DCIS patients, and the diagnostic values were evaluated. Results: The mean and percentiles of Ktrans parameters, the mean, median, P50, P75 and P90 of Kep parameters, the mean, median, P25, P50 and P75 of Vp parameters of DCIS-Mi patients were all higher than those of DCIS patients (all P0.80. The joint variable Logistic regression model had the highest AUC (0.968), and its cut-off value, sensitivity and specificity was 2.152, 0.962 and 0.947, respectively. Conclusion: DCE-MRI global histogram analysis can quantitatively reflect tumor characteristics, accurately differentiate breast DCIS and DCIS-Mi.
ABSTRACT
Objective: To study the CT findings of hepatic lesions without obvious enhancement in arterial phase, and to analyze the characteristics of the hepatic lesions. Methods: The clinical materials of 118 cases of hepatic lesions without obvious enhancement in arterial phase scanned by enhanced CT were collected. The basic CT signs, characteristic CT signs and enhancement patterns were analyzed. Results: Among 118 cases, there were 40 hepatic metastases, 29 liver abscesses, 21 intrahepatic cholangiocelloma, 17 hepatocellular carcinoma, 6 inflammatory pseudotumor of liver and 5 hepatic lymphoma; 54 cases showed single lesion and 64 cases showed multiple lesioas; 24 cases were sharp and 94 cases were indistinct; 41 cases located in right hepatic lobe, 26 cases located in left hepatic lobe, 50 cases located in left and right hepatic lobe, and 1 case located in hepatic caudate lobe. The diameters of lesions were 0. 2 13. 4 cm. 40 cases of hepatic metastases showed mild marginal enhancement, while the incidence rate of bull eye sign was 12.50% (5/40); 29 cases of liver abscess showed ring or honeycomb-1 ike enhancement, while the incidence rates of double ring sign and gas bubbles were 13.79% (4/29) and 13.79% (4/29). Seventeen cases of intrahepatic cholangiocelloma showed slow progressive enhancement, while the incidence rates of intrahepatic bile duct dilatation, hepatic capsular depression and calcification were 57.14% (12/21), 23.81% (5/21) and 9.52% (2/21). .Seventeen cases of hepatocellular carcinoma showed various enhancement patterns, while the incidence rates of liver contour change, hepatic artery enlargement and vessel invasion were 41. 18% (7/17), 41.18% (7/17) and 35.29 % (6/17). Four cases of inflammatory pseudotumor of liver showed septal and nodular enhancement; 5 cases of hepatic lymphoma showed internal minimal homogeneous enhancement, while the incidence rate of vascular floating sign was 40.00% (2/5). Conclusion: Spiral CT examination of the hepatic lesions without obvious enhancement in arterial phase should be combined with CT signs and enhancement patterns for synthetic judgment, which is helpful to provide an important basis for the qualitative and differential diagnosis of liver lesions.
ABSTRACT
Objective@#To investigate the predictive value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) quantitative parameters for the efficacy of neoadjuvant chemotherapy in locally advanced gastric cancer.@*Methods@#Sixty-five patients with locally advanced gastric cancer (LAGC) confirmed by gastroscopy and received neoadjuvant chemotherapy (NCT) were enrolled in this study. Quantitative DCE-MRI was performed before NCT, and the quantitative parameters were measured, including volume transfer constant (Ktrans), rate constant (Kep), volume fraction of extravascular extracellular space (Ve) and volume fraction of plasma (Vp). After NCT, all patients received radical gastrectomy. According to postoperative pathological tumor regression grade, patients were divided into response group and non-response group, and the differences of DCE quantitative parameters between the two groups were compared. ROC curve was utilized to analyze the predictive efficacy of DCE quantitative parameters for NCT response of LAGC, and multivariate logistic regression analysis was performed to analyze the predictive efficacy of combined parameters.@*Results@#Thirty-seven patients were in response group and 28 patients were in non-response group. The pretreatment Ktrans in the response group were [0.216 min-1 (0.130 min-1, 0.252 min-1)], significantly higher than [0.091 min-1 (0.069 min-1, 0.146 min-1)] of non-response group (P<0.001), and Ve in the response group were [0.354(0.228, 0.463)], significantly higher than [0.200(0.177, 0.253)]of non-response group (P<0.001). ROC analysis showed the AUCS of Ktrans and Ve in predicting NCT efficacy were 0.881 and 0.756, respectively. Multiple logistic regression analysis showed that the combination of the two parameters could improve the AUC to 0.921, with the sensitivity and specificity of 86.5% and 89.3%, respectively.@*Conclusion@#DCE-MRI quantitative parameters could help to predict the NCT response of LAGC, and the combination of parameters could improve the predictive efficacy.
ABSTRACT
Objective To analyze the features and diagnostic value of 3.0T multiparametric MRI for prostate cancer(PCa).Methods The clinical and MRI data of 48 patients with PCa and 52 patients with benign prostatic hyperplasia (BPH)were analyzed retrospectively. All patients underwent plain MRI,DWI,DCE-MRI and MRS.Results The PCa were hyperintensity on DWI and hypointensity on ADC,respectively.There was significant difference in the ADC values between the benign and malignant lesions.DWI using the high b-value was sensitivitive to diagnosing the PCa.The distribution of the S-I T was significant difference between the two groups.The SI-T curves of the PCa were type Ⅲ in 40 cases,type Ⅱ in 5 cases and type Ⅰ in 3 cases.The SI-T curves of the BPH were type Ⅰ in 27 cases,type Ⅱ in 23 cases and type Ⅲ in 2 cases.The peak value of choline (Cho)increased and citrate (Cit)decreased on MRS.The ratio of (Cho+Cre)value/Cit value of the PCa was increased.Conclusion DWI,DCE-MRI and MRS can present the specific findings of PCa.The combining application of the three technics could increase the accuracy in diagnosing PCa.
ABSTRACT
We described for the first time the contrast enhancement of a giant fibrovascular esophageal polyp using ultrasound contrast agent, Sonovue® (Bracco, Milan, Italy) during echoendoscopy. Fine Doppler was unsuccessful in showing vascularization due to the mobile characteristic of the tumor. In contrast, via Sonovue®, tissue microcirculation was highlighted inside the entire head of the polyp, leading to better appreciate the risk of bleeding related to its resection. In a second part, we showed the feasibility of classic polypectomy for this giant polyp (5×5 cm) without complication and results of control endoscopy at 3 months. The present case is summarized in a video.
Subject(s)
Endoscopy , Head , Hemorrhage , Microcirculation , Polyps , UltrasonographyABSTRACT
Objective:To study the CT findings of hepatic lesions without obvious enhancement in arterial phase, and to analyze the characteristics of the hepatic lesions.Methods:The clinical materials of 118cases of hepatic lesions without obvious enhancement in arterial phase scanned by enhanced CT were collected.The basic CT signs, characteristic CT signs and enhancement patterns were analyzed.Results:Among 118cases, there were 40hepatic metastases, 29liver abscesses, 21intrahepatic cholangiocelloma, 17hepatocellular carcinoma, 6inflammatory pseudotumor of liver and 5hepatic lymphoma;54cases showed single lesion and 64cases showed multiple lesions;24cases were sharp and 94cases were indistinct;41cases located in right hepatic lobe, 26cases located in left hepatic lobe, 50cases located in left and right hepatic lobe, and 1case located in hepatic caudate lobe.The diameters of lesions were 0.2-13.4cm.40cases of hepatic metastases showed mild marginal enhancement, while the incidence rate of bull eye sign was 12.50％ (5/40) ;29cases of liver abscess showed ring or honeycomb-like enhancement, while the incidence rates of double ring sign and gas bubbles were 13.79％ (4/29) and 13.79％ (4/29) .Seventeen cases of intrahepatic cholangiocelloma showed slow progressive enhancement, while the incidence rates of intrahepatic bile duct dilatation, hepatic capsular depression and calcification were 57.14％ (12/21) , 23.81％ (5/21) and 9.52％ (2/21) .Seventeen cases of hepatocellular carcinoma showed various enhancement patterns, while the incidence rates of liver contour change, hepatic artery enlargement and vessel invasion were 41.18％ (7/17) , 41.18％ (7/17) and 35.29％ (6/17) .Four cases of inflammatory pseudotumor of liver showed septal and nodular enhancement;5cases of hepatic lymphoma showed internal minimal homogeneous enhancement, while the incidence rate of'vascular floating'sign was 40.00％ (2/5) .Conclusion:Spiral CT examination of the hepatic lesions without obvious enhancement in arterial phase should be combined with CT signs and enhancement patterns for synthetic judgment, which is helpful to provide an important basis for the qualitative and differential diagnosis of liver lesions.
ABSTRACT
PURPOSE: The purpose of this study is to compare the performance of the T1 3D subtraction technique and the conventional 2D dynamic contrast enhancement (DCE) technique in diagnosing Cushing's disease. MATERIALS AND METHODS: Twelve patients with clinically and biochemically proven Cushing's disease were included in the study. In addition, 23 patients with a Rathke's cleft cyst (RCC) diagnosed on an MRI with normal pituitary hormone levels were included as a control, to prevent non-blinded positive results. Postcontrast T1 3D fast spin echo (FSE) images were acquired after DCE images in 3T MRI and image subtraction of pre- and postcontrast T1 3D FSE images were performed. Inter-observer agreement, interpretation time, multiobserver receiver operating characteristic (ROC), and net benefit analyses were performed to compare 2D DCE and T1 3D subtraction techniques. RESULTS: Inter-observer agreement for a visual scale of contrast enhancement was poor in DCE (κ = 0.57) and good in T1 3D subtraction images (κ = 0.75). The time taken for determining contrast-enhancement in pituitary lesions was significantly shorter in the T1 3D subtraction images compared to the DCE sequence (P < 0.05). ROC values demonstrated increased reader confidence range with T1 3D subtraction images (95% confidence interval [CI]: 0.94–1.00) compared with DCE (95% CI: 0.70–0.92) (P < 0.01). The net benefit effect of T1 3D subtraction images over DCE was 0.34 (95% CI: 0.12–0.56). For Cushing's disease, both reviewers misclassified one case as a nonenhancing lesion on the DCE images, while no cases were misclassified on T1 3D subtraction images. CONCLUSION: The T1 3D subtraction technique shows superior performance for determining the presence of enhancement on pituitary lesions compared with conventional DCE techniques, which may aid in diagnosing Cushing's disease.
Subject(s)
Humans , Magnetic Resonance Imaging , ROC Curve , Subtraction TechniqueABSTRACT
Objective To evaluate the diagnostic efficacy of MRI diffusion kurtosis imaging (DKI) and quantitative dynamic contrast enhancement MRI (DCE-MRI) in benign and malignant breast lesions, and to explore the differential diagnosis ability for different pathological types and molecular subtype lesions. Methods Sixty four females were retrospectively enrolled in the study of MRI diffusion kurtosis imaging and quantitative dynamic contrast enhancement between November 20 and May 2017. All of them were confirmed to have benign or malignant lesions after surgical resection or puncture. All patients underwent axial T1WI, DKI and DCE-MRI examinations. The mean kurtosis (MK) and mean diffusivity (MD) values were calculated by the DKI model, and the hemodynamic parameters were obtained by quantitative dynamic contrast enhancement, including volume transfer constant (Ktrans), rate constant (Kep), extravascular extracellular space distribute volume per unit tissue volume (Ve) and blood volume fraction (Vp). Pathological analysis was performed to monitor the expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER-2) and nuclear proliferation index Ki67. The breast cancer was divided into Luminal A type, Luminal B type, HER-2 positive and triple-negative 4 subtypes. The differences of DKI parameters and DCE-MRI parameters between benign and malignant breast lesions were compared using two independent samples t test (normal distribution and homogeneity of variance) or Mann-Whitney U test (skewed distribution or variance). ROC analysis was used to evaluate the value of DKI and DCE-MRI parameters in differential diagnosis of benign and malignant breast lesions with pathological results as the gold standard. The Mann-Whitney U test and Kruskal-Wallis H test were used to compare the differences of DKI and DCE-MRI parameters among different prognostic factors and molecular subtypes of breast cancer. Spearman rank correlation analysis was used to evaluate the correlation between DKI and DCE-MRI parameters and different prognostic factors. Results Sixty-four cases were single lesions, with breast cancer in 23 cases and 41 cases of benign lesions. In breast cancer, there were 9 cases of Luminal A type, 7 cases of Luminal B type, 3 cases of HER-2 positive type and 4 cases of triple negative type. The positive numbers of ER, PR and HER-2 were 14, 11 and 10 cases respectively. Nineteen cases showed high expression of Ki67, while 4 cases showed low expression. There were significant differences in MK, MD, Ktrans and Kep between benign and malignant lesions (P<0.05). However, there was no significant difference between Ve and Vp (P>0.05). The area under the ROC for the differential diagnosis of benign and malignant breast lesions were 0.897, 0.808, 0.844 and 0.842, respectively. The combined multi-parameter differential diagnosis improved the efficacy. Combined with the above four parameters, the area under the ROC was 0.950. The diagnosis Sensitivity, specificity and accuracy were 0.870, 0.951 and 0.922 respectively. The Ktrans and Vp values of patients with ER positive and ER negative, as well as Ve value of deferent lymph node status, were significantly different (P<0.05), but there was no significant difference between the other prognostic factors (P>0.05). There was a moderate positive correlation between ER and Ktrans and Vp values. There was a low positive correlation between lymph node status and Ve value (r= 0.6, 0.5 and 0.4, respectively, P<0.05). No correlation was found among other parameters and prognostic factors (P>0.05). There were no significant differences in DKI and DCE-MRI parameters among different subtypes of breast cancer patients (all P>0.05). Conclusion DKI combined with DCE-MRI can improve the differential diagnosis of breast lesions and some DCE-MRI parameters are related to prognostic factors.
ABSTRACT
Objective To compare the accuracy of dynamic contrast-enhanced magnetic resonance (DCE-MRI) and SPECT in the measurement of glomerular filtration rate (GFR) in renal allografts.Methods Sixty renal transplant recipients were enrolled in this study.DCE-MRI and SPECT were used to measure the GFR of the transplanted kidneys,and compared with the endogenous creatinine clearance rate (Ccr).Bias,precision,correlation and Bland-Altman agreement were calculated for each modality compared with the endogenous Ccr.Results In 60 renal transplant recipients,the corrected Ccr was (60.63 ± 24.83) ml · min-1 · 1.73 m-2.The GFR measured by SPECT was (65.31 ± 17.08) ml · min-1 · 1.73 m-2,and (50.44 ± 22.78) ml · min-1 · 1.73 m-2 by MRI,respectively.The bias of GFR-SPECT was 4.69 ml·min-1 · 1.73 m-2,and the precision was 23.76 ml·min-1 1.73 m-2.The bias of GFR-MRI was-10.18 ml·min-1 ·1.73 m-2,and the precision was 13.87 ml·min-1 · 1.73 m-2.Correlation analysis showed that GFR-MRI and the endogenous Ccr had a good correlation (r=0.833,P＜0.01),GFR-SPECT and the endogenous Ccr had a moderate correlation (r=0.406,P＜0.01),and GFR-MRI and GFR-MRI had a poor correlation (r=0.342,P ＜0.01).Bland-Altman analysis showed a confidence interval of 95.3 ml·min-1 ·1.73 m-2 for GFR-SPECT and 62.3 ml· min-1 · 1.73 m-2 for GFR-MRI.Conclusion DCE-MRI can be used as confidently as SPECT to evaluate the renal function of transplanted kidneys in the same time of determining anatomical information.
ABSTRACT
Objective@#To investigate the value of preoperative dynamic contrast-enhanced MRI in reducing the rate of tumor-positive resection margins after breast conserving surgery in patients with early non-mass breast carcinoma.@*Methods@#Seventy-two patients with early non-mass breast carcinoma received ultrasonographic and mammographic examination and subsequently underwent dynamic contrast-enhanced MRI examination before breast conserving surgery. The control group consisted of 74 patients who had early non-mass breast carcinoma. They only received ultrasonographic and mammographic examination and didn′t undergo contrast-enhanced MRI examination. The comparison of the rate of tumor-positive resection margins between two groups was performed. The MRI findings that had the significant influence on the rate of tumor-positive resection margins were analyzed using Logistic regression model.@*Results@#In 28 patients (28/72, 38.9%), dynamic contrast-enhanced MRI could correct or supplement the ultrasonographic and mammographic findings and resulted in the reasonable change of surgical program. The preoperative MRI examination group (n=30) had lower rate of tumor-positive resection margins than control group for invasive ductal carcinoma (23.3% vs 40.0%, P=0.02), but there was no significant difference (21.4% vs 26.9%, P=0.10) between two groups for ductal carcinoma in situ (n=28). The preoperative MRI examination group (n=14) had lower rate of tumor-positive resection margins than control group for the other pathologic types of breast carcinoma (14.3% vs 38.9%, P=0.02). The statistical analysis on the basis of Logistic regression model showed that some main MRI findings, including change surrounding the tumor, distance between tumor and nipple and tumor size, had the significant influence on the rate of tumor-positive resection margins.@*Conclusion@#Preoperative dynamic contrast-enhanced MRI significantly increased the accuracy of resection margins evaluation, and greatly reduced the rate of tumor-positive resection margins after breast conserving surgery in patients with early non-mass breast carcinoma.
ABSTRACT
Objective To evaluate the differential diagnostic value of dynamic contrast enhanced magnetic resonance imaging(DCE-MRI) and diffusion weighted imaging(DWI) in adenosis of the breast and breast cancer.Methods 30 cases of adenosis and 45 cases of breast cancer with pathological verification were scanned with DCE-MRI and DWI.The MRI features of the lesions were analyzed, including shape,margin,T2WI singal, features of enhancement, time intensity curve(TIC) type, early enhancement rate(EER),peak time, background enhancement and ADC value.Results The irregular margin with or without spiculation and the heterogeneous enhancement were mostly seen in breast cancer (P=0.002,P=0.009, respectively).The TIC type Ⅲ, EER larger than 100% and peak time within 2 minutes were mostly seen in breast cancer(P0.05).Conclusion DCE-MRI combined with DWI will be helpful to the diagnosis of breast lesions.
ABSTRACT
Objective To explore the fibrotic stroma characteristics of orthotopic liver cancer in rat and the relationship with MR delayed contrast enhancement.Methods 4 Wistar rats with orthotopic liver cancer underwent conventional triphasal and longer-de-layed contrast-enhancement MR scanning.12 HCC specimens obtained from the four Wistar rats were sliced and stained with HE, picric-sirius red,Verhoeff Van-Gieson elastic fiber,Gordon-Sweets reticular fiber and anti-α-SMA immunohistochemical staining.The relationshp between intratumoral fibrotic stroma and MR delayed phases of the 1 2 tumors were analyzed.Results Collagen fiber was expressed mainly in tumor fibrous septum.Elastic fiber distributed in tumor fibrous septum and the artery wall.Reticular fiber dis-tributed in fibrous septum of the regenerative nodules,portal area and tumor psuedocapsule.Integrated optical density (IOD)value of collagen fiber,elastic fiber and reticular fiber analyzed by Image-pro Plus6.0 were 0.102±0.020,0.063±0.018 and 0.109±0.032, respectively.As a result,the amount of collagen and elastic fibers were statistically different (P<0.01),and so were reticular fibers and elastic fibers (P<0.01).And there was a positive correlation between collagen fiber and MR delayed contrast enhancement (P<0.05).Conclusion MR delayed contrast enhancement of hepatic cancer in rat is closely associated with the collagen fiber,thus this fiber in liver cancer can be evaluated noninvasively by MRI.
ABSTRACT
OBJECTIVE: To simulate the B₁-inhomogeneity-induced variation of pharmacokinetic parameters on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). MATERIALS AND METHODS: B₁-inhomogeneity-induced flip angle (FA) variation was estimated in a phantom study. Monte Carlo simulation was performed to assess the FA-deviation-induced measurement error of the pre-contrast R₁, contrast-enhancement ratio, Gd-concentration, and two-compartment pharmacokinetic parameters (K(trans), v(e), and v(p)). RESULTS: B₁-inhomogeneity resulted in −23–5% fluctuations (95% confidence interval [CI] of % error) of FA. The 95% CIs of FA-dependent % errors in the gray matter and blood were as follows: −16.7–61.8% and −16.7–61.8% for the pre-contrast R₁, −1.0–0.3% and −5.2–1.3% for the contrast-enhancement ratio, and −14.2–58.1% and −14.1–57.8% for the Gd-concentration, respectively. These resulted in −43.1–48.4% error for K(trans), −32.3–48.6% error for the v(e), and −43.2–48.6% error for v(p). The pre-contrast R₁ was more vulnerable to FA error than the contrast-enhancement ratio, and was therefore a significant cause of the Gd-concentration error. For example, a −10% FA error led to a 23.6% deviation in the pre-contrast R₁, −0.4% in the contrast-enhancement ratio, and 23.6% in the Gd-concentration. In a simulated condition with a 3% FA error in a target lesion and a −10% FA error in a feeding vessel, the % errors of the pharmacokinetic parameters were −23.7% for K(trans), −23.7% for v(e), and −23.7% for v(p). CONCLUSION: Even a small degree of B₁-inhomogeneity can cause a significant error in the measurement of pharmacokinetic parameters on DCE-MRI, while the vulnerability of the pre-contrast R₁ calculations to FA deviations is a significant cause of the miscalculation.
Subject(s)
Brain , Gray Matter , Magnetic Resonance Imaging , Monte Carlo Method , Phantoms, ImagingABSTRACT
Object: Gadolinium chelates are relatively safe contrast media used in MRI. Immediate severe adverse effects are exceptionally rare.The incidence of immediate hypersensitivity reactions to MR contrast media was 0.079%, and the recurrence rate of hypersensitivity reactions was 30% in patients with previous reactions. The risk factors for immediate hypersensitivity reactions to MR contrast media were the female sex, allergies and asthma. Case: We report a case of anaphylactic shock due to Gadobenate dimeglumine. While undergoing a magnetic resonance imaging examination, 36 year-old female patient became severely hypotensive, lost consciousness, and had generalized erythema immediately after the intravenous injection of this product. She recovered rapidly after injection of epinephrine and her blood volume was restored with intravenous fluids. Conclusions: Although gadolinium is a safe contrast medium, anaphylactoid reactions do occur. Some are severe. Reactions to MR imaging contrast media are uncommon enough that radiologists may not be as familiar with their management as they are with the treatment of complications associated with iodinated radiographic contrast media. Gadobenate dimeglumine is comparable to gadodiamide in terms of safety and efficacy for imaging of CNS lesions.
ABSTRACT
Objective To describe the changes of thrombosed venous sinus on MRI after administration of contrast material and evaluate the sensitivity and specificity of thread-like enhancement around sinus to diagnose thrombosis in the corresponding sinus.Methods Patients with cerebral venous sinus thrombosis (CVST) admitted to our department from January 2005 to December 2014 and undergone a MRI scan with administration of contrast material were included in this study.The enhancement features of venous sinus were studied in the plane parallel to the interested sinus.The features of enhancement were classified as peripheral thread-like enhancement, partial enhancement and complete enhancement.The proportion of these three type of enhancement in thrombosed sinuses and normal sinuses were described and compared.The sensitivity and specificity of peripheral thread-like enhancement to diagnose thrombosis in corresponding sinus were calculated.The proportion of each type of enhancement was also described and compared in acute (≤ 7 d), subacute (8-30 d) and chronic (≥ 31 d) stage after onset of symptoms.Results Peripheral thread-like enhancement, partial enhancement and complete enhancement were all found in both thrombosed and normal sinuses.There was a significant difference of enhancement features between normal and thrombosed sinus in superior sagittal sinus (100％ (30/30) vs 60％ (27/45), x2 =13.789, P =0.001), left trans verse sinus, and right sigrnoid sinus.The sensitivity and specificity of peripheral thread-like enhancement to diagnose thrombosis in the corresponding sinus were 10.5％-44.4％ and 53.3％-76.7％ respectively.There was no significant difference of contrast features at different stage after onset.Conclusion The value of peripheral thread-like enhancement to diagnose CVST is limited because of low sensitivity and specificity.
ABSTRACT
Objective To evaluate the diagnostic value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI)for the differential diagnosis of the adenoid cystic carcinoma and pleomorphic adenoma of the head and neck.Methods Thirty-one pa-tients with histopathologically proved adenoid cystic carcinoma and pleomorphic adenoma were examined with DCE-MRI,in which 10 cases were benign and 21 cases were malignant.The data of the conventional 3.0T DCE-MRI were improved by the 3D fast spoiled gradient-echo sequence (FSPGR)method.Z-test was performed on the quantitative parameters for benign and malignant le-sions,including volume transfer constant (Ktrans ),rate constant (Kep )and extravascular extracellular space fraction (Ve ).The re-ceiver operating characteristic (ROC)curves were plotted to investigate the diagnosis.Results The mean Ktranss of the adenoid cystic carcinoma group and pleomorphic adenoma group were (0.266 ± 0.103 )min-1 and (0.1 55 ± 0.080)min-1 respectively,and the difference between them were statistically significant (Z =-2.699,P 0.05).The areas under the ROC curves of the Ktrans and kep were 0.813 and 0.763 respectively.Choosing the optimal diagnostic cut-off points corresponding to the maximum Youden indexes 0.173 min-1 and 0.818 min-1 ,the sensitivities of Ktrans and kep for identifying the adenoid cystic carcinoma and pleomorphic adenoma were 90.9% and 81.8%,and the specificities were 77.8% and 66.7%.Ktrans was of the highest sensitivity and specificity for the identification of the adenoid cystic carcinoma and pleomorphic adenoma.Conclu-sion The dynamic contrast-enhanced parameter Ktrans plays a certain role in the differential diagnosis of the adenoid cystic carcinoma and pleomorphic adenoma of the head and neck.
ABSTRACT
Objective To study the feasibility of dual-source CT with dual-energy imaging based on single contrast enhancement. Methods The clinical data of 60 cases of patients who underwent dual-energy CT (DECT)examination of the heart in our hospital were analyzed.statistically.Results The success rate of 60 cases were 100% for displaying all 600 coronary artery segments at all stages.The total mean score of image quality was 4.68 ±0.57,and the good image rate reached 95%.6 cases of patients who ac-cepted DSA examination were unanimous with DECT findings;In 6 cases of patients who accepted SPECT examination,60 segments were no perfusion abnormalities,but DECT iodine figures of 54 segments were normal,and 6 segments showed perfusion defect. Conclusion DECT with dual-energy imaging based on single contrast enhancement can get excellent coronary and myocardial perfu-sion imaging in the circumstance of appropriate heart rate,which has some potentials for clinical application.
ABSTRACT
Multiparametric MR (mpMR) imaging is rapidly evolving into the mainstay in prostate cancer (PCa) imaging. Generally, the examination consists of T2-weighted sequences, diffusion-weighted imaging (DWI), dynamic contrast-enhanced (DCE) evaluation, and less often proton MR spectroscopy imaging (MRSI). Those functional techniques are related to biological properties of the tumor, so that DWI correlates to cellularity and Gleason scores, DCE correlates to angiogenesis, and MRSI correlates to cell membrane turnover. The combined use of those techniques enhances the diagnostic confidence and allows for better characterization of PCa. The present article reviews and illustrates the technical aspects and clinical applications of each component of mpMR imaging, in a practical approach from the urological standpoint.
O estudo por ressonância magnética multiparamétrica, ou funcional, vem evoluindo para se tornar o pilar fundamental no manejo diagnóstico de pacientes com câncer de próstata. Geralmente, o exame consiste em imagens pesadas em T2, difusão, realce dinâmico pelo contraste (permeabilidade), e cada vez menos frequentemente espectroscopia de prótons. Tais técnicas funcionais relacionam-se com propriedades biológicas do tumor, de modo que a difusão se relaciona com a celularidade e os escores de Gleason, a permeabilidade se relaciona com a angiogênese, e a espectroscopia de prótons se relaciona com o metabolismo da membrana celular. O uso destas técnicas em combinação aumenta a confiança diagnóstica e permite uma melhor caracterização do câncer de próstata. Este artigo tem o objetivo de revisar e ilustrar os aspectos técnicos e as aplicações clínicas de cada componente do estudo de ressonância magnética multiparamétrica da próstata, mediante uma abordagem prática.
ABSTRACT
Objective To explore the combination of dynamic contrast enhancement and diffusion weighted imaging in the diagno-sis of breast diseases.Methods 67 patients with breast mass proven by operation or biopsy underwent dynamic contrast enhance-ment and diffusion weighted imaging.Fischer scoring system and BI-RADS were used to distinguish the benign lesions from the ma-lignant mass.The optimal boundary value of ROC curve was set as the threshold in DWI.The independent and conj unctive diagnos-tic efficacy of DCE and DWI were calculated and compared.The conj unctive methods included combinated properly method and DCE used as the chief diagnostic method while DWI as the adj unctive method.Results the best diagnostic boundary of ADC values was 1.1×10-3 mm2/s,The sensitivity,specificity and diagnostic accuracy of DWI and DCE were 71.4%,88.6%,80% and 100%, 80%,90%,respectively.The value was 85.7%,94.3%,90%,when using DCE chiefly and DWI adjunctively,while it was 91.4%respectively in combinating properly method.Conclusion DWI can improve the specificity of MRI in diagnosing breast lesions while it can reduce the sensitivity,which can results in the missed diagnosis of malignant diseases.DWI can used as an auxiliary examina-tion method to increase the diagnostic confidence of DCE method.