Time-intensity Curve Patterns Research Articles

Diagnostic efficacy of diffusion-weighted imaging and semiquantitative and quantitative dynamic contrast-enhanced magnetic resonance imaging in salivary gland tumors.

Increased use of functional magnetic resonance imaging (MRI) methods such as diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) MRI consisting of sequential contrast series, allows us to obtain more information on the microstructure, cellularity, interstitial distance, and vascularity of tumors, which has increased the discrimination power for benign and malignant salivary gland tumors (SGTs). In the last few years, quantitative DCE MRI data containing T1 perfusion parameters (Ktrans, Kep and Ve), were reported to contribute to the differentiation of benign or malignant subtypes in SGTs. To evaluate the diagnostic efficacy of DWI and semiquantitative and quantitative perfusion MRI parameters in SGTs. Diffusion MRI [apparent diffusion coefficient (ADC) value] with a 1.5 T MR machine, semiquantitative perfusion MRI [time intensity curve (TIC) pattern], and quantitative perfusion MRI examinations (Ktrans, Kep and Ve) of 73 tumors in 67 patients with histopathological diagnosis performed from 2017 to 2021 were retrospectively evaluated. In the ADC value and semiquantitative perfusion MRI measurements, cystic components of the tumors were not considered, and the region of interest (ROI) was manually placed through the widest axial section of the tumor. TIC patterns were divided into four groups: Type A = Tpeak > 120 s; type B = Tpeak ≤ 120 s, washout ratio (WR) ≥ 30%; type C = Tpeak ≤ 120 s, WR < 30%; and type D = flat TIC. For the quantitative perfusion MRI analysis, a 3D ROI was placed in the largest solid component of the tumor, and the Ktrans, Kep and Ve values were automatically generated. The majority of SGTs were located in the parotid glands (86.3%). Of all the SGTs, 68.5% were benign and 31.5% were malignant. Significant differences were found for ADC values among pleomorphic adenomas (PMAs), Warthin's tumors (WTs), and malignant tumors (MTs) (P < 0.001). PMAs had type A and WTs had type B TIC pattern while the vast majority of MTs and other benign tumors (OBTs) (54.5% and 45.5%, respectively) displayed type C TIC pattern. PMAs showed no washout, while the highest mean WR was observed in WTs (59% ± 11%). Ktrans values of PMAs, WTs, OBTs, and MTs were not significantly different. Kep values of PMAs and WTs were significantly different from those of OBTs and MTs. Mean Ve value of WTs was significantly different from those of PMAs, OBTs, and MTs (P < 0.001). The use of quantitative DCE parameters along with diffusion MRI and semiquantitative contrast-enhanced MRI in SGTs could improve the diagnostic accuracy.

Imaging Features Derived From Dynamic Contrast-Enhanced Magnetic Resonance Imaging to Differentiate Malignant From Benign Breast Lesions: A Systematic Review and Meta-Analysis.

The PubMed, Web of Science, Embase, and the Cochrane Library databases were searched up to January 2021 to identify original studies that investigated the accuracy of individual DCE-MRI features in differentiating malignant from benign breast lesions. Pooled sensitivity, specificity, and area under the curve were calculated by STATA software based on the data extracted from included studies. Moreover, quality assessment, subgroup analysis, and publication bias evaluation were performed. Twenty-nine studies comprising 2976 patients and 3365 suspicious breast lesions were included. Malignant breast lesions tended to present irregular shapes (83.59%), noncircumscribed margins (85.50%), mass enhancement (52.31%), heterogeneous internal enhancement (71.72%), and type II or III time intensity curve (TIC) patterns (91.17%), showing significant differences compared with benign breast lesions (P < 0.05). For differentiating malignant from benign breast lesions, the area under the curve values of irregular shape, noncircumscribed margin, mass enhancement, heterogeneous internal enhancement, and type II or III TIC patterns were 0.79 (0.76-0.83), 0.87 (0.84-0.90), 0.63 (0.58-0.67), 0.82 (0.78-0.85), and 0.89 (0.86-0.92), respectively. Imaging features derived from DCE-MRI, especially TIC patterns, are important for diagnosing and differentiating malignant from benign breast lesions.

Breast Cancer Subtypes and Quantitative Magnetic Resonance Imaging: A Systemic Review.

Magnetic resonance imaging (MRI) is the most sensitive imaging modality for breast cancer detection. This systematic review investigated the role of quantitative MRI features in classifying molecular subtypes of breast cancer. We performed a literature search of articles published on the application of quantitative MRI features in invasive breast cancer molecular subtype classification in PubMed from 1 January 2002 to 30 September 2021. Of the 1275 studies identified, 106 studies with a total of 12,989 patients fulfilled the inclusion criteria. Bias was assessed based using the Quality Assessment of Diagnostic Studies. All studies were case-controlled and research-based. Most studies assessed quantitative MRI features using dynamic contrast-enhanced (DCE) kinetic features and apparent diffusion coefficient (ADC) values. We present a summary of the quantitative MRI features and their correlations with breast cancer subtypes. In DCE studies, conflicting results have been reported; therefore, we performed a meta-analysis. Significant differences in the time intensity curve patterns were observed between receptor statuses. In 10 studies, including a total of 1276 lesions, the pooled difference in proportions of type Ⅲ curves (wash-out) between oestrogen receptor-positive and -negative cancers was not significant (95% confidence interval (CI): [−0.10, 0.03]). In nine studies, including a total of 1070 lesions, the pooled difference in proportions of type 3 curves between human epidermal growth factor receptor 2-positive and -negative cancers was significant (95% CI: [0.01, 0.14]). In six studies including a total of 622 lesions, the pooled difference in proportions of type 3 curves between the high and low Ki-67 groups was significant (95% CI: [0.17, 0.44]). However, the type 3 curve itself is a nonspecific finding in breast cancer. Many studies have examined the relationship between mean ADC and breast cancer subtypes; however, the ADC values overlapped significantly between subtypes. The heterogeneity of ADC using kurtosis or difference, diffusion tensor imaging parameters, and relaxation time was reported recently with promising results; however, current evidence is limited, and further studies are required to explore these potential applications.

Diffusion Weighted and Dynamic Contrast Enhanced Magnetic Resonance Imaging in Carcinoma of Cervix: Role of Apparent Diffusion Coefficient Value and Time Intensity Curve Pattern in Chemoradiotherapeutic Response Evaluation

Introduction: Magnetic resonance imaging (MRI) is a widely used imaging modality in the imaging evaluation of carcinoma of cervix. The aim of our study was to evaluate the response in carcinoma cervix patients following chemoradiotherapy by Diffusion weighted (DW-MRI) and Dynamic contrast enhanced-MRI (DCE-MRI). Methods: 21 inoperable biopsy proven patients (mean age 48.43 years) of carcinoma cervix were included in the study. All patients underwent MRI (conventional, DW and DCE) of the pelvis thrice. Baseline MRI, Post chemotherapy MRI after neoadjuvant chemotherapy and Post chemoradiotherapy MRI after completion of concurrent chemoradiotherapy. Post treatment apparent diffusion coefficient(ADC) values and Time intensity curve(TIC) pattern were compared with baseline values. Results: Baseline meanADC value of all patients was 0.82 x10-3 mm2/s. After completion of treatment, 18 patients showed complete resolution of tumor and showed 0.50 x10-3 mm2/s increase in meanADC value from baseline MRI which was significantly higher than remaining 3 patients with residual tumor (0.50 x10-3 mm2/s v/s 0.17 x10-3 mm2/s). ADC threshold value of 1.15 x10-3 mm2/s was defined, differentiating the residual tumor from the healthy cervical tissue after chemoradiation. On post treatment MRI, 17 out of 18 patients with complete resolution of tumor showed increasing trend of enhancement on TIC and only one patient showed plateau pattern. 2 of the 3 patients with residual tumor showed washout pattern and one patient showed plateau pattern. Conclusion: ADC values and TIC pattern differ in patients with complete response to chemoradiotherapy from patients with residual tumor, so helps in differentiating residual tumor from cancer free cervix. Keywords: Carcinoma of cervix; Chemoradiotherapy; Diffusion weighted MRI; Dynamic contrast enhanced MRI; Time intensity curve.

The value of diffusion-weighted and dynamic contrast-enhanced imaging in the diagnosis of thymic epithelial tumors.

Background: Thymic epithelial tumors (TETs) are clinically the most frequently encountered neoplasm of the prevascular mediastinum in adults. The role of chest magnetic resonance (MR) imaging has been increasingly stressed thanks to its excellent contrast resolution, freedom from ionizing radiation, and capability to provide additional information regarding tumors' cellular structure and vascularity.Methods: This study aimed to establish the relationship between the MR findings and pathological classification of TETs, focusing on diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) imaging. This retrospective cross-sectional study included 44 TET patients who underwent chest MR scanning. The tumors were classified into three groups according to the WHO classification: low-risk thymoma (LRT), high-risk thymoma (HRT), and non-thymoma (NT). Along with morphological characteristics, the apparent diffusion coefficient (ADC) value, time-intensity curve (TIC) pattern, and time to peak enhancement (TTP) of the tumors were recorded and compared between the three groups.Results: A smooth contour and complete or almost complete capsule were suggestive of LRTs. The median ADC value of the 44 tumors was 0.95 × 10-3 mm2/sec. Among the three groups, LRTs had the highest ADC values, while NTs had the lowest. The differences between the ADC values of the three groups were statistically significant (p = 0.006). Using an ADC cutoff of 0.82 × 10-3 mm2/sec to differentiate between LRTs and tumors of the two remaining groups, the area under the curve was 0.775, sensitivity was 100%, specificity was 50%, and accuracy was 65.91%. The washout (type 3) TIC pattern was the most prevalent, accounting for 45.45% of the population; this pattern was also predominantly observed in LRTs (71.43%). Although the median TTP of LRTs was lower than that of HRTs or NTs, no statistically significant differences were found between the TTPs of the three groups (p = 0.170).Conclusions: MR is a good imaging modality to preoperatively assess TETs. Morphological features, ADC value, TIC pattern, and TTP are helpful in preoperatively predicting TET pathology.

The Predictive Value of Magnetic Resonance Imaging-based Texture Analysis in Evaluating Histopathological Grades of Breast Phyllodes Tumor.

PurposeKnowing the distinction between benign and borderline/malignant phyllodes tumors (PTs) can help in the surgical treatment course. Herein, we investigated the value of magnetic resonance imaging-based texture analysis (MRI-TA) in differentiating between benign and borderline/malignant PTs.MethodsForty-three women with 44 histologically proven PTs underwent breast MRI before surgery and were classified into benign (n = 26) and borderline/malignant groups (n = 18 [15 borderline, 3 malignant]). Clinical and routine MRI parameters (CRMP) and MRI-TA were used to distinguish benign from borderline/malignant PT. In total, 298 texture parameters were extracted from fat-suppression (FS) T2-weighted, FS unenhanced T1-weighted, and FS first-enhanced T1-weighted sequences. To evaluate the diagnostic performance, receiver operating characteristic curve analysis was performed for the K-nearest neighbor classifier trained with significantly different parameters of CRMP, MRI sequence-based TA, and the combination strategy.ResultsCompared with benign PTs, borderline/malignant ones presented a higher local recurrence (p = 0.045); larger size (p < 0.001); different time-intensity curve pattern (p = 0.010); and higher frequency of strong lobulation (p = 0.024), septation enhancement (p = 0.048), cystic component (p = 0.023), and irregular cystic wall (p = 0.045). TA of FS T2-weighted images (0.86) showed a significantly higher area under the curve (AUC) than that of FS unenhanced T1-weighted (0.65, p = 0.010) or first-enhanced phase (0.72, p = 0.049) images. The texture parameters of FS T2-weighted sequences tended to have a higher AUC than CRMP (0.79, p = 0.404). Additionally, the combination strategy exhibited a similar AUC (0.89, p = 0.622) in comparison with the texture parameters of FS T2-weighted sequences.ConclusionMRI-TA demonstrated good predictive performance for breast PT pathological grading and could provide surgical planning guidance. Clinical data and routine MRI features were also valuable for grading PTs.

Differential diagnosis of parotid gland tumours: Application of SWI combined with DWI and DCE-MRI

BackgroundParotid tumours (PTs) have a variety of pathological types, and the surgical procedures differ depending on the tumour type. However, accurate diagnosis of PTs from the current preoperative examinations is unsatisfactory. MethodsThis retrospective study was approved by the Ethics Committee of our hospital, and the requirement for informed consent was waived. A total of 73 patients with PTs, including 55 benign and 18 malignant tumours confirmed by surgical pathology, were enrolled. All patients underwent diffusion-weighted imaging (DWI), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), susceptibility-weighted imaging (SWI), T2-weighted imaging (T2WI), and T1-weighted imaging (T1WI). The signal uniformity and capsule on T2WI, apparent diffusion coefficient (ADC) derived from DWI, semi-quantitative parameter time-intensity curve (TIC) pattern, and quantitative parameters including transfer constant (Ktrans), extravascular extracellular volume fraction (Ve), wash-out constant (Kep) calculated from DCE-MRI, and intratumoural susceptibility signal (ITSS) obtained from SWI were assessed and compared between benign and malignant PTs. Logistic regression analysis was used to select the predictive parameters for the classification of benign and malignant parotid gland tumours, and receiver operating characteristic (ROC) curve analysis was used to evaluate their diagnostic performance. ResultsMalignant PTs tended to exhibit a type C TIC pattern, whereas benign tumours tended to be type A and B (p < 0.001). Benign PTs had less ITSS than malignant tumours (p < 0.001). Multivariate analyses showed that ADC, Ve, and ITSS were predictors of tumour classification. ROC analysis showed that the area under the curve (AUC) of ADC, Ve, ITSS, and ADC combined with Ve were 0.623, 0.615, 0.826, and 0.782, respectively, in differentiating between malignant and benign PTs. When ITSS was added, the AUCs of ADC, Ve, and ADC combined with Ve increased to 0.882, 0.848, and 0.930, respectively. ConclusionSWI offers incremental diagnostic value to DWI and DCE-MRI in the characterisation of parotid gland tumours.

Characterization of parotid gland tumors: added value of permeability MR imaging to DWI and DCE-MRI.

To determine added value of permeability MRI in parotid tumor characterization to T2-weighted imaging (T2WI), semi-quantitative analysis of time-intensity curve (TIC), and intra-voxel incoherent motion diffusion-weighted imaging (IVIM-DWI). This retrospective study was approved by the institutional review board, and the informed consent was waived. Sixty-one parotid tumors in 61 patients were examined using T2WI, IVIM-DWI, and permeability MRI. TIC patterns were categorized as persistent, washout, or plateau. Signal intensity ratio of lesion-to-muscle on T2WI, apparent diffusion coefficients (ADCs), D and f values from IVIM-DWI, and Ktrans, kep, Ve, and Vp values from permeability MRI were measured. Multiple comparisons were applied to determine whether any differences among 4 histopathologic types (pleomorphic adenomas, Warthin's tumors, other benign tumors, and malignant tumors) existed. Diagnostic accuracy was compared before and after modification diagnosis referring to permeability MRI. In a validation study, 60 parotid tumors in 60 patients were examined. ADC and D values of malignant tumors were significantly lower than those of benign tumors other than Warthin's tumors, but higher than those of Warthin's tumors. kep and Vp values of Warthin's tumors were significantly higher than those of malignant tumors. Multivariate analyses showed that TIC pattern, D, and kep values were suitable parameters. McNemar's test showed a significant increase of sensitivity (11/12, 92%) and specificity (46/49, 94%) with adding kep. The validation study yielded high sensitivity (14/16, 88%) and specificity (41/44, 93%). Permeability MRI offers added value to IVIM-MRI and semi-quantitative TIC analysis of DCE-MRI in characterization of parotid tumors KEY POINTS: • Permeability MR imaging offers added value in the characterization of parotid gland tumors in combination with semi-quantitative TIC analysis and IVIM analyses with D parameter. • The combination of TIC pattern, D, and kep might facilitate accurate characterization of parotid gland tumor, thereby avoiding unnecessary surgery for benign tumors or delayed treatment for malignant tumors. • A combination of permeability and diffusion MR imaging can be used to guide the selection of an appropriate biopsy site.

The kinetic analysis of breast cancer: An investigation of the optimal temporal resolution for dynamic contrast-enhanced MR imaging

IntroductionThere is wide agreement that morphologic features and enhancement kinetics should be evaluated for MRI of the breast, although there has been no clear consensus concerning optimal temporal resolutions. The objective of this study was to investigate the optimal temporal resolution for the kinetic analysis of breast cancers. MethodsThirty-four patients with 34 enhancing lesions of breast cancer who underwent dynamic contrast-enhanced MRI (DCE-MRI) on a 3.0-T scanner were included in this retrospective study. DCE-MRI was performed with an original temporal resolution of 10-s, and the values of pharmacokinetic parameters (Ktrans, Ve, Kep, and area under the curve (AUC)) were compared with selected data of 30-s and 60-s time intervals. ResultsAmong the 34 lesions, 10 showed a wash out pattern, 16 showed a plateau pattern, and 8 showed a persistent enhancement pattern. The Ktrans value in the wash-out pattern was significantly higher than that of other time-intensity curve patterns (p < 0.01). The Kep and AUC also showed significant differences between the wash-out pattern and other types (p < 0.01). On comparing the perfusion parameters among different temporal resolutions, simulations showed that only the AUC differed significantly between the data acquired at a 10-s temporal resolution and that acquired at a 60-s time interval (p < 0.01). Although the comparison of the AUC between the 30-s and 60-s data also showed significant differences (p = 0.01), there was no significant difference between the 10-s and 30-s data (p = 0.17). ConclusionsDCE-MRI with a temporal resolution of 30-s preserves the kinetic information. Further prospective studies will be needed to investigate the trade-off between temporal and spatial resolution in DCE-MRI.

A multiparametric analysis based on DCE-MRI to improve the accuracy of parotid tumor discrimination.

Recently, semiquantitative time-intensity curve (TIC) analysis based on DCE-MRI and apparent diffusion coefficient (ADC) value-based diffusion-weighted imaging (DWI) were used to improve the diagnostic efficiency when diagnosing parotid tumors (PTs). However, quantitative DCE-MRI biomarkers have not been emphasized previously. To explore the diagnostic efficiency of perfusion parameters alone or in combination based on quantitative DCE-MRI and DWI in the differential diagnosis of PTs. In total, 112 patients with parotid masses were prospectively recruited in our hospital from August 2013 to March 2017. All patients were evaluated with DCE-MRI and DWI before surgery. TIC and quantitative parameters based on DCE MRI and ADCs were analyzed. Receiver operating characteristic analysis and linear discriminant analysis (LDA) was used to determine their diagnostic performance. In total, 87% (27/31) of pleomorphic adenoma (PA) showed type A TIC, 74% (65/88) of Warthin's tumors showed type B TIC, and 95% (19/20) of malignant tumors showed TIC type C. Pearson X2 test showed a significant difference between TIC patterns in benign and malignant tumors (X2 = 38.78, p < 0.001). ROC analysis revealed that ADC achieved the best diagnostic performance for distinguishing PA and Warthin's tumor from others, with area under the curve (AUC) values of 0.945 and 0.925 (p < 0.01), respectively. Furthermore, the TIC type was the only useful biomarker for distinguishing malignant from benign PTs, with an AUC of 0.846 (p < 0.01). Concerning the accuracy of the combined application of multiple parameters of DCE-MRI and ADC values, a combination of TIC pattern and extracellular volume ratio (Ve) provided the best results among five protocols, producing the highest accuracy of 0.75, followed by the combined use of the TIC pattern and ADC (accuracy was 0.70). TIC pattern in combination with the Ve biomarker based on DCE-MRI could achieve optimal diagnostic accuracy in the differential diagnosis of PTs.

Pseudo-continuous arterial spin labeling MR images in Warthin tumors and pleomorphic adenomas of the parotid gland: qualitative and quantitative analyses and their correlation with histopathologic and DWI and dynamic contrast enhanced MRI findings.

We investigated the correlation between tumor blood flow (TBF) and histopathologic features of Warthin tumors (WTs) and pleomorphic adenomas (PAs) to determine the TBF in the differential diagnosis of these tumors and evaluated how well pCASL-MRI can differentiate PAs from WTs compared to conventional MRI. The ADC, time intensity curve (TIC) pattern of dynamic contrast enhancement, and pCASL (visual assessment and TBF of the MR images of 10 WTs and 13 PAs) were reviewed. We compared the pCASL and ADC or TIC patterns in WT and PA images. Tissue sections were stained with CD34 to evaluate microvessel density (MVD). The TBF and MVD results were compared. The Mann-Whitney U test was used to compare the TBFs, ADCs, and MVDs of these tumors. The diagnostic accuracy was determined by analyzing the receiver operating characteristic curve. On visual assessment, the signal intensity was higher in all but three cases of WT. The TBF and MVD of the WTs were significantly higher (both, p < 0.01) than the PAs, and the ADC was significantly lower (p < 0.01). Many WTs had early enhancement of the TIC pattern and high washout; many PAs had gradual enhancement. The diagnostic accuracies of visual analysis, TBF, and ADC for differentiation between WTs and PAs were 91.3, 95.7, and 87.0%, respectively. The TBF were significantly higher in WTs than in PAs, and there was a positive correlation between TBF and MVD. Moreover, pCASL-MRI provides more accurate imaging than conventional MRI to differentiate WTs and PAs.

MR imaging characteristics of breast cancer diagnosed during lactation.

To describe the MR imaging characteristics of breast cancer diagnosed during lactation and evaluate the usefulness of MR imaging. The MR images of nine patients (age range, 29-37 years) with pathologically confirmed breast carcinoma during lactation were evaluated retrospectively. Background parenchymal enhancement of the lactating mammary tissue was determined. The images were reviewed for evaluation of lesion detection, enhancement type (mass/non-mass), shape, margin, contrast enhancement and time-intensity curve pattern in the dynamic study. The breast MR images after neoadjuvant chemotherapy were also reviewed. Although the breasts showed marked (n = 7) or moderate (n = 2) background parenchymal enhancement, MR imaging depicted breast cancer in all patients. All nine tumours were visible as masses. The most common shape and margin of the masses were an irregular mass (n = 5) with an irregular margin (n = 9). Contrast enhancement was heterogeneous or rim enhancement. The predominant kinetic pattern was rapid increase (n = 9) in the initial phase and washout (n = 5) in the delayed phase. Additional sites of cancer other than the index lesion were detected with MR imaging in three patients (33.3%). MR imaging demonstrated partial response in five of six patients who were evaluated for response to chemotherapy. All breast cancers in lactating females in this study were observed on breast MR imaging despite the moderate-to-marked background parenchymal enhancement of lactating mammary tissue. Advances in knowledge: MR imaging can be used in the evaluation of disease extent and assessment of therapeutic response after neoadjuvant chemotherapy of breast cancer diagnosed during lactation.

A Novel Approach to Detecting Postpartum Hemorrhage Using Contrast-Enhanced Ultrasound

The aim of this study was to estimate the efficacy of contrast-enhanced ultrasound (CEUS) in detecting postpartum hemorrhage (PPH) after cesarean section. This is the first study of CEUS in obstetric hemorrhage. A total of 37 patients, operated at Nagoya University Hospital, underwent CEUS. We evaluated the findings of CEUS, which were qualitatively defined as positive when pooling or leakage of contrast agent was observed in the uterine cavity, by measuring the amount of bleeding during the first 4 h after cesarean section. The time–intensity curve patterns of leaked contrast agents were also analyzed for quantitative prediction of the amount of blood loss. Significant differences between the excessive hemorrhage (N = 7) and non-excessive hemorrhage groups (N = 30) were noted in the occurrence of positive CEUS (p = 0.011). Additionally, mean postpartum blood loss markedly increased in patients with a positive CEUS (p = 0.002). From a quantitative perspective, the time until leakage of contrast agents was detected correlated with the amount of bleeding, but the other characteristics of the time–intensity curve pattern did not provide valuable information. In conclusion, CEUS, which enables bedside assessment and rapid diagnosis, is a promising strategy for the detection of PPH.

Magnetic Resonance Imaging Features of Extraocular Muscle Lymphoma in Five Cases.

Magnetic Resonance Imaging Features of Extraocular Muscle Lymphoma in Five Cases.

Use of BI-RADS-MRI descriptors for differentiation between mucinous carcinoma and fibroadenoma

ObjectiveWe evaluated the latest breast imaging reporting and data system (BI-RADS) magnetic resonance imaging (MRI) (5th edition) descriptors and non BI-RADS MRI factors that contribute to differentiation between mucinous carcinomas (MCs) and fibroadenomas (FAs). Materials and methodsThis retrospective study included 27 patients with P-MCs or M-MCs similar to P-MCs and 22 patients with FAs who underwent breast MRI between October 2008 and July 2014 at our institution. Definitive histopathological diagnoses were made for all of the MCs and FAs. The latest BI-RADS MRI descriptors for abnormal enhancement, including maximum diameter, shape (irregular or round/oval), margin (irregular or circumscribed), rim enhancement (present or absent), dark internal septation (absent or present), delayed internal enhancement (heterogeneous or homogeneous), and the time–intensity curve pattern (not persistent or persistent) were evaluated. As additional non BI-RADS MRI factors related to differentiation between MC and FA, age, signal intensity in the T2-weighted image (high or not high), extent of lobulation (strong or weak), enhancing internal septation (present or absent), and the apparent diffusion coefficient value were also evaluated. One radiologist retrospectively evaluated interpreted MR findings and analyzed the findings. Statistically significant findings were identified through univariate and multivariate analyses. Then, three blinded radiologists reviewed the MR images where MR findings had shown a significant association with outcomes during univariate analyses. Independently, the three blinded readers reviewed the MR images for the evaluation of inter-observer variability, and then arrived at a consensus for the evaluation of observer performance. Observer performance and inter-observer variability were determined via a receiver-operating-characteristic curve analysis and weighted k statistics. The sensitivity, specificity, and accuracy of each of the MR findings were calculated. ResultsUnivariate analyses showed that irregular margins were observed more frequently in MCs than in FAs (11/27, 41% vs. 1/22, 0.5%, p<0.05). MCs also showed rim enhancement, delayed heterogeneous enhancement, and enhancing internal septation more frequently than FAs (p<0.05). FAs showed circumscribed margins more frequently than MCs (21/22, 95% vs. 16/27, 59%, p<0.05). FAs also showed dark internal septation more frequently than MCs (18/22, 82% vs. 3/27, 11%, p<0.05). In multivariate analyses, the most significant feature in lesion characterization was delayed heterogeneous enhancement. In the blinded reading, a combination of irregular margin and delayed heterogeneous enhancement showed the highest sensitivity (96.3%) and accuracy (87.8%). Enhancing internal septation showed the highest specificity (90.9%). The κ values with confidence ratings for differentiation between MCs and FAs were 0.63–0.67, which showed substantial agreement among the three radiologists. ConclusionsThe combination of irregular margin and delayed heterogeneous enhancement and enhancing internal septation were significant findings for differentiation between P-MC or M-MC similar to P-MC and FA.

Enhancement characterization of breast masses of contrast-enhanced ultrasound: comparison with MRI

Objective To assess the enhancement characteristic of breast lesions of contrast-enhanced ultrasound (CEUS) in comparison with contrast-enhanced magnetic resonance imaging (MRI).Methods Between August 2011 and March 2013,72 women with 72 lesions were enrolled.All patients underwent ultrasound,CEUS and MRI.The histopathologic results obtained from ultrasound-guided core biopsy or operation excisions were used as the reference standard.CEUS section evaluations were made similar with MRI regarding the size and shape of lesions.Different contrast enhancement patterns including homogeneous/heterogeneous,the tumor areas,the perfusion defect areas,and modality of time-intensity curve were evaluated.Pearson's correlation coefficient,Student's t-tests,and the concordance test were used for evaluation.Results Of the 72 lesions,pathologic examination revealed 56 (77.8％) malignant lesions and 16 (22.2％) benign lesions.The tumor areas measured by CEUS and MRI agreed well,with a correlation of r =0.894,P =0.000.The difference between the two measurements was not significant according to a paired t test (P =0.886).The concordance tests gave a value of the coefficient Kappa =-0.153 (P =0.061),indicating a low concordance between the results obtained with CEUS and those obtained with MRI regarding the enhanced uniformity.There were statistically significant differences in the perfusion defect areas as measured by CEUS and MRI (P =0.01).The CEUS estimates [(0.837 ± 0.827)cm2] were consistently higher than the MRI estimates [(0.576 ± 0.524)cm2].The time-intensity curve patterns between the two groups showed no correlation.Conclusions The enhancement patterns evaluated by CEUS and MRI partly agreed well.There was no direct association between the two methods regarding the enhancement patterns because of the different contrast agent. Key words: Ultrasonography; Microbubbles ; Breast neoplasms ; Magnetic resonance imaging

Routine and Dynamic MR Imaging Study of Lobular Capillary Hemangioma of the Nasal Cavity with Comparison to Inverting Papilloma

Lobular capillary hemangioma is an uncommon lesion, and its MR imaging appearance has not been fully characterized. The purpose of this study was to determine the MR imaging features of nasal lobular capillary hemangioma and contrast its imaging characteristics to inverting papilloma. The MR imaging signals of 32 patients with histopathologically proven nasal lobular capillary hemangiomas and 53 patients with nasal inverted papillomas were retrospectively studied. The findings of dynamic contrast-enhanced MR imaging in 24 lobular capillary hemangiomas and in 53 inverted papillomas were also analyzed. The Monte Carlo exact test was used for comparison of the time-intensity curve patterns of lobular capillary hemangioma and inverted papilloma. All lobular capillary hemangiomas appeared to be homogeneously isointense to gray matter on T1-weighted images. On T2-weighted images, all lesions showed heterogeneous hyperintensity, and a thin peripheral isointense or hypointense ring was seen in 28 patients. All lesions showed marked enhancement on enhanced images, with the exception of enhancement of the T2 isointense or hypointense ring. Forty-three (81.1%) inverted papillomas had moderate heterogeneous T2 signal intensity, and a characteristic "cerebriform" appearance was detected in 45 (84.91%) of 53 inverted papillomas. The time-intensity curves showed a washout pattern in 18 and a plateau pattern in 6 patients, whereas inverted papillomas showed a washout pattern in 12, a plateau pattern in 35, and a persistent pattern in 6 patients. There was a statistically significant difference as to time-intensity curve pattern between the 2 groups (P < .05). Hyperintensity on T2-weighted images, marked enhancement of tumor with a nonenhancing thin peripheral ring, and a washout time-intensity curve pattern are characteristic MR imaging features of nasal lobular capillary hemangiomas.

Assessment of dynamic contrast-enhanced magnetic resonance imaging in the differentiation of malignant from benign orbital masses

ObjectiveDynamic contrast enhanced MR imaging (DCE-MRI) allows imaging of the physiology of the microcirculation. The purpose of this study was to determine the diagnostic efficacy of time intensity curve (TIC) and DCE parameters for characterization of orbital masses. MethodsFifty-nine patients with untreated orbital lesions underwent DCE-MRI before surgery. For each lesion, peak height (PH), maximum enhancement ratio (ERmax), time of peak enhancement (Tpeak) and maximum rise slope (Slopemax) were plotted and calculated. Receiver operator characteristics (ROC) analysis was conducted to assess the appropriate cut-off value. ResultsAll 26 lesions that demonstrated persistent pattern (type-I) TICs were benign. Most of the masses with the washout pattern (type-III) TIC were malignant (10/14), including lymphoma (n=6) and melanoma (n=4). The Slopemax of benign lesions was statistically lower than malignant ones, while the ERmax and Tpeak values of benign lesions were significantly higher. No statistical difference was found in PH (P=0.121). The AUC for ERmax, Tpeak and Slopemax in differentiating benign orbital lesions from malignant ones were 0.683, 0.837 and 0.738, respectively. In the three DCE parameters, Slopemax cut-off value of 1.10 provided the highest sensitivity of 93.8%; however, the corresponding specificity was low (58.1%). The ERmax cut-off value of 1.37 and Tpeak cut-off value of 35.14 respectively offered the best diagnostic performances. ConclusionDCE-MRI, especially the qualitative TIC pattern and quantitative value of Slopemax, ERmax and Tpeak, could be a complementary investigation in distinguishing malignant orbital tumor from benign ones.

Abstract TP53: Simple And Easy Way Using Time-Intensity Curve of Perfusion-Weighted Images to Find Penumbra In Stroke Patients Within 4.5 Hours Of Onset Due To The Carotid Artery Occlusion

[Purpose] It is not clear how to find penumbra from MR-PWI for reperfusion therapy (RT). The aim of our retrospective study was to investigate whether or not a simple way using time-intensity curve (TIC) of PWI can find penumbra in stroke patients admitted within 4.5 hours from sudden onset due to acute carotid artery occlusion. [Subjects and Methods] Included for analysis were stroke patients 1) who were admitted within 4.5 hours of onset between Jan 2006 and January 2011, 2) who presented NIHSS score of 6 or more on admission, and 3) who underwent emergency MR imaging , which suggested the affected carotid artery occlusion. We assessed, NIHSS on admission (NIH adm), DWI-ASPECT score, TIC types, successful recanalization (SR), NIHSS on the 7th day (NIH 7 th ), and in-hospital death. Early neurological improvement (ENI) was defined as NIH adm - NIH 7 th &gt;0. TICs were generated on region of interests set at symmetrical positions of the bilateral MCA territories. According to the time to peak (TP) and the peak signal (PS) comparing the affected side (a) with the contralateral side (c), we classified TIC pattern into four types and defined type 1 as TPa&gt;TPc and PSa&lt;PSc/2, type2 as TPa&gt;TPc and PSc/2≦PSa&lt;PSc, type 3 as TPa &gt;TPc and PSa≧PSc, and type 4 as TPa=TPc. Relationship between TIC types, in-hospital death and ENI were assessed. [Result] Eighty-seven patients were analyzed. There were 36, 39, 12 and 0 patients in TIC type 1, 2, 3 and 4, 39 patients (44.8%: 39/87) underwent RT and SR was achieved in 18 patients (46.2%), and 29 patients died. Among variables, TIC type 1 was the only determinant of in-hospital death (p&lt;0.01) and SR coupled with TIC type 2 was the determinant of ENI (p&lt;0.01). [Conclusion] TIC type 1 predetermines poor clinical outcome and type 2 means penumbra, where SR may early improve neurological symptoms. TIC is an easy way to find penumbra in an emergency setting.

Invasive Micropapillary Carcinoma of the Breast: MR Imaging Findings

ObjectiveTo analyze the magnetic resonance (MR) imaging findings of invasive micropapillary carcinoma of the breast.Materials and MethodsMR images were retrospectively evaluated in 14 patients (age range: 37-67, mean age: 49 years) with pathologically confirmed invasive micropapillary carcinoma of the breast. The enhancement type (mass/non-mass), shape, margin, contrast enhancement, and time-intensity curve pattern on the dynamic study were correlated with the histopathologic features. Associated findings, such as edema, nipple change, skin change and enlarged axillary lymph nodes were also studied.ResultsThe most common features of the masses were irregular shape (12 of 14 patients, 85.8%) and irregular or spiculated margin (11 of 14 patients, 78.7%). The contrast enhancement was heterogeneous in 11 patients (78.7%), rim enhancement in 2 cases (14.2%), and homogeneous in one patient (7.1%). The predominant kinetic pattern was rapid increase (14 of 14, 100%) in the initial phase and washout (11 of 14, 78.7%) in the delayed phase. Associated non-mass like enhancement was shown in 4 patients, representing ductal carcinoma in situ. MR imaging helped detect additional sites of cancer other than the index lesion in 3 patients (21.4%). Enlarged axillary lymphadenopathy was identified in 7 of the 14 patients (50%).ConclusionInvasive micropapillary carcinoma appears as a mass with an irregular shape, irregular or spiculated margin and heterogeneous enhancement on MR imaging. Though these findings are not specific and are also observed with other breast malignancies, invasive micropapillary carcinoma frequently showed multiple lesions, accompanying non-mass enhancement and axillary lymph node enlargement.