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Rationale and Objectives: A variety of morphologic and kinetic signs of benign or malignant breast lesions contribute to a final diagnosis and differential diagnosis in magnetic resonance (MR) mammography (MRM). As a new sign, prepectoral edema (PE) in patients without any history of previous biopsy, operation, radiation, or chemotherapy was detected during routine breast MR examinations. The purpose of this study was to retrospectively evaluate the role of this morphologic sign in the differential diagnosis of breast lesions., Materials and Methods: Between January 2005 and October 2006, a total of 1109 consecutive MRM examinations have been performed in our institution. In this study, only patients who would later be biopsied or operated in our own hospital were included. They had no previous operation, biopsy, intervention, chemotherapy, hormone replacement therapy, or previous mastitis. In total, 162 patients with 180 lesions were included, histologically correlated later-on by open biopsy (124 patients and 136 lesions) or core biopsy (38 patients and 44 lesions). The evaluations were performed by four experienced radiologists in consensus., Results: One hundred eighty evaluated lesions included 104 malignant lesions (93 invasive and 11 noninvasive cancers) and 76 benign lesions. PE was detected in 2.6% of benign lesions (2 of 76), in none of the Ductal cacinoma in situ (DCIS) cases (0 of 11), and in 25.8% of malignant lesions (24 of 93; P < .000). PE was found significantly more frequently in presence of malignant tumors >2 cm in diameter (48.5%, 17 of 35 vs. 13.8%, 8 of 58; P < .001). PE was not statistically associated to malignant tumor type, presence or absence of additional DCIS, and number of lesions. This resulted in the following diagnostic parameters for PE as an indicator for malignancy: sensitivity of 19.3%, specificity of 97.3%, positive predictive value (PPV) of 92.3%, negative predictive value of 48%, and accuracy of 57.7%., Conclusions: In case of occurrence, the "PE sign" seems to be a specific indicator for malignant tumors with a high PPV, independent from its entity., (Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate the influence of lesion type (mass versus non-mass) and reader experience on the diagnostic performance of breast MRI (BMRI) in a non-screening setting., Materials and Methods: Consecutive patients (mean age, 55 ± 12 years) with breast lesions that were verified by biopsy or surgery, and who had had BMRI as part of their diagnostic workup, were eligible for this retrospective single-center study. Cancers diagnosed by biopsy before BMRI were excluded to eliminate biological and interpretation bias due to biopsy or chemotherapy effects (n=103). Six blinded readers (experience level, high (HE, n=2); intermediate (IE, n=2); and low (LE, n=2)) evaluated all examinations and assigned independent MRI BI-RADS ratings. Lesion type (mass, non-mass, focal) was noted. Receiver operating characteristics (ROC) and logistic regression analysis was performed to compare diagnostic accuracies., Results: There were 259 histologically verified lesions (123 malignant, 136 benign) investigated. There were 169 mass (103 malignant, 66 benign) and 48 non-mass lesions (19 malignant, 29 benign). Another 42 lesions that met the inclusion criteria were biopsied due to conventional findings (i.e., microcalcifications, architectural distortions), but did not enhance on MRI (41 benign, one DCIS). ROC analysis revealed a total area under the curve (AUC) between 0.834 (LE) and 0.935 (HI). Logistic regression identified a significant effect of non-mass lesions (P<0.0001) and reader experience (P=0.005) on diagnostic performance., Conclusions: Non-mass lesion type and low reader experience negatively affect the diagnostic performance of breast MRI in a non-screening setting., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Objectives: In the face of multiple available diagnostic criteria in MR-mammography (MRM), a practical algorithm for lesion classification is needed. Such an algorithm should be as simple as possible and include only important independent lesion features to differentiate benign from malignant lesions. This investigation aimed to develop a simple classification tree for differential diagnosis in MRM., Methods: A total of 1,084 lesions in standardised MRM with subsequent histological verification (648 malignant, 436 benign) were investigated. Seventeen lesion criteria were assessed by 2 readers in consensus. Classification analysis was performed using the chi-squared automatic interaction detection (CHAID) method. Results include the probability for malignancy for every descriptor combination in the classification tree., Results: A classification tree incorporating 5 lesion descriptors with a depth of 3 ramifications (1, root sign; 2, delayed enhancement pattern; 3, border, internal enhancement and oedema) was calculated. Of all 1,084 lesions, 262 (40.4 %) and 106 (24.3 %) could be classified as malignant and benign with an accuracy above 95 %, respectively. Overall diagnostic accuracy was 88.4 %., Conclusions: The classification algorithm reduced the number of categorical descriptors from 17 to 5 (29.4 %), resulting in a high classification accuracy. More than one third of all lesions could be classified with accuracy above 95 %., Key Points: • A practical algorithm has been developed to classify lesions found in MR-mammography. • A simple decision tree consisting of five criteria reaches high accuracy of 88.4 %. • Unique to this approach, each classification is associated with a diagnostic certainty. • Diagnostic certainty of greater than 95 % is achieved in 34 % of all cases.

Purpose: To identify the potential of semi-quantitative enhancement-analysis in breast MRI to predict disease-related death in primary breast cancer patients., Materials and Methods: The present study was planned and conducted according to international recommendations. All patients referred for pretherapeutic staging of primary breast cancer during 24 consecutive months were included into the study collective. They were followed-up by our multidisciplinary breast center. For semi-quantitative MRI-analysis dedicated CAD-software (computer assisted diagnosis) was used. Association between enhancement parameters and disease-related survival was investigated using Cox proportional-hazards -regression (CR)., Results: A total of 115 patients were eligible for CR analysis. Median follow-up time was 52 months. In 15 patients, disease-related death occurred. CR analysis identified four enhancement parameters as independent and significant (P < 0.001) predictors of the endpoint. Coefficients were "Initial enhancement" (B = 0.0166), "Time to peak-enhancement" (B = 1.0573), "Tumor volume" (B = 0.0175), and proportion of "tumor volume" showing "slow initial enhancement" followed by a "persistent" curve-type (B = -0.0586)., Conclusion: This study demonstrates the significant relationship between semi-quantitative enhancement analysis in breast MRI and disease-related death of breast cancer patients. As results were extracted from a routine staging examination, MRI noninvasively provides not only diagnostic information but also outcome data at one step. Future studies should address the impact of these findings on patient management and therapeutic approach., (Copyright © 2012 Wiley Periodicals, Inc.)

Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) is able to detect breast cancer with high sensitivity. Furthermore, this method provides functional information on tissue composition and vascularization. This study aims to identify the potential of DCE-MRI to predict distant metastasis in breast cancer patients using computer assisted interpretation of dynamic enhancement data. For this purpose, 59 consecutive patients with newly diagnosed invasive breast cancer received pretherapeutic DCE-MRI at 1.5 Tesla according to international recommendations. In all patients, follow up interval and occurrence of distant metastasis was documented. For DCE-MRI analysis dedicated software was used (Brevis, Siemens Healthcare, Erlangen, Germany). It allows semiautomatic identification of the most suspect curve in a lesion analyzed. Enhancement parameters assessed were "Initial Enhancement", "Washout", "Peak-Enhancement", and "Time to Peak Enhancement". Cox proportional hazards regression (CPHR) was used to analyze the effect of these parameters on the probability of metachronous distant metastasis. Median follow up period was 52.0 months. 6 patients developed distant metastases between 11 and 35 months after breast cancer diagnosis. In CPHR, Washout could be identified as significant and independent predictor for occurrence of distant metastasis (P = 0.0134). Our initial data demonstrate an association between computer measured enhancement parameters in DCE-MRI and occurrence of distant metastasis by quantification of Washout.

Purpose: To evaluate the diagnostic accuracy of qualitative descriptors alone and in combination for the classification of focal liver lesions (FLLs) suspicious for metastasis in gadolinium-EOB-DTPA-enhanced liver MR imaging., Materials and Methods: Consecutive patients with clinically suspected liver metastases were eligible for this retrospective investigation. 50 patients met the inclusion criteria. All underwent Gd-EOB-DTPA-enhanced liver MRI (T2w, chemical shift T1w, dynamic T1w). Primary liver malignancies or treated lesions were excluded. All investigations were read by two blinded observers (O1, O2). Both independently identified the presence of lesions and evaluated predefined qualitative lesion descriptors (signal intensities, enhancement pattern and morphology). A reference standard was determined under consideration of all clinical and follow-up information. Statistical analysis besides contingency tables (chi square, kappa statistics) included descriptor combinations using classification trees (CHAID methodology) as well as ROC analysis., Results: In 38 patients, 120 FLLs (52 benign, 68 malignant) were present. 115 (48 benign, 67 malignant) were identified by the observers. The enhancement pattern, relative SI upon T2w and late enhanced T1w images contributed significantly to the differentiation of FLLs. The overall classification accuracy was 91.3 % (O1) and 88.7 % (O2), kappa = 0.902., Conclusion: The combination of qualitative lesion descriptors proposed in this work revealed high diagnostic accuracy and interobserver agreement in the differentiation of focal liver lesions suspicious for metastases using Gd-EOB-DTPA-enhanced liver MRI., (© Georg Thieme Verlag KG Stuttgart · New York.)

Many different nanostructures have been developed for biomedical applications to date. Among them, iron oxide nanoparticles have been very prominent in MRI in diagnostic radiology. Nowadays, nanoparticle-based therapeutic applications have gained increased interest, leading to the development of a great variety of different and, in parts, sophisticated nanoparticle formulations. Whereas nanotherapy has been confined to the preclinical phase, magnetic hyperthermia has entered into the clinical phase via controlled studies in patients. Owing to the versatility of nanoparticles, researchers envision the combination of multiple modalities (e.g., targeting, diagnostics and therapy) to one carrier. Nevertheless, such approaches have been challenging due to the necessity of the adaptation of at least partially counteracting parameters between the different modalities, which will be analyzed in this review.

Rationale and Objectives: Differential diagnosis of lesions in MR-Mammography (MRM) remains a complex task. The aim of this MRM study was to design and to test robustness of Artificial Neural Network architectures to predict malignancy using a large clinical database., Materials and Methods: For this IRB-approved investigation standardized protocols and study design were applied (T1w-FLASH; 0.1 mmol/kgBW Gd-DTPA; T2w-TSE; histological verification after MRM). All lesions were evaluated by two experienced (>500 MRM) radiologists in consensus. In every lesion, 18 previously published descriptors were assessed and documented in the database. An Artificial Neural Network (ANN) was developed to process this database (The-MathWorks/Inc., feed-forward-architecture/resilient back-propagation-algorithm). All 18 descriptors were set as input variables, whereas histological results (malignant vs. benign) was defined as classification variable. Initially, the ANN was optimized in terms of "Training Epochs" (TE), "Hidden Layers" (HL), "Learning Rate" (LR) and "Neurons" (N). Robustness of the ANN was addressed by repeated evaluation cycles (n: 9) with receiver operating characteristics (ROC) analysis of the results applying 4-fold Cross Validation. The best network architecture was identified comparing the corresponding Area under the ROC curve (AUC)., Results: Histopathology revealed 436 benign and 648 malignant lesions. Enhancing the level of complexity could not increase diagnostic accuracy of the network (P: n.s.). The optimized ANN architecture (TE: 20, HL: 1, N: 5, LR: 1.2) was accurate (mean-AUC 0.888; P: <0.001) and robust (CI: 0.885-0.892; range: 0.880-0.898)., Conclusion: The optimized neural network showed robust performance and high diagnostic accuracy for prediction of malignancy on unknown data., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Purpose: Accurate staging of primary breast cancer is essential for the therapeutic approach. Modern whole-body MR scanners would allow local and distant staging during a single examination. Accordingly, we designed a dedicated protocol for this purpose and prospectively evaluated the diagnostic accuracy., Materials and Methods: 65 consecutive breast cancer patients underwent pre-therapeutic MRI (1.5 T). A bilateral breast protocol (axial: T1w/GRE dynamic contrast-enhanced, T2w/TSE; TA: 10 min) was extended to screen for distant metastasis at one stop without repositioning (coronal: T2w/HASTE, T1w/VIBE; FOV: thorax, abdomen and spine; TA: 90 sec; multichannel surface coils). The standard of reference was S3 guideline-compliant staging examinations. Global assessment regarding the presence of distant metastasis was performed independently by two experienced and blinded radiologists (five-level confidence score). Inter-rater agreement (weighted kappa) and observer scoring were analyzed (contingency tables)., Results: The prevalence of synchronous metastases was 7.7 % (n = 5). The protocol enabled global assessment regarding the presence of distant metastasis with high accuracy (sensitivity: 100 %; specificity: 98.3 %) and inter-rater agreement (kappa: 0.92)., Conclusion: Applying the extended MRI protocol, accurate screening for distant metastasis was possible in combination with a dedicated breast examination., (© Georg Thieme Verlag KG Stuttgart · New York.)

Objective: Perifocal edema, defined as high T2w signal intensity around an enhancing lesion has been described as a specific feature of malignancy. In clinical MR-mammography (MRM), both fatsat and non-fatsat T2w sequences are available. However, there is no consensus on which technique should be used for edema assessment. Consequently, this investigation was performed to compare two commonly used pulse sequences for edema assessment in MRM., Materials and Methods: 321 consecutive patients from a 22 month period were included in this investigation. Further selection criteria were histopathological verification of enhancing lesions and absence of presurgical chemotherapy or biopsy, resulting in 108 malignant and 107 benign lesions. All underwent MRM according to international guidelines including a non-fatsat T2w-TSE sequence (TR/TE: 8900/207 ms) and a short tau inversion recovery fatsat sequence (STIR, TR/TE: 8420/70 ms). All images were acquired in the same orientation (axial) and slice thickness. Two experienced radiologists in consensus rated presence of perifocal edema according to an ordinal scale: 0 = not present, 1 = little, 2 = intermediate, and 3 = distinct. Data analysis was performed using crosstabs and Visual Grading Characteristics (VGC) analysis., Results: Overall sensitivity/specificity was calculated with 53.7%/94.4% (T2w-TSE) and 52.8%/95.3% (STIR). VGC revealed an area under the VGC curve of 0.502 (standard error 0.026), P = 0.814., Conclusion: Perifocal edema is a specific feature of malignancy with moderate sensitivity. VGC analysis did not reveal significant differences between both pulse sequences analysed. Consequently, both T2w-TSE and STIR images are suitable for assessment of perifocal edema., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Purpose: Breast cancer is the most common cancer among women. The established screening method to detect breast cancer is X-ray mammography. Additionally, MRI is used for diagnosis in clinical routine. Due to complementary diagnostic information, both modalities are often read in combination. Yet, the correlation is challenging due to different dimensionality of images and different patient positioning. In this paper, we describe a method to fuse X-ray mammograms with DCE-MRI. The present study was conducted to evaluate the feasibility of the approach., Methods: For the combination of information from both modalities, the images have to be registered using a compression simulation based on a patient-specific biomechanical model. The registered images can be compared directly. The contrast enhancement in the DCE-MRI volume is evaluated using parametric enhancement maps. A projection image of the contrast enhancement is created. The image fusion combines it with X-ray mammograms for intuitive multimodal diagnosis., Results: The image fusion was evaluated using 11 clinical datasets. For 10 of 11 datasets, a good accuracy of the image registration was achieved. The overlap of contrast-enhanced regions with marked lesions in the mammogram is 61%. Lesions are clearly differentiable from surrounding tissue by the DCE-MRI projection in 10 of 11 cases., Conclusion: The described preliminary results are promising, thus we expect the visualization of quantitative information from dynamic MRI together with mammograms to be beneficial for multimodal diagnosis. Because of the use of clinical standard modalities, no additional image acquisition is needed.

Purpose: To retrospectively assess collinearity among lesion feature of the MRI BI-RADS lexicon. Collinearity denotes a situation in which two or more (independent) variables are correlated to some degree, thus partly conveying the same information. Collinearity may cause problems in the interpretation of logistic regression models., Materials and Methods: We analysed the BI-RADS features of 351 lesions in 325 consecutive patients. Patients with biopsy proven breast disease or treated with chemotherapy were excluded. All lesion features were dichotomised into "present" or "not present". Correlation matrices were generated for mass and non-mass lesions separately, focus lesions were omitted. The phi coefficient was used as measure for correlation., Results: There were 253 mass (175 malignant, 78 benign), 66 non-mass (21 malignant, 45 benign) and 32 focus (5 malignant, 27 benign) lesions among the study population. The strongest inter-subgroup correlations among mass lesion features were: slow initial enhancement with persistent kinetics, phi=0.64 (0.56-0.71), rapid initial enhancement with washout kinetics, phi=0.52 (0.43-0.61) and rapid initial enhancement with persistent kinetics, phi=-0.43 (-0.53 to -0.32). The strongest inter-subgroup correlation among non-mass lesion features were: rapid initial enhancement with washout kinetics, phi=0.51 (0.30-0.67), slow initial enhancement with persistent kinetics, phi=0.43 (0.21-0.61) and rapid initial enhancement with persistent kinetics, phi=-0.41 (-0.18 to -0.60)., Conclusion: There is a noticeable overlap of information, especially between kinetic features and initial enhancement types for both, mass and non-mass lesions. This should be considered when generating logistic regression models with the MRI BI-RADS lesion features., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Rationale and Objectives: Magnetic resonance imaging olfactory bulb (OB) volumetry (OBV) is already used as a complementary prognostic tool to assess olfactory disorders. However, a reference standard in imaging for OBV has not been established. The aim of this in vitro study was to compare volumetric results of different magnetic resonance sequences for OBV at 3 T to genuine OB volumes measured by water displacement., Materials and Methods: The volumes of 15 human cadaveric OBs were measured using the water displacement method in this institutional review board-approved prospective study. The magnetic resonance imaging protocol at 3 T included constructive interference in steady state (CISS), T2-weighted (T2w) three-dimensional (3D) sampling perfection with application-optimized contrasts using different flip-angle evolutions (SPACE), T2w two-dimensional (2D) turbo spin-echo (TSE), and T1-weighted (T1w) 3D fast low-angle shot (FLASH) sequences. Two blinded observers independently performed two OB volumetric assessments per bulbus and sequence. Intraobserver and interobserver reliabilities were assessed by intraclass correlation coefficients. Bland-Altman plots were analyzed to evaluate systematic biases and concordance correlation coefficients to assess reproducibility., Results: For both observers, intraclass correlation coefficient analysis yielded almost perfect results for intraobserver reliability (CISS, 0.94-0.98; T2w 3D SPACE, 0.93-0.98; T2w 2D TSE, 0.98-0.98; T1w 3D FLASH, 0.95-0.99). Interobserver reliability showed almost perfect agreement for all sequences (CISS, 0.98; T2w 3D SPACE, 0.89; T2w 2D TSE, 0.93; T1w 3D FLASH, 0.97). The CISS sequence yielded the highest mean concordance correlation coefficient (0.95) and the highest combination of precision (0.97) and accuracy (0.98) values. In comparison with the water displacement method, Bland-Altman analyses revealed the lowest systematic bias (-0.5%) for the CISS sequence, followed by T1w 3D FLASH (-1.3%), T2w 3D SPACE (-7.5%), and T2w 2D TSE (-10.9%) sequences., Conclusions: Compared to the water displacement method, the CISS sequence is suited best to validly and reliably measure OB volumes because of its highest values for accuracy and precision and lowest systematic bias., (Copyright © 2011 AUR. Published by Elsevier Inc. All rights reserved.)

This prospective study on Bell's palsy investigated the value of 3 T MRI as a diagnostic tool to evaluate pathophysiological changes (i.e. edema) of facial nerve segments and the possibility to differentiate patients with high risk for incomplete recovery from patients who recover completely within 3 days after symptoms onset. For this institutional review board approved investigation, thirty patients (14 male, 16 female, mean age 44 years) with Bell's palsy underwent pre and postcontrast 3 T MRI of the cerebellopontine angle. T1-weighted imaging was performed (TR 20.0 ms, TE 2.46 ms, isotropic voxel size: 0.6 mm). Region-of-interest measurements were performed on the healthy and paralyzed side. To obtain normalized values, signal intensity increase percentage (SIIP) values were divided by contralateral results of the healthy side. Signal intensity measurements of examined nerve segments were compared using Wilcoxon and Mann-Whitney U tests and correlated to clinical findings categorized by the House-Brackmann score. The lesion side showed significantly higher signal intensities in the premeatal segment before and after contrast agent administration (P < 0.001). SIIP was highest in the premeatal segment compared to the geniculate ganglion (P < 0.001). Correlation analyses revealed no association between signal intensity measurements, clinical findings or early recovery rates after 3 months (P > 0.05). According to our results, early palsy-associated pathophysiological changes in the facial nerve premeatal segment might also be related to accumulation of proteins and not exclusively to edema. However, contrast agent enhancement quantification was not suitable as a diagnostic tool to distinguish different prognostic groups.

Purpose: Tumor grading (TG) is one of the most widely used prognostic factors in the case of breast cancer. This study aims to identify the potential of magnetic resonance mammography (MRM) to non-invasively assess TG., Materials and Methods: 399 invasive breast cancers were included (IRB approval; standardized clinical MRM protocols). All breast cancers were prospectively evaluated by two experienced (> 500 MRM) and blinded radiologists in consensus. In every cancer a set of 18 previously published MRM descriptors was assessed. These were assessed by univariate and multivariate analysis to identify the potential of MRM to predict TG (X2 statistics; binary logistic regression; area under the ROC curve [AUC])., Results: 8 of 18 MRM descriptors were associated with TG, e. g. internal structure, edema (p < 0.001), as well as skin thickening and destruction of the nipple line (p < 0.05). MRM was feasible to predict TG by multivariate analysis (p < 0.001). The highest potential could be identified to predict well differentiated breast cancers with good prognosis (AUC = 0.930)., Conclusion: MR mammography was able to non-invasively assess tumor grading in a standard protocol. Since tumor grading is a surrogate for overall survival, these results provide further evidence to the clinical application of MR mammography as a noninvasive prognostic tool., (© Georg Thieme Verlag KG Stuttgart · New York.)

Rationale and Objectives: To evaluate the semi-automatic image registration accuracy of X-ray-mammography (XR-M) with high-resolution high-field (3.0T) MR-mammography (MR-M) in an initial pilot study., Material and Methods: MR-M was acquired on a high-field clinical scanner at 3.0T (T1-weighted 3D VIBE ± Gd). XR-M was obtained with state-of-the-art full-field digital systems. Seven patients with clearly delineable mass lesions >10mm both in XR-M and MR-M were enrolled (exclusion criteria: previous breast surgery; surgical intervention between XR-M and MR-M). XR-M and MR-M were matched using a dedicated image-registration algorithm allowing semi-automatic non-linear deformation of MR-M based on finite-element modeling. To identify registration errors (RE) a virtual craniocaudal 2D mammogram was calculated by the software from MR-M (with and w/o Gadodiamide/Gd) and matched with corresponding XR-M. To quantify REs the geometric center of the lesions in the virtual vs. conventional mammogram were subtracted. The robustness of registration was quantified by registration of X-MRs to both MR-Ms with and w/o Gadodiamide., Results: Image registration was performed successfully for all patients. Overall RE was 8.2mm (1 min after Gd; confidence interval/CI: 2.0-14.4mm, standard deviation/SD: 6.7 mm) vs. 8.9 mm (no Gd; CI: 4.0-13.9 mm, SD: 5.4mm). The mean difference between pre- vs. post-contrast was 0.7 mm (SD: 1.9 mm)., Conclusion: Image registration of high-field 3.0T MR-mammography with X-ray-mammography is feasible. For this study applying a high-resolution protocol at 3.0T, the registration was robust and the overall registration error was sufficient for clinical application., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Background: Routine assessment of body iron load in patients with acute leukemia is usually done by serum ferritin (SF) assay; however, its sensitivity is impaired by different conditions including inflammation and malignancy., Objective: To estimate, using MRI, the extent of liver iron overload in children with acute leukemia and receiving blood transfusions, and to examine the association between the degree of hepatic iron overload and clinical parameters including SF and the transfusion iron load (TIL)., Material and Methods: A total of 25 MRI measurements of the liver were performed in 15 children with acute leukemia (mean age 9.75 years) using gradient-echo sequences. Signal intensity ratios between the liver and the vertebral muscle (L/M ratio) were calculated and compared with SF-levels. TIL was estimated from the cumulative blood volume received, assuming an amount of 200 mg iron per transfused red blood cell unit., Results: Statistical analysis revealed good correlation between the L/M SI ratio and TIL (r = -0.67, P = 0.002, 95% confidence interval CI = -0.83 to -0.34) in patients with acute leukemia as well as between L/M SI ratio and SF (r = -0.76, P = 0.0003, 95% CI = -0.89 to -0.52)., Conclusion: SF may reliably reflect liver iron stores as a routine marker in patients suffering from acute leukemia.

Rationale and Objectives: The aim of this study was to compare different sequences for olfactory bulb volumetry using 3-T magnetic resonance imaging, evaluating reproducibility, repeatability, and systematic biases., Materials and Methods: Twenty-two volunteers underwent 3-T magnetic resonance imaging of the frontal skull base in this prospective study. Imaging included constructive interference in steady state (CISS), T2-weighted (T2w) three-dimensional (3D) sampling perfection with application-optimized contrasts using different flip-angle evolutions, and T2w two-dimensional (2D) turbo spin-echo sequences. Two observers independently performed two olfactory bulb volumetric studies per bulb and sequence. Intraobserver and interobserver reliability was assessed using intraclass correlation coefficients. For the evaluation of reproducibility, concordance correlation coefficients were determined, and for repeatability and systematic biases, Bland-Altman plots were analyzed., Results: Intraclass correlation coefficient analysis of the specialized observer yielded almost perfect results for intraobserver reliability (0.94, 0.85, and 0.93 for the CISS, T2w 3D, and T2w 2D sequences, respectively). For the less experienced observer, the results were 0.86 0.78, and 0.74 for the CISS, T2w 3D, and T2w 2D sequences, respectively. Interobserver reliability showed almost perfect agreement for all sequences (0.92, 0.86, and 0.86, respectively). The CISS sequence yielded the highest concordance correlation coefficient (0.84), precision (0.85), and accuracy (0.99). Bland-Altman plot analyses revealed the lowest repeatability coefficients for the T2w 2D sequence. Volumetric measurements of T2w 2D imaging showed systematically lower volumetric results compared to the CISS sequence (-22.7%) and the T2w 3D sequence (-8.3%)., Conclusions: Comparison of three imaging sequences for olfactory bulb volumetry yielded the best values for the CISS sequence in terms of intraobserver and interobserver reliability, reproducibility, accuracy, and precision. Given that even less experienced observers achieve almost perfect results, the CISS sequence is recommended for olfactory bulb volumetry., (Copyright © 2011 AUR. Published by Elsevier Inc. All rights reserved.)

Objective: In magnetic resonance imaging (MRI) of the breast, contrast enhancements present as mass or nonmass (NM) lesions. This study aimed to test the usefulness of currently accepted T1-weighted Breast Imaging Reporting and Data System predictors and to determine the incremental value of new T2-weighted predictors for differentiation of benign from malignant NM lesions., Methods: Consecutive patients undergoing surgery after MRI (1.5-T contrast-enhanced T1- and T2-weighted images) were investigated. Lesions were rated by 2 observers in consensus. Breast Imaging Reporting and Data System criteria for NM included spatial distribution, internal enhancement, and dynamic enhancement pattern. Additional criteria on T2-weighted images were signal intensity, presence of intraductal fluid, or cysts at the enhancements location. Independent differentiation criteria (benign vs malignant) were identified by logistic regression followed by receiver operating characteristics analysis., Results: Of 316 patients, 65 demonstrated NM. The NM lesions were split almost equally into malignant (34) and benign (31) histology. Breast Imaging Reporting and Data System predictors did not differentiate benign from malignant lesions, whereas signal intensity and the presence of cysts on contrast-enhanced T2-weighted images did, with a sensitivity of 91.2% and a specificity of 64.5%., Conclusions: Differentiation of NM can be improved using additional T2-weighted images.

Targeted magnetic resonance contrast agents (e.g. iron oxide nanoparticles) have the potential to become highly selective imaging tools. In this context, quantification of the coupled amount of protein is essential for the design of antibody- or antibody fragment-conjugated nanoparticles. Nevertheless, the presence of magnetic iron oxide nanoparticles is still an unsolved problem for this task. The aim of the present work was to clarify whether proteins can be reliably quantified directly in the presence of magnetic iron oxide nanoparticles without the use of fluorescence or radioactivity. Protein quantification via Bradford was not influenced by the presence of magnetic iron oxide nanoparticles (0-17.2 mmol Fe l(-1) ). Instead, bicinchoninic acid based assay was, indeed, distinctly affected by the presence of nanoparticle-iron in suspension (0.1-17.2 mmol Fe l(-1) ), although the influence was linear. This observation allowed for adequate mathematical corrections with known iron content of a given nanoparticle. The applicability of our approach was demonstrated by the determination of bovine serum albumin (BSA) content coupled to dextrane-coated magnetic nanoparticles, which was found with the QuantiPro Bicinchoninic acid assay to be of 1.5 ± 0.2 µg BSA per 1 mg nanoparticle. Both Bradford and bicinchoninic acid assay protein assays allow for direct quantification of proteins in the presence of iron oxide containing magnetic nanoparticles, without the need for the introduction of radioactivity or fluorescence modules. Thus in future it should be possible to make more precise estimations about the coupled protein amount in high-affinity targeted MRI probes for the identification of specific molecules in living organisms, an aspect which is lacking in corresponding works published so far. Additionally, the present protein coupling procedures can be drastically improved by our proposed protein quantification method., (Copyright © 2011 John Wiley & Sons, Ltd.)

Rationale and Objectives: The aim of this study was to evaluate the suitability of 3-T magnetic resonance imaging (MRI) for olfactory bulb volumetry, comparing image quality obtained using different sequences on the basis of physical characteristics in combination with observer performance., Materials and Methods: Twenty-two healthy volunteers (11 men, 11 women; mean age, 25 years) underwent 3-T MRI of the frontal skull base in this prospective study. Imaging was performed using a constructive interference in steady state (CISS) three-dimensional Fourier transformation sequence, a three-dimensional T2-weighted (3D-T2w) sequence, and a two-dimensional T2-weighted (2D-T2w) sequence. The relative performance of sequences was assessed using visual grading characteristic analysis. Interobserver agreement was assessed using κ statistics. For evaluation of physical image quality characteristics, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated and compared using Wilcoxon's test. SNR and CNR measurements were correlated with visual grading results., Results: Visual grading characteristic analysis showed significantly better image quality ratings for the CISS sequence compared to the 3D-T2w and 2D-T2w sequence, and the 2D-T2w sequence performed significantly better compared to the 3D-T2w sequence (P < .001). Interobserver agreement was substantial (κ = 0.66-0.73). Wilcoxon's test revealed significantly higher SNR and CNR values for the 2D-T2w sequence compared to the 3D-T2w and CISS sequences, and SNR and CNR values for the 3D-T2w sequence were significantly higher compared to those for the CISS sequence (P < .001 for each). Significant correlation between SNR and CNR and visual grading was found for the 3D-T2w sequence (SNR: ρ = 0.510, P = .015; CNR: ρ = 0.546, P = .009)., Conclusions: High-resolution 3-T MRI resulted in excellent values for SNR and CNR, suggesting the appropriateness of the sequences for olfactory bulb MRI volumetry. Visual grading characteristic analysis revealed the CISS sequence to be the most suitable for olfactory bulb volumetry., (Copyright © 2011 AUR. Published by Elsevier Inc. All rights reserved.)

Purpose: Hormonal stimulation can induce background enhancement (BE) in MR mammography (MRM). This fact has been assumed to decrease the accuracy of MRM. Consequently, this report investigates: 1. The prevalence of BE in postmenopausal vs. premenopausal women in correlation to hormonal cycle phase (CP). 2. The impact of hormonal status (HS) and BE on diagnostic accuracy., Materials and Methods: Consecutive patients over 22 months with complete HS information (week of CP or postmenopausal) were included in this prospective investigation. Exclusion criteria were any hormonal therapy, hysterectomy as well as cancer proven by biopsy. The standard of reference was histopathology. All MRM scans were acquired using the same protocol (1.5 T, dynamic T 1w GRE after 0.1 mmol/kg bw Gd-DTPA i. v.). Two radiologists rated all examinations in consensus according to BI-RADS. BE was defined as: 0 = missing, 1 = moderate, 2 = distinct., Results: 224 patients (150 postmenopausal, 74 premenopausal, 45 in the second week of CP) were included in this study (83 benign and 141 malignant findings). BE was more frequent in premenopausal women (p = 0.006), but did not differ between CP (p = 0.460). Neither HS nor BE had a significant impact on the diagnostic parameters of MRM (p ≥ 0.375). However, regarding BE, the relative number of false positive (FP) findings was highest (5 / 10; 50 %) in the distinct BE group. Regarding HS, 17 % more FP findings were observed in premenopausal women examined outside the second week of CP., Conclusion: In premenopausal women, HS leads to increased BE of breast tissue, independent of CP. Distinct BE and less pronounced, non-optimal CP may lead to an increased number of false positive findings., (© Georg Thieme Verlag KG Stuttgart · New York.)

Objective: To analyse the kinetic characteristics of lesions without mass effect in dynamic breast MRI using manual and computer assisted methods., Methods: The enhancement pattern of 82 histopathologically verified lesions without mass effect (36 malignant, 46 benign) was evaluated on breast MRI using manual placement of a region of interest. Commercially available computer analysis software automatically assessed volume enhancement characteristics of a lesion voxelwise. Kinetic features evaluated included classification of the signal-intensity time curve as washout, plateau or persistent enhancement., Results: Unlike manual ROI placement, computer-aided analysis demonstrated a significant difference in enhancement pattern between benign (washout: 32.6%, plateau: 32.6%, persistent: 34.8%) and malignant lesions without mass effect (77.1%, 8.6%, 14.3% respectively, P < 0.01, two-sided Chi-squared test) following initial rapid signal increase. Mean percentage of washout voxel volumes within a lesion was significantly higher in malignant lesions than in benign lesions (11.9% +/-12.7 (SD) vs. 6.9% +/-11.3 (SD), P < 0.01, Mann-Whitney U Test). Conversely, the mean percentage of persistent voxel volumes was significantly lower in malignant lesions than in benign lesions (60.1% +/-21.1 (SD) vs. 79% +/-23 (SD), P < 0.01, Mann-Whitney U Test)., Conclusion: Computer-assisted enhancement pattern analysis might have diagnostic benefit in the evaluation of lesions without mass effect.

Objective: The purpose of our study was to clinically test an extended MR mammography (MRM) protocol for combined local staging (T-staging) and locoregional staging (N-staging) of breast cancer within one single examination using a dedicated whole-body scanner., Subjects and Methods: Fifty-six consecutive primary breast cancer patients without prior treatment underwent MRM and surgicopathological N-staging. The MRM protocol (10 minutes; axial T1-weighted gradient-recalled echo; dynamic contrast-enhanced; T2-weighted; turbo spin-echo) was extended to evaluate axillary lymph nodes (90 seconds; coronal T2-weighted HASTE; T1-weighted volumetric breath-hold examination; field of view, both axillae, supraclavicular nodes, and cervical nodes). A dedicated whole-body scanner was used. First, two experienced radiologists independently rated the presence of lymph node metastasis (present or absent, weighted kappa). Second, predefined descriptors were applied by both readers to differentiate lymph node status. These were statistically analyzed using univariate chi-square statistics, sensitivity and specificity, positive likelihood ratio, diagnostic odds ratio (OR), and multivariate statistics (binary logistic-regression, receiver operating characteristics, and chi-squared automatic interaction detection [CHAID] tree)., Results: Most significant predictors (p < 0.001) of present metastasis were "irregular margin" (diagnostic OR, 14.0), "inhomogeneous cortex" (diagnostic OR, 8.4), "perifocal edema" (positive likelihood ratio, 100) and "asymmetry" (diagnostic OR, 19.5). CHAID tree identified "asymmetry" and "irregular margin" as significant predictors (adjusted-p < 0.05) for present metastasis (PPV: 100%), whereas absence of "asymmetry" and "homogeneous internal structure" were highly predictive of absent metastasis (negative predictive value, 94.3%). Combination of significant descriptors using binary logistic regression revealed an area under the receiver operating characteristic curve of 0.93 (p < 0.001). Interrater agreement was "almost-perfect" (κ = 0.95)., Conclusion: Combined T-staging and locoregional staging (N-staging) was possible within one imaging session using the proposed protocol. Despite a minimal increase in examination time, high diagnostic accuracy and excellent interrater reliability were achieved.

Introduction: Although several reports about volumetric determination of the pituitary gland exist, volumetries have been solely performed by indirect measurements or manual tracing on the gland's boundaries. The purpose of this study was to evaluate the accuracy and reproducibility of a novel semi-automatic MR-based segmentation technique., Methods: In an initial technical investigation, T1-weighted 3D native magnetised prepared rapid gradient echo sequences (1.5 T) with 1 mm isotropic voxel size achieved high reliability and were utilised in different in vitro and in vivo studies. The computer-assisted segmentation technique was based on an interactive watershed transform after resampling and gradient computation. Volumetry was performed by three observers with different software and neuroradiologic experiences, evaluating phantoms of known volume (0.3, 0.9 and 1.62 ml) and healthy subjects (26 to 38 years; overall 135 volumetries)., Results: High accuracy of the volumetry was shown by phantom analysis; measurement errors were <4% with a mean error of 2.2%. In vitro, reproducibility was also promising with intra-observer variability of 0.7% for observer 1 and 0.3% for observers 2 and 3; mean inter-observer variability was in vitro 1.2%. In vivo, scan-rescan, intra-observer and inter-observer variability showed mean values of 3.2%, 1.8% and 3.3%, respectively. Unifactorial analysis of variance demonstrated no significant differences between pituitary volumes for various MR scans or software calculations in the healthy study groups (p > 0.05)., Conclusion: The analysed semi-automatic MR volumetry of the pituitary gland is a valid, reliable and fast technique. Possible clinical applications are hyperplasia or atrophy of the gland in pathological circumstances either by a single assessment or by monitoring in follow-up studies.

Background and Purpose: Improved MR imaging at higher field strengths enables more detailed imaging of cranial nerves. The aim of this study was to assess the identifiability of the NI in the CPA and IAC by using high-resolution 3T MR imaging., Materials and Methods: Twenty-seven healthy volunteers (13 men and 14 women; mean age, 33 years) underwent 3T MR imaging of the CPA. The section thicknesses of the CISS sequence was 0.4 mm (TR, 12.18 ms; TE, 6.09 ms) using a 12-channel head coil. Evaluation was performed by using MPR mode. Image quality and identifiability of the NI were rated independently by 2 observers according to predefined criteria on an ordinal scale. Interobserver agreement was assessed by κ statistics., Results: Fifty-four NIs were evaluated. Both observers were able to identify the NI in nearly 60% of cases. It was possible to indentify at least 1 NI in 70% of all volunteers in the CPA and/or IAC. Image quality ratings showed a substantial agreement (κ = 0.65) and identifiability ratings an almost perfect (κ = 0.83) agreement., Conclusions: Careful evaluation of all nervous and vascular structures in the CPA and IAC at high-resolution 3T MR imaging allows reliable depiction of the NI.

Purpose: This study was conducted to investigate the appearance of breast lesions in MR mammography (MRM) as a function of size and to identify the potential impact on diagnostic accuracy., Materials and Methods: 936 histologically verified breast lesions (standardized MRM protocol; consecutive 12-year period at our institution, diameter 5 - 50 mm) were prospectively evaluated in consensus by two radiologists with significant MRM experience. For this purpose previously published descriptors (n = 17) were used. These were summarized as the "basic catalog and extended catalog" of descriptors (BC vs. EC). According to a cut-off of 20 mm, the database was divided into the subgroups "small" (n = 669) and "advanced" (n = 267). The diagnostic accuracy of MRM in these two subgroups was then determined using BC and EC, separately (binary logistic regression analysis; AUC analysis)., Results: The majority of descriptors (n = 11) showed a significantly different prevalence in correlation with size (p < 0.05). The diagnostic accuracy of MRM for "advanced" lesions (AUC = 0.969) was significantly higher (p < 0.001). This difference was significantly decreased (p < 0.001), if instead of BC (AUC = 0.865) EC was applied for the assessment of "small" lesions (AUC: 0.908 vs. 0.865)., Conclusion: The typical appearance of breast lesions in MRM depends on lesion size. This resulted in lower diagnostic accuracy in small lesions compared to advanced findings. This difference was able to be significantly decreased by applying the catalog of extended descriptors., (© Georg Thieme Verlag KG Stuttgart · New York.)

Data on the prevalence of persistent olfactory bulb ventricles (OBV) in humans remain contradictory. The aim of this study was to investigate the hypothesis of large cystic-like OBVs filled with cerebrospinal fluid (CSF) as a frequent finding in magnetic resonance imaging (MRI). Fifty normosmic volunteers (25 men and 25 women, mean 40 years) underwent 3 Tesla MRI of the anterior skull base. Normal smell function was determined by testing of the odor threshold discrimination identification score using the Sniffin' Sticks test kit. The voxel size of the constructive interference in steady state (CISS) sequence was 0.4×0.4×0.4 mm (TR 12.18 ms, TE 6.09 ms) using a 12-channel head coil. Image quality was rated by three observers according to predefined criteria on an ordinal scale. Additionally, contrast-to-noise (CNR) and signal-to-noise (SNR) ratios were calculated. Quantitative signal intensity (SI) measurement of olfactory bulb (OB) structures and small Virchow-Robin spaces (VRS) was performed using multi planar reconstruction mode. Ninety-one OBs were eligible for evaluation. Image quality was rated as adequate in 55% and as excellent in 36% of cases. CNR and SNR calculations resulted in values of 21.59 and 19.06, respectively. Wilcoxon signed rank test revealed significant higher SI values for OB center compared to OB surface (P<0.001) and to OB base (P<0.001) but also significant lower SI values compared to small VRS (P<0.001) in 94.5%. In 5.5%, SI measurement revealed signs for CSF-filled structures in the OB. High-resolution 3 Tesla MRI did not verify the hypothesis of large cystic CSF-filled OBVs as a frequent finding although evidence is growing that the hyperintense signal in the center of OBs might be associated with interstitial or finely dispersed CSF/fluid or with tiny, histologically detectable remnants of OBVs., (Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.)

Necrosis sign (NS) is a new descriptor for differential diagnosis of breast lesions in magnetic resonance (MR)-mammography (MRM). This study was designed: (a) to analyze diagnostic accuracy of NS in 1,084 histologically verified breast lesions, (b) to assess performance of NS in subgroups. This study was approved by the local ethical committee. All histologically verified lesions having undergone MR-mammography at our institution over 12 years were evaluated by experienced radiologists (> 500 MRM) according to standard protocols and study design (T1w; 0.1 mmol/kg bw gadolinium diethylenetriamine penta-acetic acid; T2-turbo spin echo (TSE)). Patients with history of breast biopsy (surgically, minimal-invasive), radiation- or chemotherapy ≤ 1 year before MRM were excluded. NS was assessed on T2w-TSE sequences and was rated positive if a hyperintense center in a hypointense lesion could be visualized (chi-squared test). One thousand and eighty-four lesions were available for statistical analysis (648: malignant, 436: benign). NS was significantly associated with malignancy (p < 0.001), providing specificity and positive predictive value (PPV) of 96.1% and 78.8%. Malignant lesions > 20 mm presented significantly more often NS (p < 0.001) than neoplasias ≤ 20 mm. There was no difference regarding prevalence of NS in small versus advanced benign lesions (n.s.), leading to better performance of NS in lesions > 20 mm (PPV: 87.8%). Correlation between NS and Grading of invasive carcinomas was significant. In this study of 1,084 lesions necrosis sign was a specific and highly predictive feature for differential diagnosis in MRM (Specificity: 96.1%; PPV: 78.8%). This particularly counts for advanced lesions (PPV 87.8%). As this new descriptor correlates with Grading, it could be used as an initial estimate of patient's prognosis., (© 2010 Wiley Periodicals, Inc.)

Background: Enhancement characteristics of breast lesions are regarded as a major criterion for their differential diagnosis in dynamic breast MRI (bMRI). However, ductal carcinoma in situ (DCIS) exhibits a highly heterogeneous enhancement pattern when kinetic analysis is performed conventionally by manual placement of region of interest (ROI) and therefore its diagnosis remains challenging., Purpose: To compare enhancement characteristics of DCIS lesions on dynamic bMRI using manual ROI placement with computer-aided analysis and to evaluate whether the latter might increase the detection rate of kinetic features suspicious for malignancy., Material and Methods: The enhancement patterns of 47 histopathologically verified pure DCIS lesions were evaluated on bMRI images using manual ROI placement as well as a commercially available computer analysis software. The latter is able to automatically assess enhancement characteristics of a whole lesion pixelwise. Kinetic features evaluated included classification of lesion enhancement pattern into washout, plateau or persistent curve type. A washout and plateau enhancement pattern are regarded as suggestive for malignancy., Results: Morphological classification revealed focus-like enhancement in 2 lesions, mass enhancement in 11, and non-mass enhancement in 34. Manual placement of ROI demonstrated a suspicious enhancement pattern in 51.1% of the DCIS lesions, which could not be significantly increased using computer-aided analysis. Of the mass and non-mass-enhancing DCIS lesions, 90.9% and 38.3%, respectively, demonstrated suspicious kinetic curves. After application of the automated analysis software, the detection rate of suspicious enhancement patterns was unchanged in mass DCIS lesions and increased to 52.9% in non-mass DCIS lesions (P=0.33). However, the increase in the detection of washout curves alone was significant (P=0.02). In all, 40% of G1, 41.1% of G2, and 60% of G3 lesions demonstrated a suspicious curve type with manual evaluation. Computer analysis increased the detection of suspicious enhancement patterns in a non-significant manner to 50%, 58.8%, and 70%, respectively., Conclusion: The detection of suspicious enhancement curves could not be significantly increased in DCIS lesions when using computer-aided analysis despite a significantly higher detection rate of washout curves alone.

Background: The presence of lymph node metastases (LNMs) is one of the most important prognostic factors in breast cancer., Purpose: To correlate a detailed catalog of 17 descriptors in breast MRI (bMRI) with the presence of LNMs and to identify useful combinations of such descriptors for the prediction of LNMs using a dedicated decision tree., Material and Methods: A standardized protocol and study design was applied in this IRB-approved study (T1-weighted FLASH; 0.1 mmol/kg body weight Gd-DTPA; T2-weighted TSE; histological verification after bMRI). Two experienced radiologists performed prospective evaluation of the previously acquired examination in consensus. In every lesion 17 previously published descriptors were assessed. Subgroups of primary breast cancers with (N+: 97) and without LNM were created (N-: 253). The prevalence and diagnostic accuracy of each descriptor were correlated with the presence of LNM (chi-square test; diagnostic odds ratio/DOR). To identify useful combinations of descriptors for the prediction of LNM a chi-squared automatic interaction detection (CHAID) decision tree was applied., Results: Seven of 17 descriptors were significantly associated with LNMs. The most accurate were "Skin thickening" (P < 0.001; DOR 5.9) and "Internal enhancement" (P < 0.001; DOR

Background: Reports on the specificity of breast MRI are heterogeneous, depending on the respective setting of the performed study., Purpose: To retrospectively estimate the sensitivity and especially the specificity of breast MRI in the non-screening setting as an adjunct to mammography sorted by breast density and to estimate the accuracy of breast MRI in cases rated BI-RADS 0 and 3 mammographically., Material and Methods: A total of 216 consecutive patients with referral to breast MRI and previously acquired mammography were enrolled in this analysis. Negative findings were followed up with a mean time of 26.7 months. The loss to follow-up was 10.8%. The single breast was regarded as the study subject (n=399, 364 cases were eligible for calculation of diagnostic accuracy). BI-RADS 1 and 2 were rated as benign, 4 and 5 as malignant. BI-RADS 0 and 3 were analyzed separately. The 95% confidence intervals (CIs) were calculated from the normally approximated binomial distribution and taken to represent significant differences for the two imaging modalities if they did not overlap., Results: Among the study population, 62 malignant neoplasms were detected. For cases rated BI-RADS 1, 2, 4, and 5 (n=251), the sensitivity of breast MRI was 95.7% (95% CI 89.9-100.0%) and 74.5% (95% CI 62.0-87.0%) for mammography, respectively. The specificity of breast MRI was 96.1% (95% CI 93.4-98.8%) and 92.2% (95% CI 88.5-95.9%) for mammography, respectively. The diagnostic accuracy of breast MRI did not depend on breast density. In cases rated BI-RADS 0, n=57 (3, n=56), breast MRI achieved a sensitivity of 100% (90.9%) and a specificity of 98.1% (88.9%). There was a significant (P< 0.01) accumulation of dense breast tissue (ACR IV) in breasts rated BI-RADS 0 in mammography. Breast MRI missed three malignant lesions, two of them being smaller than 3 mm., Conclusion: There is no rationale to criticize the low specificity of breast MRI when used as an adjunct to mammography. The independency of the diagnostic accuracy of breast MRI from breast density makes it a worthwhile choice in mammographic BI-RADS 0 cases.

Purpose: MR-Mammography (MRM) is regarded as the most sensitive method for detection of breast cancer without a broad consensus on specificity. There is room for improvement of the existing ACR BIRADS lexicon by adding new and specific descriptors. Dilated ducts have been described in association with papillomas. However, the differential diagnostic value of this finding has not been investigated yet., Materials and Methods: 316 consecutive patients, undergoing histopathologic workup after MR-Mammography were included in this prospective, ethical review board approved study. Two blinded radiologists rated the images in consensus. Ductal obstruction was defined as dilated liquid filled ducts proximal an enhancing lesion. Sensitivity, specificity as well as positive and negative likelihood ratio (LR+, LR-) were calculated., Results: Dilated ducts were found in 60 cases (19%), 20 of these showed an association with enhancing lesions and were categorized as ductal obstruction (6.3%). Malignancy was found in two cases (one invasive ductal carcinoma and one DCIS) and benign tissue in 18 cases (15 papillomas). The difference of ductal obstruction between these groups was found to be highly significant in two-sided Fisher's exact test (p<0.001). Because of the clear association with benign lesions, benign lesions showing ductal obstruction were characterized as true positive findings. Therefore, following diagnostic parameters were calculated: sensitivity 15.4%, specificity 99.0%, LR+ 15.3, LR- 0.9., Discussion: If ductal obstruction is found to be positive, the associated lesion is most likely benign. Therefore, though a rare finding, this descriptor should be taken into account for improved lesion differentiation., (Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.)

Objective: Invasive lobular (ILC) and ductal carcinomas (IDC) are the most frequent subtypes of breast cancer. Diagnosis of ILC is often challenging. This study was conducted to (1) evaluate dynamic and morphologic profiles and to (2) compare the diagnostic accuracy of IDC and ILC in magnetic resonance mammography (MRM)., Methods: Our database consisted of all consecutive MRMs over a 12-year period (standardized protocol: T1-weighted fast low-angle shot; 0.1-mmol gadolinium-diethylenetriaminepentaacetate per kilogram of body weight; T2-weighted turbo spin-echo, 1.5 T; histological verification after MRM), which were evaluated by experienced (>500 MRMs) radiologists in consensus, applying 17 predefined descriptors. All the patients gave written consent; this study was approved by the local institutional review board. Extracting all the ILCs (n = 108), IDCs (n = 347), and benign lesions (n = 436) from the database, the data set of the study was created.In ILC and IDC diagnostic accuracy of single descriptors was calculated and compared separately (chi test). Using all the descriptors, a combined binary logistic regression analysis was applied to calculate the overall diagnostic accuracy for ILC and IDC. The corresponding areas under the curve were compared., Results: ILC and IDC, showed wash-in and an irregular shape without difference (P = 1.0 and P = 0.4). Wash-out was more typical of IDC (72.6%; ILC, 57.4%; P = 0.007). Perifocal edema was diagnosed more frequently in IDC (45.5%; P = 0.05). For overall accuracy, the areas under the curve were 0.929 for ILC and 0.939 for IDC (P = 0.5)., Conclusions: The dynamic and morphologic profiles of ILC and IDC were overlapping, and minor differences between both subgroups could be identified. Accordingly, the overall diagnostic accuracy of MRM was high and without difference between both subtypes of breast cancer.

Objective: Breast MRI has high sensitivity in breast cancer detection, and the BI-RADS MRI lexicon was a step toward standardized description of lesions. However, false-positive findings occur and lead to unnecessary biopsy. The purpose of this investigation was to identify criteria for false-positive findings in clinical practice., Materials and Methods: Eligible for investigation were all breast MRI examinations from a consecutive 16-month time period that had histopathologic verification and findings classified as BI-RADS category 4-6 in the initial MRI report. Accordingly, 132 patients with 120 malignant and 31 benign lesions were enrolled. Two blinded observers categorized lesions into mass or nonmass and used BI-RADS to identify descriptor distribution differences between the benign and malignant subgroups., Results: The ratio of mass to nonmass lesions differed significantly (p < 0.001) between benign (1.2:1) and malignant (7:1) findings. Seventeen mass and 14 nonmass lesions were false-positive, and 105 mass and 15 nonmass lesions were true-positive. Among mass lesions, it was possible to differentiate malignant and benign lesions on the basis of margin (smooth, irregular, or spiculated) and dynamic enhancement features (p < 0.05). Among nonmass lesions, only stippled enhancement had a significant difference between the subgroups (p < 0.05). Tumor diameter had no influence on the correct diagnosis of nonmass lesions (p = 0.301). Conversely, among mass lesions, false-positive lesions were smaller than true-positive lesions (p = 0.01)., Conclusion: Nonmass lesions were the major cause of false-positive breast MRI findings. BI-RADS descriptors are not sufficient for differentiating benign and malignant nonmass lesions.

Modern imaging techniques used for depicting the facial nerve include multi-slice spiral computed tomography (CT) and high-field magnetic resonance imaging (MRI). CT is the gold standard for imaging the osseous structures of the temporal bone. As a result of its excellent soft tissue contrast, MRI enables identification of the facial nerve itself. Due to high spatial resolution and the possibility to generate multiplanar reconstructions, both CT and MRI facilitate an exact evaluation of anatomical structures in all three spatial planes. The present article provides an overview of relevant anatomical structures, a thorough knowledge of which is the basic prerequisite to understanding pathologies and interpreting radiological findings correctly. Furthermore, basic techniques and strategies for imaging the facial nerve using CT and MRI are explained in general. The articles concludes with specific requirements for the radiological diagnosis of dysplasia, neoplasms and trauma, as well as vascular and inflammatory diseases.

The objective of this investigation was to determine the diagnostic value of unilateral edema in differentiating benign from malignant breast disease on T2w-TSE images in MR-Mammography (MRM). All patients from a 10-year period undergoing surgery in the same institution after having received MRM in our department were included in this prospective analysis of previous acquired examinations. To eliminate bias caused by prior procedures, all patients having had biopsy, operation, radiation therapy, or chemotherapy before MRM were excluded. T2w-TSE images were acquired after a dynamic contrast-enhanced series of T1-weighted images in a standardized examination protocol (1.5 T). Edema was defined as a high-signal intensity on T2w-TSE images and it was categorized as absent, perifocal, or diffuse. Examinations were rated by two experienced observers blinded to all procedures and results following MRM. In cases of disconcordance, the opinion of a third radiologist decided. Statistical testing included Pearson's Chi-squared test and Fisher's exact testing. A total of 1,010 patients with a mean age of 55 years (SD: 11.6 years, range: 16-87 years) with 1,129 histologically verified lesions were included in this investigation. After removing all patients with prior procedures from the patient collective, 974 lesions were left for statistical analysis. Perifocal edema was highly significantly (p < 0.001) associated with malignant disease, leading to a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 33.5%, 93.9%, 89.6, and 57.1%, respectively. Unilateral edema in general showed the following diagnostic parameters: sensitivity 53.0%, specificity 80.5%, PPV 80.9%, and NPV 52.3%. Edema seems to be associated with malignancy in the majority of cases. Especially, specificity and PPV were found to be high. These findings may be helpful in diagnostic decisions on otherwise equivocal cases.

Objective: This study was performed to assess the sensitivity and specificity for malignant and benign mass lesions of a diagnostic approach combining DWI with T2-weighted images (unenhanced MR mammography, ueMRM) and compare the results with contrast-enhanced MR mammography (ceMRM)., Materials and Methods: Consecutive patients undergoing histopathological verification of mass lesions after MR mammography without prior breast interventions (contrast-enhanced T1-weighted, T2-weighted and DWI sequences) were eligible for this retrospective investigation. Two blinded observers first rated ueMRM and then ceMRM according to the BIRADS scale. Lesion size, ADC values and T2-weighted TSE descriptors were assessed., Results: This study examined 81 lesions (27 benign, 54 malignant). Sensitivity of ueMRM was 93% (observer 1) and 86% (observer 2), respectively. Sensitivity of ceMRM was 96.5% (observer 1) and 98.3% (observer 2). Specificity was 85.2% (ueMRM) and 92.6% (ceMRM) for both observers. The differences between both methods and observers were not significant (P > or = 0.09). Lesion size measurements did not differ significantly among all sequences analyzed. Tumor visibility was worse using ueMRM for both benign (P < 0.001) and malignant lesions (P = 0.004)., Conclusion: Sensitivity and specificity of ueMRM in mass lesions equal that of ceMRM. However, a reduced lesion visibility in ueMRM may lead to more false-negative findings.

The use of breast magnetic resonance imaging (MRI) is rapidly increasing. EUSOMA organised a workshop in Milan on 20-21st October 2008 to evaluate the evidence currently available on clinical value and indications for breast MRI. Twenty-three experts from the disciplines involved in breast disease management - including epidemiologists, geneticists, oncologists, radiologists, radiation oncologists, and surgeons - discussed the evidence for the use of this technology in plenary and focused sessions. This paper presents the consensus reached by this working group. General recommendations, technical requirements, methodology, and interpretation were firstly considered. For the following ten indications, an overview of the evidence, a list of recommendations, and a number of research issues were defined: staging before treatment planning; screening of high-risk women; evaluation of response to neoadjuvant chemotherapy; patients with breast augmentation or reconstruction; occult primary breast cancer; breast cancer recurrence; nipple discharge; characterisation of equivocal findings at conventional imaging; inflammatory breast cancer; and male breast. The working group strongly suggests that all breast cancer specialists cooperate for an optimal clinical use of this emerging technology and for future research, focusing on patient outcome as primary end-point., (Copyright (c) 2010 Elsevier Ltd. All rights reserved.)

Objectives: According to magnetic resonance (MR) imaging Breast Imaging Reporting and Data System, foci are small enhanced lesions 5 mm or less in diameter. This study was conducted to (a) assess morphological and dynamic profiles in malignant versus benign foci in breast MR imaging (MRM) and to (b) identify overall diagnostic accuracy of MRM for differential diagnosis of foci., Methods: This study was approved by the local institutional review board; all patients gave written consent. All MRM (T1w-FLASH; 0.1 mmol/kg body weight gadolinium-diethylenetriamine penta-acetic acid; T2w-TSE; consecutive 12-year period; with histological verification after MRM were evaluated by 2 experienced (>500 MRM) radiologists in consensus using 16 predefined descriptors and were included into a database. A data set was created by extracting all lesions 5 mm or less (benign, 27; malignant, 61). Accuracy of individual descriptors was assessed (Crosstabs, chi2-test; positive/negative likelihood ratios (LR+/-); diagnostic odds ratio [DOR]). Binary logistic regression analysis was applied to identify overall diagnostic accuracy using all descriptors combined (area under the receiver operating characteristic curve,)., Results: Washout was typically associated with malignancy (P < 0.05; DOR, 3.5). Irregular shape was feasible for differential diagnosis of foci (DOR, 7.3), yet majority of malignancies demonstrated a round shape (55.6%). Additional descriptors such as blooming (DOR, 4.0, LR+, 2.8), adjacent vessel (DOR, 4.8; LR+, 4.5), and root sign (DOR, 5.6; LR+, 4.1) showed a high accuracy. Overall accuracy for differentiation of benign versus malignant foci showed an area under the curve of 0.887 (P = 0.0001)., Conclusions: Assessment of dynamic and morphological profiles in foci 5 mm or less was feasible. Using all descriptors combined, a high potential for differential diagnosis of foci in magnetic resonance-mammography could be identified.

Purpose: Post-contrast enhancement characteristics (PEC) are a major criterion for differential diagnosis in MR mammography (MRM). Manual placement of regions of interest (ROIs) to obtain time/signal intensity curves (TSIC) is the standard approach to assess dynamic enhancement data. Computers can automatically calculate the TSIC in every lesion voxel and combine this data to form one color-coded parametric map (CCPM). Thus, the TSIC of the whole lesion can be assessed. This investigation was conducted to compare the diagnostic accuracy (DA) of CCPM with TSIC for the assessment of PEC., Materials and Methods: 329 consecutive patients with 469 histologically verified lesions were examined. MRM was performed according to a standard protocol (1.5 T, 0.1 mmol/kgbw Gd-DTPA). ROIs were drawn manually within any lesion to calculate the TSIC. CCPMs were created in all patients using dedicated software (CAD Sciences). Both methods were rated by 2 observers in consensus on an ordinal scale. Receiver operating characteristics (ROC) analysis was used to compare both methods., Results: The area under the curve (AUC) was significantly (p=0.026) higher for CCPM (0.829) than TSIC (0.749). The sensitivity was 88.5% (CCPM) vs. 82.8% (TSIC), whereas equal specificity levels were found (CCPM: 63.7%, TSIC: 63.0%)., Conclusion: The color-coded parametric maps (CCPMs) showed a significantly higher DA compared to TSIC, in particular the sensitivity could be increased. Therefore, the CCPM method is a feasible approach to assessing dynamic data in MRM and condenses several imaging series into one parametric map., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background: The hook sign (HS) has recently been introduced as a new descriptor for differential diagnosis in magnetic resonance mammography (MRM)., Purpose: To analyze the diagnostic value of HS in a large collection of 1084 cases., Material and Methods: This study was approved by the local ethics committee, and 1084 consecutive lesions (no manipulations of the breast up to 12 months before MRM) with histological verification after MRM were included. HS was analyzed according to standard study protocols and was rated positive if a hook-like spiculated dendrite connecting a lesion with the pectoral muscle could be visualized. Examinations were rated by experienced observers (>500 examinations). Prevalence of HS was correlated with histological diagnosis, grading, and size (chi-square test). Diagnostic accuracy was assessed using sensitivity, specificity, positive likelihood ratio (LR+), and diagnostic odds ratio (DOR)., Results: HS was significantly associated with malignancy (P < 0.001), providing high specificity, LR+, and DOR (96.8%, 9.1, and 12.5, respectively). Malignant lesions >20 mm presented with HS significantly more often than those <20 mm (P < 0.001). HS was characteristic of invasive cancers and rare in preinvasive malignomas (P < 0.001). Prevalence of HS did not differ between invasive lobular and ductal carcinomas (n.s.). There was no correlation between HS and the grading of invasive carcinomas., Conclusion: In 1084 lesions, the hook sign was a specific descriptor for differentiation of benign and malignant lesions in MRM, with high evidence for prediction of malignancy, particularly in the case of advanced lesions and invasive carcinomas.