[O-Twist Marker for marking breast cancer under neoadjuvant chemotherapy--first results]. / Einsatz des O-Twist-Markers zur Lokalisation von Mammakarzinomen unter neoadjuvanter Chemotherapie--erste Ergebnisse.

PURPOSE: Evaluation of ultrasound-guided percutaneous marking of breast cancer using an "O-Twist Marker" (BARD GmbH, Karlsruhe, Germany) in patients undergoing neoadjuvant chemotherapy. In the event of complete remission, the lesion of interest can be missed after completion of therapy. In these cases marking of the tumor site is essential. MATERIALS AND METHODS: We monitored patients with breast cancer proven by biopsy who were undergoing neoadjuvant chemotherapy with ultrasound. In cases in which the follow-up ultrasound examination after the second chemotherapy cycle showed a significant tumor mass reduction (> 30 %), we pinpointed the lesion with an ultrasound-guided "O-Twist Marker". The position of the marker was documented by ultrasound and mammography. Between January and November 2006, we marked 7 patients. RESULTS: The visibility of the marker was excellent on mammography, but only moderate on ultrasound. The marker did not cause any imaging interference. The instrument was easy to operate. We did not detect any migration of the marker. In 3/7 patients it would have been possible to locate the remaining tumor tissue after the completion of neoadjuvant chemotherapy without the marking. In 4/7 cases the clip was very useful or even essential for preoperative site determination. CONCLUSION: The use of "O-Twist Marker" is a reliable and effective technique for locating breast cancer sites in remission during neoadjuvant chemotherapy. The visibility of the marker on ultrasound should be improved. In 57 % of the cases tumor marking was advantageous for surgical procedures.

MR-guided intervention in women with a family history of breast cancer.

OBJECTIVE: A study was undertaken to assess the clinical value of magnetic resonance (MR) imaging-guided interventions in women with a family history, but no personal history of breast cancer. METHODS AND PATIENTS: Retrospective review was performed on 63 consecutive women who had a family history, but no personal history of breast cancer. A total of 97 lesions were referred for an MR-guided intervention. Standardized MR examinations (1.0 T, T1-weighted 3D FLASH, 0.15 mmolGd-DTPA/kg body weight, prone position) were performed using a dedicated system which allows vacuum assisted breast biopsy or wire localization. RESULTS: Histologic findings in 87 procedures revealed 9 (10%) invasive carcinomas, 12 (14%) ductal carcinomas in situ, 2 atypical ductal hyperplasias (2.5%) and 2 atypical lobular hyperplasias (2.5%). Sixty-two (71%) benign histologic results are verified by an MR-guided intervention, retrospective correlation of imaging and histology and by subsequent follow-up. In ten lesions the indication dropped since the enhancing lesion was no longer visible. Absent enhancement was confirmed by short-term re-imaging of the noncompressed breast and by follow-up. CONCLUSION: Malignancy was found in 24%, high-risk lesions in 5% of successfully performed MR-guided biopsy procedures. A 57% of MR-detected malignancies were ductal carcinoma in situ. In 10% of the lesions the intervention was not performed, since no enhancing lesion could be reproduced at the date of anticipated intervention. Such problems may be avoided if the initial MRI is performed in the appropriate phase of the menstrual cycle and without hormonal replacement therapy.

MR-guided interventional breast procedures considering vacuum biopsy in particular.

Histologic work-up of just MR-detected breast lesions has become essential with increasing use of contrast-enhanced MR imaging. In the present article an overview is given about the different MR-guided breast interventions, performed since 1990. Presently, for reasons of costs and image quality closed magnets are most widely used. The following approaches have been described: MR-guided freehand localization in supine position, stereotaxic localization in supine position and most frequently used localization in the prone position by means of a compression device that immobilises the breast to prevent tissue shift during intervention. Only limited experience exists with interventions on open magnets. MR-guided wire localization is a well-established procedure. Recently, percutaneous vacuum biopsy of enhancing breast lesions has become possible under MR guidance. The new system allows accurate and safe access to lesions in any location of the breast and direct check-up of representative excision by visualisation of the cavity. Thus reliable histologic evaluation of lesions smaller than 10 mm is possible with this approach.

Development, standardization, and testing of a lexicon for reporting contrast-enhanced breast magnetic resonance imaging studies.

The purpose of this study was to develop, standardize, and test reproducibility of a lexicon for reporting contrast-enhanced breast magnetic resonance imaging (MRI) examinations. To standardize breast MRI lesion description and reporting, seven radiologists with extensive breast MRI experience developed consensus on technical detail, clinical history, and terminology reporting to describe kinetic and architectural features of lesions detected on contrast-enhanced breast MR images. This lexicon adapted American College of Radiology Breast Imaging and Data Reporting System terminology for breast MRI reporting, including recommendations for reporting clinical history, technical parameters for breast MRI, descriptions for general breast composition, morphologic and kinetic characteristics of mass lesions or regions of abnormal enhancement, and overall impression and management recommendations. To test morphology reproducibility, seven radiologists assessed morphology characteristics of 85 contrast-enhanced breast MRI studies. Data from each independent reader were used to compute weighted and unweighted kappa (kappa) statistics for interobserver agreement among readers. The MR lexicon differentiates two lesion types, mass and non-mass-like enhancement based on morphology and geographical distribution, with descriptors of shape, margin, and internal enhancement. Lexicon testing showed substantial agreement for breast density (kappa = 0.63) and moderate agreement for lesion type (kappa = 0.57), mass margins (kappa = 0.55), and mass shape (kappa = 0.42). Agreement was fair for internal enhancement characteristics. Unweighted kappa statistics showed highest agreement for the terms dense in the breast composition category, mass in lesion type, spiculated and smooth in mass margins, irregular in mass shape, and both dark septations and rim enhancement for internal enhancement characteristics within a mass. The newly developed breast MR lexicon demonstrated moderate interobserver agreement. While breast density and lesion type appear reproducible, other terms require further refinement and testing to lead to a uniform standard language and reporting system for breast MRI. J. Magn. Reson. Imaging 2001;13:889-895.

In situ and minimally invasive breast cancer: morphologic and kinetic features on contrast-enhanced MR imaging.

PURPOSE: This retrospective study was undertaken to investigate the morphologic and dynamic features of in situ and minimally invasive breast cancer on contrast-enhanced (c.-e.) MR imaging and to examine possible associations to pathology features. MATERIAL AND METHODS: A total of 71 patients underwent MR imaging. T1-weighted FLASH-3D images were obtained before and after intravenous administration of Gd-DTPA. Histopathologic analysis of 78 lesions revealed ductal carcinoma in situ (DCIS) n = 50 and DCIS with microinvasion n = 28. MR features were correlated with histopathologic findings. RESULTS: Enhancement in DCIS was focal (73%), diffuse (10%) or ductal (17%). No enhancement occurred in two cases (4%). In 65% enhancement speed was classified as delayed. There was a tendency toward a more ill-defined (83 vs. 43%) enhancement pattern in high grade DCIS and a more ductal (29 vs. 12%) and faster (50 vs. 29%) enhancement in comedo type DCIS. However, significant differences in the enhancement behaviour could neither be demonstrated between high grade and non high grade DCIS nor between comedo and non comedo type DCIS. No significant differences were noted between pure and microinvasive DCIS. CONCLUSION: In this retrospective analysis the majority (96%) of DCIS lesions show contrast enhancement. However, in only about 50% of DCIS the criteria of a so-called 'typical' enhancement behaviour was fulfilled, that means strong, early, focal ill-circumscribed or ductal. Enhancement that follows a duct is often associated with malignancy, however this feature was only present in 17% of the cases. c.-e. MR imaging allowed the detection of 25 additional foci of DCIS. Therefore malignant in situ lesions can be present with atypical enhancement, and should be taken into consideration in high-risk patients in particular.

MR-guided percutaneous excisional and incisional biopsy of breast lesions.

The aim of this study was the realisation and clinical application of MR-guided vacuum biopsy for percutaneous excisional and incisional biopsy of enhancing breast lesions. A breast biopsy system and procedure have been developed which allow precise and safe access to breast lesions in any location and use of vacuum biopsy (VB) under MR guidance. Fifty-one patients with 55 MR-detected lesions were examined. Verification of these diagnoses included re-excision histology of all 14 malignancies and for benign lesions retrospective correlation of histology and imaging, assessment of complete or partial removal of the enhancing area directly after VB (40 of 40 lesions) and follow-up MRI (33 of 40 lesions), which in contrast to conventional needle biopsy can be used as proof of representative removal. Fifty-four of 55 procedures (including 15 lesions

Contrast-enhanced magnetic resonance imaging of the breast: interpretation guidelines.

In the past decade, most studies have shown that in selected indications of breast imaging, the overall accuracy can be improved by the additional use of contrast-enhanced magnetic resonance imaging (MRI). The sensitivity of contrast-enhanced MRI for invasive malignancy is >98%; reported specificity, however, ranges from 37% to 97%. This range of values is predominantly caused by different patient preselection and interpretation criteria. Other factors, such as technique (e.g., choice of pulse sequence and echo time, slice thickness, reduction in artifacts, dosage of contrast agent, and methods for elimination of fat signal), hormonal influences (menstrual cycle and hormonal replacement therapy), and levels of verification, influence the accuracy and reproducibility of contrast-enhanced MRI. An appropriate application of MRI is highly desirable because of the increased costs of imaging, increased rates of biopsy due to false-positive results, and possibility of false-negative results caused by technical failures and interpretation errors. We present an overview of the sensible application and interpretation of contrast-enhanced MRI of the breast based on our experience and on published data.

Minimally invasive stereotaxic vacuum core breast biopsy.

The purpose of our study was the assessment of the diagnostic value of vacuum core biopsy, which promises high accuracy by minimally invasive percutaneous excision of 1-2 cm3 of tissue. The materials used were a digital stereotaxic biopsy table (Fischer Imaging) and a Mammotome-gun (Biopsys). A total of 236 patients with 261 predominantly indeterminate lesions (indeterminate: 230; suspicious: 26; malignant: 5) underwent vacuum core biopsy (VCB). Verification was as follows: (a) demonstration of complete or partial removal of the lesion or replacement of the lesion by a small hematoma by comparison of the pre- and post-VCB mammogram; (b) reexcision of 45 malignant and 6 borderline lesions; (c) radiologic-histologic correlation; and (d) 6-month-follow-up mammograms in 129 cases. Two VCBs were not possible because very fine microcalcifications could not be visualized. Two puncture errors occurred which, however, were immediately recognized and VCB was repeated. Based on the above verification a 100 % accuracy was achieved. No relevant side effects occurred. Except for 2 cases mammographically hardly any scarring was visible. Based on the excellent accuracy and excellent tolerance of the procedure VCB appears to be the future method of choice for the workup of those indeterminate mammographically detected lesions that up to now have still required surgical biopsy.

Retrospective analysis for evaluation of the value of contrast-enhanced MRI in patients treated with breast conservative therapy.

PURPOSE: The aim of this study was to assess the value of contrast-enhanced (c.-e.) MRI in the follow-up of patients with conservatively treated breast cancer since detection and exclusion of malignancy may interfere significantly with posttherapeutic changes within the treated breast. MATERIAL AND METHODS: A total of 207 patients with a history of limited surgery and radiation therapy underwent MR imaging, 40 patients were examined 0-12 months and 167 patients were examined later than 12 months after radiotherapy. Suspicious or indeterminate findings were suggested by clinical examination or conventional imaging in 80 studies. In 127 women, MRI was performed within breast tissue that was difficult to assess due to scarring or dense breast tissue. RESULTS: Recurrent carcinoma was confirmed in 27 patients by surgical biopsy. All 27 carcinomas, except for one with a slow signal increase, demonstrated early rise of signal intensity on dynamic T1-weighted contrast enhanced images. During the first year after therapy, the diagnostic accuracy could not be improved by additional use of c.-e. MRI. Differentiation between posttherapeutic changes and recurrent carcinoma was frequently not possible because of strong and sometimes early and ill-circumscribed enhancement. Later than 12 months after therapy enhancement decreased significantly, thus the false positive calls could be reduced from 49 (conventional imaging) to 12 (conventional imaging plus MRI). A total of 12 of 26 recurrences and multifocality in 4/5 cases were diagnosed by MR imaging alone at this time interval. CONCLUSION: In the first year after therapy, c.-e. MRI is only indicated in selected cases. The results later than 12 months emphasize that c.-e. MRI may contribute significant additional information. It allows better distinction of posttherapeutic fibrosis from recurrent carcinoma and proved to be able to detect recurrent disease more sensitive and at an earlier stage.

[Vacuum punch biopsy of the breast with a stereotaxic guide. A new procedure for percutaneous diagnostic biopsy based on 120 cases]. / Vakuumstanzbiopsie der Mamma mittels stereotaktischem Zielgerät. Ein neues Verfahren zur perkutanen diagnostischen Biopsie anhand von 120 Fällen.

PURPOSE: To test the capabilities of vacuum core biopsy (VCB) in the diagnosis of mammographically indeterminate lesions. MATERIALS AND METHODS: 120 patients (131 lesions) were examined using VCB with 14G or 11G vacuum core. RESULTS: VCB was mostly performed because of indeterminate microcalcifications (67 cases) or soft tissue densities/architectural distortion (64 cases). 112 benign changes, 14 DCIS and 5 invasive carcinomas were found. Excellent accuracy was achieved (presently 100%), since complete excision of small lesions/areas (< or = 1 cm) or partial excision of larger lesions was possible. No relevant hematomas or infections occurred. Patients tolerated the painless procedure very well. DISCUSSION: This report confirms our previous experiences. This method promises to replace diagnostic open biopsy of indeterminate or suspicious nonpalpable lesions.

[A new needle system for the MR-guided localization and transcutaneous biopsy of suspicious breast lesions. In vitro studies with 1.0 tesla]. / Ein neues Nadelsystem zur MR-gestützten Lokalisation und transkutanen Biopsie von suspekten Befunden in der Brust. In-vitro-Untersuchungen bei 1,0 Tesla.

PURPOSE: Examinations of a new needle system for localisation and core biopsies of suspicious breast lesions, detected by MRI alone, were performed. It was investigated whether this new needle system could reduce and avoid artifacts. MATERIAL AND METHODS: The new needle system was examined by Spin Echo Sequence and a Fast Gradient Echo Sequence on Magnetom Impact, 1.0 Tesla (in vitro-examinations). The sizes of the coaxial needle system on the MR images were examined on various slice thicknesses and with several wires in this needle system. RESULTS: In the Spin Echo Sequence the measured size of the coaxial needle is the same as its real size. In the Fast Gradient Echo Sequence the measured size is about double that of the real size. CONCLUSION: The presented coaxial system will allow improved visualisation for both preoperative localisation and core biopsy.

Contrast-enhanced MRI of the breast: accuracy, value, controversies, solutions.

OBJECTIVE: Contrast-enhanced MRI of the breast has been one of the most controversial areas of MRI. Even though most investigators have, in selected indications, been able to improve accuracy by the additional use of contrast-enhanced MRI, its abuse has been feared not only because of increased costs for imaging, but also because of increased biopsy rates caused by false positive calls and because of errors caused by insufficient standardisation. In this article an overview is given of the present knowledge about contrast-enhanced MRI of the breast. Factors that influence the accuracy and reproducibility of contrast-enhanced MRI are analysed. METHOD: Factors that influence accuracy include: (1) technical factors that influence accuracy, e.g. slice thickness (partial volume effect), motion reduction, reduction of (cardiac) artifacts, dosage of contrast agent, choice of pulse sequence and echotime, and choice of the method for elimination of fat signal. (2) Hormonal factors (timing of the examination with reference to the menstrual cycle, hormonal replacement therapy). They influence accuracy and must be taken into account. (3) Interpretation guidelines-their choice influences sensitivity and specificity mostly inversely and the use of information from conventional imaging appears necessary. (4) Patient selection influences accuracy for statistical and for biological reasons. RESULTS: Based on the present literature and on the experiences gathered in six German universities (> 12000 examinations) an excellent sensitivity (> 98%) can be achieved for the combination of mammography and MRI. However, specificity strongly varies with the indications. Recommended indications include examination of breasts with impaired evaluation due to severe scarring, after silicon implants and in the dense breast, exclusion of multicentricity and search for primary tumor. Indications under investigation include high risk patients and strictly selected problem cases. CONCLUSION: If appropriately applied and used for selected indications, contrast-enhanced MRI may allow a significant diagnostic gain. In order to take advantage of the full potentials of contrast-enhanced MRI the development of commercially available biopsy coils is essential.

[Value of contrast medium magnetic resonance tomography of the breast in breast reconstruction with implant]. / Wertigkeit der Kontrastmittelmagnetresonanz-tomographie der Mamma bei Wiederaufbau mittels Implantat.

Early recognition of recurrence and work-up of clinically indeterminate lesions may be impaired after reconstruction with silicone implants due to superimposition of the implant or to scarring. This study was undertaken to evaluate the use of contrast-enhanced MRI in patients with silicone implant after breast cancer. Contrast-enhanced MRI was offered to 169 patients. Comparative two- to three-view mammography was also performed in 169 patients, as well as comparative sonography in 144 patients. Conventional imaging and clinical examination detected only 8/13 recurrences, whereas 12/13 were detected by MRI. One recurrence had been visible as a strongly enhancing 2-mm dot in a previous examination (2 years before), but was not called. It was therefore counted as false negative. In addition, multicentricity was detected by MRI alone in two of three cases. MRI correctly diagnosed scar tissue in all cases with indeterminate findings. However, due to false-positive calls caused by enhancing granulomas specificity could not be improved. Contrast-enhanced MRI allowed decisive additional information in our study group and improved the sensitivity significantly (concerning all diagnoses). Contrast-enhanced MRI is recommended in patients with diagnostic problems or high risk of recurrence after silicone implants.

Sensitivity of contrast-enhanced MR imaging of the breast.

High sensitivity is a major advantage of contrast-enhanced MR imaging when it is applied as an additional tool in difficult cases. Several factors, such as technique, guidelines, patient preselection, and varying levels of verification influence sensitivity and specificity of contrast-enhanced MR imaging. This article explores these issues, and reviews data based on the authors' own experience and on the published literature.

Prototype breast coil for MR-guided needle localization.

OBJECTIVE: Evaluation of breast lesions detected by MR alone is a problem: Preoperative MR-guided localization is difficult, since the breast is not accessible by a needle within the breast coil. Magnetic resonance-guided core biopsy and needle aspiration are impossible. Together with Siemens Erlangen, a prototype localization breast coil has been developed and tested. MATERIALS AND METHODS: The device consists of a circular polarized coil, which contains two plates for mediolateral breast compression. They are perforated with numerous holes and thus allow access to the breast from both sides. By means of bushings, which fit into the holes, sterile needle insertion in a horizontal path is possible. RESULTS: So far, precise needle insertion has been possible in 10 of 11 lesions, allowing exact needle insertion into 5 invasive carcinomas (1 MR-detected), 1 MR-detected additional focus, 2 in situ carcinomas (1 MR-detected), and 3 benign lesions. CONCLUSION: Our studies show that MR-guided needle localization is possible.