This DE CT virtual noncalcium technique can subtract calcium from cancellous bone, allowing bone marrow assessment and potentially making posttraumatic bone bruises of the knee detectable with CT.
Introduction: The gastrin-releasing peptide receptor (GRPR) is overexpressed in breast cancer. The present study evaluates GRPR imaging as a novel imaging modality in breast cancer by employing positron emission tomography (PET) and the GRPR antagonist 68Ga-RM2.Methods: Fifteen female patients with biopsy confirmed primary breast carcinoma (3 bilateral tumors; median clinical stage IIB) underwent 68Ga-RM2-PET/CT for pretreatment staging. In vivo tumor uptake of 68Ga-RM2 was correlated with estrogen (ER) and progesterone (PR) receptor expression, HER2/neu status and MIB-1 proliferation index in breast core biopsy specimens.Results: 13/18 tumors demonstrated strongly increased 68Ga-RM2 uptake compared to normal breast tissue (defined as PET-positive). All PET-positive primary tumors were ER- and PR-positive (13/13) in contrast to only 1/5 PET-negative tumors. Mean SUVMAX of ER-positive tumors was 10.6±6.0 compared to 2.3±1.0 in ER-negative tumors (p=0.016). In a multivariate analysis including ER, PR, HER2/neu and MIB-1, only ER expression predicted 68Ga-RM2 uptake (model: r2=0.55, p=0.025). Normal breast tissue showed inter- and intraindividually variable, moderate GRPR binding (SUVMAX 2.3±1.0), while physiological uptake of other organs was considerably less except pancreas. Of note, 68Ga-RM2-PET/CT detected internal mammary lymph nodes with high 68Ga-RM2 uptake (n=8), a contralateral axillary lymph node metastasis (verified by biopsy) and bone metastases (n=1; not detected by bone scan and CT).Conclusion: Our study demonstrates that 68Ga-RM2-PET/CT is a promising imaging method in ER-positive breast cancer. In vivo GRPR binding assessed by 68Ga-RM2-PET/CT correlated with ER expression in primary tumors of untreated patients.
Purpose: Cochlear implantation (CI) represents the gold standard in the treatment of children born deaf and postlingually deafened adults. Initial magnetic resonance imaging (MRI) was contraindicated in CI users. Meanwhile, there are specific recommendations concerning MRI compatibility depending on the type of CI system and the device manufacturer. Some CI systems are even approved for MRI with the internal magnet left in place. The aim of this study was to analyze all magnet revision surgeries in CI patients at one CI center and the relationship to MRI scans over time.
Materials and Methods: Between 2000 and 2013, a total of 2027 CIs were implanted. The number of magnet dislocation (MD) surgeries and their causes was assessed retrospectively.
Results: In total 12 cases of MD resulting from an MRI scan (0.59?%) were observed, accounting for 52.2?% of all magnetic revision surgeries. As per the labeling, it was considered safe to leave the internal magnet in place during MRI while following specific manufacturer recommendations: MRI intensity of 1.5 Tesla (T) and compression head bandage during examination.
Conclusion: A compression head bandage in a 1.5?T MRI unit does not safely prevent MD and the related serious complications in CI recipients. We recommend a Stenvers view radiograph after MRI with the internal magnet in place for early identification of MD, at least in the case of pain during or after MRI examination. MRI in CI patients should be indicated with restraint and patients should be explicitly informed about the possible risks. Recommendations regarding MRI compatibility and the handling of CI patients issued with MRI for the most common CI systems are summarized.
Key Points:
??MRI in CI patients: manufacturer recommendations must be followed.
??Magnet dislocation due to MRI is a serious complication.
??In case of suspected magnet dislocation: Use Stenvers view radiograph for diagnosis.
??Instant presentation to a CI center is mandatory for proper management of dislocation.
??Immediate CI revision surgery must be performed in the case of magnet dislocation.
Citation Format:
??Hassepass F, Stabenau V, Arndt S et?al. Magnet Dislocation: An Increasing and Serious Complication Following MRI in Patients with Cochlear Implants. Fortschr R?ntgenstr 2014; 186: 680???685
The present results suggest that similar insertion depth and angle as well as similar low-frequency hearing preservation can be achieved in cochlear implantation with this straight narrow electrode via either cochleostomy approach or round window approach at least at initial activation. This fact gives the surgeon the opportunity to adapt access to the scala tympani as needed.
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