Dual-energy contrast-enhanced spectral mammography (CESM).

Dual-energy contrast-enhanced mammography is one of the latest developments in breast care. Imaging with contrast agents in breast cancer was already known from previous magnetic resonance imaging and computed tomography studies. However, high costs, limited availability-or high radiation dose-led to the development of contrast-enhanced spectral mammography (CESM). We reviewed the current literature, present our experience, discuss the advantages and drawbacks of CESM and look at the future of this innovative technique.

Variability of clinical functional MR imaging results: a multicenter study.

PURPOSE: To investigate intersite variability of clinical functional magnetic resonance (MR) imaging, including influence of task standardization on variability and use of various parameters to inform the clinician whether the reliability of a given functional localization is high or low. MATERIALS AND METHODS: Local ethics committees approved the study; all participants gave written informed consent. Eight women and seven men (mean age, 40 years) were prospectively investigated at three experienced functional MR sites with 1.5- (two sites) or 3-T (one site) MR. Nonstandardized motor and highly standardized somatosensory versions of a frequently requested clinical task (localization of the primary sensorimotor cortex) were used. Perirolandic functional MR variability was assessed (peak activation variability, center of mass [COM] variability, intraclass correlation values, overlap ratio [OR], activation size ratio). Data quality measures for functional MR images included percentage signal change (PSC), contrast-to-noise ratio (CNR), and head motion parameters. Data were analyzed with analysis of variance and a correlation analysis. RESULTS: Localization of perirolandic functional MR activity differed by 8 mm (peak activity) and 6 mm (COM activity) among sites. Peak activation varied up to 16.5 mm (COM range, 0.4-16.5 mm) and 45.5 mm (peak activity range, 1.8-45.5 mm). Signal strength (PSC, CNR) was significantly lower for the somatosensory task (mean PSC, 1.0% ± 0.5 [standard deviation]; mean CNR, 1.2 ± 0.4) than for the motor task (mean PSC, 2.4% ± 0.8; mean CNR, 2.9 ± 0.9) (P < .001, both). Intersite variability was larger with low signal strength (negative correlations between signal strength and peak activation variability) even if the task was highly standardized (mean OR, 22.0% ± 18.9 [somatosensory task] and 50.1% ± 18.8 [motor task]). CONCLUSION: Clinical practice and clinical functional MR biomarker studies should consider that the center of task-specific brain activation may vary up to 16.5 mm, with the investigating site, and should maximize functional MR signal strength and evaluate reliability of local results with PSC and CNR.

Decision making under ambiguity and under risk in mesial temporal lobe epilepsy.

Decision making is essential in everyday life. Though the importance of the mesial temporal lobe in emotional processing and feedback learning is generally recognized, decision making in mesial temporal lobe epilepsy (mTLE) is almost unexplored so far. Twenty-eight consecutive epilepsy patients with drug resistant mTLE and fifty healthy controls performed decision tasks under initial ambiguity (participants have to learn by feedback to make advantageous decisions) and under risk (advantageous choices may be made by estimating risks and by rational strategies). A subgroup analysis compared the performance of patients affected by MRI-verified abnormalities of the hippocampus or amygdala. The effect of lesion side was also assessed. In decision under ambiguity, mTLE patients showed marked deficits and did not improve over the task. Patients with hippocampus abnormality and patients with amygdala abnormality showed comparable deficits. No difference was found between right and left TLE groups. In decision under risk, mTLE patients performed at the same level as controls. Results suggest that mTLE patients have difficulties in learning from feedback and in making decisions in uncertain, ambiguous situations. By contrast, they are able to make advantageous decisions when full information is given and risks, possible gains and losses are exactly defined.

How specifically do we learn? Imaging the learning of multiplication and subtraction.

The present functional magnetic resonance imaging (fMRI) study investigates modifications of brain activation patterns related to the training of two different arithmetic operations, multiplication and subtraction. Healthy young adults were trained in five sessions to answer multiplication and subtraction problems. In the following fMRI session, trained and new untrained problems closely matched for difficulty were presented in blocked order. Contrasts between untrained and trained operations showed stronger activation of inferior frontal and parietal regions, especially along the banks of the intraparietal sulcus. The reverse contrasts, trained minus untrained operations, yielded significantly higher activation in the left angular gyrus for multiplication but no significantly activated area for subtraction. This suggests that training leads to a reduction of general purpose processes, such as working memory and executive control in both operations, indicated by the decrease of activation in inferior frontal areas. For multiplication, however, the increase of activation in the left angular gyrus indicates a switching of cognitive processes. Trained subtraction therefore seems to lead to faster and more efficient strategies, while trained multiplication showed a shift from quantity-based processing (supported by the areas along the intraparietal sulci) to more automatic retrieval (supported by the left angular gyrus). The same training method caused changes in brain activation patterns that depended on the given operation. The effects of learning on the brain therefore seem not only to depend on the method of learning but also on its content.

Are transition zone biopsies still necessary to improve prostate cancer detection? Results from the tyrol screening project.

OBJECTIVES: The present retrospective study was designed to investigate the value of transition zone (TZ) biopsies for prostate cancer (PC) detection rate in a combined contrast enhanced color Doppler targeted (CECD) and gray-scale systematic biopsy (SB) approach. METHODS: PSA screening participants totalling 1475 with tPSA of >1.25 ng/ml (fPSA< or =18%) were assessed. Ten SB and additionally 5 or fewer CECD were performed. The impact of TZ biopsies on the PC detection rate and the biological significance of the detected TZ-cancers were analyzed. RESULTS: Out of 1475 biopsied patients, 395 (26.8%) were identified as PC patients; 5925 biopsy cores from these patients were analyzed. In 86 patients (21.8% of PC), we found 102 PC- positive cores in the TZ, and only in 9 of them solitary TZ-cancers without any other PC-location (2.3% of PC or 0.6% of all investigated patients). Pathologic findings after retropubic prostatectomy (RPE) revealed multifocal adenocarcinoma including involved peripheral zone (PZ) in eight of these nine patients, and solitary TZ-cancer in one patient. There was no positive correlation between prostate volume and TZ-detection rate and no patient with solitary TZ-PC after rebiopsy. CONCLUSION: Biopsy revealed 9 solitary TZ cancers (1.8%) and RPE revealed only one of them to be truly TZ-confined cancer (0.6%). Furthermore PC-detection did not improve, even in patients with rebiopsy, and there was no correlation between detection of TZ-cancers and prostate volume. A combined use of CECD and SB to investigate participants of a PSA-screening program suggests that TZ-biopsies do not improve PC detection rate and are therefore unnecessary.