Shedding Light on T2 Bright Masses on Breast MRI: Benign and Malignant Causes.

While T2 hyperintense masses on breast MRI are often benign, there are several malignant etiologies that can also be T2 hyperintense. Delineation between benign and malignant entities is important for the accurate interpretation of breast MRI. Common benign T2 hyperintense masses include cysts, fibroadenomas, and lymph nodes. Malignant processes that are T2 hyperintense include metastatic lymph nodes, mucinous breast carcinomas, papillary breast carcinomas, and breast cancers with central necrosis. Evaluation of the morphology and enhancement pattern of a T2 hyperintense mass can help to differentiate a benign process from a malignant one. This educational review will present both benign and malignant causes of T2 hyperintense masses on breast MRI and review common imaging findings and pertinent imaging characteristics that can be used to help accurately identify benign entities while also recognizing suspicious lesions that require additional evaluation.

Comparison of psychophysical, electrophysiological, and fMRI assessment of visual contrast responses in patients with schizophrenia.

Perception has been identified by the NIMH-sponsored Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS) group as a useful domain for assessing cognitive deficits in patients with schizophrenia. Specific measures of contrast gain derived from recordings of steady-state visual evoked potentials (ssVEP) have demonstrated neural deficits within the visual pathways of patients with schizophrenia. Psychophysical measures of contrast sensitivity have also shown functional loss in these patients. In the current study, functional magnetic resonance imaging (fMRI) was used in conjunction with ssVEP and contrast sensitivity testing to elucidate the neural underpinnings of these deficits. During fMRI scanning, participants viewed 1) the same low and higher spatial frequency stimuli used in the psychophysical contrast sensitivity task, at both individual detection threshold contrast and at a high contrast; and 2) the same stimuli used in the ssVEP paradigm, which were designed to be biased toward either the magnocellular or parvocellular visual pathway. Patients showed significant impairment in contrast sensitivity at both spatial frequencies in the psychophysical task, but showed reduced occipital activation volume for low, but not higher, spatial frequency at the low and high contrasts tested in the magnet. As expected, patients exhibited selective deficits under the magnocellular-biased ssVEP condition. However, occipital lobe fMRI responses demonstrated the same general pattern for magnocellular- and parvocellular-biased stimuli across groups. These results indicate dissociation between the fMRI measures and the psychophysical/ssVEP measures. These latter measures appear to have greater value for the functional assessment of the contrast deficits explored here.