Claire Boutet

How to manage central nervous system MRI with a cardiac implantable electronic device

With the ageing of our population and an increase of MRI indications, it is estimated that 50 to 75% [1] of patients with a cardiac implantable electronic device (CIED), pacemaker (PM) or implanted cardiac defibrillator (ICD) will need an MRI during their CIED lifetime. This medical and economic challenge requires constructers to develop MRI compatible CIED. Even though most CIED were absolute MRI contraindications until 2012, it is no longer the case today [2]. Confronted with the increasing demands of clinicians, it is thus essential that radiologists know which devices are compatible with an MRI machine as well as their conditions of use. The principal risks of an MRI among patients carrying a CIED are linked to the effect of the magnetic field, the gradients and the impulses of radio frequency on equipment: heating of the probes, switch to an asynchronous pacing mode, deprogramming or inhibition of the device [3,4]. Clinical consequences are tissue lesions and disturbance of rhythm or conduction of the heart. The technical evolutions have been made to:

Impaired cortico-limbic functional connectivity in schizophrenia patients during emotion processing

Abstract Functional dysconnection is increasingly recognized as a core pathological feature in schizophrenia. Aberrant interactions between regions of the cortico-limbic circuit may underpin the abnormal emotional processing associated with this illness. We used a functional magnetic resonance imaging paradigm designed to dissociate the various components of the cortico-limbic circuit (i.e. a ventral automatic circuit that is intertwined with a dorsal cognitive circuit), to explore bottom-up appraisal as well as top-down control during emotion processing. In schizophrenia patients compared with healthy controls, bottom-up processes were associated with reduced interaction between the amygdala and both the anterior cingulate cortex (ACC) and the dorsolateral prefrontal cortex. Contrariwise, top-down control processes led to stronger connectivity between the ventral affective and the dorsal cognitive circuits, i.e. heightened interactions between the ventral ACC and the dorsolateral prefrontal cortex as well as between dorsal and ventral ACC. These findings offer a comprehensive view of the cortico-limbic dysfunction in schizophrenia. They confirm previous results of impaired propagation of information between the amygdala and the prefrontal cortex and suggest a defective functional segregation in the dorsal cognitive part of the cortico-limbic circuit.

A 48-YEar-Old Male with a Pituitary Tumor

A 48-year-old patient without significant medical history or without bleeding disorder is addressed to our institution for acute headache and bitemporal hemianopsia. No hormonal secretion was detected, and the patient had a pituitary insufficiency with loss of libido, diffuse hair loss, asthenia and slowing. An MRI showed a 47 mm pituitary lesion occupying the sella turcica with central necrosis. This lesion was hypointense in T1 sequence, enhanced with gadolinium injection and hyperintense in T2 sequence (Figure 1A). Then, a transsphenoidal excision surgery was decided. A first surgery was performed, but the resection of the tumor lead to an extensive bleeding and the tumor could not be resected entirely. Three days later, because of incomplete resection a second excision procedure was decided leading to an extensive bleeding and a subtotal surgical resection. The visual symptoms of the patient improved quickly after the surgery.