Pituitary fossa: chemical shift effect in MR imaging

The effect of chemical shift on magnetic resonance (MR) imaging of the pituitary fossa was studied. Healthy volunteers underwent conventional MR imaging of the pituitary fossa and then imaging with the frequency-encoding gradient reversed or with the phase- and frequency-encoding gradients interchanged. Comparison of the image pairs in each subject showed that the thin, black stripe evident at the water-fat interface within the pituitary fossa was altered when the gradients were changed. Therefore, the low-intensity signal within the pituitary fossa is a chemical shift misregistration effect.     

Anulus fibrosus in bulging intervertebral disks

In this investigation the association of radial tears of the anulus fibrosus and bulging of the intervertebral disk was studied. An index of disk bulging was measured in sagittal anatomic sections in 149 lumbar disks from 31 cadavers. The indexes of disk bulging were correlated with stages of disk development and the presence of an annular tear. The largest disk-bulging indexes were always associated with radial tears of the anulus. Eighty-four percent of the disks with radial tears had disk-bulging indexes greater than 2.5 mm. Most normal adult disks had an index of less than 2.5 mm. The results challenge the concept that the anulus fibrosus is intact in bulging disks, although ruptured in herniated disks.     

Osteopetrosis: MR characteristics at 1.5 T

Four patients with proved osteopetrosis (three with the infantile malignant form and one with the benign form) were examined with magnetic resonance imaging at 1.5 T. All patients were studied in the coronal and sagittal planes using both short and long repetition time/echo time sequences. The infantile malignant form was characterized by a complete lack of signal from the marrow alternating with a signal intensity equivalent to that of the intervertebral disks, resulting in a "stepladder" appearance. In the benign form or after successful marrow transplantation in the infantile malignant form, intermediate or high signal intensity in the vertebrae was noted, suggesting the presence of some marrow elements.     

Switching between biologics in severe asthma patients. When the first choice is not proven to be the best

During the last decades, new treatments targeting disease mechanisms referred as biologics have been introduced in the therapy of asthma and currently, five monoclonal antibodies have been approved. Although these therapeutic agents have been formulated to target specific asthma endotypes, it is often difficult for the treating physician to identify which patient is the best candidate for each one of these specific treatments especially in the clinical scenario of a patient in whom clinical characteristics overlap between different endotypes, allowing the selection of more than one biologic agent. As no head-to-head comparisons between these biologics have been attempted, there is no evidence on the superiority of one biologic agent over the other. Furthermore, a physician's first therapeutic decision, no matter how carefully has been made, may often result in suboptimal clinical response and drug discontinuation, indicating the need for switching to a different biologic. In this short review, we discuss the available evidence regarding the switching between biologics in patients with severe asthma and we propose a simple algorithm on switching possibilities in case that the physicians’ initial choice is proven not to be the best.     

Solvent-dehydrated fascia lata allograft for covering intraoral defects: our experience

Mucosal defects in the oral cavity as a result of tumors, preprosthetic surgical procedure, or trauma are always a concern for surgeons. The aim of this study is to present our experience and discuss the advantages and problems arising with the use of solvent-dried human fascia lata allografts in oral mucosal defects, thus evaluating its clinical efficacy. Sixteen intraoral lesions were removed from 15 patients. The rehabilitation of the mucosal defects was achieved using solvent-dehydrated human fascia lata allografts. No graft rejection or infections were detected. The material was effective for enhancing the hemostasis, relieving the pain, and inducing rapid epithelization. The final result was excellent, even though in 2 cases complications were experienced. Hence, the use of the material proved to be reliable, practical, and safe.