Alexandra Borges

Chondroid tumors of the larynx: Computed tomography findings

PURPOSE Chondromas and chondrosarcomas of the larynx are rare cartilaginous tumors making up less than 1% of all laryngeal tumors. Patients typically present with symptoms of hoarseness, dysphagia, or dyspnea. The most common location in the larynx for these tumors is the cricoid cartilage. Radiographically, these lesions are typically hypodense, well-circumscribed masses containing mottled calcifications with smooth walls centered within the cartilage. MATERIALS AND METHODS We present 6 cases of chondroid tumors of the larynx. RESULTS One patient had a chondroma, 4 patients had low-grade chondrosarcomas, and 1 patient had an intermediate-grade chondrosarcoma. Two partial laryngeal resections and 4 total laryngectomies were performed. CONCLUSIONS In most cases of chondroma or chondrosarcoma of the larynx, conservative surgery should be attempted, but total laryngectomy may be required for large or recurrent lesions.

Laryngeal involvement in multiple symmetric lipomatosis: The role of computed tomography in diagnosis

Madelung’s disease (MD) is a rare lipodystrophy characterized by the presence of multiple, nonencapsulated fatty, infiltrative lesions that occur in a symmetric distribution. The disease predominately involves the neck, face, supralavicular and deltoid regions, the mediastinum, and the tongue. l Men are affected more often than women, and for unclear reasons, Mediterranean males are predominately afflicted.2-4 Patients generally seek medical attention for cosmetic or compressive symptoms. Symptoms related to the larynx have been reported2-lo and are generally caused by extrinsic compression or, more rarely, compression of the recurrent laryngeal nerve by infiltration of fat, leading to dyspnea and dysphonia. Direct involvement of the larynx by proliferating adipose tissue is rare, with only five cases reported in the literature.4,6~7,sJ0 We report two pathologically proven cases of MD, with striking direct involvement of the larynx, diagnosed by computed tomography (CT).

MR-guided procedures using contemporaneous imaging frameless stereotaxis in an open-configuration system

Frameless MR-guided procedures have had limited application using conventional closed magnets, due largely to the technical difficulties involved. As a result of in-room MR image-monitoring capabilities, new open-design magnets now allow frameless stereotaxis using contemporaneous imaging to guide more invasive procedures. We evaluate our clinical experience with this new technique. An open-design 0.2 T magnet (Siemens OPEN) combined with an in-room monitor was used for 33 frameless MR-guided procedures (aspiration cytology, biopsy, and/or treatment) in a variety of locations in the head, neck, spine, brain, pelvis, and abdomen. Success of the procedure was based on the ability to accurately position the instrument in the target region to allow biopsy and/or treatment. The open-design magnet allowed the physician to directly access the patient for frameless stereotaxis as the procedure was performed. The in-room monitor provided contemporaneous imaging feedback during the procedure for successful placement of the instrument in the target region. Twenty-eight biopsy and five treatment procedures were performed. In all cases the technique resulted in successful placement of the instrument within the target tissue to complete the procedure. MR-guided procedures using contemporaneous imaging frameless stereotaxis are possible in an open-design magnet with in-room image monitoring and offer exciting possibilities for further development.

MRI-guided needle localization in the head and neck using contemporaneous imaging in an open configuration system.

MRI‐guided procedures have previously been limited by technical difficulties, including the need for MRI‐compatible instruments, slow image acquisition time, and the closed nature of conventional MRI scanners. The development of open configuration MRI systems with in‐room, contemporaneous imaging has greatly increased the potential for MRI‐guided interventional procedures. We evaluate our clinical experience applying this technology to the head and neck.

Magnetic Resonance Imaging–Guided Fine‐Needle Aspiration Biopsies of Retropharyngeal Lesions

Objective The retropharyngeal space is a deep neck space susceptible to a host of disease processes. Surgical access to this space is technically difficult and associated with potential morbidity. An image‐guided fine‐needle aspiration (FNA) biopsy, if proven accurate and safe, would be of great benefit as an alternative diagnostic approach to this space. This study reports on the use of magnetic resonance imaging (MRI)–guided FNA for diagnostic evaluation of retropharyngeal lesions. Technical details of needle systems, approach to this space, and reliability of this method are described.

Frequency-selective fat suppression MR imaging. Localized asymmetric failure of fat suppression mimicking orbital disease.

Our objectives were to further characterize an artifact related to the localized failure of the frequency-selective (FATSAT) fat suppression magnetic resonance (MR) imaging technique. We constructed two phantoms simulating human orbital anatomy and imaged them on a 1.5-T MR scanner using (FATSAT) and short T1 inversion recovery (STIR) techniques of fat suppression. The first phantom resembled orbit structural configurations; it was imaged in coronal and axial planes and in varying orientations with respect to the main magnetic field (Z axis) to study the features of the artifact and to reproduce the asymmetry seen in clinical cases. We designed the second phantom to enable quantification of the change in artifact size with change in orientation. We imaged the orbits of a normal human volunteer in similar planes and orientations, and compared the results to clinical cases demonstrating the artifact and true orbital disease. The artifact identified with localized failure of FATSAT fat suppression manifested as regions of hyperintensity maximal at fat-air interfaces, with gradual fading of the increased signal with distance from the interfaces. The artifact was most prominent when the interfaces were perpendicular to the axis of the main magnetic field (Z axis). The regions of increased brightness obscured normal orbital structures but were not associated with alterations in the geometry of these structures. Changes in orientation of the interfaces with respect to the Z axis, both in the phantoms and normal volunteer, reproduced the asymmetry of fat suppression failure seen in clinical cases. The relationship of size of the artifact to change in orientation was nonlinear. The artifact was not seen on STIR images. We concluded that failure of FATSAT fat suppression may mimic orbital disease, particularly if asymmetric. As predicted by the Maxwell electromagnetism equation, slight variations in orientation of the fat-air interface to the Z axis may produce large asymmetries in fat suppression failure in the orbit. Confirmation may require either comparison with additional pulse sequences [T1-weighted spin echo (T1W SE) or STIR] or repositioning the patients head to check for persistence of the finding with varying orientations.

MRI-guided access to the retropharynx

To describe MR‐guided access to the retropharynx for precise fine‐needle aspiration cytology (FNAC), and other indications for needle placement.