Do the upper lateral nasal cartilages exist? The concept of septolateral cartilages.

BACKGROUND: In the cartilaginous nose, classical surgical anatomy describes 2 triangular upper lateral cartilages (ULCs) framing the lateral sides of the mid-third of the nasal pyramid, which articulate with to the superior edge of the quadrangular cartilage (QC) of the nasal septum. This anatomic arrangement in 3 distinct cartilage parts is, however, controversial. OBJECTIVE: The present study aimed to describe the articulation between the ULCs and the QC, avoiding dissection artefacts. MATERIALS AND METHODS: Six nasal pyramids were taken in monobloc from fresh cadavers and imaged on micro-MRI with 0.4mm slice thickness. Images were interpreted jointly by 2 head and neck surgeons and a radiologist. RESULTS: The cartilage skeleton supporting the mid-third of the nasal dorsum in all specimens presented as 2 septal plates backing onto the midline and curving on either side to form a continuous dome under the inferior aspect of the piriform aperture. CONCLUSION: Like the alar cartilages framing the tip of the nose, there are two continuous septolateral cartilages (SLCs) framing the mid-third of the nasal pyramid, likewise showing 2 cruras, medial and lateral, joined in a dome. The SLCs (also known as triangular cartilages) thus cannot be separated as 2 individual anatomic structures. These findings are in line with the shared embryological origin of all the elements composing the fibrocartilaginous nose in evo-devo theory.

Motion compensated generalized reconstruction for free-breathing dynamic contrast-enhanced MRI.

The analysis of abdominal and thoracic dynamic contrast-enhanced MRI is often impaired by artifacts and misregistration caused by physiological motion. Breath-hold is too short to cover long acquisitions. A novel multipurpose reconstruction technique, entitled dynamic contrast-enhanced generalized reconstruction by inversion of coupled systems, is presented. It performs respiratory motion compensation in terms of both motion artefact correction and registration. It comprises motion modeling and contrast-change modeling. The method feeds on physiological signals and x-f space properties of dynamic series to invert a coupled system of linear equations. The unknowns solved for represent the parameters for a linear nonrigid motion model and the parameters for a linear contrast-change model based on B-splines. Performance is demonstrated on myocardial perfusion imaging, on six simulated data sets and six clinical exams. The main purpose consists in removing motion-induced errors from time-intensity curves, thus improving curve analysis and postprocessing in general. This method alleviates postprocessing difficulties in dynamic contrast-enhanced MRI and opens new possibilities for dynamic contrast-enhanced MRI analysis.